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General => General Forum => Topic started by: MountainDon on January 12, 2009, 10:18:39 PM

Title: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 12, 2009, 10:18:39 PM
I spoke with an Outback Power Systems engineer recently. I had some specific questions about one of their inverters. He answered them quite clearly. I've always thought their products to be top line, if not the best. Anyhow he confirmed my main concern about the inverter I had a chance to buy on a deal. He also clarified one point that I was also wondering about.

The question relates to inverter/chargers, like Outback, Magnum Energy, Trace/Xantrex. Plain vanilla inverters, like most square wave inverters, are just inverters. They do not have battery charging circuitry incorporated within them. You need a separate charger to recharge the batteries from a generator or other AC power source when you have an economy inverter. Inverter/chargers have a battery charger incorporated into the unit. In the case of my Outback VFX3524M the charger has a maximum charge rate of 85 amps at 24 VDC.

These inverter/chargers all are setup so when the connected generator is fired up, the AC power to the inverter causes the inverter section to switch out. The AC power to the cabin then is coming from the generator. The generator power is also powering the battery charger section. I have wondered why this was? Why was the generator power not just used to power the battery charger section, while any AC loads would still be supplied by the inverter section?   ??? 

Since I have a small generator this was of concern. By past experience I know that when my 2800 watt generator (derated by altitude to about 2300 watts) is working hard enough to power the old 75 amp Iota charger, it is not a good move to use the microwave at the same time. There's just not enough power available from the generator. Buying a larger generator would be a solution, but that's not a part of this scenario. Ideally I would like to be able to use the generator power to charge the batteries and leave the inverter to supply any cabin electrical needs.

Outbacks engineer supplied the answer. Keep in mind I have a planned 24 VDC system. The Outback 3524 inverter is designed to operate with an input voltage maximum of 32 volts. There are similar limits with other brands. Some are even less, like 30 volts maximum.

Batteries should be subjected to an 'equalization charge' about once a month to assist in achieving maximum battery life. An equalization charge is a higher than usual voltage, low current, charge rate. An equalization charge is done at 2.57 to 2.68 volts per cell (in a wet lead acid cell battery). In a 24 VDC system that is 31 to 32 volts.

Do you see the issue? The voltages are getting too close for the comfort of an engineer. In a real world situation it might happen that the charging voltage could spike higher than 32 and thus it might cause damage to the inverter/charger. Hence, the inverter manufacturer usually elects to program the inverter to drop out when the AC power in, is active.

I am not certain, but I do believe I killed my Exeltech 1100 watt inverter when I was equalizing the batteries. The Exeltech does not have a charger built in. I left it connected to the batteries. At the same time I bumped my stand alone charger into high voltage mode. It might have exceeded the design input voltage for the inverter. Poooof!    Or maybe it was 'just one of those things'.  ??? ???

Anyhow, I thought it was interesting.

I think this would be a good place to talk about good things, bad things, odd things, that we have encountered in alternative power systems.

Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 12, 2009, 10:29:37 PM
My Trace inverters go off at about 21 volts low or  30 volts max. I have two 4024 Trace sine wave inverters stacked to make 240v.  They are also over-current protected internally so that any short will trip them out and a manual reset is required if a short happens.

I know as I sometimes equalize and bulk charge with my DC welder.  I doubt I am treating my batteries as well as possible but when doing it I monitor them pretty closely.  I generally charge at between 60 to 100 amps but the welder does not taper off on charge as the batteries get full therefore monitoring is necessary.  This is across 12 375ah batteries or 1125ah at 24v.
Title: Re: Off Grid Power; various thoughts on...
Post by: Okie_Bob on January 13, 2009, 03:26:16 AM
Excellent information guys and maybe Glenn, you could start up a separate section on off grid power? I love this idea.
Just some FYI, I had some free time between Christmas and New Years and decided to take a little road trip, just drive alone for hours and see some country to try to get rid of all the crap in my brain from the past year. Anyway, as I traveled west on old Route 66 as I was coming into Tucumcari, NM, I saw this huge wind turbin and as I got closer I could see that I could get right up to the base so I did. This thing was huge, I'm guessing 20' or more at the base and at least 150' tall with blades that had to be 100' long.
I took a bunch of pics if anyone is interested. On my way home a few days later, I was a billboard on I-40 eastbound that said it was the largest wind turbin in the world!!! Suspect that maybe it was when installed but, maybe not anymore. It is 1.6Megawatts!
I had heard that these big turbins were quite noisy and that is way some people object to them. Well, let me tell you this monster was so quiet I couldn't hear it running at all.
I was also amazed at the 100's of wind turbins I saw in Oklahoma, Tx, NM and even AZ. Someone sure believes in them!
PS: I went all the way to the Grand Canyon. Highly recommend the trip on the old Mother Road.
Okie Bob
Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 13, 2009, 06:57:48 AM
Lets just go ahead and add our thought's , pix and everything to this thread, BoB.  :)  It will be easy to find here and this thread can expand endlessly on off grid power.
Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 13, 2009, 07:14:16 AM
Getting ready to change my solar tracker cylinder to a larger one so I have to rotate the panels to the sun in the morning after which it tracks all day.

Readings .... set 1 in light but 160 degrees away from the sun at 8 AM(back of tracker toward the sun) -  1 amp  immediately change to 16 amps when toward the sun.

set 2  .5 amps away     10 amps when toward the sun.
Title: Re: Off Grid Power; various thoughts on...
Post by: soomb on January 13, 2009, 03:21:02 PM
So happy to see this thread start up.
Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 13, 2009, 09:24:02 PM
My planned solar PV installation is probably fairly unique. I say that because the favored cabin spot is not at all close to the favored PV panel spot. Three hundred and twenty five feet separate the two.  :o 

Running low voltages like 12 or even 24 volts over a distance like that would suffer huge power losses to electrical resistance unless the cables were huge. Huge copper cable costs a huge amount of money. What to do? Run the panels in series to up the voltage and keep the amps low. The problem with this is that many charge controllers cannot handle high input voltages. Some of the popular charge controllers only accept up to 24 VDC, some 48 VDC. The three panels I'm buying put out about 86 VDC maximum power voltage when connected in series. With the 7.3 amp maximum power output I can get away with using 4 gauge copper wire from the panels to the cabin and charge controller and have less than 2% voltage drop. That's pretty good.

The catch is most charge controllers can not handle that voltage. The Outback MX-60 or the newer replacement FlexMAX 60 can handle it. So even though the FlexMAX60 will cost about $500, I'll save a bundle on wire costs.

Some of you may have noted I seem to be big on Outback. I don't work for them and none of my relatives do. They make an excellent product, that's all.

The Outback charge controller can also be programmed for just about any voltage combination you could come up with for both input and output (battery bank) voltages.


Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 13, 2009, 09:51:12 PM
More trouble for monitoring etc, but you could build a battery house at the panels and just send 120 or 240 underground to the cabin, but I'm sure you considered that already.  Thought I'd bring it up for pro and con discussion.
Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 13, 2009, 09:57:57 PM
Some other things to be aware of when choosing PV panels and charge controllers....

PV panels get hot with the sun shining on them and they are producing power.

PV panel output voltage drops as the panel heats up. A panel laid flat or nearly flat on a roof will run at a higher temperature than a panel mounted so air can freely move around it, like on a pole top mount.

Conversely, as a panel is cooled, as on a -20 degree day, it's output voltage rises. Cold weather performance is enhanced. This is good as cold weather usually means shorter days, fewer hours of sunshine. That won;t make up for the greater number of hours os summer sunshine, but it helps.

However, along with cold weather and the higher output voltages comes a danger. All electronics have a design range for input voltages; a lower limit and a higher limit. Drop below the lower limit and the unit may just stop functioning until the voltage rises. Exceed the upper limit and the unit may stop functioning permanently. Toast.

What this means is that on a frosty January morning as the temperature hits its low point and the sun peeks over the hill and strikes the PV panels, the voltage may spike well over the normal operating range. With panels in series this could easily overrun the maximum voltage of the charge controller. Therefore this low temperature voltage condition must be taken into account when designing a system where low temperatures may be encountered.

There is a specification called 'open circuit voltage' or Voc listed for all PV panels. This is supposed to be the maximum output voltage but cold temperatures can cause this to be exceeded. A general rule of thumb is to take that figure and multiply it by 1.3 to obtain the maximum likely voltage output and select the charge controller, or the PV panel strings with that figure in mind. Destruction of the charge controller is possible, maybe even likely if that voltage maximum is exceeded for even a split second.

My location in the Jemez has reached a lowest temperature of -32 degrees in the past ten years according to the hour by hour weather records I researched. Running the numbers on my prospective setup indicates I should not have any cold weather over voltage problems. Hurray!

There is a 'tool' on the Outback website that can assist in checking whether or not a particular arrangement of panels can be safely used with Outback charge controllers. Go to   http://outbackpower.com/resources/string_sizing_tool/ (http://outbackpower.com/resources/string_sizing_tool/).   The tool allows you to choose your panels from a list or to enter custom data in case you panel is not listed. You select battery bank voltage and the maximum and minimum temperatures for the location. The graph chart then indicates whats okay and what is not.

Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 13, 2009, 10:20:02 PM
More trouble for monitoring etc, but you could build a battery house at the panels and just send 120 or 240 underground to the cabin, but I'm sure you considered that already.  Thought I'd bring it up for pro and con discussion.

Excellent point.  :)

I ran the numbers for 120 VAC. I didn't run 240 VAC because my installation does not need 240 VAC (and two inverters stacked).

I found there was little difference. By inverting the DC panel power to 120 VAC at the panels I could have changed the wire size to 6 AWG, instead of 4 AWG.

However, that would have meant locating the batteries down at the panels, or very near them. Somehow I prefer to have the batteries up at the cabin. It would have also entailed running some cat5 cable from the batteries to the cabin, where the remote control panel would be, to allow remote control of the inverter; on-off functions and programming of the charge controller from the Outback Mate2.

It didn't seem to be a great net gain to me, in this particular situation. However, this is something that should be considered for any installation where the PV panels are not located right nearby the point of use.

Another factor in deciding against placing the batteries and inverter down at the batteries, and running 120 VAC up to the cabin, was the placement of the generator. The generator would be used about once a month to equalize the batteries. If the batteries and inverter were down the hill at the solar PV and battery location it would make sense to place the generator down there as well. If I didn't do that I'd be faced with running 325 feet of proper sized wire from cabin to panel/inverter/battery location. I didn't really want the genset down the hill. I'd rather have it up near the shed or cabin. Maybe that's just my personal quirks showing.  :-\ 

So there's another chapter in the mysterious workings of my brain.  ::)
Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 13, 2009, 10:34:43 PM
I like the stuff nearby also.  You just don't know what those little machines are up to when they are down there by themselves.

I wanted this information on my solar tracker on the Underground Cabin Update but I will link it here for those who don't get over there.  http://countryplans.com/smf/index.php?topic=151.msg78994#msg78994  Info and pix on the previous page also.  Will update pix soon.  I hope... [waiting]
Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 13, 2009, 10:43:02 PM
Plus like right now, according to my spies in them thar mountains  ;D there's three feet of snow.  :o :o 

With my planned installation of the batteries and related peripherals at the cabin it is much handier. More so since it didn't really make all that much difference on wire size.
Title: Re: Off Grid Power; various thoughts on...
Post by: glenn kangiser on January 13, 2009, 10:49:45 PM
The cost of the larger wire would likely have been exceeded by the building materials for a secure battery house.
Title: Re: Off Grid Power; various thoughts on...
Post by: NM_Shooter on January 14, 2009, 05:50:15 AM

Conversely, as a panel is cooled, as on a -20 degree day, it's output voltage rises. Cold weather performance is enhanced. This is good as cold weather usually means shorter days, fewer hours of sunshine. That won;t make up for the greater number of hours os summer sunshine, but it helps.

However, along with cold weather and the higher output voltages comes a danger. All electronics have a design range for input voltages; a lower limit and a higher limit. Drop below the lower limit and the unit may just stop functioning until the voltage rises. Exceed the upper limit and the unit may stop functioning permanently. Toast.


1.3 should be plenty of safety factor.  Totally unloaded, I think that the theoretical maximum for a PV cell is .7V and it goes down from there with temperature.  The other good thing is that as soon as you apply any load to the cell, the voltage drops dramatically.  That's why you need a much higher PV voltage to charge batteries... 18 to 28V for a 12V battery. 

Don, I'd be surprised if the nice inverters don't have overvoltage input protection, and overcurrent output protection.  Anyway... 1.3xpanel voltage seems like a good rule of thumb.

-f-
Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 14, 2009, 06:29:17 AM
First, I must correct an error. I realized as my brain woke up this morning, that I posted some slightly incorrect info in the post regarding where to place the inverter in my situation and the wire sizes.

I had stated that for running AC from the panel/batteries/inverter location down the hill the wire size would have been 6 AWG. That is wrong. 6 AWG is the maximum size wire the VFX3524 inverter will accept on the AC connections.

When I originally ran the numbers the wire size fir the DC or AC run up the hill turned out to be the same; 4 AWG. However that was with a smaller output inverter. With the VFX3524 capable of putting out 3500 watts the actual computed wire size would be 3 AWG, which is a bit larger. That's calculated at full capacity which it is true, would likely never be reached.   ???

My apologies for any confusion. 
Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 14, 2009, 06:54:11 AM
You are right on Frank, with a couple of footnotes.

It depends in part how close to the input limit your setup is running during normal operation. Many installations would never have a problem. In my case I'm getting close to pushing the limits with the panels I want, but according to Outback still within bounds.

During those periods of early morning very cold weather times there may not be enough of a load to help bring the voltage spike down. The charge controllers do not act instantly when they receive the wakeup call from the power coming from the PV panels. That is, they receive the power, wakeup, scan the batteries to see what they need, then turn the input into output. Enough of a delay to potentially cause problems. The 'nice' ones go to sleep during the hours of darkness. That could allow plenty of time for a spike to zap something. At least that's what the Outback tech guys have told me.

Although I don't have any figures on this, altitude can play a factor in the output power of a PV panel. At higher altitudes there is less air between the panel and the sun. This could have a small effect on over volting.   ???

There is a device available that can help with cold morning start up over volt protection for panels connected in series. The Apollo Low Temperature Overvoltage Bypass (http://Apollo Low Temperature Overvoltage Bypass) will cut one panel in the string out of the circuit at either 32 or 50 degrees F (panel temperature). It automatically reconnects when the temperature rises. More $$ to spend though.

Title: Re: Off Grid Power; various thoughts on...
Post by: MountainDon on January 14, 2009, 09:43:45 AM
This topic is not meant to be an organized coherent lecture series; it's just like any other topic here. Everyone can pitch in, query and discuss. Much of what may be presented may be slightly opinionated, but I try to keep it factual. I will be trying to keep anything I present within NEC guidelines. If you are off in the boonies or simply don't feel the need to "toe the line" by all means follow your own drummer.


Wiring, that is wiring in the DC areas of an alternative power system, is an area where many folks make errors. One of the first and most common errors is in the colors of wires selected for the DC side. The confusion, or errors, come from our familiarity with DC automotive wiring. When looking at the automobile battery the positive or hot lead is usually red and the negative, or ground lead is black. Using red and black like this would cause your system to fail an electrical inspection.

The NEC makes no distinction between AC and DC wiring as far as color codes are concerned. The neutral or negative wire is permitted to be white or grey. That's all. No black neutrals or negatives. Black is reserved for a hot or positive wire. Red may also be a hot or positive wire.

Also automotive battery cables do not have the necessary UL approval and are not approved by the NEC for any wiring, including battery hookups. Ditto for welding cables;not approved. This may only be important to you if your installation has to be inspected by an inspector who follows the book.

More on wires for specific tasks will come later in another post.

Fuses and Circuit Breakers and Switches may be listed for only AC use, some can be used with both. This is because AC power and DC power react differently. The AC power we use changes direction 60 times per second (60 Hz). This change of state makes it easier to break the circuit cleanly. One thing that distinguishes a DC switch are the much heavier contacts. Using an ordinary home wall switch (AC only) to operate a DC powered device will lead to switch failure. The contacts may weld themselves shut in a worst case scenario.

For DC circuit protection there are acceptable fuses and breakers. Square D makes a line of household circuit breakers that are approved for use in circuits up to 24 VDC. The actual breaker info says it can handle up to 48 VDC, but the NEC limits it to 24 VDC as under some conditions a 48 VDC system may go over the 48 volt limit. So the Square D  QO  series panels and breakers are ideal for many DC circuits that may be used in cabin off grid systems. Don't try to mix AC and DC in the same panels though.

Inverters should be wired with a disconnect and a fuse or circuit breaker in the DC supply line. The wiring and fuse or breaker must be sized according to the inverter requirements. If you use a circuit breaker as protection they will usually be accepted as a suitable disconnect as well. I have found solarseller.com (http://solarseller.com/) to be a good source for many off grid power items, including high amp capacity breakers.

Proper boxes and panels for enclosing these breakers may need some fabrication. Whether or not they meet NEC approval is another matter.  ??? UL approved enclosures are expensive. Let your conscience and the inspector be your guide.

Gotta go for now
Title: Re: Off Grid Power; various thoughts on...
Post by: JRR on January 14, 2009, 01:13:39 PM
Okie Bob,
We also rode a bit of Route 66 last Feb.  My first drive out in that area.  My first look at American windfarms.  Quite impressive ... as was the whole 9k mile driving vacation. 

I wonder how many windfarms that we saw were owned/intangled by Enron?  I know they owned a number of them.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 16, 2009, 02:16:36 PM
I had a question under my cabin topic (http://countryplans.com/smf/index.php?topic=2335.msg79344#msg79344) that I thought I would answer here.

I had heard that you wanted to keep an even number of panels.  Is that incorrect? 



Yes, I am using an odd number of panels. Panels are used in even numbers quite often. There is no real reason to do that though. Panel mounts do very often come in 2x2 or 2x3 configurations. That could be one reason. The number of panels should be driven by the total number of watts that are required from the panels.

In my case I decided that I wanted about 500 watts total. More would be alright too. In a location where the cabin and panels are close together there are many configurations that could supply that easily. My 325 foot distance renders some solutions less practical.

For example many panels are basically putting out 12 VDC. Many folks here with small systems have based their systems on such panels and use 12 VDC battery banks. They may have several batteries in parallel connections to maintain that basic 12 VDC configuration.  Right now I won't bother with getting into the pros and cons. Rather I want to explain the reasoning behind my choice of three panels, an odd number.

Panels come in many different base voltages; 12 VDC, 16 VDC, 20 VDC, 24 VDC and even higher like 50 VDC. Some panel combinations would have required both series and parallel connecting. Some of those would have resulted in 48 VDC at 12 amps or more. Raising the amps transmitted to to that level resulted in wires that would have to be larger.


The three Sharp 208 watt panels in series have a Vmp (maximum power voltage) of 85.5 volts. Each panel puts out an Imp (maximum power amperage) of 7.63 amps. Connected in series the amperage (Imp) stays at 7.63. Keeping the amps low and bringing the volts high results in being able to use a smaller wire.

Using as small a wire gauge as I could was important to my situation where the panels and batteries are separated by 325 feet. At maximum output  I will have less than a 2% voltage drop which is what I was aiming for. If I parallel connected the panels the wire would need to be much larger to avoid excessive power loss. It would have been very expensive as well.. As it is I have $450 worth of wire and I got a good price on it.

Series stringing like that is only possible with a charge controller like the Outback MX or FlexMATE 60 or 80. They allow virtually infinite voltages up to their maximum of 145/150 and also work with virtually any battery bank voltage. They are extremely versatile. There are some other charge controllers that could be used with higher voltage arrays. One other reason I'm going with Outback equipment is all their components can be interconnected to one central indoor remote control for programming and monitoring.

I hope that is clear.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MaineRhino on January 16, 2009, 04:29:58 PM
Great post Mtn.Don! One I will be sure to refer to many times in my quest for solar power.  Has anyone mentioned Home Power magazine? I recently subscribed to it, and it seems to fit the bill for the DIY'er, with lots of buyers guides.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on January 16, 2009, 04:43:21 PM
I can't help but feel overwhelmed by the calculations that go into solar.  I work with Ohms law now and then at work, but solar gets me worried every time.  Is there any books or links you would suggest to combat fear with education?  Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 16, 2009, 06:52:21 PM
Most of what I've learned about solar PV has been gleaned from a variety of sources. That and simple application of what electrical/electronic knowledge I already had.

The following websites do have information, sometimes you have to search and read through the entire site. They also sell a variety of solar equipment.

I have purchased from the first four businesses listed and have no fault with any of them.

Affordable Solar, Albuquerque, NM (http://www.affordable-solar.com/)

TheSolar.Biz, in SW NM (http://thesolar.biz/default.htm)

solarseller.com    Long Beach, CA (http://solarseller.com/)

Northern Arizona Wind & Sun
(http://store.solar-electric.com/)
 Northern AZ also has a pretty good info section (http://www.solar-electric.com/).


Backwoods Solar (http://backwoodssolar.com/)  I've not bought from them, but there's useful information.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on January 16, 2009, 07:49:16 PM
Don,
Thanks for the links.  What have you read about using microwaves and other such appliances with such a heavy draw at start up?  Is there anything special that need to be taken into consideration in your opinion.

Thanks,

Craig
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 16, 2009, 07:56:34 PM
Depends on the size of your inverter and additional loads, soomb. 

I can run my 5 horsepower rock crusher motor on mine but it likely is only drawing about 2 or 3 horsepower most of the time actual load.  Forgot --- I'm actually running it on 240v or two 4000 watt inverters.  d*

Mine and others have no problem.  I don't know that microwaves have such a surge as just plain heavy current draw, but since it is usually for a short time, they can work out fine.  I'd say a 2000 watt inverter with some surge capability would handle it though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on January 16, 2009, 08:03:44 PM
Glenn,

Thanks for the input.  I need to sit down and get to reading.  I want to be able to prove to my wife that when we build a cabin she will not be sitting in a cold corner reading by oil lamp light (I like the rustic idea, but I like having my wife around more).

Thanks again.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 16, 2009, 08:04:10 PM
Craig,

The inverter has to be sized to be able to operate the microwave. The advertised rating you see, say 600 watts, is the cooking power. A 600 watt cooking power microwave will probably draw about 1100 watts from the inverter. Sometimes you can only find that info on the microwave itself, not in the info or on the box.

The inverter should be a pure sine wave inverter. Personal experience has shown that some microwaves don't work on (cheap) square wave inverters. That may vary.  ???  Even if the microwave works on square wave it will be noisier and fan may run slower. The unit will run hotter; not cooking hotter, but the electronics will waste energy and run hotter with a square wave.

The battery bank and cabling has to be able to supply the current draw. That's one reason why I prefer in 24 VDC systems over 12 VDC battery systems.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 16, 2009, 08:10:38 PM
FWIW, I don't even consider modified sine wave for anything but misc. use - say plugged into the truck cigarette lighter or something to charge Ryobi batteries - phone etc. 

For anything serious relating to living, only pure sine wave.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 16, 2009, 08:26:33 PM
Since the subject has come up, I'll get into some pure sine wave vs square wave inverters. I call them square wave, not modified square wave like all the ad talk does. That's because modified or not, if the word square is in there there are disadvantages. Pure sine wave is the only way to go if you are running anything but simple lights.

Advantages of Pure Sine Wave Inverters.

Never any doubt anything you plug in will work if the inverter can supply enough watts.

Items that can have issues are...
Microwvaes as noted above.

Inductive loads like motors (and the microwave) run quieter, cooler and faster. Running cooler means they last longer. This applies to a lot of tools.

Some devices like FL lights, radios, TV's, answering machines, etc might have a hum. Some do and some don't. Some are worse than others. We have a TV that is fine and a couple CFL's that have a slight, usually inaudible, hum.

Laser printer and photocopiers may have problems with output on square wave.

My wife's electronic sewing machine does not work on square wave.

Some variable speed plug in power tools will burn out.

Some microprocessor controlled furnace and pellet stoves may not operate correctly.

Battery chargers that have the little cube that plugs into the outlet may not work or may get very hot and burn out. This may also apply to things like flashlights that you plug directly into an outlet. Not all of them, but I did a number on an AC adapter for a portable radio. Very smelly event. However, most battery chargers that have a regular AC cord and plug that connects a charger to the wall outlet should work fine.

Digital clocks in radios may not work.

As you can see there are a lot of 'may not work'. Electrical devices are not all created equal. In some cases the item works but draws more current putting more load on the batteries. Those items will be running hotter as well and as mentioned above may not last as long due to the heating.

Advantages of Square Wave Inverters, AKA Disadvantages of Pure Sine Wave Inverters.
Pure sine wave are more expensive, much more expensive.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 16, 2009, 08:31:23 PM
Some things will burn out -- such as my $600 Bosch rotohammer w/soft start drilling -- Square wave took the speed control out of it.

My water pump  only pumped about 1/2 as much water on the same power on square wave.  I understand there is something else you can add to make it run better but why bother -- get a sine wave and save money elsewhere.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 16, 2009, 08:40:37 PM
As stated, motors run hotter, slower and run longer (not longer in lasting longer, but runs longer as in more time per day). Sort of counter productive making a refrigerator motor run hotter with it located right under the cold box of most refrigerators. And since they are one of the biggest power users that will but much more load on the batteries.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Okie_Bob on January 20, 2009, 04:48:44 AM
Don and Glenn, I am really enjoying this topic and would like to see it moved up to the top as one of the regular what ever you call it prime topics. I still believe that the more time goes by the more people are going to be getting off grid. Obviously, not those in town but, those outside the city limits and the further outside the city limits the more people are going to be getting off grid.
Don, you have certainly added some useful notes that I would never have considered had you not posted them and for that I think you.
I may be the only one that is interested in wind power too but, maybe that will change with time? I'd sure like to see more on wind and know Glenn has a wind turbin or two? And I'd really like to hear this same sort of exchange where I can learn from your mistakes!
Okie Bob
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 20, 2009, 05:49:18 AM
I don't make mistakes, BoB.  [crz]

It is called planned obsolescence. Some sooner than others. [waiting]

For those who don't care to go through the whole Underground Cabin Update looking, here's a link to the start of my Solar Tracker Project, which I might add is a huge success. :)

http://countryplans.com/smf/index.php?topic=151.msg77051#msg77051

A pix of the tracker and Wind Generator together.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi35.photobucket.com%2Falbums%2Fd184%2Fglennkangiser%2Ftrackerandwindgenerator.jpg&hash=0727e1568cef8bbdb4339b9e483f3f02)

I'll sticky it for a bit and well see how long interest continues. :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: NM_Shooter on January 20, 2009, 12:20:02 PM
Hmmmm... I wonder if you were to use a big isolation transformer on the output of a modified-square wave inverter.  Seems like that should result in a sine at the output of the secondary....

-f-
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 20, 2009, 06:47:10 PM
You think it would knock the corners off the squares, Frank?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 22, 2009, 10:18:16 PM
Don, or anybody else,  I have some copper plate - maybe about .065 or so.  Stole it from my son, but when I mentioned that fact he gave it to me -- didn't want me to look bad I guess... 

I haven't found much on plate or strip - maybe 1 inch or so wide, ampacity. There must be something on it. hmm
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 22, 2009, 10:25:15 PM
Goto Storm Copper (http://stormcopper.com/design/Buss-Bar-Ampacities.htm)  click on ampacity tables.


I'm pondering using copper straps in place of regular battery cables.   ???

1/16 x 1 would just about cover my needs... 175 amps max more or less.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 22, 2009, 10:30:32 PM
That's what I was thinking about.  I think these were parts of metal roofing or for a copper range hood he made for a customer - probably the range hood now that I think about it.  He put a copper roof on in Santa Monica I think it was.

I also want to build my own knife switches so I don't have to leave an Ax nearby to cut the cables in case of emergency.  Shouldn't be any worse than welding though, eh?  'cept for that hydrogen... [crz]

Thanks for the link.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 22, 2009, 10:33:26 PM
Ax = the ultimate knife switch     rofl rofl


Storm Copper offers loads of copper goods. They claim they have 1,000,000 pounds of copper stock in inventory.     :o



FYI, they also sell copper nails and silicon bronze nuts and bolts.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 22, 2009, 10:43:29 PM
Cool -- I just picked up my milkbox full of silicon bronze scrap from the valley house.  I think it must have been 150 to 200 lbs.  I use it for casting replica parts though I haven't done it in years.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 23, 2009, 07:26:13 AM
Interesting discussion on DC vs AC buss bars.

"  50556
Copper Size for DC low-voltage high-amperage

November 18, 2008

Hello all,

I'm a new plating learner.

Now I have a rectifier which the rating the output rating is 12VDC,4000A. The current size of copper busbar which link from rectifier to chrome tank is 12mm x 100mm. To me, I think it is under size since the the current ampacity of it should be around 2600A (in AC, DC should be less). My question are:

1) What is the actual size of busbar i have to used in this case?
2) How to calculate for DC busbar?
3) Is that the size will be different for DC and AC 50 Hz? In same current, copper which apply to DC circuit should be more larger than AC 50Hz circuit?

Thanks

Khor Patrick
Plating Learner - Malaysia
contact button

November 24, 2008

This link should give you all the info you need.


http://www.stormcopper.com/design/Buss-Bar-Ampacities.htm

Kurt Sammons
- Inman, SC

November 24, 2008

Thanks, Kurt. I think that page should be fine for AC current calculations.

For DC bussing for a rectifier, however, I think the standard number used for decades, 1000 amps/square inch, is an easier and safer approach.

Khor, for an electroplating bussing installation I would consider the ampacity of a 12 mm x 100 mm busbar (slightly under 1/2" x slightly under 4") to be about 1860 Amps, but we could call it 2000 Amps. You need two, not one, 12 mm x 100 mm busbars, although most experienced installers would probably use four 6 mm x 100 mm bars instead. Isn't that what is coming out of the rectifier?

Regards,

   


Ted Mooney, P.E.
finishing.com
Brick, New Jersey

December 5, 2008

Ted
I have never claimed to be an electrical engineer, but have run alot of wire in my day. I never considered that there would be a difference in ampacity for AC vs DC. I reached out to the folks at Storm Copper for validation. My question was very simple:

Is there a significant difference between AC ampacity and DC ampacity?

There response was:

Yes. DC causes greater heating of the bus. I believe de-rate AC values around 30%.

A quick study of their ampacity tables complicates the issue even more. a 1/2"x2" buss is listed at 1000 amps. Fits your number perfectly. A 1/4"x4" buss however is at 1250 amps. Maybe more heat transfer area to keep it cool.

However, Storm is suggesting to derate the AC by 30% for DC current meaning those two bars would be 700 and 875 amps.

Kurt Sammons
- Inman, SC

December 15, 2008

Thanks again, Kurt. I've been sizing bus bar the same way for 40 years and would dearly love to get out of that rut and hear a newer and better way. And I understand that a 1/4 x 4 bar has greater surface area and cooling, and consequently higher current carrying capacity, than a 1/2 by 2 bar.

But the fact is, 1000 Amps/sq. in has proven itself for decades. If these charts indicated higher ampacity than the simple old-fashioned method, I would want to go along with them. But when they suggest that copper can only carry 70 to 87 percent of what we know it has safely and reliably carried in tens of thousands of plating and anodizing installations over 5 or more decades, I think it is they who need to go back to the drawing board :-)

Their figures may be for bus bars enclosed in power distribution boxes or ducts rather than out in the open air though.

Regards,


Ted Mooney, P.E.
finishing.com
Brick, New Jersey"

http://www.finishing.com/505/56.shtml
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 07:57:10 AM
I put my new bank of batteries in last night using copper buss bars.  Boy is that easier than cables.  I cut my bars off sheet copper with a power hacksaw (band saw) as it was raining and I did not want to start my shear - had to move a welder/generator - two trucks and a trailer  for power. 

I drilled holes low near the ends so they would fit the terminal bolts easily.  I would have spent hours making cables.  The buss bars took less than an hour for all 8 of them and are much neater in appearance.  I may split hose to slip over them for insulation - lots of bare copper there.  I'd hate to drop a wrench across them. d*

Reading the charts over I decided that 1/6 x 1" was big enough but I went about 1 1/4" on the buss tying the two banks together and attaching to the inverters.  I drilled 2 extra holes in the center of that buss for future connections.  Possibly I'll get a pix today.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on January 24, 2009, 08:18:08 AM
Please post the pics when you get them.  I am still learning and I think I have a visual on what you are discussing but the photos will be of great help.

Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 08:31:34 AM
Like these. These are lead coated or silver plated copper.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.stormcopper.com%2FBattery%2520Straps2.JPG&hash=8984d459074ff7321c80b0027dab6e97)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on January 24, 2009, 08:46:18 AM
thank you sir.

Based on the discussion of using hose to jacket them, do they get all that hot?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 08:47:41 AM
No. But sheathing them will give more protection against accidental short circuiting.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 09:56:26 AM
Those are the commercial version of what I did - I wonder if they will go sideways like mine as there is only about 5/16 clearance from the bolt to the lead of the terminal.  I guess a tin snips could take care of that though. 

Here's mine - love that old wiring on the original set. :)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi35.photobucket.com%2Falbums%2Fd184%2Fglennkangiser%2Fbatterybank.jpg&hash=8c7536264d8bf6524e2ed7894e69dcf4)

I wonder if the lead or tin coat makes a significant difference?  There is something called skin effect - seems more to do with a/c but it is effected by the coating such as copper over steel works pretty good.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 10:22:30 AM
thank you sir.

Based on the discussion of using hose to jacket them, do they get all that hot?

soomb, there is no heating involved especially with the amount of batteries I have using several different supply paths.  I sized the strips I cut assuming maybe near 200 amps max current so the 187 was close enough for me for the 1/16 x 1" copper and like the old engoineers comments above - I am not worried about derating it.  I will never reach near that load.

Assuming 4000 watts per inverter - I have 2, so 4000 watts / 24 volts = 166 amps  - round up to 180 amps for inefficiencies - so running 240 volts with both inverters I could pull max 360 amps or so.  180 amps each - the bars I used would do that at 30 degrees C according to the chart or 86f temp. rise. I would not hit that often as my biggest load is the pump at 10 amps per inverter - or possibly some of my machines may be more.  Also though - that would be on 2 banks of batteries only - I now have 5 banks of 4 batteries so each would only get about 70 amps at maximum current draw of both inverters. 

Even the 1/16 x 1/2 is good for 103 amps under the following conditions.

"* Applicable to typical in-service conditions (indoors, 40C ambient temperature), horizontal run on edge, and free from external magnetic influences." So I have used twice as big a buss as necessary for my purposes.  I myself would not like to see the temperature rise they allow as that is just power being wasted to create heat -- so I went for the larger buss bars.

I do find heating under heavy charge or heavy use if a terminal is corroded increasing it's resistance.  When heavy charging with the welder I often take the non-contact thermometer and take temp readings at all of the terminal connections cleaning any that get a temperature rise.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 11:24:27 AM

I wonder if the lead or tin coat makes a significant difference?  There is something called skin effect - seems more to do with a/c but it is effected by the coating such as copper over steel works pretty good.

Something to do with removing the oxidation of Cu from the battery bank I would imagine; though that is conjecture. From the Storm Copper website on battery interconnects...

Generally, Battery Connectors are plated in Tin for sealed battery applications and Lead or a Tin/Lead Alloy for Flooded Battery Connector applications.

I figure one could cheat and simply apply solder to the ends of the straps once the holes are drilled/punched.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 11:26:44 AM
Glenn, I got to tell you I would not have believed those were your batteries with the nice neat battery strap connectors if I had not seen the familiar rats nest wiring job behind it.   ;D ;D  I am impressed to no end.  :D

My GC2's have vertical threaded stud mounts so I could run the straps flat. I think that is what I will do between batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 11:48:37 AM
[rofl2]  I couldn't even believe the difference.  :)

I think I will coat the ends with protectant of some sort - petroleum jelly ? Grease - guess I'll google it.  The NAPA battery protector stuff doesn't seem to last.

I see from the quote above they are rated standing on edge, but with the smaller batteries cooling should not be a problem.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 11:52:16 AM
Note that the cables coming off of the new batteries are  something like 000 aluminum service entrance cable with the ends protected with the special dissimilar metal grease and then a copper pipe sleeve smashed flat over them and drilled.  No corrosion of any kind on them noted in a couple years.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 12:16:50 PM
The batteries with the straps invite maintenance   :D, whereas with the rat's nest it's difficult to see the cell caps let alone get at them at times.   ;D ;D  I use cables in the 4 GC2's in the RV and I'm afraid it looks a little scary too. I was going to do cables (home made) but I believe the straps are now a no brainer.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 12:28:37 PM
I use a gallon water jug with a hose in the cap to get through the mess but it's still not fun.  I like the straps.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on January 24, 2009, 01:21:42 PM
Hey Glenn, I'm not sure if it is appropriate for this application, but you could mask off the ends of your straps and dip them in that plastic dip coating they make for tool handles. 

-- Pritch
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 24, 2009, 01:31:00 PM
That is a good idea, Pritch.  Plastic is plastic I think. Good idea.

As an alternative rather than that I could likely also get away with the 2" wide 10 or 20 mill tape they make I think - that would be easy.  Not as heavy but likely sufficient.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 24, 2009, 11:04:19 PM
To DC or to AC the small off grid cabin?

With apologies to William Shakespeare.

When I began to design my cabin I knew it would be off the electrical grid; the connection would cost more than the land and the cabin. Way more. I first thought I would build a power system that used a lot of the DC power directly to power DC lighting. The first advantage to going in the direction of a DC power based cabin that I thought of was the apparent simplicity. No inverter losses involved to run simple things like lights, I thought. I was willing to include a medium size inverter of 1100 to 1500 watts to enable the use of a microwave, perhaps a vacuum cleaner or the occasional use of a toaster.

I discovered the availability of DC voltage CFL lighting;12, 24 or 48 VDC. Good I thought. Yes they cost more than the 120 VAC CFL I could buy in bulk at Costco, Sam’s or even Lowe’s. Yeah, and I’d have to order them and pay for shipping. Fair enough.

So I drew plans. I had a DC panel. I had an AC panel. Even though I was building off the beaten track, under the radar I wanted to keep the building and it’s components within the scope of the building codes and the NEC. Pretty much. Therefore I would need to keep the DC separate from the AC. I soon discovered that automotive type fuses and switches would be problematic. But then I got lucky and discovered that the Square D line of circuit breakers were UL approved for up to 48 VDC! On-off switches remained a problem. Let it be noted that virtually all on-off household switches are not DC rated. They will burn out quickly when used on DC circuits. Automobile switches are not UL listed. I did find some DC rated switches, UL listed for about $12 apiece.

My wife wanted to use some table lamps in the cabin. Alright no problem, I can use some of those DC CFL’s in them. Ooops, the socket switches would not survive the DC experience for long. Well, OK, I’d figure something out on that.

The next thought was how to ensure keeping the DC separate from the AC, for it was a ‘given’ that there must be outlets for the microwave, toaster, possibly a vacuum cleaner, and now outlets for the DC lamps. Not a big deal I said.  ::) I knew that the NEC allowed the use of 240 VAC receptacles and plugs for DC use as long as there was no 240 VAC power systems in the cabin. Home free, I thought.

For the AC power I figured I’d use either a modified square wave inverter or possibly a pure sine wave inverter such as the Exeltech 1100 watt unit in the RV. (Note: I refer to a modified square wave inverter. I refuse to call them a modified sine wave inverter as that is a marketing lie. Square wave is square wave, modified or not. Some devices work fine on square wave; incandescent lamps for example. Some devices work, but under duress; like motors. Motors run slower and hotter. They waste power. In some cases they burn out prematurely. Some devices simply won’t work at all. The microwave in our RV is an example. It makes all the proper noises, the turntable turns, and after nuking a cup of water for 2 minutes it emerges as cold as it was when it was placed in the microwave. Some devices like a small battery charger for NiCad cells destroy themselves when powered by square wave power. I had a very odoriferous event on a camping trip in UT when I attempted to recharge some flashlight batteries. I was very leery of allowing my wife to use her computerized sewing machine off a square wave inverter.

Ok, I said. I’ll move the Exeltech pure sine wave 1100 watt inverter from the RV to the cabin. Perfect! NO, wait a sec. Not so perfect.  d* How many times has my dear wonderful, beautiful, warm, loving, adorable, accepting of all my foibles and idiosyncrasies, wife started the microwave (it needs 1000 watts to run) and then simultaneously attempted to use some other AC operated appliance. This won’t fly, I realized. Add to that the different outlets, some for DC, some for AC; this was becoming complicated. Momentarily I considered no electricity at all; Aladdin oil lamps for lights and the rest be dammed.  :o  No. 

FYI, Exeltech makes some very fine pure sine wave inverters that are stand alone, no battery charger included and priced fairly. They also have a stackable series.

OK. I know there are many folks out there who have a DC based power system; some are members of this forum. What they have set up works for them according to what I see. That’s great! More power to them!  ;D My point in this is that you should take the time to run through your expectations of your off grid power system before deciding on the final plan.

My hybrid AC/DC system had me using more wire. DC systems usually require larger gauge wires because of the higher amperage the wires are asked to carry. There is the problem of DC listed switches. Then there’s the fact that DC powered CFL’s cost more than the commonly available SC versions. FYI, the only difference between an AC fluorescent lamp and a DC powered one is the ballast. The tubes are the same. It had two service panels instead of one, and more wire of a heavier gauge.

After the considerable amount of time devoted to considering all the above I decided that for this particular cabin of ours it did not make sense to do a DC based system. The PV panels have remained more or less constant. Ditto the charge controller and batteries.

However the big change comes with the wiring. Our cabin is basically wired like the typical home. AC circuits for virtually everything; 14-2 wire; the AC power coming from a pure sine wave inverter capable of supplying 3500 watts continuously (30 amps). I have fudged a little; I have three 12 VDC lights that will operate directly off DC , just in case the inverter craps out at some point. I also have a 24 VDC ceiling fan because it’s efficiency is so vastly superior to the best of the 120 VAC units. Everything else is just like at home on the grid. No strange light bulbs, no strange receptacles, no wondering if I can use the microwave and the toaster at the same time.

Anyhow, my purpose here was to incite thought. I’m sure there are folks who will have no issues with a DC based system To them, I say, good show! You have simplified beyondd where I draw the line. I’m just not quite ready to venture there. Think it through before you finalize your off grid plans.

I hope all that makes some sense. Any comments will be appreciated.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 25, 2009, 11:43:21 AM
I agree with you, Don. 

With the efficiencies of modern Sine Wave inverters, and the lower cost of standard A/C equipment plus the availability of the normal A/C items, it only makes sense to me to run standard A/C for anything other than a small system.  Even the small system is likely easier to do with A/C in my opinion.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 08:48:02 AM
My brain cells got prompted to recall this by a comment in another topic.

In our cabin wiring I have wired several outlet halves to be switched (on-off) by a wall switch. Some of these are designated for items like the microwave, the TV and the stereo. All these have phantom loads; the clock in the microwave and the remote control circuitry in the TV and stereo. For those who are not aware, anything that has a cordless remote control is using a small amount of power even when turned off. While it sits there waiting for the wake up signal it uses a timy bit of power.

Same thing applies to the cordless phone base station, and many other items in any home. Around home I don't worry about it. Right now I know there are a couple battery chargers in the garage that are sitting there wasting a little power. Plus there's the garage door opener waiting for the signal to open the door. And the sensor activated lighting around the building exterior. And the sensor activated light that turns the front entry light on when one comes through the front door; handy when carrying stuff. Also guaranteed to surprise anyone breaking through the door.

Back to the topic of switched outlets for off grid power. I also used a switch with a pilot light. The light is low power neon and only comes on when the switch is in the ON position, no light when turned off. I've also used those for the exterior lights. A glance at the switches by the door will let you know you forgot to turn off the lights outside.

Similar to this one (mine are the standard toggle type)...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fassets.twacomm.com%2Fassets%2F2055108707%2Fproduct_images%2F17895.jpg&hash=53edf0905e84d2f9859e5bbc8baac594)

Also available in a three way type.  If you go for these beware that some pilot eqipped switches have the pilot illuminated when the switch is off; handy for finding in the dark, but not what we want for this purpose.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 02:10:25 PM
topic on battery cable connections (http://countryplans.com/smf/index.php?topic=6181.msg80649#msg80649)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 05:03:41 PM
Off Grid Power System Calculators.

Here are several sites I've had bookmarked for some time. I like some more than others. Some have online forms that can be filled in. You click a button and it does the math. Others have print out forms and you do the math yourself. They may not be perfect in that the resulting recommended configuration is not necessarily the only way or the best way. However, they are a reasonable place to start. Remember, as always, garbage in = garbage out. You must enter realistic power usage, not want to wish for, but what you will use. Then add a little extra as insurance.

I think this one is my favorite
http://www.wagonmaker.com/script_calculator.html (http://www.wagonmaker.com/script_calculator.html)

Not bad either
http://store.altenergystore.com/calculators/off_grid_calculator/#load-calc (http://store.altenergystore.com/calculators/off_grid_calculator/#load-calc)

http://www.me.utexas.edu/~me374s/javatop.html (http://www.me.utexas.edu/~me374s/javatop.html)

http://www.evsolar.com/worksheet.html (http://www.evsolar.com/worksheet.html)

And a few more...
http://www.bigfrogmountain.com/calculators.cfm (http://www.bigfrogmountain.com/calculators.cfm)

http://www.solar4power.com/solar-power-sizing.html#battery (http://www.solar4power.com/solar-power-sizing.html#battery)

http://www.green-trust.org/2003/pvsizing/default.htm (http://www.green-trust.org/2003/pvsizing/default.htm)

http://www.solar-power-answers.co.uk/design.php (http://www.solar-power-answers.co.uk/design.php)

PLUS, the following is a good one that is meant for determining how many panels of your choosing can be safely used with your Outback Charge Controller. It was mentioned previously.
http://outbackpower.com/resources/string_sizing_tool/ (http://outbackpower.com/resources/string_sizing_tool/)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 06:59:22 PM
Batteries, Series VS Parallel

Most of us will likely end up with batteries in some sort of a series - parallel system, partly because golf cart and L16 style batteries are reasonably priced and because our system may need to be enlarged at some point. I figure that eight 6 volt golf cart batteries will fill our needs; two strings of four in series connected in parallel. If I need to increase capacity I'll add another string of four in series to be paralleled with the others. I'll know about that soon after getting it going. My battery box is going to be sized to accept up to twelve batteries of the L16 size just in case.

There are advantages and disadvantages to this. On the advantage side we just added batteries, didn't have to ditch the ones we had and buy larger ones. We can add four of the same capacity and increase our reserve power. One disadvantage to this series / parallel system is the large number of cells to maintain. Another is the increased number of cable or buss connections.

Another disadvantage to paralleling may be viewed as a positive to some. That is that a failed cell will not drop the design voltage as there are the parallel ones to make up the difference. It may not be obvious that there is a problem, until you notice that cell requiring more watering. So while the battery bank will maintain design voltage and still have pretty good capacity it will self discharge at a higher rate. A parallel bank with a bad cell will sap energy as the other cells try to charge it (this occurs continuously, even with no system load, which adds up in sapping energy).

This does not occur in a series only string. A bad cell in series will drag the voltage of the system down, but it will not absorb power from the other cells. The power passes through the bad cell. The failed cell may add some resistance (which does sap energy, but only when a load is applied) and, since it does not contribute any voltage, it will show as a reduced battery bank voltage. The lowered voltage makes it easier to spot a bad cell.

Bigger cells in series also mean fewer cells to maintain. Of course bigger cells also mean heavier more bulky cells, a downside in many remote locations.

My dream battery bank for our cabin would be:
 - Twelve 2 volt 845 amp/hr HUP-One cells in series for a 24 VDC system; approx $7000+. There are some others by Rolls or Surette, but they are in the same price range. These are expected to last 15 - 20 years. Many have been in service longer.

So while the ideal may be a series only string, you need deep pockets to start with that.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 07:24:15 PM
Further to the above. A series /parallel also have the advantage of redundancy. A bad cell or battery in one series string could be temporarily dealt with by removing that string from the parallel array, until the cell/battery is replaced.

However to counter that a properly maintained battery bank consisting of HUP's or Rolls/Surettes is not very likely to give problems for many many years.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 26, 2009, 07:49:59 PM
I knew you'd have some good points on this.

Now how to handle this problem of a cell dropping in a series of a parallel set.  I found that equalizing as you and a dealer mentioned to me seems to help greatly -- head for 32 volts for a few hours.  This is a hard one.  Many chargers or inverter chargers don't want to go there. 

I find that a charger working on just 2 of the 6 volt batteries - since I have a 12 volt charger can remove power from the group and charge certain parts of the series group without pulling the group down much -- recycling - pull it out of all and put it into 2 of them only, bringing them back up to meet the rest.  The most effective is using the welder to get the equalization charge for me.

Soon I hope to be able to report on a new charger - MikeyB is checking on it tomorrow.

Locating the bad cells is easy - I pull all of the caps off of one series group and check every cell with the Hydrometer. 
when done with that group I do the next one.  Record the readings or mark the low cells for future monitoring after charging or equalizing.  Specific Gravity of all should be in the good range.  If one cell is significantly lower than the rest, then it needs attention or the whole pack will suffer.  Distilled water only as necessary then equalize them.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 26, 2009, 09:04:46 PM
-- head for 32 volts for a few hours.  This is a hard one.  Many chargers or inverter chargers don't want to go there. 

 That is yet another wonderful thing about the Outback equipment.  :D  The charge rates are all user programmable. On a 24 VDC system the EQ charge can be set all the way up to 34 volts.  :o 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 27, 2009, 07:50:30 AM
The Trace 4024 kicks out at 30.4 or maybe .2 I think as far as when inverting and equalizing with an outside source.   Once it hits that voltage the system shuts down untill the voltage drops back to within he normal range.  I have not checked for programmable settings as I don't use it for equalization.  I should check it to see -- it is not fun to get lost in the programming menus on the Trace.  Lots of owner manual study might help.

I did not notice sulfation releasing and battery improvement until equalization voltage got to 31.2 then the voltage would drop back to 30.8 as internal resistance dropped and additional charge was allowed in by the battery.  SG (specific Gravity) improved in my worst cells also.  I had at least 3 that were below to well below normal.  All it takes is 1 below the rest in the string to kill a string of batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 27, 2009, 08:21:44 AM
Here are the Trojans that were given to me - they were a bit over 3 years old.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi35.photobucket.com%2Falbums%2Fd184%2Fglennkangiser%2FL16s.jpg&hash=45c67da2b3fea2fad06ac9db4d44cc80)

An inadequately sized system and overuse along with insufficient equalization and lack of sufficient maintenance has caused sulfation to the point that the owners couldn't get them to keep enough charge to keep their house running.

Somehow they had changed them out and just wanted them removed from their crawlspace.  I thought this would be a great opportunity for me to play with desulfation.  Here is one of the cells that is in worse shape.  I marked it and took a pix so I could keep track of progress.  I filled adjacent cells with rain water as one was dry on top and put the small desulfator on the two worst batteries until I get a bigger desulfator through Mike.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi35.photobucket.com%2Falbums%2Fd184%2Fglennkangiser%2FsulfationTrojan-A-.jpg&hash=2d04eb2d30d7ad4c9a1f3450b61e0a42)As you can see, the plates are nearly not visible through the sulfate crystallization in the above pix.  I was able to get the 2 volt and 4 volt batter to take a charge with my 10 amp NAPA PWM charger.  Some of the new NAPA chargers use pulse technology and are superior to the old chargers using much less power to make a better charge.  I heard about it but they don't give any info in their catalog.  I went to the Shumaker website to verify what the charger did.  They manufacture it.

I have found this battery listed from $389 to $559 each  on the net depending on the quality of dealer - some seem a bit unscrupulous.

I can still buy them in other brands for around $250 or maybe a bit less wholesale - just a guide price so you don't get taken advantage of.

The moral to all of this.  I guess it would be, take good care of your Trojans and they will take care of you. [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 27, 2009, 08:46:18 AM
Here is a link to another picture of the Two batteries I currently have the desulfator on showing what you should be able to see if the batteries were not sulfated as well as some more commentary on my tracker.

 Trojans being repaired at the Underground Cabin!  (http://countryplans.com/smf/index.php?topic=151.msg80770#msg80770)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 30, 2009, 02:13:51 PM
Tesa, I split your questions off to  "tesa's Off Grid System"

http://countryplans.com/smf/index.php?topic=6230.msg81195#msg81195 (http://countryplans.com/smf/index.php?topic=6230.msg81195#msg81195)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Blake on January 31, 2009, 03:16:23 AM
Don,
 I may have missed it, but if you don't mind, have you had a hard time keeping your system charged from the panels alone down there?  I helped a friend install his genset on his system in Fort Davis a month ago,  and he is having a problem getting  a good charge during the day.  We sized the system properly,  but he bought the pv panels on his own.  Another outfit installed his controller, batteries and inverter.  He's been telling me even during the sunny days,  at night the genset kicks on twice for about a half hour.  His genset is used soley for charging the batteries right now.  Panels are in an open area at the highest point on his property.  I am going off by assumption and the last time I was over your way,  but I remember Jemez mountains being simiar to the fort davis area.  Any pointers are greatly appreciated,  as I am lost on the solar side of things.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 31, 2009, 06:15:39 AM
If he has clear skies and no shadows over his panels then there is something wrong - maybe not enough panels or wired wrong.

Cold does not matter.  Cloudy skies will drop panel output to maybe 1%to 5% in my experience.

Too much voltage loss on the wire - Long wire run?  Small wire?

My panels put out great when the sun is out in the winter.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 31, 2009, 06:25:39 AM
Lots of possible reasons this is happening...

The first thing I would do is to check the specific gravity of the battery electrolyte in each cell. Does the hydrometer reading indicate full charge after the charge controller indicates it's full? Is there one or more low cells? Some charge controllers are programmable; perhaps it is not allowing the batteries to actually reach full charge.

Check all the DC connections for corrosion and tightness. Using a non contact infrared thermometer on all connections with a good load applied can help find a connection with high resistance.

If the batteries check out fully charged on all cells after solar charging, then it would seem he's using, or losing, more power than anticipated. Or the battery bank is simply too small for what it's being asked to do.

The set points for the auto start generator may be set incorrectly. It seems to me if the generator is coming on for only a half hour something is wrong there.  ???  I'd tell him to go and take a reading on the cells with the hydrometer when the generator kicks in. See what the state of charge really is; if charging is really needed at that point.

Does the generator only kick in during or immediately after a heavy load like running a big microwave for a while? That could be indicating battery capacity is insufficient to prevent rapid draw down of the battery voltage, which would cause the generator to kick in.

Anyhow that's where I would start.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 31, 2009, 06:33:52 AM
How cold do the batteries get? Capacity of the batteries fall with cold. 32 degrees F = approx 20% less

Correct the sp gr for temp.

If the batteries are AGM's forget all the above about checking sp gr. That's the only thing I don't like about AGM's.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 31, 2009, 07:09:07 AM
Update on the tracker and how to tell the level of propane in the pressure tubes. 

http://countryplans.com/smf/index.php?topic=151.msg81271#msg81271
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Blake on January 31, 2009, 02:29:37 PM
His panels are in the sun almost all day. 

Don, 
I appreciate your help.  I have forwarded your response to him and am going to let him look at it and confront the people who installed/programmed his inverter.  I just dropped it off of the back of the truck,  hooked up the two wire-start,  hooked up the l.p..  and test ran it.  The brief tour I took of the setup looked professionally done.  Thanks for the help and maybe I can help him out.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 01, 2009, 09:39:37 AM
This a great topic
I plan to be off grid later this year (I hope)

I am trying to decide what batteries  to buy

Someone here mentioned "HUP" -- not sure what these are

I have some experience with Trojan 'cart batteries' and they seem ok but for a serious system I think I need a serious battery bank

I have 6 AirX 48 volt wind generators (from Ebay at a very good price)

the plans call for 1500 watts of PV planels too

I am having difficulty calculating the size of the battery bank

On another note ...

I just bought a 8000 watt inverter from ebay -- made in Taiwan

I looked great and was priced right at $2700 --free shipping

now for the rest of the story

Yesterday I hooked it up to some four 12volt batts   in series


the output is 218 VAC across the 'N" and "L" lines but

ground an "L" reads 125 VAC

and ground and "N" reads only 85 VAC  :(


email to KIPOINT in TAiwan says they will get back to me after "new moon holiday"  Feb 2

anyway back to the batteries

I am almost decided to go with the 12V L-16 Trojans

but maybe Concord or Surrette would be worth the money  :-\
 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 11:35:00 AM
HUP One, or Solar One batteries info...

http://www.hupsolarone.com/benefits.htm (http://www.hupsolarone.com/benefits.htm)

http://thesolar.biz/hup_solar_one_batteries.htm (http://thesolar.biz/hup_solar_one_batteries.htm)

They warrant their batteries to have 2100 cycles at 80% Depth Of Discharge.: 4000 cycles at 5%, I think.

------------------

sizing tool
http://www.wagonmaker.com/script_calculator.html (http://www.wagonmaker.com/script_calculator.html)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 01, 2009, 11:45:57 AM
Thanks Don

I hadn't come across that brand before

now I just need to take out a second mortgage ....... ;D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 11:58:19 AM
$$$   That's one of the big reasons L-16's enjoy great popularity.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 02:37:29 PM
Batteries are the heart of off grid power systems. I have loads of notes collected over time. I plan on sorting, condensing and adding to previous posts here.

FIRST… BATTERY ACID is HAZARDOUS. At the very least eye goggles should be worn. Having a bottle of sterile eye wash at hand is also a very good idea. Having it “at hand” so you can grasp it readily when you have your eyes screwed shut because they have acid in them is very important. It does little good if it’s in the shed “someplace”.

Get a plastic bottle and fill it with baking soda and water solution. Keep it by the batteries or with you tool kit. Use it to neutralize accidental splash or spills and to clean normal acid spatter from battery tops. Don't ever wear your favorite blue jeans! You won't know if you ruined them till you wash them next time.



Let's have a look at determining State of Charge on wet cell batteries. That includes standard and low maintenance. The key thing is the ability to remove the cap from the cell and measure specific gravity and/or add water as needed. These are sometimes referred to as Flooded cell batteries.

There are a variety of devices to measure specific gravity. Some use floating colored balls or disks. Do NOT bother with these. Others use a swinging “scale” that “floats” as the electrolyte is sucked into its chamber. Do NOT buy one of those either. Purchase a good old fashioned graduated float style, preferably one with a built in thermometer. NAPA auto parts sell one like that.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fpartimages2.genpt.com%2Fpartimages%2F215521.jpg&hash=9241788debdc48fb8518fed3c8dfcceb)

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=BK&PartNumber=7001145&Description=Battery+Tester+%2f+Hand+Held (http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=BK&PartNumber=7001145&Description=Battery+Tester+%2f+Hand+Held)

You want the thermometer as lead-acid batteries are rated at a temperature of 25 degrees Celsius (77 F). Battery capacity, how much power can be pulled from a wet cell battery, falls as the temperature falls. Conversely battery capacity increases as the temperature rises. Battery life is increased at lower temperatures and reduced at elevated temperatures.

Hydrometer readings should not vary more than .05 difference between cells.


A voltmeter may also be used to determine the state of charge. However, the battery must have been sitting with no charge or load having been applied to it for a period of three hours minimum. The reason for this is the battery will hold onto a “surface charge voltage” for some time after being charged. It takes several hours to dissipate. For those in a hurry a load of approx 20 amps for ten minutes will remove the surface charge, more or less and will MTL give a usable reading.


Here’s a chart showing specific gravities for several different States of Charge for wet cell batteries, at temperatures from zero to 120 degrees F. Also included are open circuit voltage readings, based on a 12 VDC battery. Halve the voltage readings for a 6 VDC battery.

The chart uses rounded off figures so in it we refer to the standard temperature as 80 degrees F  (26.7 C)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FStateofCharge-wet.jpg&hash=b40a1502143d188b3326cef18463582d)

Lastly, for now, only add water to a charged cell. The electrolyte expands as it goes from less charged to fully charged. The exception to this rule would be if the electrolyte is below the top of the plates; then add just enough to cover the plates.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 05:16:14 PM
WHY a MPPT CHARGE CONTROLLER is BEST
(Maximum Power Point Tracking)

Because PV cells and batteries are both not very smart; in fact panels are dumb and batteries plain stupid.

Many PV panels are built to put out a nominal 12 volts. The catch is "nominal". In actual fact, almost all "12 volt" solar panels are designed to put out from 16 to 18 volts. The problem is that a nominal 12 volt battery is pretty close to an actual 12 volts - 10.5 to 12.7 volts, depending on state of charge. Under charge, most batteries want from around 13.2 to 14.4 volts to fully charge - quite a bit different than what most panels are designed to put out.

OK, so let’s use the popular Kyocera 130 watt solar panel as an example. Catch #1 is that it is rated at 130 watts at a particular voltage and current. The Kyocera KC-130 is rated at 7.39 amps at 17.6 volts. (7.39 amps times 17.6 volts = 130 watts).

So what happens when you hook up this 130 watt panel to your battery through a regular charge controller?

Your panel puts out 7.4 amps. Your battery is sitting at 12 volts under charge: 7.4 amps times 12 volts = 88.8 watts. You lost over 41 watts. That 41 watts is not going anywhere, it just is not being produced because there is a poor match between the panel and the battery. With a very low battery, say 10.5 volts, it's even worse - you could be losing as much as 35% (11 volts x 7.4 amps = 81.4 watts. You lost about 48 watts.

One solution you might think of; why not just make panels so that they put out 14 volts or so to match the battery?

Catch #22a is that the panel is rated at 130 watts at full sunlight at a particular temperature (STC - or standard test conditions). If temperature of the solar panel is high, you don't get 17.4 volts. At the temperatures seen in many hot climate areas, you might get under 16 volts. If you started with a 15 volt panel (like some of the so-called "self regulating" panels), you are in trouble, as you won't have enough voltage to put a charge into the battery. Solar panels have to have enough leeway built in to perform under the worst of conditions. The panel will just sit there looking dumb, and your batteries will get even stupider than usual.


How Maximum Power Point Tracking helps.

This is not tracking like Glenn has his panels tracking the sun. This is digital tracking of the power output of the PV panels and the needs of the batteries, then using high frequency DC to DC converters. They take the DC input from the solar panels, change it to high frequency AC, and convert it back down to a different DC voltage and current to exactly match the panels to the batteries. Digital MPPT controllers are microprocessor controlled. They know when to adjust the output that it is being sent to the battery, and they actually shut down for a few microseconds and "look" at the solar panel and battery and make any needed adjustments.

Assume your battery is low, at 12 volts. A MPPT takes that 17.6 volts at 7.4 amps and converts it down, so that what the battery gets is now 10.8 amps at 12 volts. Now you still have almost 130 watts, and everyone is happy.

Ideally, for 100% power conversion you would get around 11.3 amps at 11.5 volts, but you have to feed the battery a higher voltage to force the amps in. And this is a simplified explanation - in actual fact the output of the MPPT charge controller might vary continually to adjust for getting the maximum amps into the battery.

A MPPT tracks the maximum power point, which is going to be different from the STC (Standard Test Conditions) rating under almost all situations. Under very cold conditions a 120 watt panel is actually capable of putting over 130+ watts because the power output goes up as panel temperature goes down - but if you don't have some way of tracking that power point, you are going to lose it. On the other hand under very hot conditions, the power drops - you lose power as the temperature goes up. That is why you get less gain in summer.

MPPT's are most effective under these conditions:

**Cloudy or hazy days - when the extra power is needed the most.

**Cold weather - solar panels work better at cold temperatures, but without a MPPT you are losing most of that. Cold weather is most likely in winter - the time when sun hours are low and you need the power to recharge batteries the most.

**Low battery charge - the lower the state of charge in your battery, the more current a MPPT puts into them - another time when the extra power is needed the most. You can have both cold weather and low battery at the same time.

**Long wire runs - If you are charging a 12 volt battery, and your panels are 100 feet away, the voltage drop and power loss can be considerable unless you use very large wire. That can be very expensive. But if you have four 12 volt panels wired in series for 48 volts, the power loss is much less, and the controller will convert that high voltage to 12 volts at the battery. That also means that if you have a high voltage panel setup feeding the controller, you can use much smaller wire. That’s my situation, except my cable run is more like 325 feet.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 01, 2009, 05:30:57 PM
The L16's are 6 volts at 375ah each plus or minus a bit depending on brand and model.  You can series or parallel them for whatever voltage and amps you need.

For a start, running a pretty full house with quite a bit of power probably 2 sets of 4 (or 8 batteries total) for a decent 24 volt system or all 8 in series for a decent 48 volt system will get you going.  That is in lieu of proper figurinng and calculating - Ideally I would like to see 16 of them for a decent 48v system or - 2 groups of 8 batteries paralleled.

I find that a voltmeter can be misleading in that it could show a full voltage, but not the state of the electrolyte like the Hydrometer will.  

The Hydrometer is the most important low cost tool for the state of the individual cells, and in a group of batteries one low cell can cut the capacity of the entire group.  Getting over 31. 2 volts on up toward 32 volts seems to be a critical point of equalization although I have heard as high as 34 volts in several places.  When hitting that point I noted a drop in voltage then increasing acceptance of charge.  That seems to be the point that the low cell starts coming back with the rest and it may take several hours to do it - ideally once a month.  If on a good maintenance schedule , it may not take that long.... I wouldn't know about that.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 06:19:48 PM

I find that a voltmeter can be misleading in that it could show a full voltage, but not the state of the electrolyte like the Hydrometer will.  

That's the only bad thing about AGM batteries, which I plan on getting into later. They have no available liquid electrolyte. So you need to use volts. The difficult part to me, is having the time for the batteries to sit there with no charge going in, no loads coming out for a long enough time. I've heard three hours is the minimum time. Better is at least 8 to 10 hours. I guess that means shutting down for the night and pulling the PV input breaker/disconnect so the morning sun doesn't start the next charge cycle.  ???

The voltmeter won't find which cell is dead, only narrow down to the battery. But in a multiple cell battery I guess that doesn't matter much.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 01, 2009, 06:28:09 PM
A good carbon pile load checker could do that but the cost of a good one is up there.  Mike is supposed to get us a good deal on some of the new testers that are electronic pretty soon I think  I may spring for one of them to see how well they work.  Bad thing about the load testers like this is they do pull a lot of current from the battery.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 07:45:42 PM
Sealed cell AGM BATTERIES  (AGM = Absorbed Glass Mats)

I’ve used AGM batteries for years, actually over a decade, in my modified Jeeps. I used them because they are extremely resistant to vibration and shock. As well they are a true maintenance free battery and long lived. I’ve got 5 years of service and most have been still strong at that point. I’ve changed them out of concerns for reliability when off in the boonies. A side benefit for off road use is their sealed nature; no dripping acid if you find yourself dirty side up.  n*

For an off grid power storage battery system AGM batteries have some advantages as well. AGM’s are not gel cell batteries, they are better. The electrolyte in an AGM is not gelled; the electrolyte is still liquid. It is held within a very fine fiber Boron-Silicate glass mat. If the case of an AGM battery is cracked the liquid will still not leak out. The AGM take more abuse than a gel cell. Let it be noted that gel cells do not take kindly to deep discharges or to overcharging. As well gel cells can not be fast charged; they require special chargers. Most good inverter-chargers can be programmed to the required charge rates though.

AGM’s can be mounted sideways or upside down. (Handy for a second battery in the Jeep.) AGM’s are cheaper to ship as there is no Hazmat fee. Nearly all AGM batteries are "recombinant"; that means the Oxygen and Hydrogen recombine INSIDE the battery. These use gas phase transfer of oxygen to the negative plates to recombine them back into water while charging and prevent the loss of water through electrolysis. The recombining is typically 99+% efficient, so almost no water is lost.

The charging voltages are the same as for any standard battery. The internal resistance is extremely low; there is almost no heating of the battery even under heavy charge and discharge currents.

AGM's have a very low self-discharge - from 1% to 3% per month is usual. This means that they can sit in storage for much longer periods without charging than standard batteries. Less to worry about in a three season off grid cabin for example.

AGM’s emit no hydrogen under normal charge rates and under heavy charge rates the hydrogen emissions are so low there is virtually no danger of explosion. They can be safely stored indoors in a non vented enclosure.

Wow, what a super battery!  :D  Is there any downside? Not many; with one being there are not a very large number of choices for 6 volt versions with high capacities for off grid storage systems. As mentioned before the sealed nature means you can not check their charge level with a hydrometer. However, that is more than counterbalanced by their ability to absorb overcharges and to not deteriorate as quickly with high discharges, and being sealed against water loss.

The biggest downside is their cost. An AGM will cost at least 2 to 3 times as much as a conventional wet cell battery of comparable capacity.  :o 

Concorde Sunextender does make a 6 volt 220 amp hour battery, comparable to a golf cart battery, as well as a 305 amp hour battery. The 305 cost about $400+ and the 220 about $275-350. Concorde also has a 2 volt 915 amp hour battery I’ve seen on sale at $200; regular up to $450.

As you can see the advantages do cost. I would use them if the cost was less.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 01, 2009, 07:55:10 PM
The standard lead acid batteries with the new desulfators we are working on getting set up with may last as long as 15 years they claim. 

I am anxiously awaiting getting the unit from Mike to see what it will do to reclaim the used L16's I have.  That would mean a very substantial savings in battery costs.

That could make them more cost effective than the AGM's I think and no mystery regarding what the cells are up to.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 01, 2009, 07:57:46 PM
Are you using those low cost desulphators you mentioned some time back?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 01, 2009, 08:25:54 PM
I currently have the low cost one on two of the batteries - I accidently wet one of them washing the batts with the hose so now have only one.  I sealed it with silicone rubber.  Improvement is slow - not much improvement in SG yet but it seems there is some.  I put the desulfator on full time and charger on every other day or so as I get excess power to play with it.

The one we are supposed to get set up as dealers on is around 20 amps of desulfating and charging power built specifically for recovering batteries.  Most battery companies are not interested in selling these desulfator/chargers because they would rather sell batteries.

Mike has used their small 2.5 amp one and recovered a big Caterpillar battery - 8D that had been sitting for about 6 years.  I am not sure of the quality of the recovery yet as I don't have hydrometer readings - I keep forgetting to ask him to check.  He just has the one for experimenting now - I have already ordered the bigger one.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 02, 2009, 08:39:33 AM
On my tracker - as the sun continues to come up, a few minor adjustments in the tracker wake-up trough arm geometry and timing (by moving the center attachment point forward - back - up or down on the angle iron frame) has it waking up around 7:40 with most movement complete around 7:46 - pressure rises on the west side during the rapid movement toward the east so movement slows but it is getting sun to all panels by that time and by 8 AM I am getting about 19 amps at 25 volts. 

I haven't added the rest of the panels to the tracker yet.  6 more 100 watt or so panels to go on there.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 02, 2009, 11:21:26 AM
 :o  That's going to be some array!!!


I picked up my top of pole mount from the Uni-Rac warehouse today. Can't wait for the snow to melt.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 02, 2009, 07:51:11 PM
It is pushing the envelope a bit.  I worked out the maximum expected wind force and think it will take it - but I'm not an engineer.  I do want to truss the bottom and center frames.   I added 3 pipe braces to the top of the post - a 2 inch and 2 one inch pipe ones to the I beam and purlins below. 

I will friction mount the top two so they will blow down decreasing resistance in high wind. d*  I think.... :)  The green house should deflect the wind over it on the front - the mountain should along with turbulence from the trees on the back.  I am going to set my thin film panels up on the green house as a 3' high wind deflecting fence also.  They will be permanent mounted as they take too large an area to track cost effectively - only 40 watts per panel in about the same area as the others. 

I have thought of using the big one as a master and making slaves though. 

Could be a Rube Goldberg, eh?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: JRR on February 05, 2009, 05:04:18 AM
Sealed cell AGM BATTERIES  (AGM = Absorbed Glass Mats)

 Concorde also has a 2 volt 915 amp hour battery I’ve seen on sale at $200.


Velly interesting!  I assume each battery is a single cell ... allowing significant single-cell testing at the terminals.  60 batteries in series ... 120 volts ... $12,000 ... and approx 28 kilowatt-hours (at a 50% discharge ... if I did the math correctly).  That's a lot of stored energy for the bucks!

In my neck of the woods, stored energy in a pumped storage (kinda) makes sense ... that battery array would equate to 100k gallons of water dropping 100 ft ... ain't bad!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 06:35:01 AM
  I assume each battery is a single cell ... allowing significant single-cell testing at the terminals. 

Absolutely correct! Big cells.   :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 05, 2009, 01:26:14 PM



(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.trojanbattery.com%2FProducts%2Fimages%2FJ185H-AC.jpg&hash=579a2778216eeb8c04e1f3a536eb36ed)


Has anyone got any experieince with these

I can get them locally for about $330

12 V  225 AH @ 20hr

they are actually for floor buffing machines

the the guy at Batteries Plus said he had sold several to solar system users with good luck (but then he is a salesman)


Since I have decided on a 48 V sytem it would cut the number to 8 or 12 for my wind solar system

about  30 % of a HUP or Concorde or Surrette cost

For my off grid system I plan to use
 
  Six AirX (48 V)  These should give about 180 KW-Hr per month  plus 1500 watts of solar panels (haven't got these yet)  but these are looking good cost wise

http://cgi.ebay.com/Pallet-of-SIX-200-Watt-Solar-Panels-NEW-2-60-Per-Watt_W0QQitemZ220356552797QQcmdZViewItemQQptZElectrical_Solar_US?hash=item220356552797&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1309%7C301%3A1%7C293%3A1%7C294%3A50 (http://cgi.ebay.com/Pallet-of-SIX-200-Watt-Solar-Panels-NEW-2-60-Per-Watt_W0QQitemZ220356552797QQcmdZViewItemQQptZElectrical_Solar_US?hash=item220356552797&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1309%7C301%3A1%7C293%3A1%7C294%3A50)

For the battery bank I am thinking

12 X 225 AH = 2700

50 % charge = 1350 AH

or about 67 KwHrs 

Any Ideas --- this is in south west Wisconsin so only averages about 4.2 hours of effective sunshine according to this site


http://www.wholesalesolar.com/StartHere/OFFGRID/OFFGRIDCalculator.html


I know I should wait until the last minute to buy the batts but I am worried the price is going to skyrocket (along with everything else in hyperinflation) I plan to get this wind/PV system up by fall 2009


I may be in the market for a heavy duty inverter (if the Taiwan unit doesn't work out ) at least 4000 watts to kick the deep well pump over

Outback or  ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 03:22:23 PM
You have confused me; sometimes that is easy to do  ??? You stated...

12 x 225 = 2700 amp-hr    and you also stated you were going to use a 48 volt system.

That 2700 amp-hr is true if those 12 volt batteries were all connected in parallel in a 12 volt system. That would be 2700 amp-hrs rated at 12 volts, not 48 volts.

With four 12 volt batteries in series to supply the 48 volt basis for the system, one string of four would have a capacity of 225 amp-hrs. Two series strings in parallel would have a capacity of 450 amp-hrs and a battery bank of three series strings in parallel would be equal to 675 amp-hrs. All at 48 volts.

I guess it depends on whether or not you are taking 48 volts as the system basis into account when calculating loads and reserves.


Regarding those J185H-AC batteries, I'm not familiar with them. How do those prices work out compared to L-16's. They are rated as deep cycle. It would be interesting to know if the plates are the same thickness as in an L-16 or if they are thinner like the T-105's. That could make a difference to their life.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: JRR on February 05, 2009, 04:25:14 PM



(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.trojanbattery.com%2FProducts%2Fimages%2FJ185H-AC.jpg&hash=579a2778216eeb8c04e1f3a536eb36ed)


For the battery bank I am thinking

12 X 225 AH = 2700  the math is correct, its the absense of terms that get us in trouble: 12v x 225 AH = 2700watt-hr.

50 % charge = 1350 AH  50% discharge = 1350 watt-hr, or 1.35 kw-hr.

or about 67 KwHrs  ??


1.35 kw-hr for $330 is close to, but not quite as good a purchase as .915 kw-hr for $200.  (This assumes "everything else" is equal.)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 04:28:05 PM
Before buying those J185H-AC batteries I'd really want to know about the plate thickness. Going by the weight I would believe that one of those 12 volt batteries is about as good as two 6 volt T-105 GC batteries in series. The T-105 weighs in at 62 lbs. each. The J185H-AC weighs in at 128 lbs. Both are rated at 225 amp-hrs.

Info taken from Trojan's website (http://www.trojanbattery.com/Index.aspx)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 05:14:43 PM
Windpower, does your system have to be inspected and up to NEC code??

...from the website link to the PV panels "SUN MODULES ARE NOT UL CERTIFIED"

Good price otherwise



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 05:24:59 PM
The formula is    (amp-hours * voltage) / 1000 = kilowatthours

 225 amphours x 12 volts = 2700 / 1000 = 2.7 KwH per battery
50% of 2.7 = 1.35 KwH per battery

1.35 KwH x 12 batteries = 16.2 KwH

Windpower references a 67 KwH figure... 

I still think he believes that battery array is more powerful than it really is, by a factor of approximately 4.

67 / 16.2 = 4.13

 ???   ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 05, 2009, 05:54:17 PM
Thanks Don for catching the math error

I thought that seemed too high for  KwHr(that will teach me to do the arithmetic in my head  NOT)

duh

 d*

 :-[

let's try this again

 4 batteries in series times 3 parallel equals 675 AH at 48 V

 675 AH X 50 %  = 330 (Recommended useful discharge capacity)

330 AH X 48 V = (about) 16 Kw Hrs


anyway, now that we're on the same page (planet ?) mathematically


What do you think Don, enough battery capacity at 16 KW Hr

I think we will, on average, use up about 6 to 10 KW Hr per day between business and shop use

I forgot to mention we do have a  diesel back up generator running on biodiesel (just in case)

The nice thing about the farm is that it is quite windy and the wind usually is there when it is not sunny


but my gut feel here is that I need more battery capacity ---maybe 32 KW Hr


whoa    the mind boggles -- that seems like a big battery bank


This is a great forum

Thanks guys

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 06:16:14 PM
What do the power company bills / records indicate your use to be. Ours has about 4 years worth available online.  We run 14 to 28 per day depending on time of year. (summer A/C)

Big battery banks are sometimes needed and that's where those big 2 volt cells come in handy. And they come in expensive.  :(

You could also add one string if it proved necessary. Is most of your use going to be during daytime or nightime?

How about grid tie, using the grid as the "battery"?

Depending on the local power company it can work advantageously. Of course I'm seeing that from a NM point of view where the power company (has to) pays us more (13 cents) than what the user pays them for purchased power (9 to 10 cents).
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 05, 2009, 06:37:44 PM
The "People's Republic of Wisconsin" is fraught with regulations

I really want to get off grid at (almost) all costs

I think the future is not good and the best thing is to get away from the 'system' as far as possible even if it costs more short term capital

WI has tax credits too -- but I don't even want to take those -- fine print and all that

I can really see the advantage of 2 V cell especially if one fails ---  a  'cheap' replacement

I see most of our power draw during the day -- night: heating and monitoring ---relatively low and steady power draw

I am starting to think of 2 battery banks -- one solar and one wind tied to one inverter   HHHmmmmm


 :-\

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 05, 2009, 06:48:57 PM
I was wondering about day use vs night use, as solar will be replenishing the batteries as you use it, during sunny periods. That helps "extend" the battery capacity. Of course the same thing for wind whenever the wind blows. So 16 KwH may be okay.

Of course a bigger battery bank would have the advantage of not drawing the batteries down so far and they will last longer because of that.


I wouldn't sell the tax credits short... the federal ones are very simple. Keep the receipts just in case you are asked to prove you bought solar equipment. Here in NM there is no sales tax on solar equipment (panels, inverters like the Outback, Magnum, etc. , charge controllers, panel mounts...) that is bought and used in state. Another reason I like dealing with the locals.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 05, 2009, 07:20:00 PM

Thanks again Don

There are tax credits for wind in WI too but you have to jump through lots of hoops

I wish I thought there was more time to jump through them   but sadly I think we are set for "the second very great depression" economically

good website here run by George Ure:

http://www.urbansurvival.com

George  is into PV, goats and economics

For me I feel that there is little time to get up there and get it runnin' (less han a year)

I admire those of you that have seen the avalanche comming and taken action

I am now in the catch up mode  (maybe the story of my life LOL)

over and out for tonite

cheers

bill




Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 05, 2009, 09:43:23 PM
I think you have the idea, bill.

I didn't want the credits as I would be on their list and taxed every year on the equipment.  I don't want anything from them and don't want them taking anymore from me.  They have to take about twice as much as they give back.  Gotta cover overhead.

I'd put all of the power in to one bank I think - they compliment each other and wind and solar may or may not be available at the same time - you can still have multiple parallel strings of batteries in series --   hmm?

Note - I'm on the road for a day or two starting tomorrow morning.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 10, 2009, 04:43:07 PM
my latest plan is 3 battery banks of 48 V DC

I think each bank should be about 16 KW-Hr

Theoretically I can switch the charge in and output between solar and wind


need to find some big friggin DC switches (relays ?)

but then this is little more than a seat of the pants estimate or a SWAG (Scientific Wild Ass Guess )

there are precious few hard models out there on the net that I have seen for sizing battery banks

maybe we are all SWAGing it

maybe some big relays switched by voltage in the banks   -- starting to sound complicated











Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 10, 2009, 05:01:55 PM
We have 5 banks of 375ah @ 24 volts so 375x24=9000 x 5= 45000 so similar to what you are talking I think.  About half of that would be usable for best battery life. 

Is that right, Don? hmm

I don't see a need to switch them.  DC big stuff gets expensive due to possible long arcs. 

I am just going to make big copper pipe or bar?  knife switches eventually to isolate banks for equalization, safety and repair  purposes.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 10, 2009, 05:51:54 PM

Is that right, Don? hmm


Ideally, one would normally use only 25% of the battery rated capacity. However, in reality most users probably draw down to 50% fairly regularly.


DC switches are much larger with much heavier contacts than AC devices. The alternating nature of AC power greatly assists the breaking of an AC circuit under load. That's one reason hi amp DC breakers and switches cost so much. Another contributing factor to price would be low market volume, compared to AC.

There are some deals available on high amp DC rated breakers at solarseller.com (http://solarseller.com/dc_circuit_breakers__dc_circuit_breaker_ul_listed_to_125_volts_dc.htm) , if that would help in any planning.

DC breakers are supposed to be mounted vertically, although not everyone does that.  n*  ... something to do with arc flame travel.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 10, 2009, 08:03:14 PM
Thanks Don -

A side note - being a welder, long DC arcs don't scare me as long as they are not setting my house on fire at the time. d*

Around 24 volts at 100 to 250 amps is a very common DC welding volt and amperage. :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 12, 2009, 02:05:25 AM
I just made a big mistake

I bought an inverter from a Taiwancompany on Ebay

Advertised as a "pure sine wave inverter"

see here

http://cgi.ebay.com/8000W-Solar-Pure-Sine-Wave-Inverter-48V-220V-240V_W0QQitemZ180302969213QQcmdZViewItemQQptZCar_Electronics_Parts_Accessories?hash=item180302969213&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50



BUT

when I hooked it up to a 48 volt battery bankand measure the voltage

I get grd to "L" of 135 VAC and

 Ground to "N" of only 84 VAC

N to L is 218 VAC


I do notsee how I can use this with the low voltage side

the company says I cannot return it for a refund becase I did not specify the voltages needed

I specified in an email that irequired U. S. standard 220 VAC

I believe US voltage is plus or minus 10 % from 115 VAC which is what we specify on hte lab instruments my company sells

anybody know where I can find hte spec ?

I am really pissed off  >:(

any ideas ....

Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on February 12, 2009, 02:18:42 AM
can you involve EBay by reporting the seller and requesting mediation?  I would think it is better to make you happy than to be taken off of EBay and risk losing the income from selling to others less informed.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: tesa on February 12, 2009, 04:43:24 AM
ouch! daniel and i were just last night, speaking about searching on ebay for some things

i told him i'd rather not, not that i'm knockin' ebay, and i've bought a few things in my day,
but it would be just my luck i'd get involved in something like that, and our budget being
what it is, i can't afford any "losses"

i know there are great folks on ebay, trust worthy folks, but for some things, for me anyway
i'd rather not

but you've also gotta balance that with a great deal, and when you do find a great deal from
a reputable source on ebay, jump on it!

good luck

tesa
Title: Re: OFF GRID POWER; various thoughts on...
Post by: tesa on February 12, 2009, 04:50:42 AM
regarding the tax breaks.  i was sort of skeptical too, as i like flyin' under the government radar, for
lack of a better term, but i think i'm still gonna go for it, and claim it on this years taxes

being homeschoolers, the homeschooling community, for years, has tried to get people to
come together, and lobby washington for tax breaks, since most of us still pay school
taxes, even tho we don't send our kids to school

however, most of the homeschoolers i know don't want to jump thru washingtons hoops is
we were to get a tax break, all the strings and such

so most of us smile, and pay our school taxes, and leave it be

a tax break would be nice, but i'm not willing to give them (the government) anymore controll
than they already have

tesa
Title: Re: OFF GRID POWER; various thoughts on...
Post by: harry51 on February 12, 2009, 06:25:39 AM
Windpower, FWIW, most of the name inverter mfgs label their units for use in the U.S. as 240v ac, not 220. Regardless, 84 volts on one leg is way too low and would indicate a defective inverter, IMO. They should at least replace it, and Soomb is likely right, pressure them through Ebay. Also, if you paid through PayPal, I think you can stop payment to the vendor through them, or even get their account frozen, if there's an unresolved dispute about the merchandise. PayPal (owned for some time by Ebay) puts the burden on the seller, which is where it sounds like it should be in this case. G/L!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 12, 2009, 07:59:28 AM
G/L on the dispute with eBay / PayPal.

Quote
I believe US voltage is plus or minus 10 % from 115 VAC which is what we specify on hte lab instruments my company sells

Standard voltages in the USA and Canada have evolved/changed over the years. It was 110 years back, then 115-117, and for some time has been 120. Most electrical devices have no problem adjusting to anything in that range.

For the curious... Voltages and Plug Styles Around the World (http://www.kropla.com/electric2.htm)

Did they send a 50 Hz or a 60 Hz, or is that user adjustable?

It does seem that the one leg is way too high and the other way too low. I wouldn't call that to be operating properly; what does the vendor have to say about that?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 12, 2009, 08:37:06 AM
regarding the tax breaks.  i was sort of skeptical too, as i like flyin' under the government radar, for
lack of a better term, but i think i'm still gonna go for it, and claim it on this years taxes....

....being homeschoolers, the homeschooling community, for years, has tried to get people to
come together, and lobby washington for tax breaks, since most of us still pay school
taxes, even tho we don't send our kids to school

Re: energy tax credit. A 30% credit on my federal taxes for 2009 (and available for several years into the future), is well worth the slight effort required to fill in one line, IMO. I doubt the acceptance of that credit will directly result in the raising of taxable property value. For one thing, there is no assignation of the credit to any particular parcel or property on the federal form. If and when the property is reassessed the actual tax dollar increase is a small fraction of what I'll receive in that tax credit. 



We don't home school, but I have a thought or two on the related tax issues.... Everybody pays school taxes. At the local level it's most visible on the property tax bill. Of course a portion of all general taxes collected by the state and federal governments go towards schools as well. Since even people who do not ever have children are also paying taxes that go to schools and education, why should a person who elects to go to a private school, or to homeschool, be exempt from, or credited, those taxes? That would only be fair is the single childless person could get a rebate/credit/exemption as well.

At the same time that I say that I believe there is a lot of wasted money being spent on public schools. They do not do a great job on the whole. So, I can understand why some homeschool, some use private schools. School taxes and education is a difficult question, perhaps deserving of it's own topic, if anyone is so inclined.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 12, 2009, 03:46:00 PM
Thanks for the input Soomb Don Harry tesa

The specs on their ads look great

but they sent me an email saying that I didn't specify the voltages I needed, so it is not defective and no one else is complaining yada yada yada

I did send an email to ebay reporting the item and ebay has responded

I figure few even check the voltage but being a Field engineer and seeing my share of expensive instruments fried up by bad power ....

A little about me-- I install and repair Chromatography and Mass spectrometer laboratory instrument --for the last 30 years or so -- I am not a novice at this -- if you watch CSI you can see some our instruments


what is scary is that with this imbalance in the legs there is going to be a lot of equipment fried up -- and most won't even know why --  hopefully it won't cause any fires


really sucks

Thanks again for the input

In the mean time DON"T BUY ONE OF THESE POS

I'll keep you posted
Title: Re: OFF GRID POWER; various thoughts on...
Post by: tesa on February 13, 2009, 02:11:42 PM
regarding the tax break, so i should keep all my paperwork from thing i buy as documentation, right?

we're getting everything from parts on sale, so i'll just keep that paperwork, and the batteires were
buying, we'll be sure and save that receipt as well

i also downloaded the tax form, i think its form 5695, or something like that so i'll have it come
tax time

i think its good they (the man) offers it, i think it might help give people incentive to use renewable
sources, for us, it didn't matter, we were gonna do it no matter what, but a wee break is nice

we're looking at maby 4K for our whole system, (oh, speaking of that, should i try and claim the
generator too?? i mean, it is part of our system) a big house, could be in the tens of thousands
for a system, which would be a bigger break, bigger write off

tesa
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 13, 2009, 02:43:46 PM
I would say so - it is a required part of the system.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 13, 2009, 02:47:28 PM
Yes, save the receipts.




I could be wrong, but I think you are jumping the gun on taking the tax credit on the year 2008.  :-\ :-\

You haven't bought the items yet so I don't see those purchases being eligible for filing on the 2008 tax year.  ???

At least that was my interpretation for the items I've bought this spring; 2009.

So, if that's why you are seemingly in a hurry on the solar power thing, you might want to verify what tax year you can claim on.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 13, 2009, 02:59:15 PM
As far as the generator goes; I'm not certain about it being eligible. That could be open to interpretation, as a generator is not necessary for grid tied system, for example.  ??? ???

Good question, though. I've not thought of that as I've owned the generator for years already and it didn't make sense to me to reach way back and claim it now.

 ??? ??? ??? ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 14, 2009, 01:50:51 PM
I finally got the various Pulse Chargers and Tester in for my testing so I can see if I want to sell these things or not.  If they work as we hope I could save myself and my customers hundreds to thousands of dollars per year or two.

I had decent sun today so started testing them.  I have the unusable L-16s that sulfated up on a friend and she gave them to me.  I also have my own older battery packs which are low with some problems as well as my Jeep battery which I have recovered some with my original small desulfator.

As I gather some data I will likely break this testing off into another thread and we can follow it from there.  The recovery charger while expensive is one of the most interesting to me.  We will see if it can bring some of these back from the dead.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 24, 2009, 02:38:56 PM
The following question was asked on another topic. I thought it would be relevant to post my reply here.

Quote
Do you plan on taking down your solar panels when you leave for the season or will you leave the system operational?  If the latter, what special considerations will need to be given for the batteries during the winter?

When our cabin's solar PV system is completed this year, my plan for subsequent winters follows.

1. Make certain the batteries are fully charged.
2. Run an equalization charge if it has not been performed in the last 30 days.
3. Add water to the cells if they need any to be at their maximum fluid level.

If you do that there should be no problem with leaving the system to take care of itself. All system loads will be disconnected by pulling the cabin breaker panel disconnects.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 24, 2009, 07:31:51 PM
To clarify my previous post:

I will actually be throwing the breaker on the + cable between the batteries and the inverter, rather than the main breaker at the service panel. That will ensure that the inverter is not making any ghost demands. I have an Airpax 250 amp 160 VDC circuit breaker to act as a disconnect as well as a safety electrical interrupter.


Furthermore, the PV panels will be left up and connected to the charge controller. This part of the system will be left active and will allow the batteries to maintain full charge even if there is some slight self discharge.


For the winter period of absence I may drop one panel from the normal series array of three to avoid any complications that could arise if the weather would turn to a near impossible low temp some evening in the coldest part of a winter storm. That would be one of those 100 or maybe even 500 year events, but why tempt fate?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on February 24, 2009, 09:02:14 PM
What does dropping one panel do?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 24, 2009, 09:56:32 PM
The panels I have, the Sharp ND-208, are rated at a maximum open circuit output of 36.1 volts. Three in series = a maximum theoretical voltage of 108.3 volts. The Outback charge controller has a maximum start up of 145 volts and 150 volts absolute peak. As the sun first strikes the panels in the morning the voltage will likely hit the peak or near to the peak voltage, and then settle downwards to around the rated operating voltage of 28.5 (X3 = 85.5 volts @ 77 degrees).

PV panels outputs are rated at an ambient temperature of 77 degrees F (25 C). As the air temperature drops the output voltage of the three panel PV series array rises.

At 77 degrees we have a temp corrected maximum voltage of 108
At 50 degrees we have a temp corrected maximum voltage of 115
At 32 degrees we have a temp corrected maximum voltage of 119
At  0 degrees we have a temp corrected maximum voltage of 126
At -10 degrees we have a temp corrected maximum voltage of 128
At -20 degrees we have a temp corrected maximum voltage of 131
At -30 degrees we have a temp corrected maximum voltage of 133
At -40 degrees we have a temp corrected maximum voltage of 135

So, in theory, my setup should be within the design (and warranty) parameters set by Outback. However, PV panel output voltage can surge when sunlight first hits them. If this happens on a real frosty morning it is possible, maybe not likely but still possible, that the voltage could spike higher than the design limits of the charge controller. That could result in a unit with a problem.

Therefore, even though it is a very longshot that it would get cold enough and that the morning would be clear enough to conspire to spike the voltage high enough to cause a problem, the safe solution is to remove one panel from the series array. That reduces those voltages by 1/3. The disconnected panel will not be damaged. The two panels left connected in series will be able to supply more than enough power to maintain the battery charge.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: soomb on February 25, 2009, 11:17:05 AM
thank you for the excellent explanation.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 01, 2009, 08:09:05 AM
I really like the Backwoods Solar catalog.  It's practically an instruction book for getting set up.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 01, 2009, 08:16:32 AM
They do have good information in it and on their website. I do find their prices just a little higher than some other places like Affordable Solar or TheSolar.biz
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 04:07:34 AM
MountainDon,

How frequently do you equalize your batteries?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 06:22:39 AM

The goal is to equalize every 30 days. In reality that may turn out to be 45-60 days or so.  d* Keeping a log book, rather then relying on a faulty memory is a good idea. Also logging the specific gravity of each cell may be helpful in tracking changes in performance. (Remember to apply temperature corrections if the temperature of the batteries varies seasonally.)

That's for flooded wet cell batteries. AGM types can be equalized three to four times a year.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 06:32:27 AM
Is it possible to over equalize? What I mean is, can you damage the batteries by equalizing twice per month?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 06:36:03 AM
You will just use more water and have to replenish more often. That's for wet cell.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 06:39:15 AM
That's what I was thinking, but someone told me they thought it would damage the plates and equalizing should be done four times per year. I've only had my system since October 2008 so I'm still learning, but it seems that I get a little better performance if I equalize monthly.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 06:44:41 AM
... it seems that I get a little better performance if I equalize monthly.

You're onto something...  :D :D

I believe the only way to damage the batteries by equalizing is to initiate the process and then forget about it and run the water down below plate tops. You can do that by overcharging too, or with total neglect.

I believe total neglect is how Glenn got the L16's he's playing with.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 19, 2009, 08:18:37 AM
I think they failed to equalize often enough and allowed the system to run low for way too long in the winter before kicking the generator in.  Low charge for long periods is conducive to bad sulfation.

I did some serious equalizing yesterday.  I am capable of cooking batteries when I equalize, however most will not be able too and in fact ill have a hard time getting the voltage high enough to do a good job of equalizing.  I believe Don mentioned getting to 32 to 34 volts on a 24v system and many systems cannot get that high.

I use a DC welder on constant current - Variable voltage.  I unhooked the batteries from the system yesterday on the above mentioned set of Trojans I am playing with.  The Xtreme recovery charger is doing the job over a week or two but I think it is better to use for the serious polishing off after a good equalization gives it something to work with.

I first hooked up all eight batts in parallel - 2 sets of 24 volts and I saw that the better set was equalizing but the worse set was not so that told me each string has to be equalized individually.  I hooked the bad set alone and put about 100 to 150 amps to it - slowly raising the voltage for the first half hour or so then raising it to around 32.5 and maintaining that.  As sulfation breaks away from the plates, internal resistance drops and voltage drops across the set.  I monitored it on the voltmeter.  I find that it always seems to drop to around 31.8 or so then slows -likely building a charge in the new found area.  At that point I again up the amps to get the voltage around 32.5.  It is necessary to watch terminal temps doing this also - I overheated one yesterday - didn't destroy it though.

I watched the acid in the cells.  I capped the boiling ones and uncapped the rather dead looking ones.  As each of them started to boil I capped them and continued until all 12 were pretty much boiling acid.  This seems to be an indication of the sulfation being removed.  The acid also turns dark as the sulfation is removed.  It did not seem to be over heating the batteries but they did heat up.  This was done over a period of a couple of hours.  I assume the last ones to boil are not as clean as the first ones and intend to do more after the batteries cool  if the Xtreme Recovery charger does not bring them back.  I will monitor acid SG as that seems to be the best indicator of state of charge and condition. 

The Xtreme Tester - don't know the real name  now - but same company gives a great indication of health also but they must be offline.

As to over equalizing - I think more research is in order.  I have seen old batteries with the plates eaten up - I don't know what the definite cause was.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 08:30:36 AM
I can get 31 volts from my panels and I think this is what the charge controller is actually set at, I've thought about opening it up and changing it to 32 volts. I can hear the batteries bubbling so I know they're getting over charged. Do you think this is necessary or is 31 volts enough to break up the deposits? When I charge with the generator I get the full 32 volts.

The strange thing is, and maybe Glenn or Don can fill me in a bit, I have an Outback Inverter with the Mate and my charge controller is a Xantrex. The Xantrex will show battery voltage at 31 while the Outback Mate gives me a voltage of 31.6. Which is more accurate? Does it even matter? I've been considering getting a good battery monitor this summer but then I wonder how necessary that is as well.

Thanks for the information.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 19, 2009, 08:38:58 AM
I think the higher voltages should only be used for equalizing.  I think that may eat the plates if done all of the time.  I think about 28.5 is about all you want for normal charge.  Don may pop in with that info - I'm about out of time but more research is in order I think.  My cheaper MPPT (BK?) only goes to about 29.5 which I set it at because the batts only get to about 28 something normally.  I don't want it kicking out too soon.

Could be a discrepancy in calibration or a loose connection giving higher resistance raising the reading.

It seems that over the 31.8 is what does the desulfation but that high all of the time could shorten battery life I think.  I think it removes a bit of the surface of one plate.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 08:59:16 AM
It only goes to 31 volts during equalization and in normal charge mode it goes to the bulk charge rate of 29 volts and then drops down to the float stage of 27 volts.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 19, 2009, 09:06:21 AM
Sounds good.

The solar dealer in Arizona  - 9Lake Powell? - Page? It was over the phone) told me that over 32 volts was necessary to do good on equalizing - My testing seems to confirm that.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 19, 2009, 09:08:20 AM
How far over 32 volts? Also is the MPPT worth the money?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on March 19, 2009, 12:50:21 PM
Just got off the phone with the battery place

http://www.staabbattery.com/

Trojan L16 PA C   420 AH for $303

seems like a fair price -- includes delivery locally

so I'll need  8 in series for about 11 KW Hr  of storage (at 50% discharge)

 I'll need at least 2 banks one for the wind generators and one bank for the solar panels (-- I think I will need about 1500 watts of SP) according to this calculator

http://www.wholesalesolar.com/StartHere/OFFGRID/OFFGRIDCalculator.html


unfortunately this is about $5000 in batteries -- ouch

Forget the Rolls -- it would be $10,000 and change, (but they do carry a 10 year warranty)

I think this will be close to optimum -- about 330 KW Hrs per month from both wind and solar


Leaning towards the Xantrex XW4548 inverter

http://www.wholesalesolar.com/products.folder/inverter-folder/xantrexxw4548.html

but I have heard good things about the Outbacks too

I need the high surge to kick start the 3/4 Hp well pump (460 feet deep -- some of the coldest best tasting water ever)

I am thinking that the batteries should get bumped up on priorities -- went to price them at several solar/wind net suppliers and saw a lot of "out of stock" on batteries


Any recomendations on Charge controllers ?

Dave, the battery guy said that the charge controller is critical to battery life in solar applications and is a big reason why many battery manufacturers only give a 1 year warranty on solar apps
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 02:31:14 PM
An MPPT charge controller is a must, not a luxury, in my opinion. Use of an MPPT controller will allow every last watt of power to be wrung from your panels. This becomes even more important the further north you go. No I'll rephrase that; if you are not in AZ or NM you are not making proper use of the power the panels put out if you do not have an MPPT controller. My opinion, but also that of a lot of other folks.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 03:07:38 PM
I favor the Outback Flexmate 60 or 80 for a great MPPT charge controller. Someplace else in this thread I believe I addressed my reasons. They are well engineered and solidly built. I believe they are the most programmable of all the units out there.

The Flexmate controllers also connect to the Mate, the Outback remote control panel and programming device. The Mate is also used with the Outback Inverters, so to me it makes a lot of sense to go all Outback. Xantrex probably makes fine equipment too.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 19, 2009, 07:26:43 PM
Re: the above post. I am enamored with Outback. I'll admit it. Don't let that deter from choosing something else. As I stated someplace previously my criteria for charge controller included the long distance between panels and batteries. Running the panels in series for 72 VDC nominal reduced the cable size saving a bundle of money. That necessitated a charge controller like the Outback. After that choosing an Outback Inverter seemed best because of the ability to use one Mate control panel for both.


The charging and equalization info I go by...
                             one cell             12 VDC      24 VDC         48 VDC
Equalization       2.58 -2.67 (max)    15.5-16.0    31.0-32.0     61.9-64.1

Absorption/Bulk     2.37-2.45 (max)     14.2-14.7    28.4-29.4     56.9-58.8

Float                 2.20-2.23 (max)     13.2-13.4    26.4-26.8     52.8-53.5

The ideal float voltage is the lowest voltage setting that will maintain the battery at full charge. The higher the voltage the more water the cell will consume. The minimum equalization voltage is highly recommended unless it is suspected a sulphation problem exists.

Equalization is required when the cell specific gravities vary from highest to lowest by +/- 0.015 (1.245 - 1.260 at full charge)

The point is to bring the batteries up to the equalization voltage and continue charging for 1-2 hours at a low current, without excessive heat. The final or finishing charging current should be 3-7% (we recommend 5%) of the 20 hr capacity in amps.

If battery temperature exceeds 125ºF the battery should be taken off of charge and allowed to cool before equalization is continued. When two consistent specific gravity readings are taken a half hour apart the battery is equalized. It is recommended to water the battery cells before or half way through the equalization. This is to assure the water is completely mixed into the electrolyte.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 19, 2009, 07:56:53 PM
How far over 32 volts? Also is the MPPT worth the money?

Looks like Don got some of this same info but I have other stuff too so I will repeat it :)

I just go between 32 and 33 - maybe 32.5 but I use the welder

Some info from Sens charger site

"Q: What does "equalize" charging do, and why is it needed?
 
A: All batteries, even those assembled into unitized blocks, are all built of individual battery cells connected in series to obtain the required DC voltage. Like all manufactured products, there is variation between the capacities of each cell in the battery. As the battery ages this variation increases. Since the battery is a chain of cells that is only as strong as the weakest link some scheme is required to ensure that all cells stay at peak capacity.
 
A scheme called "equalizing" is commonly used in both lead-acid and nickel cadmium batteries. Equalizing temporarily elevates the charging voltage of the entire battery string above the normal "float" voltage. The elevated charging voltage allows all cells, including the weak ones, to accept more current from the charger than they would at float voltage. A consequence of the elevated equalize voltage is that all cells in the battery are overcharged. This is acceptable for short periods provided the battery has sufficient electrolyte.
 
Overcharging greatly increases the rate at which the water in battery electrolyte is electrolyzed into oxygen and hydrogen gas. Since low electrolyte level will permanently damage the battery it is important to limit when, and for how long, the battery is charged at the equalize voltage."
 
This article says 31 to 32 max. for a 24 V system.  Their info seems good and to be safe I would recommend following it.  I have bought from them before - good people.

http://www.thesolar.biz/Battery_charging_article.htm

I do go over the 32 but it drops to the 31.8 pretty fast .  It seems that this is where the action of removing the sulfation takes place.  They say not to overheat the batteries above 125f and to add water as needed - I read that letting them dry out below the plates when equalizing is real bad and will destroy them.

I tested the batteries I equalized this morning with the Xtreme tester and all batteries got a passing grade with some showing good and charge.  Now that they are getting back usable I will spend a bit more time with the equalizing.  I noted that the Sens charger uses Constant voltage DC - that is also a capability of my welder so I may play with that a bit also. -- that will provide a tapering charge as the batteries come up.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 20, 2009, 03:00:54 AM
Don and Glenn,

Thanks for all of the information. It looks like I'm right in line with everything you've both recommended, which is nice. I'm happy with the Outback inverter, and the Xantrex charge controller works fine, I'm just thinking an Outback MPPT would give me some extra charging in November and December, which were my worst months so far. Our loads are so minimal, a few hundred watts per day, that I wonder if it’s worth the money. A personal choice, I suppose.

Also your houses are very nice, at some point I'm going to start a thread and explain what I'm considering building.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 20, 2009, 08:40:25 PM
Our pleasure.

I would think it would take a bigger load to make it pay but if you like quality and tweaking it for the most it may be worth it for the satisfaction.

The panels on it should be matched for best effect but it will also give the best available with what you have if mixed too.

I have one that I checked is  BZ controller but no features - just bulk and float - no equalize.  It does maximize the panel output well though.  I like to equalize manually anyway.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2009, 12:54:53 PM
pagancelt, I'm thinking that if during Nov and Dec you were not getting enough power from the PV array, necessitating running the generator for general charging, then an MPPT controller could be a big help. I think you stated someplace you got it operational in October? You might want to hold off until you see what happens over the summer. If you're in VT, like I seem to recall, summer should be much better.

The solution could also be more PV panels. Hard to say for sure. ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 21, 2009, 05:46:13 PM
It also depends on the weather.  If there are lots of storms and little direct sun then you may need the generator no matter what.  Dark cloudy days may only produce a 10th or less power than a sunny day.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 23, 2009, 06:22:29 AM
Central Vermont and it's cloudy through November and December, plus the shortening days. We averaged about 8 to 9 amps per day through those months and now we're averaging 20 to 50 amps per day, depending on state of charge. We're getting to the float stage 4 or 5 times per week so we're easily replacing what we use and this is also showing as fewer amps per day because once we get to float the controller shuts down. We hit float last Saturday by 11 AM so the total for that day was only 18 amps even though it was sunny the whole day. During November and December we never drained the batteries to 50%, I think we drew them down to 80% or so. We ran the generator three times, twice because we were leaving and wanted the batteries at full charge because our place is wood heat and we couldn't find anybody to house sit, and once we did an equalization charge. We'd had the system running for almost 4 months when we equalized and saw an immediate result.

I figure I'll give it another winter before I decide if I want to go with an MPPT or add more panels. Ultimately I want to get to a point where I don't need to use the generator, which might be difficult given my location.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 23, 2009, 06:50:31 AM
I have to use the generator every so often in long storms in winter so it is a bit of a problem unless you are way overbuilt.

Our wind generator really helped during this storm - it took over so no need to run the generator.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 23, 2009, 07:40:37 AM
That's the balance. If you can generate enough power through the winter you're probably way overbuilt for summer, but then you run the generator which you want to avoid.

At some point I would like to have some wind generation, but right now I think it would be cheaper to just hook up another four panels to the array. My wife thinks I should stop thinking about it so much and look at the fact that we ran the generator for about ten hours all winter, and around four hours of that was necessary to charge and then equalize the batteries.

Maybe she has a point.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 23, 2009, 09:24:42 AM
If that's all the genny had to run, and if things are working well you're probably okay. Your wife may be right; time to leave well enough alone.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 23, 2009, 09:27:00 AM
Yeah, you're both probably right, Don.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on April 08, 2009, 09:24:29 PM
Recovering the batteries.... not a fast process but it is working.  I find that the fastest improvement is gained from the controlled equalizing and again the critical point seems to be about 31.8 on 24v or 15.9 on the 12v system.  That seems to be where we come back to after going to around 32v or 16v for equalizing voltage. 

Per a tip on a charger site I have gone to equalizing with the constant voltage (wire feed) function of my DC generator welder. 

The rewards?  These are 3 year old Trojan L16's valued at around $3000 and once they are fully recovered I think they will be usable for another 10 years if I keep the desulfators running on the system and charge health sufficient most of the time and good.  Stuff does happen though - extended storms - pumping during cloudy days - things that need watching but don't always get it.

Changing to a Grundfos SQFlex pump could help a lot also.

Xtreme says even average batteries have enough material in them to go 10 years.  Keeping enough water in them is key to good life also - as they get older they need more - as they equalize monitor them and don't allow water to go below the top of  plates.

The Xtreme recovery charger (list around $800) seems to be helping also but the equalization with the welder was necessary to help it along on these big batteries.  Not allowing overheating is necessary.  The voltage rise to 16 or 32 with plenty of water over the plates is necessary for a speedier recovery.  Sulfation is almost not seen on the plates now but I don't want to overdo the recovery with the welder.  I monitor with a voltmeter as I do the equalization. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on April 08, 2009, 10:41:59 PM
Glenn,

Is the cost of all this battery rehab going to be offset by their added life? 

--Pritch
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on April 09, 2009, 06:08:24 AM
The recovery charger I got at wholesale as my friend is a regional distributor and I am set up at dealer rates.  I was going to get it anyway when I found out what it would do as I have a lot of machinery that is randomly abused in a sort of nonsensical rotation--- producing lots of damaged batteries. d*  ...so I would not include the total cost in there for it.  Say $200 of it.

The equalization is something which could have prevented the problem in advance but needs to be done on a continuing basis, so lets say an added cost of $100 for extra welder fuel. 

Somewhere between the time I get paid for and the time I don't get paid for is the reality of what it costs me to gain something I wouldn't have otherwise.  I try to work on this as I work on in shop projects so I can monitor it  while I work.  All in all I say yes- I should come out at least $2000 ahead at today's prices.

Note that I don't devote a lot of time to improving the condition of the batteries and that they are currently in use along with my 20 other L16's.  That is why this is taking a long time.  I leave the desulfator recovery charger running and switch it around to different pairs of batteries every few days. I have improved them enough to have put them online and they prevent having to turn on the generator in all but the longest storms ar cloudy periods.  We have used maybe 5 to 10 gallons of generator gas in about the last 2 months.

The trick seems to be to get the specific gravity SG of all cells up to good - not having one cell with low SG in a group.  A hydrometer will monitor it on Lead Acid  batteries - not so on AGMs, Gel or others so it is my opinion that Lead Acid are easier to and have a greater chance of recovery from abuse.  It is common to accidently abuse your batteries - especially if you are not aware of the problems... and even if you are.  That is where the proper knowledge to do this comes in handy.  Also - what if there is ever a problem getting them - due to the economic downturn and destruction of US industry or energy sources?

Badly abused batteries can take several months to improve as is mentioned in the book by another free battery proponent, Poor Man's Guide to Wind Power - or close to that.  He tells how to build your own desulfator.  It was not for sale on line the last time I checked, an e-book--- but I bought it when it was.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on April 20, 2009, 01:02:34 AM
Thanks Glenn.  Do you have any experience with the automatic battery waterers that are out there? 

-- Pritch
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on April 25, 2009, 07:45:17 PM
Haven't come across them, Pritch.  Years ago when I worked at Dodge, I believe, we had a battery filler that was spring loaded on the spout, as I recall - you would push it down and it would stop when the battery was properly filled. 

I currently have a plastic gallon milk jug with a snap on top and a stiff hose pushed through that.  It works well to fill them.   I fill it with rainwater from a 50 gallon drum and use that to fill the batteries.  Probably time to check the drum for mosquito larvae.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 25, 2009, 07:58:52 PM
I still have one of those Glenn. They work well.



I don't know anyone who uses the auto waterers
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 28, 2009, 08:35:23 AM
I’ve touted the advantages of a MPPT [Maximum Power Point Tracking] Charge Controller in many places on the forum without saying anymore than they are more efficient. Just what does more efficient mean and how is it accomplished?


I’ll begin with a description of how a conventional charge controller, that is any non-MPPT type, works.

In use a conventional charge controller basically connects the output from the PV panels to the batteries. This forces the PV panels to operate at the battery voltage. Battery voltage is not the ideal operating point at which modules produce their rated maximum power.

For an example, let’s look at a system one of my neighbors use, since I already have the numbers. He uses six BP 80 watt panels. They are nominally rated as 12 Volts; 17.6 Volts at maximum power rating (Vmp), maximum current output of 4.5 amps (Imp). 17.6 x 4.5 = 79.2 watts. Close enough to be sold as 80 watts. He uses four 12 volt batteries to store the power. The panels are connected in parallel. For the purpose of comparison I’m going to simplify the system down to a single panel.

Situation #1.
The panel puts out a maximum of 4.5 amps. The batteries are sitting at 12 volts. That drags the panel voltage down to 12; 12 x 4.5 = 54 watts. We’ve just lost 26 watts worth of power; 32% of what was purchased. Those 26 watts are not going anywhere, they are not being produced because the panels don’t match the batteries.

The panels need to have a higher voltage rating than the batteries though to make up for cloudy days when their output falls. Panel output also falls under high temperature conditions.

Situation #2.
The same 4.5 amp panels, but the batteries have been discharged to where their voltage is down to 11 volts. That drags the voltage of the panels down and we end up with 11 x 4.5 = 49.5 watts, a loss of 30.5 watts; 38% of the rated power.

With MPPT the charge controller momentarily disconnects the panels from the batteries. It then looks at the output of the PV panels and the voltage of the batteries.  It then calculates the best combination of volts and amps to charge the batteries with the maximum amount of power. In other words the MPPT controller can reduce the voltage to match the battery and increase the amps. A conventional controller can not increase the amps.

Inside the MPPT controller is a high efficiency DC to DC converter controlled by a computer chip. It samples the PV panel output and battery voltage continuously; this only takes micro seconds. The DC to DC converter can increase the amperage output to the batteries.

MPPT controllers are best at increasing power output in cold weather and conditions of low battery state of charge. Since cold weather usually means winter that also usually equates to fewer hours of useful sunshine for generating power.

Typical cold weather increases can range from 20 to 40% more power with a MPPT controller. Warm weather increases will be less, maybe only 10 – 20% depending on battery use.

The MPPT controller also excels at making best use of the PV panel power over long runs of wire. The PV panels can be connected in series for lower losses in transmission and then brought down to the 12 volts needed for the batteries. There are limits to the upper voltage range for every controller, so that must not be exceeded.


The DC to DC converter actually takes the input DC and changes it to a high frequency AC. Then it converts that AC down to a voltage better suited to the battery condition. They are extremely efficient and small in size.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 28, 2009, 08:40:10 AM
Further note to the above:

The gain in current of a MPPT controller is roughly the same proportion as the percentage difference between the panel voltage and the battery voltage. If the panel is 17 volts and the battery 12 V the gain is 17/12 = 1.41 or 40%. This is under ideal conditions and never happens in real life.

The above equation assumes that the current at 17 volts and 12 V is identical. In real life it is not. The nameplate panel ratings are at bright sun and 25 deg panels. If you have bright sun, it heats your panels and you no longer have 25 deg panels. A good rule of thumb is take the nameplate MPP rating and multiply by 0.9 - 0.95.

Heat affects the equation by decreasing the 17 V MPPT and of course lowering the gain. As the battery fills, the 12 is increasing to say 13 or 14, hence the proportion increase in charge current decreases. Note however that the highest increase occurs where you need it the most - into discharged batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on April 29, 2009, 10:41:26 AM
Thanks Don

I am convinced I need the mppt type

I have almost talked myself into the Xantrex XW 60

the outback has some very nice features but the Xantrex line of inverters and controlers look very compatible with my plans -- they have a single status panel and a remote output that can be programed to start the genny if needed
( a great feature if I go away for a couple days and my DW has to deal with a low power situtation)

and the Xantrex is on sale at the Solar Biz for $470


basically I will have the 2460 watts of solar panels

6  Air X   400 watt wind generators

and a back up diesel (or propane or gas)  genny 

conservatively I should get about 300 KW Hrs a month from the panels and about 180 from the air 400's per month

16 KW hrs per day should be more than enough without the genny unless I really start running the power tools in the shop


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 29, 2009, 05:47:31 PM

the outback has some very nice ..... the Xantrex line of inverters and controlers .....they have a single status panel and a remote output that can be programed to start the genny if needed
( a great feature if I go away for a couple days and my DW has to deal with a low power situtation)
Outbacks can do all that too. Either should get the job done though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on May 04, 2009, 08:51:28 PM
Battery Wall Chart.

http://nofrillstech.info/Wallchart.pdf

Battery Info

http://www.theresourcestore.ca/toolbox-batteries.php
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Source_to_Sea on May 07, 2009, 04:38:24 AM
Don - how's the reliability on these things? Any more/less than a typical controller.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 07, 2009, 05:36:40 AM
Good reliability from what different vendors have said and from the few people I know with them.


The biggest problem source would be from voltage spikes. Use proper lightning arrestors and size the PV string to prevent cold weather wake up shock.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on May 10, 2009, 07:36:13 PM
I have been looking at the Outback system.

Can you explain to me how the MATE and FLEXNET works?

I'm not rapping my head around this at all. so if you can just explain what they do would be great.

I think the Flexnet shows you the info about how your system is operating, but where does the MATE come into play?

as I said totally lost here and might have confused my self.


Also you guys talk about tools in your shop, could you give me a rough idea if I have a hobby wood working shop, for making small things like cutting boards how much extra capacity I'm looking at needing in a battery system? I'm not worried about extra panels as I would only be in the shop maybe one day out of two weeks, so the battery system should be all topped up by then. I just need a rough bases here as to what kind of load someone might use playing with a drill press and a plainer, maybe half a days worth of playing around in the shop might not need more battery capacity? after counting in the added margin in the system anyway?

Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on May 10, 2009, 08:08:22 PM
I think the whole system would have to take into consideration the size of the tools you may want to use in the shop.

I think if you are capable of powering your washing machine you could be capable of powering some of the small shop tools.  Many of these tools are used only for a small amount of time and likely if you are not using them a the same time as the washing machine is running then you would be OK.  I have two 4024's making 240 volts or 120 and find that I can do most anything in the shop with about 2500 watts of panels and a 1000 watt wind generator.  For heavy use I can charge or power with the welder generator.  I seldom do though.  I would recommend at least 8 to 12 L16 batteries for shop use.  I also power a wire feed welder sometimes for several hours of off and on welding without the generator.

Even one 4000 watt inverter will handle a lot of shop tools.  A 2 horse motor only takes about 1500 watts under full load but requires extra starting capacity.  I commonly use that and more on my 120v inverter. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on May 10, 2009, 08:16:07 PM
Thanks that was my thoughts too, but wanted to make sure I wasn't missing anything, a small bench top drill press probly uses about the same power as a stand up vacuum.

another question, am I going to find that the majority of common well pumps are going to be wanting 240V?

I would rather not have to deal with 240V if I don't have too, but at the same time my goal is to have as common of a house as a grid tied one (I know that means big bucks in a solar system)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on May 10, 2009, 08:56:58 PM
Grundfos SQ Flex takes care of that problem- nearly any way you want to power it.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 11, 2009, 01:46:18 PM
In brief, Outbacks FlexNet is a fancy monitoring system. It acts like a "fuel gauge" style status bar, current state-of-charge and whether you are currently charging or discharging your batteries. It also shows the amount of power your system is currently producing and consuming as well as the amount of power going IN and OUT of your battery bank. Another thing it will do is monitor the cumulative energy your system has produced and consumed as well as the total amount of energy that has gone to charging your batteries. It's 'bells and whisltes'; nice but not necessary, even to a number guy like myself.   ;D

The Mate on the other hand is a remote programming management tool. One Mate can service several inverters and charge controllers. It's very good to have. The Hub will allow the connection of many items to one mate.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 15, 2009, 08:16:20 AM
Grounding the PV system.

By that I mean the DC side of the system. And by system I mean a stand alone off grid system. The AC side of the system should be treated as any normal grid tied AC system. That means the AC side should have the neutral AC wire bonded (connected) to the grounding electrode conductor (a.k.a. the bare ground wire) at one point, usually within the service panel and then connected to the grounding electrode (the 8 ft copper plated rod in the ground, metal water pipe, etc.)

The DC side is similar but has special requirements. For example, there are special ground requirements and ground fault devices required for any roof top PV panel installations. I’m not going to touch on roof top installations. The following information is intended for ground level or pole mounted panel installations. Let it be noted that references to the NEC rules are made because many of us will have to have our PV installations inspected and approved. I’m not passing judgment of the validity of the NEC rulings, I’m just relaying information as I understand it. If we do not expect to be inspected… well, take this all into consideration.

Let’s start with the PV panels themselves. All panel module frames must be connected to a ground. The modules must be bonded to the supporting framework and any other metal parts such as poles, combiner boxes and power centers. The NEC does not consider a connection bolted through an aluminum module frame to a support as a viable ground connection. That is because of the normal oxidation or the anodizing of aluminum. Current rules require special tin plated connectors that are secured to the aluminum with stainless steel 10-32 machine screws and nuts. Recent PV modules are manufactured with marked ground points and a pre-punched hole for the 10-32 fasteners. Self tapping, or self threading screws used to be allowed for ground lug connections. That has been disallowed because of the rule that requires all threaded electrical connections to be able to withstand at least 10 tightening and loosening cycles. Self-threaders fail that test on aluminum.

Here’s a more or less typical NEC drive-you-crazy ruling... Those marked ground points are the only ones recognized for use. The only thing that sets these apart from any other hole is that they are punch marked with a ground symbol and that is the point where the connection was made during testing.     So any other hole could work, it’s simply not approved.    d*   Ooops, I was editorializing.

The special approved ground lugs are expensive; (TheSolar.Biz has the best price I’ve seen, about half what most others charge.) An alternate that may be approved by some inspectors, is a stainless steel machine screw and nut with two stainless steel washers. The copper grounding wire would be wound once around the bolt between the two washers and then the bolt tightened.

The module grounding rule goes on to state that removing a panel for maintenance shall not interrupt the grounding of any other module. This also applies to any grounded equipment; removal of any piece of grounded equipment must not interrupt the grounding path of any other equipment. The special ground lugs make this easy as they use a “lay-in” method with set screw for securing the wire to the lug. So the best practice would be to use one of these lugs on each module and on any of the aluminum support arms. Connect all together using bare copper wire of the same size, or larger, as the wire used for the positive and negative module connections, usually 10 AWG. Connecting the ground to a steel component (pole) can be done with more traditional methods (screws, bolts) as long as they are approved for outdoor use. Those little green grounding screws on outlets and what not are not outside approved; they will rust. Use stainless steel and it should be okay.

It should also be noted that grounding lugs must be secured with sole purpose fasteners. That is to say the bolt used for the grounding lug must not also be used to hold other components together. So, no doubling up a ground connector to a bolt that is securing a panel to a mount arm.

In short, the panels, all metal frames and parts should be connected with a bare copper grounding wire; everything from the modules to the combiner box. From the combiner box copper wires will more than likely be connected to a larger diameter wire to transmit the power to the charge controller.

Where oversized wires are used to minimize voltage drop the equipment grounding connector must be of at least the same size as the over sized wires, according to the NEC. That means the third wire must be the same size as the positive and the negative wires. This is commonly overlooked or not understood. This could be expensive on a long panel to controller run, but there is an out. If the distance between the modules and the charge controller and batteries is greater than 30 feet (the NEC is vague on this), the third wire may be dispensed with. This will be referred to as a remote array. As well as the distance requirement, the second condition that must be met is the absence of any other conductive path from A to B. That is, no metal fences, water pipes, metal conduit, communication cables, etc.

There are two ways to ground such a remote array:
1) Bond the negative conductor to the grounding system at both the array and at the inverter/battery/power center location. Do not run any equipment grounding conductors between the two locations. (Run only the positive and negative wires.) Use ground rods at both locations. Do not bond the ground rods together. If the two conditions (distance and no conductive path) cannot be met, then the following method must be used:

2) Do not bond the negative to the grounding system at the array. Bond the negative only at the inverter/battery/power center. Run an equipment grounding conductor between the two locations. Use ground rods at both locations.

In a 12 volt DC system it is not necessary to bond either of the power carrying wires to the grounding electrode. Normally, we will ground the negative wire; most inverters and other equipment is made to operate with the negative grounded.  Most 24 volt DC and all higher voltage systems are required to have a single point where one of the power carrying wires, normally the negative wire, is bonded to the ground wire and the grounding electrode, the same as in an AC system. The rule is actually written around the 50 volt DC figure; below 50 VDC a grounding bond is not required, above 50 VDC it is required. Keep in mind the open circuit voltages during cold weather can be considerably higher than the nominal system voltage. That is why I say some 24 volt systems may require bonding and some may not. I think it’s best to bond in any DC system. Note that 48 is the generally acknowledged point where DC voltages become life threatening.

The 12 volt system would be exempt from this bonding but is required to have a properly sized DC rated current overcurrent protection device (fuse or breaker) in each of the negative and positive conductors. These can be expensive and it may be cheaper to install a bonding point and have a disconnect and overcurrent device in only the non grounded wire (positive wire). Also note that low voltage fluorescent lamps start with greater reliability in a grounded system.

The DC connection to the grounding electrode can be confusing. If more than one DC equipment grounding conductor is attached to the grounding electrode, those ground conductors must be the same size as the largest power conductor in the system. This would be the battery cable size in most systems. If there is only one conductor connected to the grounding electrode, the NEC allows DC grounding electrode conductors as small as number 6 AWG (copper to be used. Go figure; I dunno.  ???  The best solution to this problem is to use a common single grounding bus bar in the system. Connect the components to this point. Then connect the equipment grounding conductor from the bus bar to the grounding electrode. For this reason it is also best to use separate grounding rods for AC and DC.

Grounding would not be complete without the mention of lightning protection. The grounding wires connecting the modules to the frames and down to the grounding electrode will serve as a protective path for lightning strikes on an array. However there is still the danger of high voltage surges coursing down the wires to the charge controller and other components or yourself. A lightning arrestor is required. There are ones designed for DC and ones for AC. On the DC side an arrestor should be mounted on the combiner box. There are three wires. One is connected to the positive, another to the negative wires, after all module outputs are combined. The third wire connects to the common ground bus and then to the grounding electrode. If lightning causes a high voltage spike it is diverted to ground.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on May 16, 2009, 06:35:13 AM
Thanks Don - a lot to digest there.

For uninspected systems a solar electrical system designer clued me in on a low cost alternative for a lightening arrestor.

An automotive spark plug grounded at the base, with the hot terminal connected to the positive lead  from the wind turbine or it could be for an array.  The negatives would be grounded.  In the case of lightening it would easily jump the spark gap of the spark plug on the positive leg, but the generator or array voltage would not.

Have I done it yet.... no d* d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 18, 2009, 11:31:50 AM
Interesting idea.  :D
What heat range plug is suggested?
Should it be an resistor type?
Maybe a Bosch 4 electrode platinum, or a SpltFire?  ???

 rofl rofl rofl rofl

Delta arrestor modules are only $40.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on May 18, 2009, 11:40:33 AM
Lighting just traveled a couple miles to the earth, I don't think you have to worry about the temp rating of the spark plug, that little bit of a tolerance won't matter.  d*

Also If this spark plug works, which I see no reason not too, its kind of pointless. just make sure you have a heavy duty grounding wire with in a few thousands of an inch away from a bare terminal between the PV array and any electronics. The charge will jump this gap and bypass the electronics.

I would be more worried about the charge passing through my PV array and the wiring, So I would do what ever possible with a Lighting rod at the array instead of trying to deal with it in the house  ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 18, 2009, 12:07:02 PM
Re: Lightning.

I was hoping I had made it clear that you need both types of lightning protection.

The module frames, mounts, etc. all need to be grounded to at least one 8 ft rod, or equivalent.

You also need the circuit to be protected to prevent equipment or people down the line from electrocution from lightning strikes.




"heat range, etc." was a joke... I added a  rofl   ... didn't stop to think not everyone was familaiar with my sense of humor.    :-[ :-[
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on May 18, 2009, 12:22:15 PM
I caught your sense of humor, its mine that was mistaken  d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on May 18, 2009, 07:05:22 PM
Interesting idea.  :D
What heat range plug is suggested?
Should it be an resistor type?
Maybe a Bosch 4 electrode platinum, or a SpltFire?  ???

 rofl rofl rofl rofl

Delta arrestor modules are only $40.

I have a Delta arrestor at the power controller as he suggested, (Delta arrestors are pretty wimpy compared to a bolt of lightning - likely better to arrest it before it all makes it to the Delta)  but he said that is likely not enough and that the plug should likely be put at the wind generator tower base area on the positive cable and the negatives all earth grounded - likely following your guidelines above.

He is a real pro and does testing for Outback - they send him free stuff for evaluation.  I would suggest a non resistor type.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 21, 2009, 02:47:45 PM
Batteries. I've talked pros and cons of various ones previously. I'm not sure if I stated what I was going to use. I've been asked what I'm going to be using at our cabin. The quick short answer is golf cart batteries, arranged in series/parallel for a 24 VDC based system.

Golf cart batteries are usually 215-225 amp-hours and are 6 volt units. I believe we have pared our electrical use down to where these will do the job for us. I've run the 'numbers' a number of times over 2 years time.

I selected golf cart GC2's for several reasons, even though they are not highly recommended by many alternate energy parts suppliers.

One reason is my experience to date with a bank of golf cart batteries in the RV. I try to follow a rigid maintenance schedule and have pulled 5 years of practical use from a set.

A better choice would be the L-16 type; also 6 volt with 370-400 amp-hours. I wouldn't need as many batteries and would have fewer parallel strings. L16's weigh about 130 pounds apiece. GC-2's are about half the weight. That is important to me.

The batteries will be sitting through several winter months. I believe that the equipment I've selected, from pV panels through to the charge controller is among the best. However, if something goes wrong and the batteries do not keep receiving their maintenance charge, there's a good chance the batteries could be harmed by the freezing weather.

When I look at the costs per year of the GC-2 vs the L-16, plus the other mentioned factors I decided to go "golf". Admittedly, it's a trade off.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 12, 2009, 03:07:44 PM
Earlier on here, I spoke of grounding the PV system.

My grounding lugs finally arrived. Here's what they look like with the parts laid out and assembled.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1000994.jpg&hash=1244fbb54d6f1c6f1f491430c3060ce1)

They are made by Wiley Electronics. I got mine from thesolar.biz   Some vendors charge $10-11 each; they were half that. The thin stainless steel plate has 4 punched holes with tooth-like edges, on the bottom side. These grip and dig into the aluminum panel frame and make a very secure ground connection. The tin-plated clamp is suitable for AL and CU wiring. Here's the WEEB exploded installation image. The nuts, bolts and washers are stainless steel.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Foddnends3%2FWEEB.jpg&hash=eebfc80c2609f1308859be017532a3ee)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2FWEEB2.jpg&hash=bef1ddec31787aefade04df2feb37f2a)

I got stalled by the rain and forgotten parts, so that's all the photos until next time.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 25, 2009, 07:20:27 PM
More on the grounding...

Here's the ground rod. Right at two inches away from legal NEC depth I hit a rock that stopped the rod cold.No amount of pounding made headway.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1010048.jpg&hash=1c67f75b1ebfe0c3632aa78589f6585c)

I figure dirt piled on top will make it 8 feet or greater.

Here's the 'combiner' box I decided to use. It's an off the shelf Square D item. I added a block on the left to make it easy to connect the Delta lightning arrestor. The box is plastic; I used a nylon bolt to mount the block. It may not meet actual NEC code, but it is as safe as a more expensive 'proper' PV item. Since there's no inspection this is what I've used.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1010043.jpg&hash=b43b4868e6dc4fb8f2c3ef3d2ec4124c)

Please also note that the disconnect, although rated for up 48 VDC is not really legal under NEC. However, I don't plan on using it as a disconnect much at all. It's mainly a convenient and inexpensive item to use to connect the 10 AWG wire from the panels to the heavier 2 AWG wires that lead up the hill to the batteries and cabin.

The number 2 wires are not shown.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 25, 2009, 07:23:04 PM
Also on the grounding theme...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1010047.jpg&hash=9904fc8d17e2c1b9ea7af1a01a93184a)

Here are the grounding lugs as mounted to the PV frames.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1010049.jpg&hash=96555065693b24af544f856424008597)

The panels are not tilted as yet as the wires up the hill are not yet installed.  That's the dirt that will be moved to cover the in ground rod.

I drilled and tapped the steel pole and connected the ground wire there using a stainless steel 1/4 x 28 bolt and two S/S washers.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on June 26, 2009, 05:41:43 AM
Nice Job Don!
I have been lurking!  I have one last step for you (there never really is a last step) on your grounding.

The line from my mentors back at HP was "nothing electrical is complete unless it has been tested"
To test your ground system you need 2 ground bars or 2 ground systems. Here is how you find out if you need more. It is pretty simple! ??? OK, ready? Connect a decent ohm meter between the ground bars or if you have a UFER (wire in foundation) One wire to one ground bar and one to the other system. The two systems cannot be connected for this test but should be later in most cases.

If you do not read below 25 ohms you need to add another ground bar to find out which bar is not working.
Most people never do this but since we know you want to increase your odds of surviving lightning you should do this. Forgive me if you already discussed this after all I am a new guy with old tricks! Take care!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 26, 2009, 08:21:10 AM
Good point on the testing Dave. Thanks very much. It is appreciated.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on June 26, 2009, 10:06:54 AM
No problem! I almost ended up down by you instead of by Glen. It was a tuff call!

Since as I said "there never is a last step" and you are still getting this system together, I will give my humble opinion on Lightning.  You want to do all that you can, the arestors, spark-plugs, MOV's and the ultimate an 8 foot long bundle of wire from the array that you can disconnect and move  so there is an 8 foot gap.

The sad part, even the bundle disconnect can fail if your number is up! All the other steps are great if you are not at home when it hits. They are worth it!! The Arrestor may look wimpy but it is one hell of a lifesaver, if you are up on your luck!

Good Luck!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 26, 2009, 12:09:45 PM
My luck has been pretty good so far.  :D  I've been close personal witness to three strikes within close proximity; 100 foot range. Hair standing on end (that was years ago  ;D  ), bright flashes, big noises, bark flying off trees, sparks from hand to vehicle door, and so on.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on July 22, 2009, 07:37:24 PM
A recent post elsewhere made me think of this...   How does one calculate the proper angle for the solar panels?

This is a function of latitude and time of year. Ideally the panel surface would be perpendicular to the rays of the sun at all times. (note angles are measured from the horizontal.) With the sun low in the winter sky the panels would be tilted more, to a larger, steeper angle.

There is a rule of thumb for panel tilt. That is for winter (December 21) the angle should be your latitude PLUS 15 degrees. For summer (June 21) the angle would be your latitude LESS 15 degrees. Our location in NM is  35.75 degrees. Therefore winter = 50.75 degrees and summer = 20.75 degrees.

In most locations winter sunshine is less than in summer. So if you do not wish to get into seasonal adjustments, optimize the installation for the winter. Another approach would be a twice yearly adjustment. Set the tilt for the winter position in about mid October and back to summer position in mid March. Some folks will make 4 seasonal adjustments.

For those who are more anal about things like this (moi  Grin ) there is a more accurate formula. Take the latitude and multiply it by 0.9. Then add 29. That provides me with a winter optimum tilt of 61.175 degrees.

The angles apply to all things solar, PV panels as well as hot water heaters, etc.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 06, 2009, 04:59:00 PM
Nice Job Don!
I have been lurking!  I have one last step for you (there never really is a last step) on your grounding.

The line from my mentors back at HP was "nothing electrical is complete unless it has been tested"
To test your ground system you need 2 ground bars or 2 ground systems. Here is how you find out if you need more. It is pretty simple! ??? OK, ready? Connect a decent ohm meter between the ground bars or if you have a UFER (wire in foundation) One wire to one ground bar and one to the other system. The two systems cannot be connected for this test but should be later in most cases.

This seemed like a good point. My problem with performing the test was that the 8 ft. ground rod is only a foot from the steel pole in the ground/concrete which is the only other ground at this end of the system. The ohm meter gave a reading of only 6 ohms when connected between the two, which is good but is also meaningless because of the closeness. At least it's my interpretation that two grounds that close are acting more or less as one.

My solution was to add another ground rod down by the array. I sunk a second 8 foot 5/8" copper clad ground rod in the ground 8 feet away from the other and connected the ground wire to it as well. Testing the reading between the two rods came up with 12 ohms. So it appears to be within the allowable limits.  :) 


I'm uncertain if I mentioned this before...  When the array and the balance of the system (charge controller, batteries, etc.) are distant the NEC allows the system to not require a third wire (ground) between the two system sections.

The NEC does not define "distant", but my research has come up with 50 feet or greater as being generally recognized as distant. My 300 foot distance would qualify. This saves the expense of a third run of expensive wire, #2 AWG in my system.

To omit this ground wire between array and charge controller there must also not be any other possible current paths; no metallic conduit, no wire fences, metal water pipes, etc. Again our system qualifies.

I just ran non metallic conduit and the #2WG wires from the array to the cabin.

http://countryplans.com/smf/index.php?topic=2335.msg95631#msg95631

It's not connected yet at either end. That will hopefully be completed in the next week we spend up at the cabin. Photos at that time.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 07, 2009, 05:26:47 PM
In an attempt to avoid the basket of snakes look that sometimes occurs with a battery bank of series and parallel connected batteries I have elected to use copper buss bars and copper bar battery interconnects. I built the buss bar assembly today, and here it is.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FP1010383.jpg&hash=e2b22768ad78979b8ba500cab5886cef)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FP1010384.jpg&hash=b2bd3decc5733d5f781b6b3f7b9f4e82)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FP1010386.jpg&hash=6669104829e84c6483465d1efe43e8db)

The mount board is 3/4 plywood. The standoff insulators secure to the board with 1/4 x 20 bolts; ditto for mounting the bars to the insulators. The fasteners are stainless steel. The buss bars are 3/16" x 3/4" copper bar stock, 72 " long. I have drilled a few pilot holes for the charge controller and inverter connections. The battery connection holes will be drilled on site when the battery positions are determined.

As indicated the upper bar will be positive 24 VDC and the lower bar will be negative 24 VDC. That size of copper bar can safely carry 250 to 300 amps. At full output my inverter is rated to draw 170 amps so there is reserve capacity for momentary overloads.

More pictures later.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 09, 2009, 07:08:00 AM
Nice busses, Don. 

I want to make mine similar so I can isolate each bank of batteries for equalization.  More than one bank of batteries on equalization at a time will not work well especially if one bank has a low cell.  Most of the power will flow to the good set rather than correcting the low cell.

Isolating and equalizing each series set will eliminate that problem.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: harry51 on August 15, 2009, 07:40:53 PM
Here's an article on a new battery..............


 http://www.heraldextra.com/news/article_b0372fd8-3f3c-11de-ac77-001cc4c002e0.html
 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 15, 2009, 08:01:00 PM
Interesting battery Harry.  I think I would like more panels also, but we are steadily getting better.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 17, 2009, 05:57:44 AM
Don,
I know the NEC is not clear on distant grounds but you definately want the array ground bars and lightning system connected to the house or panel/battery ground system. A # 6 would be fine for this. With you second bus bar how does the 6ohm path to the concret bar ground measure? You may want to tie that ground in also.

Ciao!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 17, 2009, 08:15:21 PM
The grounding information I have used comes from my own reading as well as from John Wiles at the Southwest Technology Development Institute at New Mexico State University in Las Cruces, NM. I have used his recommendations for grounding our system.

The array position has the aforementioned twin ground rods, plus the steel pole in concrete in the ground.

Up at the cabin the AC system has a ground rod from when I did the original interior wiring. The AC system at the cabin also includes a Delta arrestor. Sixteen feet away from the AC rod is what I call the DC ground rod, even though the two are connected. The reading between them (disconnected) was less than 12 ohms; can't remember exactly. It seemed good enough and that was all I cared about.

As well, the steel roof and steel chimney have their own grounding leads and ground rod at the other end of the cabin.

I have a small fortune invested in copper and copper clad steel rods.  :D   Hope it all does its job. I was thinking I had it pretty well covered, or at least covered better than many. Maybe I'm only almost there.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 18, 2009, 06:28:06 AM
Cool Beans!  Just remember some of Wiles info is continuously updated with code changes and some of it is for residential which may or may not apply offgrid!  Also not a bad idea to have plants that get watered in summer near your ground systems if your ground resistance goes up in summer.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 18, 2009, 07:28:45 AM
Excellent point on the updating of the information over time. I've read everything I've found that he's written since the mid nineties. It is interesting to note the changes since then. I sometimes have to go back and verify what the latest info is.


Great idea on the watering. I guess that is a side benefit of the current graywater drainage area from the kitchen sink. It's near the DC ground rod. Maybe I should route the shower drain line over near the SC groun d rod. (I refer to them as the DC rod or the AC rod to keep them sorted in my mind... I could have numbered them but I find SC/DC easier... DC on the left (south) and AC on the right (north).  ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2009, 05:55:43 PM
I began building cables to connect the battery series strings to the bus bars this evening. I purchased the Brute crimping tool and gave it a try. The two ends in the photo show one lug connector just crimped and the other end with the shrink tubing. I did each end of the length of 2/0 I bought to try it out. I'll fit, cut and complete them up at the cabin this weekend.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FP1010463.jpg&hash=973bde2c0a6b7781553b2810470697cb)

The lugs are tin plated solid copper from Quickcable, as is the heat shrink tubing. I also realized the Brute tool is marketed by Quickcable; never realized that before somehow. $30 for the tool.

I did one crimp using the vice and the other using a big ball pein hammer. The hammer was easier to use and crimped a little tighter.

I took a reading with the cheap meter I had here at home. It didn't prove anything as the reading was the same as touching the probes to each other. My good meter is up at the cabin.

The Quickcable heat shrink has a heat activated adhesive inside the tube that helps with sealing the tubing to the cable and lug.

I also have 4/0 cable and lugs for the inverter.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 20, 2009, 05:22:52 PM
Cool cable lugs, Don.  Looks like that beats mashing a piece of copper tubing over the cable with a hammer and drilling a hole in it - while securely holding it with a pair of pliers. d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2009, 05:54:47 PM
Yeah, hanging onto the mashed tube while drilling a hole in copper can be a bear. The bits sure like to hog into the copper.  


I broke a few bits while trying to drill holes in the buss bar stock holding my Ryobi 18V rechargable. The bar stock was clamped to the trailer and the drill braced against my leg, so the bit was the weak point. Results were better with the drill press though there the bits would hog in and the belts slip. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2009, 06:02:47 PM
In case anyone is interested...


My source for the lugs...  http://solarseller.com/quick_cable_copper_cable_lugs.htm (http://solarseller.com/quick_cable_copper_cable_lugs.htm)

the heat shrink tubing...  scroll down a little     http://solarseller.com/distribute_quick_cable_battery_and_power_cable_products_compression_connectors__.htm (http://solarseller.com/distribute_quick_cable_battery_and_power_cable_products_compression_connectors__.htm)

the brute...  http://solarseller.com/quick_cable_crimper_cutter_stripper.htm#brute_hammer_crimp_tool (http://solarseller.com/quick_cable_crimper_cutter_stripper.htm#brute_hammer_crimp_tool)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 24, 2009, 04:18:22 PM
So my cabin PV system is now operational. It works!!!

I finally tilted the array up into power producing position. The angle adjustment brace is not completed, so this is a temporary unit. Pictures of the adjustable model after next weekend MTL.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010464.jpg&hash=6ff46ea08f07847f1e0ea6f90af186e2)

Closer view...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010465.jpg&hash=003b54d7f7c917b57e1f83bf31291ec3)

Here's the completed battery chamber with it new set of 12 golf cart 6 volt 210 amp hour batteries. There's room for 4 more plus room for the battery water dispenser, hydrometers, etc.  I keep the hydrometer that's being used stored in that section of PVC pipe. The cap on the bottom collects any acid that may drip out of the hydrometer in storage. You can see the ends of the 4/0 cables to the inverter on the right. Number 2 cable comes in from the charge controller on the left. The white cable that disappears mid wall is the CAT5e communications cable from the Outback inverter to the Mate (remote control and programming tool) that will be mounted on an interior wall. There will eventually be another CAT5e cable from the Outback charge controller that will tie into the Mate via a hub. Then both the CC and the inverter can be monitored and programmed remotely.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010475.jpg&hash=ee3592e6a218e00b0ad156bb2fdab01d)

I used a length of 2 AWG cable as the connector between the two small ground buss bars. The charge controller, inverter, etc., on the DC side of the system, are all connected to this ground buss. The ground wire to the ground rod is connected to the ground buss as well. That way there's only one connection to the ground rod. This is the preferred method according to the NEC.

Closer view of the batteries...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010476.jpg&hash=966a78ba80a34c3361b12df60a53cd2a)

The negative end of the series strings showing the 2/0 cables I made up with Brute crimper.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010478.jpg&hash=be31c574793f2b50b7094a798f571bdf)

and, the positive end...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010479.jpg&hash=31f7a41a450efdd9c7a41f3fd7574038)

You'll note that while I did use red shrink tubing for the positive leads I used black and then applied white electrician's tape to each cable end. That is because the NEC recognizes black or red as being "hot", or in the case of DC power, a positive conductor, it insists that only white be used to indicate the neutral or negative conductors. On larger wire/cable sizes it is okay to use white tape or paint on a black wire/cable to indicate the negative.

By the time I had everything connected the weather turned cloudy. Even with near full cloud cover the charge controller was putting 4 amps into the batteries doing a bulk charge at 26.something volts.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 25, 2009, 05:59:41 AM
Anyone who grew up before the age of maintenance free car batteries and also tinkered with the cars of the era should know what this is. They are hard to find these days.

The neat thing about them is the spout has a valve in it. When the dispenser is tipped the water does not pour. The tip is inserted into the battery cell opening and pressed down. The water flows until the level is at the full mark, then ceases. No overfilling the cells and no need to bend over the batteries with a flashlight trying to see the level as you pour water from a bottle.

Here's where I got mine

http://www.armysurpluswarehouse.com/product/battery-water-filler-jug-2765.cfm

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.armysurpluswarehouse.com%2F%2Fmedia%2Fimages%2FACF47A6.jpg&hash=6d83d0d3e91f31b3820121c04ffc9469)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 01, 2009, 10:48:34 AM
Alright, our cabin now has its electrical power coming from the sun! Whoo Hoo!!   :) :) :)

It didn't take long to get used to not having to go outside, start the generator, switch the power feed, go inside and use the microwave, then go back outside turn off the generator, switch the power feed back and go back inside. Whew! All that to warm something up quickly.

Now I'm going to have to change my generator habits a little. It's been used so much that I seldom have worried about the fuel going stale. Now each and every tankful will get a dose of Sta-Bil. Ditto for any fuel stored in cans. In the past I've treated the fuel meant to last over the winter with stabilizer, but have not been concerned about it the rest of the year.

Here's the panel tilt setup. The angle iron is bolted across the two longitudinal frame arms. The square steel tube has an insert welded inside and the 3/8 bolt allows the angle to change.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010506.jpg&hash=97a8b330aff848215b47c6265c2c26fe)

The lower end of the tilt bar has several holes drilled at intervals to allow best winter, summer, spring and fall angles. There's a 1/2 inch carriage bolt, with the head removed, mounted through the steel post. The headless end is drilled for a hitch pin clip to allow toolless adjustment.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010505.jpg&hash=f1792cfd9f03e47dbf63cc7d7c978385)

I used this triangle calculator (http://countryplans.com/smf/index.php?topic=7537.msg96848#msg96848) to compute the distances between adjustment holes.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 01, 2009, 11:04:21 AM
My first impressions after a week - 10 days are that I oversized the panel and battery capacity. But that's all to the good, there's room to grow and I am certain we'll find ways to use the power. It's a little strange having a 0.5 to 1 second delay in the light coming on, or the power saw starting, with the power search function enabled. However, I'm getting used to it and the feature supposedly does save battery power by greatly reducing the inverter stand by loads.

Even under partly cloudy skies the battery bank has been recharged through the bulk stage, in and out of the absorb stage and into float with hours worth of sun time left in each day. Plus, so far at least, I've barely been into the top 10% of the battery bank capacity. That's good for battery longevity. This may change some as the days grow shorter, but I believe we're good.

There has even been sufficient solar power to run through a battery equalization sequence using the power from the PV array. So  [cool].  I'm a very happy camper right now.  :D

I find myself being distracted throughout the day as I watch the numbers on the Outback Mate remote control panel. Hopefully the novelty will wear off. Or maybe it's okay; better than watching TV?


I added some insulation to the buss bars after one inadvertent display of fireworks.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property4%2FP1010512.jpg&hash=9bdd593bac60aa0fe43f336c19010923)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: rick91351 on September 01, 2009, 12:05:12 PM
Don:

The insulation on the buss bars is a great idea.  It is so good to see it all coming together for you guys.  You both seem to have put in a lot of work up there and it is good to see it paying off.

We own a ranch in the mountains and where we are going to build is on the grid.  However I have been toying around with the idea when we retire, build and move up there full time to incorporate some solar.  It almost makes sense yet I really just have a hard time justifying it.  What are your ideas and takes on the matter.

I am looking at two years in September before I can make the transition into retirement.  So I know that things may very well have changed a lot by then.  I am not really looking at saving a ton of money not buying electricity.  I am more concerned with flipping a switch and something happening; like in the middle of a January blizzard or April ice storm or power poles burnt up in a August range fire.  Or is a back up generator a better idea. Or just how safe is the power grid going to remain with terrorist threats and even solar flairs being tossed around?  The latter I really don't think anyone could really predict.

Any ideas are welcomed

Rick

 



 

   
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 01, 2009, 03:32:51 PM
Thanks Rick. I'm looking forward to being completed. Nothing is ever completely done, of course, but it will be nice to have no more obvious loose ends.

If the power company up there would have put power in to the property line for less than $2.5K we might be be grid tied. As it was they wanted twenty times that, so it became a no-brainer for me to choose PV solar. Local wind conditions made wind unfeasible and there's no hydro potential at all.

To have a grid tied system with battery capacity for those emergencies when the grid goes down would be great. You would need to calculate what loads would be deemed indispensable and how long you'd need to power them. The refrigerator, freezer, furnace would be the biggies on the list. A few lights too. Then the problem is to isolate those circuits into a separate breaker panel so it and only iy can be supplied with power from a generator or small PV system. That's easy to do on new construction, a little harder on existing buildings. Separating things out like that would allow the alternate energy system to be smaller than otherwise.

A standby generator for power outages would be a great comfort. The best would be fueled by either natural gas or propane, with diesel second and gasoline third. That's my opinion. Liquid fuels have storage issues. Also, in my opinion, a standby generator must have auto start capability for those times you are not there to manually start it if the need arises.

Batteries coupled with an autostart generator would be excellent. Our cabin inverter has the capability to be programmed to start a generator if the battery voltage falls to a pre-programmed level for more than x number of minutes. The cabin generator is not compatible though.


My ideal, and somewhat expensive, home would have electricity as the only energy source. Of course that would require a considerable array and a large battery capacity. If one was building new and took extra care on the insulation and sealing it can be done. There are a few homes around my state that are either totally off grid or on grid, but generate all the power they need. They use the grid as the battery. It works but if the grid goes down you're out of power too, unless you have a battery bank as well.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 01, 2009, 03:51:25 PM
I came across another cool tool for anyone contemplating solar energy, be it a PV array, or an air or water solar heating panel.

Rather than involving latitude figures this one makes use of drop down menus where you can choose from countries; USA, Canada, UK and Ireland. Then you work your way through a state/province list and a city/town list. Some states like NM have only one city, others like neighboring Colorado have more. Once the location is selected a list with the optimum angle for each month is presented.

I have placed the link on a topic in the Referrals section,

http://countryplans.com/smf/index.php?topic=7582.msg97318#msg97318
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dandlite on September 04, 2009, 06:25:41 PM
Well good job Don...!
I had to smile about you looking at the mate a lot...not sure if it ever goes away...
In the year or so i was off grid it was a good part of my day...watching the mate...meters and wind gens...lol...
Just something neat about the independence of making your own power...can't wait to do it again...hopefully soon...Dan...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 08, 2009, 07:38:03 AM
Here's a handy page from Trojan battery. The link goes direct to the charging rate information. There are other sections available from the menu; cleaning, watering, etc.

http://www.trojan-battery.com/BatteryMaintenance/Charging.aspx

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 08, 2009, 09:21:11 PM
A tidbit of interest.

New PV panels are introduced with the frequency o celebrity diets and the old ones are discontinued with matching speed. Therefore if one has an existing system and decides one day to increase the number of panels a quandry may arise.

If one has an MPPT charge controller it is generally agreed that the ideal situation is one where all the panels on that charge controller are the same. When it is impossible to obtain the exact same panels what is the best compromise?

There are 2 answers. If one is matching panels in series it is more important to try to match the Voc and the Vmp values. If one is matching in a parallel connection then it is best to try to match the Ioc and Imp values.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dandlite on September 09, 2009, 12:33:23 PM
and for anyone playing with the...
idea of solar the trojan t105 re's may be a good choice right now...they bumped the warranty to 5 years now...
they are relatively cheap for a small system like Don's or for someone who wants to get there feet wet...
batteries need some work yet...but some new tech is getting there...hopefully the battery problem will be solved soon...
something the size of a breadbox that stores 50kw and goes for a grand would be a hot ticket...! Dan...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on September 11, 2009, 07:36:55 AM
I have 8 T105's that are 10 years old

they still hold a charge (even after experiencing the unforgivable sin of letting them completely self discharge *doh*)

it did take a few hours at the equalizing rate to get them back

that said -- the Rolls/Surrettes are probably cheaper on a per-year-of-service rate (and highly recommended by a guy with over 30 years of experience at the Midwest Renewable Energy Fair) "I would buy a big 2 volt battery in a red case made in Canada --- Surrette"

he also recomemnded going with 2 volt batteries -- if one goes bad it is easier to find and 'cheaper' to replace

cheaper is a relative thing though -- the cheapest RS 2 volt is $910 for a 1700 AH battery

(hhmm times 24 cells for a 48 volt system  :o


For me, I think a 4 volt compromise is in order ---  546 AH for $592  would give me a nice 12KW Hr storage for about $7000   still an ouch

prices from here

http://www.staabbattery.com/


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dandlite on September 12, 2009, 01:00:46 PM
hey windpower...
yeh 24-2 volts is a lot to hook up...i had 16, L-16-6v..2 banks of 8's for my 48v system...i think i saw somewhere
that you were going to use some air-x's in your sytem...i had 3 and was going to add a few more...for me they worked pretty good in my location...they also have the breeze now...kinda the same as the X but they shifted the range down lower so they put out more power at a lower wind speed then the X...if i get back to it i'll probably have my X's switched over to breezes...which they can do...
an extra 50 watts over time per unit in the 8-15 mph windspeed would be a big benefit...

many days in my location the X's spun all day and most of the night...but they really need 15 mph or higher to put out some decent power...they did real well in the winter when the solar days were shorter but the wind was usually higher...kinda neat making some
power in the dark...lol...in any case something to check into depending on the wind at your location...

I'm not sure if i were starting now i would put that kind of money in batteries with the new tech stuff hopefully coming...
yes those batteries are probably the best out there now for are very pricey...it's a tough call right now not knowing what
may be available in a few years...hopefully some money will finally flow into this battery tech...
the cars could really be key as the application is simliar to a solar power app...some of the same ideas from electric cars could apply
to home power...rentable battery packs...things like that...people will drive cars...they just have to change to making millions of batteries rather then gas motors...maybe some day we'll get there...heck i wouldn't even mind if XOM or BP came up with a solution...they can keep there record profits...
help the oil problem...and help the people and planet...what a silly idea...Dan
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 13, 2009, 01:57:23 PM
I'm adding this post mainly for those who are thinking about using alternative power in stead of the grid. This centers around my Outback 3524M inverter, but is applicable to most any good to high end inverter.


When sitting there, turned on but supplying zero AC power to anything, inverters still consume battery power. My 3524 uses approx 22 watts of DC power at 24 volts. The better inverters have a "search" function. That is, a setting that allows the inverter to sleep, or coast along, using less power until AC power is needed. They send out a short pulse of power and see if anything in the AC circuits wants it. In search mode my inverter uses only 2.6 watts od DC power.

22 watts for 24 hours is 528 watts hours or slightly more than half a kilowatt-hour. 2.6 watts for 24 hours is 65 watt hours or only 1/8 the amount.

There are drawbacks to using the search function. Small loads may not trigger the inverter to life. There can be a delay in the time the switched on item activates. The sensitivity can be adjusted to higher or lower values on my 3524. The time between pulses can be adjusted to save even more power. That however, means a longer delay in the light or whatever coming on.


When I wired the AC circuits in the cabin I installed several switched outlets. One for the TV, one or the stereo, another for the microwave, ones for a few lights. On some I installed pilot light switches so we can tell if the power to the TV, stereo or microwave is still on even though the items may not be in use. The idea there was to do away with the phantom loads these things cause. With the TV it's the remote control, with the microwave it's the internal computer for the touch pad controls.

I have managed to program the inverter search mode sensitivity and pulse length to activate the inverter the moment the TV wall switch is turned on. Ditto the stereo. I found it impossible to get it set to allow search mode to function and have the inverter become active when the microwave power switch was turned to on though. The m-wave computer just doesn't draw enough power to trip the power cycle.  ???

That meant that a light had to be turned on to activate the inverter, then the microwave would power up. That was a bother.  >:(  I hit upon the idea of using one of those 1 into 3 outlet adapters. Plug the m-wave into one socket and a night light (with black tape over the photocell) in another. It worked! The 7.5 watt night light tripped the power on. Then I tried an LED night light. It draws only 0.3 watt. It worked too! So that solved that "problem" I just thought I'd pass that along.

I could have avoided all that by not using the search function, but the Scotsman  ;) hidden inside me balked at the power waste.  ;D


This weekend I also installed a simple DC swirch in a corner of the cabin to turn the inverter on-off without having to access the menu in the MATE remote unit. I don't think it likely we'll need it but it was so simple to do with the bathroom walls still unfinished. Easy now that later. When we leave the cabin for an absence we still throw the breaker disconnect that supplies battery power to the inverter. That's because using the remote on off doesn't kill the inverter dead. There's still some low watt power that's used being ready for the on-off switch to be turned back on.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 13, 2009, 02:17:13 PM
 :)  We've got enough solar/battery capacity that I switched from heating water for coffee, hot chocolate and tea from the propane stove to the microwave. 

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 13, 2009, 05:09:45 PM
From Sandia Labs, Albuquerque, NM

A Study of Lead-Acid Battery Efficiency Near Top-of-Charge and the Impact on PV System Design

It's a PDF document that can be downloaded HERE (http://www.google.com/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.sandia.gov%2Fpv%2Fdocs%2FPDF%2Fbatpapsteve.pdf&ei=3qKtSo_LC4a0sgPo1ODtBA&rct=j&q=batpapsteve.pdf&usg=AFQjCNEPUW8iKyzyB82BBrhufkmbhAjLfw&sig2=-MEPCppGMDcgW4H5Odt2ew).

Some interesting items from the study...

Battery charge efficiency is also a function of charge rate, with lower rates resulting in higher efficiencies.




...from zero SOC (State of Charge) to 84% SOC the average overall battery charging efficiency is 91%, 91%, and that the incremental battery charging efficiency from 79% to 84% is only 55%.

Charge efficiencies at 90% SOC and greater were measured at less than 50% for the battery tested here, requiring a PV array that supplies more than twice the energy that the load consumes for a full recovery charge. Many batteries in PV systems never reach a full state of charge, resulting in a slow battery capacity loss from stratification and sulfation over the life of the battery.




Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 19, 2009, 05:22:39 AM
All that agrees in what I see with mine, Don.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 20, 2009, 12:05:54 PM
Solar pricing going down.

http://www.ecobusinesslinks.com/solar_panels.htm

http://www.discountpv.com/charge_controllers/mppt500.htm 

500 Watt MPPT controller for $179 - takes up to 100 open circuit volts for smaller panel to controller wiring.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 24, 2009, 04:26:36 PM
I'm going to copy several posts from another thread over to here as the dialog may be of some use to somebody contemplating a PV system.

Glenn Kangiser:

We ordered our PV panel add on a few days ago and I had Sassy order an extra BZ controller, since I have been adding the panels in modules of 500 watts each - plus or minus a few depending on what the bargain is on.  $1.98 per watt this time- getting better.  :)

In this way when I have a failed controller, as I do now, I can send it in for repair and put the spare in.  The BZ MPPT 500 is an easy way to have MPPT in small modules.  Each one takes care of its own group of panels so they don't have to be the same as other groups of panels to benefit to the maximum from the MPPT.

The best deal I have found is here in California - bad thing is that means I have to pay sales tax on it. d*

http://www.discountpv.com/charge_controllers/mppt500.htm

The one I ordered from the above link a few days ago arrived today.

~~~~~~~~~~~~

Mike870:

Glen,

Did you buy the sun 130s?  If not ignore the next set of questions.  I'll be very interested in hearing a review.  Is there anything wacky about them like a positive ground?  17.8 volt VMP essentially means they are 12 volt panels?  I am thinking of buying some of these for a rainy day.

~~~~~~~~~~~~

GlennK:

Mike, yes - I ordered the Sun 130's.  Looks like they added a note about UPS considering the ones I bought oversized.

They were newly added to the site. 

They are 12 volt panels or could be but two in series makes them 24v panels and since the BZ will take up to 99.9 volts open circuit voltage I can put 4 of them in series and not exceed the voc by being 87.2 if I did the math correctly.  This will let me use small wiring from the roof to the regulator with low losses.  The BZ will run the panels at the maximum power point and convert it down to 24 volts nominal for my system.

The panels were shipped - I will update you on them, but I did not see anything weird advertised on them. 

I could also run them at 35.6 vmp with 2 in series then parallel them with no problem - the BZ would take care of them. 

I plan on setting my system up to equalize with my welder with each set of batteries so there is no need for a fancier controller.

There is not another controller that I can find by others in the 500 watt MPPT range, so I decided to standardize on the BZ.  I have a 45 amp  PWM Trace also but they work together fine as they are all independent. 

My wind generator is also hooked to the system - together on the same batteries but all work independent of each other.

I see the BZ claims to be a desulfator also due to the PWM I guess so that is likely why I still have 2004 batteries online and functioning.  Yes - they heed some care but they are working.

~~~~~~~~~~~~

MountainDon:

I gave serious consideration to the BZ 500 MPPT charge controller. It looks like a good unit. However, for my installation it's limit of 100 VDC input meant I could not use it with the panel and wire configuration I wanted. I would have required to use larger wire and much of the savings in the cost of the CC would have disappeared into the wire cost.

I was curious about those Sun130 PV panels and how they got the price so low, so did some research. First, I could not find them on the discountpv website, maybe they sold out already?

Full data sheets were difficult to find, and I found two different sets of basic specs, both being called Sun-130. One gave the Voc as 21.8 and another as 24.1 The 21.8 Voc panel is larger and on sunelec's website they are referred to as oversize.

http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=357
http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=345

One concern popped into my head when Glenn mentioned coupling into a series string of four panels. The combined series Voc of 87.2 is correct. However, that does not take into account the increased voltage that occurs at low temperatures. Panels are spec'd out at a standard temperature of 25 degrees C measured at the cell. As the temperature goes up the output voltage will fall. As temperatures fall the output voltage will rise. Now Glenn's CA location probably doesn't get as cold as my NM mountains but it can be chilly in the early AM I imagine.

Usually a multiplier of 1.25 should be applied to the Voc value to determine the highest likely open circuit voltage that could occur. Take that 87.2 Voc figure. I ran the numbers or the 21.8 Voc panel through the Outback string sizer tool and it would seem that at zero degrees C (32 F) that could rise to at least 97 V which is really too close for comfort. At zero degrees F  (-17 C) that Voc could reach 105 V. That = toast.

Just for the record and enlightenment of viewers of this thread, those high Voc's occur on cold mornings when the panels get the early morning sunlight. It may only peak briefly, but it could be enough to zap the charge controller.


One other thing I found on one web page would indicate the unadvisability of connecting more than two of these panels in series. The maximum system voltage is given as 70 V. This was or the 24.1 Voc panels, and therefore may not apply to the 21.8 Voc panels. I found that on this website where a copy of the spec sheet is listed.

http://cgi.ebay.ca/SUN-130,-130-Watt-Solar-Panel_W0QQitemZ250484550370QQcmdZViewItem

Most panels are rated 600 V. That means that connecting four of the 21.8 Voc panels in series would surpass the manufacturers rating even at the Vmp value of 17.8 V. So if the system maximum for the 21.8 Voc panels is the same 70 V then I would keep these panels limited to a series of two.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 24, 2009, 04:39:57 PM
MountainDon:

Is there anything wacky about them like a positive ground?


I found nothing about pos or neg ground on the sunelec web info. I did come across one reference to positive ground on another forum, but it was posed as a question similar to yours. Until it is known whether or not these panels have a positive ground all we can do is speculate.

BTW, positive grounded equipment is commonplace in the telecom industry. A few years back there were some folks selling some PV panels that were cheap and were positive ground. They can be difficult to incorporate safely into an off grid system. For a grid tie only system, with no batteries, apparently the neg or pos ground thing is not important. I don't know why, but that is what I've read.

~~~~~~~~~~~~

Mike870:



Most panels are rated 600 V. That means that connecting four of the 21.8 Voc panels in series would surpass the manufacturers rating even at the Vmp value of 17.8 V. So if the system maximum for the 21.8 Voc panels is the same 70 V then I would keep these panels limited to a series of two.



You lost me here, did you mean 60 V ? I wonder if that limit is based on small wire size internal to the panel?

~~~~~~~~~~~~

MtnDon:

No, the real figure is 600 volts. My Sharp panels for example are rated to 600 V, just like the house wiring is rated. Those come from UL and the NEC generally requires everything to be UL tested/approved. In a grid tie system it is not uncommon to have panels wired together into a series array that produces 250 - 400+ volts. In a big system that cuts down on the amps and that lowers component and wiring costs.

So yes, I would assume that the internal panel connections are skimpy, or the wire insulation is not up to higher voltages. I also noted that these are not NEC approved panels, probably due to the voltage limit on the internal wiring. I know that is of no concern in this application. I simply wanted to bring the points forward as something that should be considered by others contemplating alternate energy sources. I could easily see someone not familiar with electricity plugging several of these together and running into problems.

Another case that illustrates the validity of codes and the reasons they should be followed.


~~~~~~~~~~~~

GlennK:

Thanks, Don. 

I have been kicking series or series/parallel around a bit.  Think I will go series/parallel for more of a buffer and the MPPT will still run them at optimum.  The other thing is that if the controller goes out, I bypass it and hook the panels direct to the batteries.  In series/parallel the voltage would be low enough to do that - - straight series, it would not. 

Feel free to copy this over to the off grid topic also if you like, Don.


BTW, what voltage would the Outback take on VOC?

~~~~~~~~~~~~

MtnDon:


BTW, what voltage would the Outback take on VOC?

The FM60 and 80 will handle Voc up to 150 VDC input. They also have a wide operational range, -40 degrees C up to 60 degrees C.-, de-rated some above 40 C.  Some others are not rated for below freezing, some like the BZ 500 are rated to -20 C (-4 ) which could be ify up at the cabin.

FWIW, some inverters are not very well suited to cold weather. The Xantrex I was considering was not rated for below freezing.  >:(  Considering the weather in the mountains that would not be a good one for winter, or even some spring and fall days. Another vote in the favor of the Outback equipment.


~~~~~~~~~~~~

end of copy

Title: Re: OFF GRID POWER; various thoughts on...
Post by: emcvay on September 29, 2009, 04:05:56 PM
Just popping in to say thanks :)

I've been reading the first few pages but there's a lot here!

Now I'm getting carpo tunnel I think so I'd better move away from the keyboard!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 29, 2009, 08:32:06 PM
Glad you are enjoying it- we enjoy sharing our experiences - especially if it does someone else some good. :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: emcvay on October 01, 2009, 02:05:09 PM
My head is swimming a little but I'm learning!

I love it!  I can see being busy for years!

Anyway, thanks again...I've got a lot of readin to do!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on October 02, 2009, 11:54:44 AM
MountainDon:


BTW, what voltage would the Outback take on VOC?

The FM60 and 80 will handle Voc up to 150 VDC input. They also have a wide operational range, -40 degrees C up to 60 degrees C.-, de-rated some above 40 C.  Some others are not rated for below freezing, some like the BZ 500 are rated to -20 C (-4 ) which could be ify up at the cabin.

FWIW, some inverters are not very well suited to cold weather. The Xantrex I was considering was not rated for below freezing.  >:(  Considering the weather in the mountains that would not be a good one for winter, or even some spring and fall days. Another vote in the favor of the Outback equipment.


~~~~~~~~~~~~

end of copy


Rated Temperature Range (meets all
specifications) XW
32–104 °F (0–40 °C)
Operational Temperature Range -13–158 °F (-25–70 °C)
Storage Temperature Range -40–185 °F (-40–85 °C)

Don,

I do not know what Xantrex you are talking about but all the SW's and the new XW's have always been the best for temperature extremes. They are all over the world and I have a customer with one up near 12,000' that is over 12 years old.

You know that Outback started from Xantrex/Trace engineers that went out the back door.... Outback CC's shut down at 145V and some have been damaged at 155VOC. Two that I know of.
The XWCC is similar and rumored to be going up to 250VOC soon.

Better go back to hauling firewood......
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on October 05, 2009, 02:39:57 PM
Hey Dave. We were going out the door when you posted that query.

I don't recall the exact model I was considering. It was a year+ ago. What I do remember was I could not readily find the operating temperature range so I emailed Xantrax customer support. I told them my temperature range. They responded with the statement that my location was too cold; it was outside the operating temperature range they recommended.

When I asked the same question of Outback they responded with the answer that their eqipment was rated to -40 degrees. Same on their charge controller.

My installation may not be normal. I wanted both the charge controller and the inverter out in the cold. That's for a couple of reasons. I did not want the hum or the sound of the fan inside. I did not want to give up space inside either, or have the equipment dictate how the space in the one room cabin would be used.


I was aware of the story about the ounding of Outback. I heard it happened some time aroun the time Trace became Xantrex, or shortly after.

It would be great to see charge controllers with a much higher voltage rating. Series strings of PV panels make a lot of sense and panel Voc's keep getting higher.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on October 06, 2009, 05:43:50 AM
Cold temperatures can really be the worst enemy of electronics.  My other job is kind of rocket science for a little outfit here in the foothills.  Anyway, we have alot of experience with -135F and it turns out that around 0 F electrical components will crack when they start heating from cold storage.  That is why if you look at the specs most manufactures will list their operational and storage temp specs.  What kills electronics is quick temperature changes.

For instance a charge controller at -5F overnight and a cloudy cold morning and a sudden clearing of full sun.
Full power heating from cold.  No matter who puts there name on the equipment there are only so many times you can do this and sometimes once is enough.  Same scenario with the inverter sitting really cold all night and you start a generator and want to charge batteries, run laundry, and maybe something crazy like pump deep well water all at once. If you do not want to have spares for all this gear let it warm up. If you are storing electronics and batteries where humans are uncomfortable keep this in mind.  Being rated at the temp of -40F is alot different than operational for power devices. Making a reasonable (time) transition is what will keep your electronics operational over the long haul. Good Luck with winter!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on October 08, 2009, 07:13:31 PM
Thanks for the insight, Dave.  Good thing I live in mild climate as I am known to abuse equipment. d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on November 11, 2009, 11:12:52 AM
I think I have finally read over the whole topic.  If I missed something, I am sorry for reposting.

Speaking of the cold I was looking for direction on two topics.
I am building a power shed (4’x4’) for a small system (100 watts).
My thoughts were that batteries self discharge faster at colder temperatures.  Battery discharge kills batteries.  Large swings of temperature also can destroy electronics.

  Does anyone know about insulation and ventilation recommendations/requirements for battery banks?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 11, 2009, 11:38:03 AM
I believe that ideally the batteries would be in a conditioned space. That is, not exposed to high or low temperatures. In practice that can be difficult, the more so if like mine the cabin is left vacant and unheated for a week or more at a time.

Self discharge should not be a problem if the batteries are still connected to the charge controller and PV panels. Of course that would necessitate having the equipment rated for the expected temperature range. True, electronics don't like big temperature swings. Again, ideally you would not have them. I bought good equipment rated for the range that may be encountered. Hopeully that will help. Hopefully the solar gods will appreciate my efforts such as they are.

FWIW, my neighbor in the mountains has a system similar to mine. His golf cart batteries are going into their 6th year. He plans on new ones next year as their performance has dropped noticeably this past summer. They have been abused slightly with occasional deeper than recommended discharges.


Batteries do heat up when "working". So theory says that if in an insulated box that heat will be retained better. In my case the problem I have with that is when we are absent our batteries are sitting there not being asked to do anything. There are no discharge loads other than sel discharge. The charge controller hits them daily with a short bulk charge, then a short absorb charge and then floats them till the end of the day. There is very little heating involved in that. I dn't know that insulating would make much difference.  ???


If you insulate well then you have to figure out how to ventilate enough to avoid the gassing danger without sending the warm air out and bringing cold air in. One of the last things I want is to be forgetful and blow the battery chamber up, and maybe me along with it. Worse would be an unsuspecting third party.


I know someone who uses a small power ventilator. The charge controller activates a relay that turns it on when the batteries are under charge.


If you have a 100 watt system (Is that the power output of the panels?) I wonder if they is enough electrical energy going in and out of the batteries to actually make a measurable difference to the temperature.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on November 11, 2009, 01:04:42 PM
Yes 100 watts is the power of the panels and inverter.  Conditioning would be impossible.  I will make a separate post for the simple system.

My concern was that
"All batteries, regardless of their chemistry, will self-discharge. The rate of self-discharge for lead acid batteries depends on the storage or operating temperature. At a temperature of 80 degrees F. a lead acid battery will self-discharge at a rate of approximately 4% a week. A battery with a 125-amp hour rating would self-discharge at a rate of approximately five amps per week. Keeping this in mind if a 125 AH battery is stored for four months (16 weeks) winter without being charged, it will loose 80 amps of its 125-amp capacity. It will also have severe sulfation, which causes additional loss of capacity. Keep your batteries charged while not in use!"
http://www.progressivedyn.com/battery_basics.html

and

"For instance, flooded cells typically use lead alloyed with Antimony to increase their mechanical strength. However, the Antimony also increases the self-discharge rate to 8-40% per month. This is why flooded lead-acid batteries should be in use often or left on a trickle-charger. "
http://www.vonwentzel.net/Battery/00.Glossary/

IIRC, lead acid batteries can discharge 5% overnight in below zero degree temperature, but I can not find any charts for lead acid discharge rates at various temperatures.  So even two 100 amp 12v batteries could self discharge up to 240 watts a day in below 0 degree weather.  My fear is that a week of cold stormy weather could damage my batteries if left unattended. My goal would be to reduce the lowest temperature swings and discharge, but I run into the gas build up problem when insulating.  Does anyone know if the gas in heavier than air?

Just doesn't seem to be a lot of info on the to insulate or not to insulate question.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 11, 2009, 02:00:58 PM
Lead acid batteries lose capacity as their temperature drops. That is, they are unable to provide the same amount of usable power at lower temperatures as they can at 75 degrees F which is a fairly normal rating temperature. Their self discharge rate decreases as well so that is not as big a potential problem in winter as in summer. That's my understanding.


As for the gasses.. the Hydrogen is very light and rises to the battery box top quite readily. Oxygen is very slightly heavier than air. I'd say the H2 is more of a hazard than the O.


As for the batteries all I can say is that my RV batteries, 4 x 6 volt golf cart types, have sat thru 3 winters in the mountains with nothing more than 20 watts worth of PV panel and a cheap charge controller connected to them. Of course there are no loads either as I pull the disconnect. The charger is connected directly to the batteries. The panels don't get much full sun either. I leave the batteries fully charged and full of fluid in the fall and in the spring they are still charged and the fluid level fine. That goes or the cranking battery as well. It has a small 5 (?) watt panel.

I'd be worried too if there was no input into the batteries, but my experience has been good with the 20 watt panel. Of course, that is no guarantee that everyone will have the same positive experience.


An excellent battery reerence is...

http://www.windsun.com/Batteries/Battery_FAQ.htm#Temperature%20Effects%20on%20Batteries (http://www.windsun.com/Batteries/Battery_FAQ.htm#Temperature%20Effects%20on%20Batteries)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on November 11, 2009, 04:02:49 PM
Thank you.  It is good to hear from someone with experience.  My weather conditions are similar to yours and if you batteries can handle it with 20 watts mine should with 100.  I will unplug the inverter when I come an go.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on November 11, 2009, 05:54:54 PM
Don, have you thought about a thermostatically controlled electric heat element inside the power shed?  I'm thinking something like a heated floor set to keep the shed interior at, say 50o F. 

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 11, 2009, 06:37:35 PM
I've thought of it, but not very seriously. The only electrical power on site is in those batteries and what is replenished by the PV panels. I don't count the generator as it is a manual start. I have 15,000 KwH total storage capacity. That gives me about 3 KwH of useful capacity @ a 20% maximum discharge.

I simply never figured it would be feasible to use my own electrical power for resistance heating of the batteries themselves. A well insulated compartment would be needed to avoid battery run down. That leads to the question of how to safely ventilate without loosing significant heat. Related to that puzzle is the similar question of how to ventilate the charge controller and the inverter. I believe these two items must be isolated from the batteries as they do contain relays that might be able to ignite any hydrogen present. There are also circuit breakers or fuses associated with them. They also must be vented for cooling in warm or hot weather.

It presents many questions to my mind. It might be worth a discussion if anyone has any ideas. One thing to remember is any system should be able to run itself, ideally with little or no user/owner intervention. I don't even like seasonal adjustments such as inserting or removing baffles, insulation panels, or whatever might be thought of. Any system should be forgiving of forgetfulness  ;D  and able to run unattended for a few months.

Ideas are welcome!   :D

Outside low overnight temperatures typically may fall into the single digits down to zero degrees F (possibly a few hours with 3 to 4 hours at a few degrees MINUS), with daytime temperatures possibly only rising into the twenties during the coldest periods, December through February. That said, it is also possible to see minus 20 degrees at some time during snow storms. No, or little, sun at those times.

??? 

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on November 12, 2009, 07:45:36 AM
The self discharge is not really noticeable if the batteries are in daily use or have some charge daily.  I even put a small regulator on small systems as it is possible to boil a battery out if unattended. 

I did a one battery horse watering system at a ranch near here.  I have not had to service it since installed.  Likely I should go check the water levels for the customer or hopefully they have.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on November 16, 2009, 06:30:21 AM
This is what I say.  If it is part time do most of what you can to take care of the battery system. You are really not totally dependent on it are you if it is part time?  Expect that the battery will not last as long and it is the price you pay.

If you are full time, then all should be done to address keeping the batteries above 40F and below 90F.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 22, 2009, 06:47:21 PM
I'm just starting to read up on off grid solar stuff.  The more I learn the more I'm convinced that I want my 12x16 house to be off grid.

I've read this whole thread, and have learned a lot!  Also checked out the Backwoods Solar articles, along with Homepower.com.

It's just a ton of stuff to wrap your head around.  d*

Any recommendations for good how to solar books?  Looking for something that could take me all the way from design to install of a small off grid solar system.

Thanks,
Beavers
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 22, 2009, 08:00:11 PM
No recommendations on any books. I gleaned most of my information from websites.

One that I ound useful is the collection of Codecorner (http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/codecorner.html) articles by John Wiles of the College of Engineering, Southwest Technology Development Institute at New Mexico State University (NMSU) in Las Cruces, New Mexico. Being in sunny southern NM his focus is on PV power. It's hard to say where one should start the series as the information in many of the older articles have been superceded by later articles that reflect the ever changing NEC in regards to PV alternative power. It can be interesting though to see the progression.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on November 22, 2009, 08:09:39 PM
The Renewable Energy Handbook by William H. Kemp IS amazing, full of info, and explains it for any skill level, he even starts with the basics of how electricity works, but don't get me run, he goes into details for a pro to
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 23, 2009, 03:20:30 PM
Thanks,

I'll check out Amazon for the Kemp book.

I did read a few of the Codecorner articles, seemed like good info to know.  I've just scratched the surface of the Homepower website, there is just so much info there!  :o 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on November 24, 2009, 08:44:43 AM
I have not gotten through all of the Kemp book, but I found it to be rather preachy.  Seemed out of place and offputting if his intent was to expand the number of people using renewable energy.  (Not everybody approaches solar as a genuflection to Gaia!)  

Edited to add:  The Dummies book on solar was a good overview, but it only has a single chapter on off-grid applications.  Maybe you can find it at the library. (Do they still have libraries?) 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 24, 2009, 08:56:48 AM
(Do they still have libraries?)  

yes, at least we have a good one   :D  The best thing about the library is it's free to read their books. Ours has a suggested purchase program. They don't always take my suggestions but if they do I have first dibs on the book.



 Regarding the Kemp book, Amazon.com has reviews that cover the gamut, excellent to poor. The reviews are one thing I like about Amazon.com. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Mike 870 on November 24, 2009, 09:53:56 AM
I have the kemp book.  I have read it twice (there is some stuff that I skip over like hot tubs biodiesel).  I will say that it was helpful. It has some good ideas, but I found it lacking on the technical side.  I'd say it is good for primer to mid level stuff but it wont get you all the way there.  The nice thing is that it is mostly dedicated to off grid.  It is preachy.   I wish I could suggest a better book but have not come across one yet.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Mike 870 on November 24, 2009, 12:04:47 PM
Wow, the Sun 100 watt panels are at $1.74 a watt at sunelec.com  Has anyone ever seen a price that low? 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 24, 2009, 03:59:10 PM
Thanks for the book reviews guys.

While I'm ordering books, I'm want to order a copy of the NEC.  Is there much change from the 2005 to the 2008 version, as far as solar stuff?  The 2005 edition is way cheaper.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 24, 2009, 05:03:19 PM
The NEC 200x Handbook is more valuable to most DIY'ers as it contains the entire NEC plus explanations and diagrams that do not appear in the code itself.

As for which version to get/use, what does your locale use? That's what I'd use. If they use 2005 note that there are over 300 changes. Some are big, like the requirements for AFCI and some are small, like renaming self threading screws to be known as self cutting screws. Go figure that.  ???

You might want to read a free download by John Wiles, entitled Photovoltaic Power Systems and the National Electrical Code: Suggested Practices. To quote from the NMSU website...

This guide provides information on how the National Electrical Code (NEC) applies to photovoltaic systems. The guide is not intended to supplant or replace the NEC; it paraphrases the NEC where it pertains to photovoltaic systems and should be used with the full text of the NEC. Users of this guide should be thoroughly familiar with the NEC and know the engineering principles and hazards associated with electrical and photovoltaic power systems. The information in this guide is the best available at the time of publication and is believed to be technically accurate; it will be updated frequently. Application of this information and results obtained are the responsibility of the user.  Be mindful that it is still based on the 2005 NEC, but there may have been some updates.

That guide may be found at...
http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PVnecSugPract.html (http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PVnecSugPract.html)


I used the NEC in the public library (reference only, no check out) for some research as well as a lot o John Wiles information. As well I have a small handbook that covers in simplified form the basics of regular house wiring.


I also have seen a paper from the STDI, where Wiles works, PV INSTALLATIONS, A PROGRESS REPORT Only 50% of the systems surveyed passed all provisions of the NEC.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 24, 2009, 05:56:13 PM
There's also a Code Corner article, #108, that goes through some of the 2005 to 2008 NEC changes.

http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/codecorner.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on November 24, 2009, 06:03:24 PM
Wow, the Sun 100 watt panels are at $1.74 a watt at sunelec.com  Has anyone ever seen a price that low? 

I get a solar industry mag that says there is a glut on them now.  This could be a good time as who knows what the future will bring.  Lack of profits may close some of the manufacturers if it doesn't get better.

I have some that were from them for $1.98 a watt which was the best I had seen earlier.  Still haven't installed them though. d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 24, 2009, 06:32:14 PM
Thanks Don, I really appreciate the help!  I'll be sure to check out the links you gave.
Nebraska uses the 2008 NEC...makes sense to get that.  :-[

I used the load calculator at the wagonmaker site the other night.
I think it's all starting to click, but would like to run it by you guys to see if I'm close to being on the right track.  :)

This is all based on using propane and no electricity for heat, cooking, refrigeration, and hot water heater.

My total connected watts = 192

Watt hours = 1188

Adjusted Daily AH Load (24v) = 58.28

So with 5 peak sun hours I would need 279 watts of panels minimum.

For three days of storage I would then need 437 AH capacity if I only discharge to 60%.

Using Trojan 6v T105's I would need 8 to get 450 AH of capacity.

Am I looking at this right?  ???


With a 24V system and 6V batteries the number of batteries in the bank have to be a multiple of 4?

With charge controllers is it best to go with the most amps you can afford?

As far as converters for a small system, will a $300 Samlex, or Exeltech type converter be just fine?  A $3000 Outback converter can't really be necessary for a small system, can it?  :o



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 24, 2009, 07:18:43 PM
>>Am I looking at this right?  ???
Looks okay from here.   :D

Power use seems to grow with time. We already have a couple of small appliances that were not in the original plans. You might want to consider that possibility and leave room for another string of batteries. The battery gurus warn against adding batteries to an existing system. Maximum time interval seems to a year, though others have ignored that. Remember if you only draw the batteries down to 80% they will last longer than if drawn down to 60%.


>>With a 24V system and 6V batteries the number of batteries in the bank have to be a multiple of 4?
Absolutely correct.



>>With charge controllers is it best to go with the most amps you can afford?
Well, looking ahead to growth it may be advisable to have the ability to add more panels without needing a larger controller.  :-\ The flip side of that is if you add on panels at some time, you can always add a second same size controller and have the protection of some paralleled redundancy.   :D

I bought the 60 amp Outback, not because I needed the capacity right now, but because it will allow me to install another paralleled set of panels and use the same 300 feet of cable if in the future we want more power. There were other considerations as well.


>>As far as converters for a small system, will a $300 Samlex, or Exeltech type converter be just fine?  A $3000 Outback converter can't really be necessary for a small system, can it?  :o

It's not necessary, unless you want to be able to run a microwave (1200 watts draw) and not have to worry about someone (I won't name who) also popping some bread into the toaster (800 watts). Or similar things. The microwave was the complicating appliance in our case.  PS. I got ours for $1650. I had some luck and hit on a clearance loally. They'd had it in stock for over a year. It was a special RV/Marine model, but ideal for our small cabin.

I'd use a pure sine wave type in any event. Square wave can bring along problems.

I like the Exeltech inverters. I had one of their 1100 watt units in the RV for several years until I cooked it.  >:(

Keep in mind that the better quality inverters ($$) are also chargers. The ones I've looked at have the capability of performing an equalization charge with the generator running. Most standalone chargers can not do an equalization charge.

Speaking of equalizing... The principle is basically to apply a higher voltage charge (15 volts on a 12 volt battery) for a period of time. If you have loads attached to the batteries while equalizing it is possible to run into the situation where you may "over volt" something in the system. This is why good inverter/chargers switch the inverter o when the generator is activated. They will usually use a "pass through" mode where the genny now supplies the power to the cabin while also using some genny power to charge the batteries.

Anyhow, I'm rambling on as one thing reminds me of another.  :-[

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on November 25, 2009, 06:08:57 AM
Bevers,
Don't forget about water pumping.  I don't know how you get your water, but it is a factor I frequently forget to add into my calculations.  Most DC deep well pumps seem to use around 150 watts an hour for 60 gph rate.  So if you use 120 GPD per person per household that averages to 300 watts a day per person for electricity.  This is off the top of my head and I welcome any corrections.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 25, 2009, 06:31:23 AM
Good point. I tend to forget that too as our water comes in a trailer tank.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Bob S. on November 25, 2009, 01:06:47 PM
would it be feasible to design and build a off grid soler system that had several stand alone smaller systems. Like one for lighting, one to run the refigerator one to run a fan ect.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on November 25, 2009, 01:28:45 PM
Not really because its not the batteries that makes the difference its the other hardware

lets say you have a 500Ah 28v system with each battery being 100Ah at 6v, and then you want to add another load needing 100 Ah more.

A) one large system
so first you have 5 batteries in a sting to get 500Ah combined,  and you need 4 strings to make 28v. then in order to add another 100Ah all you do is get another 4 batteries and connect one each to a string. and you need to buy a bit of cable and connectors.

B) multiple systems
Lets say you have the same system as above, 5 batteries a string and 4 strings. now you want to add another 100Ah. we know you need 4 more batteries, cable and connectors. But you also need a charge controller, inverter, and power source (solar, wind, hydro ect). buying a smaller system at first might have saved you money, but buy two small systems instead of a medium one cost way more because your doubling up the equipment.

(the numbers used aren't real, you need many more betteries to take into account trying to keep a couple day reserve and not depleting all the power from your cells each day)

Think of it this way, you can either buy two 1/2 ton trucks to pull two horse trailers, and burn tones of gas in both, plus wear and tear on both trucks and trailers, or buy a larger trailer and a 3/4 ton truck and save tones of money on not doubling things up. and pull the saem nubbier of horses.  :)


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 25, 2009, 01:42:11 PM
would it be feasible to design and build a off grid soler system that had several stand alone smaller systems. Like one for lighting, one to run the refigerator one to run a fan ect.

The problem that first arises in my mind is that it is more difficult to properly size three or more small systems than one larger system. A larger system with everything drawing off one large battery bank would be more forgiving if you found it necessary to run extra lighting for some occasion for example.  That's my opinion.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 25, 2009, 03:46:26 PM
Bevers,
Don't forget about water pumping.  I don't know how you get your water, but it is a factor I frequently forget to add into my calculations.  Most DC deep well pumps seem to use around 150 watts an hour for 60 gph rate.  So if you use 120 GPD per person per household that averages to 300 watts a day per person for electricity.  This is off the top of my head and I welcome any corrections.

No water to pump, we are on city water.  Forgetting to add in water pumping could be a bummer on a real small system like what I'm planning on.  :o
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on November 25, 2009, 04:59:26 PM
My pump pulls about 10 amps at 240v or 2400 watts for 1.5 hours per day in the summer, when pumping for the garden.  That is why I need the bigger system.  The smaller pump would still have the same horsepower requirement, but just run for more time.  

I already had the pump 320 feet down the well when I decided to go solar. I like having plenty of power so I can weld and run my shop - band saw, air compressor, etc.

Horsepower requirements change a lot and go a lot higher on a deep well.  The Grundfos SQ Flex is likely one of the most efficient but the numbers should work out similar to mine I think.  We use around 600 gallons per day or more for the garden in the summer.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on November 30, 2009, 11:53:03 AM
My pump pulls about 10 amps at 240v or 2400 watts for 1.5 hours per day in the summer, when pumping for the garden.  That is why I need the bigger system.  The smaller pump would still have the same horsepower requirement, but just run for more time.  

I already had the pump 320 feet down the well when I decided to go solar. I like having plenty of power so I can weld and run my shop - band saw, air compressor, etc.

Horsepower requirements change a lot and go a lot higher on a deep well.  The Grundfos SQ Flex is likely one of the most efficient but the numbers should work out similar to mine I think.  We use around 600 gallons per day or more for the garden in the summer.

I am trying to remember your garden but....  Glen, that is alot of water! Our drip system in (3) 4x8 sq.ft. garden boxes used 1500 gallons all season! What do you get an hour from the pump? I actually like your set-up over the grundfos for solar as you can get it done fast during the afternoon. You do need the panels though! I am doing one like yours now with an xw6048 in NM.

Had Heirloom tomatoes off the vine yesterday....ah California 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 30, 2009, 03:35:53 PM
I found a PDF Inspector guide to PV systems.  [cool]

It gives suggested checklists for inpectors, and what to look for.
Would be real handy for anyone dealing with inspections, along with the PV code guide that Don posted a link to.

http://www.builditsolar.com/Projects/PV/InspectorsGuide0306.pdf
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 30, 2009, 04:01:50 PM
That made my head hurt Beavers. Thanks.   ;D ;D   It does give one an idea of what to expect. That seems to be focused a lot on grid intertie, but it is indicative of the hoops a legal installation must have.


Just a note on one thing I saw.Figure 4 illustrates a ground wire connected to what appears to be an aluminum PV panel frame. In some of the information I've read that may not be allowed anymore or maybe at some time in the future... depends what the local code enforcement gurus are doing/using.

Here's the theory... All other electrical connections must be able to be un-fastened and re-fastened ten times with no deterioration in the fasteners effectiveness. Self tapping or self threading screws do not meet that criteria. It does make some sense. So there was talk about changing this type o connection to requiring a tapped connection with a certain minimum number of threads engaged, or requiring the use of stainless screw machine screws and nuts with stainless steel washers, or those special ground lugs I used. So while I don't know for certain what is what, I went with the special clips.


http://countryplans.com/smf/index.php?topic=6059.msg92455#msg92455 (http://countryplans.com/smf/index.php?topic=6059.msg92455#msg92455)





(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Fjemez%2520mountain%2520property3%2Fmini-P1000994.jpg&hash=1244fbb54d6f1c6f1f491430c3060ce1)

http://countryplans.com/smf/index.php?topic=6059.msg92455#msg92455 (http://countryplans.com/smf/index.php?topic=6059.msg92455#msg92455)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on November 30, 2009, 04:30:15 PM
That made my head hurt Beavers. Thanks.   ;D ;D   

Really, I didn't think it was any worse than any of the other fun to read code stuff.  :) ;)

I noticed it was written in 2006, so some stuff might of changed.  I've got a copy of the 2008 NEC on the way from Amazon, so hopefully I can figure out what the latest and greatest methods are.

Those clamps look pretty heavy duty!


 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 30, 2009, 05:24:45 PM
They are nice. The thin plate is stainless steel, with punched thru holes that have a rough edge that digs thru the anodized aluminum to make secure contact. The clip itself is tin plated for conductivity and comes with stainless steel hardware. I got them from TheSolar.Biz
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 09:40:25 AM
I was looking at the Trojan Battery site and noticed something either new or something I missed.

They have an RE series of some batteries. RE = Renewable Energy. I don't recall seeing the RE's before. The capactites are the same as their industrial relatives, but the warranty is better. 24 months free replacement plus 60 months pro rated on the L-16RE series (7 year total). The 6 volt T-105 batteries have the 24 month free replacement plus a 36 month pro rated warranty (5 year total).

The real interesting this is they have an L-16RE 2 volt cell. I recall Dave Sparks mentioning in some other thread that Surrette now had an L-15 2 volt cell available so I looked it up too. It looks like the case size is in the L-16 series too.

The Surrette S-1380 is rated at 1050 amp-hours and the Trojan L-16RE-2volt at 1110 amp-hours, both at the 20 hour rate. Either one would be just about perfect for many of grid users. The one visible thing different on the T-105RE 6 volt, compared to the other iterations of that 6 volt battery are the terminals. The T-105RE has lug terminals only.

Here's a shot of the T-105RE-6 volt, the L-16RE-2 volt and the Surrette S-1380 2 volt

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FT105_RE.jpg&hash=f9a3b1a38630d5687afe23526e8df657)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FL16RE-2V.jpg&hash=8b1f907c9110c53caee45fea1e74e01b)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi133.photobucket.com%2Falbums%2Fq75%2Fdjmillerbucket%2Felectrical%2FS1380.jpg&hash=c2b3c95503612bbcde0f04106c391b95)



              Did anyone notice the oddity?  



Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 01, 2009, 02:05:41 PM
             Did anyone notice the oddity?  

With the new T105 you can use 50% less cable?  I'll have to get some of them, should save me a lot of money.  :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 02:44:16 PM
Mmmm, no, unless I don't follow what you mean.  ???    



It's to do with the L-16RE-2 volt battery  ..........

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 01, 2009, 03:00:08 PM
Looks like only one battery terminal in the T105 pic.   ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 01, 2009, 03:24:43 PM
I have an Evolution 1 tent trailer with a built in charger that works when AC power is connected to the trailer.  I'm thinking of hooking up the connections to two batteries in parallel in a box with a solar panel to provide a charge when the AC is off.  I'd like to connect both the trailer and a camper to this and be able to leave it for extended periods of time without damaging the batteries.

The plan is to be able to drive back to the site where I am building my cabin and not have to worry about  the battery being low when I need to power a propane heater (built into both) and lights (we arrive most times at night) becuase I hate to have to pull out the generator right away -- much rather settle in and relax after the long drive.

Of course this will help me learn about solar power so I can build an off grid system.

I've found this panel which seems at a decent price:  http://www.siliconsolar.com/85-watt-solar-panel-p-501611.html

and this controller:  http://www.siliconsolar.com/solar-charge-controller-p-16156.html

Have this battery:  http://www.lesschwab.com/batteries/rvdeepcycle.asp

And will use it on this trailer:  http://www.colemantrailers.com/e1 as well as an old 1978 camper with 12v lights, fan and propane heater (which may not work).

I've also got an old car battery that I'm using to power my well (12v pump) but plan to get a 2nd deep cycle battery to put into the box with the first one.

So, there are 3 wires coming to the battery in the trailer and then a standard trailer hookup on the camper (which I figure I can get a female hich connector and wire to the batteries directly).

What are your thoughts on doing this and could I install an inverter that would give me the power to run a laptop if I wanted to?  Or a toaster?

Thanks!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 03:39:11 PM
Looks like only one battery terminal in the T105 pic.   ???

It's just the angle of the shot. It has two terminals.

What I noticed was that the 2 volt L-16RE has three watering caps just like the 6 volt L-16 version and the 6 volt T-105 batteries. That struck me as unusual. Have a look at the 2 volt Surrette S-1380. It has one cap, because it is a single cell. It might be that the L-16RE-2 volt battery is simply a standard 6 volt L-16 that has the three cells internally connected in parallel instead of in series. If that is true the L-16RE-2 volt is not really any better than a collection of the normal L-16 6 volt batteries. It would cut down on the cabling though compared to a series/parallel system of L-16-6 volt batteries.

The Suerrette is a true 2 volt cell and the L-16RE is a 2 volt battery. That would make the Surrette a better choice from the view of the number of cells to water. The Surrette likely costs a lot more than the Trojan, but may really be a better unit.  ???   So ya' gotta look it over and make your choice.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 04:06:49 PM
....and this controller: ........

That controller is not suited to that panel. The panel has a maximum power current rating of 4.71 amps. The charge controller is rated at "4A maximum input charging current".

The place to start designing any system is to start with what the daily load total will be. Do that before jumping at parts.

Make a list of all the DC items you want to use. Get the power ratings on the lamps or whatever. Multiply the DC wattage of each unit by the number of hours of expected use. Be honest. Total that up to get the DC watt hours for the DC total.

Make another list of any AC loads you wish to run. A Kill-A-Watt meter is handy for determining how much power is being used by the various AC powered items. Multiply the AC wattage of each unit by the number of hours of expected use. Be honest. Total that up to get the AC watt hours for the AC total.

Then come back with the list.  With those numbers the battery capacity required to run one, two or three days can be calculated. With that known the PV power required can be calculated. You also need to know expected number of hours of usable sunshine. That changes summer to winter so you need to decide where are going to aim for.


Or go here (http://countryplans.com/smf/index.php?topic=6059.msg80681#msg80681) and use one of the calculators.

I don't like to just say, here, do this or use this and everything will be fine as your deiniation of "average" or "normal" can vary from mine. But I'll be happy to help sort it out.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 05:03:46 PM
I mention the Kill-A-Watt because I noticed that in some cases the actual power consumed is less than the rating on the name plate. My laptop is a case in point it uses about half the label rating in normal use. That was based on measuring consumption over an actual period of several hours of typical use. The LCD TV in the cabin also uses less, averaged over several hours of use. On the other hand the microwave uses every watt it says it will.

On determining power used by a microwave... note that the rating that is advertised, 650 watts, 800 watts or whatever is the cooking power not what is needed to power the unit. To illustrate what I mean our home microwave has a cooking power of 1100 watts but consumes 1630 watts out of the wall socket. The cabin unit, rated at 650 watts cooking power, consumes 1100 watts.

On picking an inverter, square wave inverters are common and lower priced than pure sine wave. As I've noted before, not everything runs well on square wave. Our small microwave does not heat on square wave; it runs the fan, the light, but no heat becasue it doesn't like the square wave power. Our vacuum runs hotter on square wave. The blower on the wood stove air inlet makes more noise on square wave, and likely runs hotter as well. Hotter operation can mean shorter life. Running hotter is also a waste of battery power as heat = power.

Yes, I am biased towards pure sine wave. It depends on how what the inverter supplied AC power is going to be used for.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 01, 2009, 05:27:10 PM
I also like only pure sine wave after low efficiency pumping and burning up power tools on modified sine wave.  My 220v water pump put out appx twice the water in the same amount of time with the pure sine wave.  Most will not pump using as much power as I need though.  I already had the big pump in the well so built the system up to handle it.  There are various adapters to smooth out the pump for modified sine but I felt that I should just do it right.

I only use modified on my small stuff or things that don't mind the choppy electricity.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 01, 2009, 07:57:29 PM
....and this controller: ........

That controller is not suited to that panel. The panel has a maximum power current rating of 4.71 amps. The charge controller is rated at "4A maximum input charging current".

The place to start designing any system is to start with what the daily load total will be. Do that before jumping at parts.

Make a list of all the DC items you want to use. Get the power ratings on the lamps or whatever. Multiply the DC wattage of each unit by the number of hours of expected use. Be honest. Total that up to get the DC watt hours for the DC total.

Make another list of any AC loads you wish to run. A Kill-A-Watt meter is handy for determining how much power is being used by the various AC powered items. Multiply the AC wattage of each unit by the number of hours of expected use. Be honest. Total that up to get the AC watt hours for the AC total.

Then come back with the list.  With those numbers the battery capacity required to run one, two or three days can be calculated. With that known the PV power required can be calculated. You also need to know expected number of hours of usable sunshine. That changes summer to winter so you need to decide where are going to aim for.


Or go here (http://countryplans.com/smf/index.php?topic=6059.msg80681#msg80681) and use one of the calculators.

I don't like to just say, here, do this or use this and everything will be fine as your deiniation of "average" or "normal" can vary from mine. But I'll be happy to help sort it out.





Understood, and was doing -- but my question is specific to what I'm doing now.  You see I'm planning on doing far more, but I want to charge a battery now -- maybe two.

Perhaps I'm not explaining myself well, but I tend to take small steps.  I run off one battery now -- I know that does what I need for the most part but also realize that will grow.

So, for now, today, I just want to run off that battery but add a 2nd for the camper and be able to charge them both.

Power tools are run off the generator.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: EcoHeliGuy on December 01, 2009, 08:01:14 PM
What he is saying is with that panel and controller set up, your going to release the smoke  c*

In direct sun light on a cold day, your going to cook that controller before you ever get the peak output on the panel.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 08:11:57 PM
Oh, I understand now OJH.

In that case we need another look. But that charge controller has to go or that panel would cook it.

But before that, what is the amp-hour rating of those batteries? You want two in parallel as I understand it.


OR pick a panel that's smaller.... have to run some numbers.....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 01, 2009, 09:02:49 PM
Oh, I understand now OJH.

In that case we need another look. But that charge controller has to go or that panel would cook it.

But before that, what is the amp-hour rating of those batteries? You want two in parallel as I understand it.


OR pick a panel that's smaller.... have to run some numbers.....

Thanks -- I'll check the amp hours (thought maybe it was on the link I gave)...the idea was the I needed to hook up one battery for the camper but figured it would be better to put them both in parallel so the trailer could draw on more reserves if needed (it's used the most).

In the end I figured it might be a good way to break into the world of solar stuff instead of trying to go full force into off grid systems like yours (which I drool over)  [cool]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2009, 09:12:40 PM
The specs didn't come up on the link, but I'll wager a donut that you have group 27's with 105 amp-hours at 12 VDC.

So if you put two of them in parallel you have 210 amp-hours total.
Limit running them down to a max of 50% so that gives you 105 amp-hours of usable power.
Keep in mind the available capacity decreases with cold.
Anyhow 105 amp hours @ 12 vdc = 1260 KwH


I ran two such batteries in our RV for years, when it was a real RV that we drove around in. Those batteries would give us a good day/night of use in cold weather with most of the power being used by the RV furnace blower. I think ours draws about 4 amps.


So if you used up 1200 watts of power and a panel puts out 85 watts, you would need 14 hours to recharge. Not good. It would be best to not use that much power, batteries last longer i not sucked down so much. To regain that sort of power fast you need 20 amps or more going into the batteries. That's about 240 watts.

The 85 watt panel would slowly charge the batteries up over a few days with no use and would definitely maintain the charge over a period of time with no use.

 :-\ :-\ :-\
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 02, 2009, 07:14:35 AM
The specs didn't come up on the link, but I'll wager a donut that you have group 27's with 105 amp-hours at 12 VDC.

So if you put two of them in parallel you have 210 amp-hours total.
Limit running them down to a max of 50% so that gives you 105 amp-hours of usable power.
Keep in mind the available capacity decreases with cold.
Anyhow 105 amp hours @ 12 vdc = 1260 KwH


I ran two such batteries in our RV for years, when it was a real RV that we drove around in. Those batteries would give us a good day/night of use in cold weather with most of the power being used by the RV furnace blower. I think ours draws about 4 amps.


So if you used up 1200 watts of power and a panel puts out 85 watts, you would need 14 hours to recharge. Not good. It would be best to not use that much power, batteries last longer i not sucked down so much. To regain that sort of power fast you need 20 amps or more going into the batteries. That's about 240 watts.

The 85 watt panel would slowly charge the batteries up over a few days with no use and would definitely maintain the charge over a period of time with no use.

 :-\ :-\ :-\


Interesting.

I'll have to do some checking to see what I'm using, at the moment with one battery I can drain it over night if it's very cold and we run the heat a lot.  I think we ran the heat one night for about 4 or 5 hours and the battery began to drain (might have been longer) so I killed the heat and we waited 'til morning to kick on the generator and were able to kick the heat on again then.

Bear in mind this is a tent trailer and it was around 5 to 10 degrees outside!  My water in the coffee pot (I always set it up the night before) froze solid!

But most nights we don't have that issue at all.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 10:35:27 AM
We had issues with running the battery down in cold weather when we had one battery. Those RV furnaces are power hungry. When we went with two batteries it was much better and the last time I replaced the batteries I went with 4 six volt golf carts batteries in a series/parallel set up. That's even better. I never bothered with solar panels as I figured I needed more than I had space for. Plus I didn't want a system for the RV once the cabin was built. I knew I wanted more PV for the cabin and I had also decided the cabin would be based on a 24 VDC system so 12 VDC things like the charge controller and the inverter would not be usable in the cabin.

That's how it worked out for us.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 02, 2009, 10:40:57 AM
We had issues with running the battery down in cold weather when we had one battery. Those RV furnaces are power hungry. When we went with two batteries it was much better and the last time I replaced the batteries I went with 4 six volt golf carts batteries in a series/parallel set up. That's even better. I never bothered with solar panels as I figured I needed more than I had space for. Plus I didn't want a system for the RV once the cabin was built. I knew I wanted more PV for the cabin and I had also decided the cabin would be based on a 24 VDC system so 12 VDC things like the charge controller and the inverter would not be usable in the cabin.

That's how it worked out for us.



Interesting.

Not sure what the cabin will need or I'll want -- I figure that's a long way off.  But I know the water pump in the well is 12v and my plan has been to put the RV battery (one of them anyway) in there with a solar charger to keep it topped up.  Of course I'd have to build a pump/well house too...but my thought was that once we're done camping in the trailer and staying in the cabin we'd use the setup for the well and start to seriously think about the cabin. 

Having learned on the trailer of course :)

There is also the likelihood that the camper and the tent trailer will get lots of use still since we hav ea big family.

Anyway, that reminds me, I ought to toss the batteries on the charger for a while.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: rick91351 on December 02, 2009, 02:56:33 PM
With all the concerns with batteries getting too hot and too cold and other components as well having to sit outside in battery sheds and boxes would it pay to build a cellar?  For example into a hillside to house all the components in.  I understand it would have to be vented perhaps with a small fan to carry away hazardous fumes.  That seems as if it would be a good solution to stabilize temps in larger systems that might have one or more banks of large batteries.   ???       
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 03:27:37 PM
I believe that would be a great way to stabilize the temperature fluctuation Rick. One could build a simple cellar set back in a slope for just the batteries. As long as there was a vent tube exiting upwards at the highest point of the enclosure I'd think the H2 would vent off readily. Some battery chambers have powered vents with the fan being activated only during equalization, when there is the greatest volume of gasses produced.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 02, 2009, 03:35:58 PM
Most flooded batteries should be charged at no more than the "C/8" rate for any sustained period. "C/8" is the battery capacity at the 20-hour rate divided by 8. For a 220 AH battery, this would equal 26 Amps. (http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Charging)

Any idea how long a "sustained period" is?  Does that mean a couple of hours charging with the generator if the panels aren't keeping up with the charging, is a no go?


I've got a cheap 3500w generator that I've been running tools with while building.  I'm thinking that making one of these lawn mower engine/car alternator generators might work better for keeping the batteries charged.  I'm pretty sure that it would use less fuel, it would be DC power (I could run it right into the charge controller), and I should be able to idle it down to put out less than 26 amps.  Anyone built one of these or have any thoughts on how well they actually work?

http://theepicenter.com/tow02077.html


One last question...

Even the small system that I'm looking at is going to run about $3000, with a pretty good chunk of that being the cost of the panels.
If I started off with just batteries, charge controller, and inverter, I should be able to keep it all charged if I ran the homemade generator 2hrs. a day.  
Within 6 months I would be able to add the panels.

What to you guys think, good or bad idea?


Thanks,
Beavers
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 04:30:41 PM
Good question on what does a "sustained period" mean, Beavers. ???  I never worried about it as the Iota IQ smart charger (http://iotaengineering.com/dls.htm) I used on the batteries in the RV switched itself beginning with the bulk charge, then absorb and ending in float. With 420 amp-hours of batteries the 55 amp charger was just about perfect.  My generator is a Yamaha 2800i inverter type and it would throttle down as the charger took less current. The Hondas throttle down even better/more.

A note on the Iota DLS chargers. It is possible to 'stack' them in parallel to increase capacity if needed. Same models only.

I believe that if you charge at the C/8 rate you will not be likely to overdo it if you cease the charge when the batteries are full.

If you built an auto alternator based generator I'd think the built in regulator should keep the batteries from being overcharged. A manual throttle control to keep the starting charge rate down to the C/8 rate would work. You'd need a good ammeter to set it. If you were to use an auto alternator charger I would rely on the built in regulator and not try feeding the charge current through a PV charge controller. Most charge controllers are really designed for use with a PV panel input. I've seen discussions on the Outback user forum and the recommendations regarding inputs other than PV are always pointed out to be ill advised by their experts, especially when it comes to mixed feeds. Some charge controllers that have diversion load capability (like you'd need with most wind generators) could likely be used to control a generator output but I don't see any advantages to that. Perhaps some else may have some solid information on that.

Note that the better PV charge controllers have a battery temperature sensor, usually as an option. They are worth it. The charge controller will make adjustments to the charge rate. If the temperature gets too high the charge rate will be reduced. The better sine wave inverter/chargers also have remote battery temperature sensors which is valuable when using them to charge the batteries.


I basically ran a small system with 4 six volt golf cart batteries (series/parallel for 12 VDC) in the RV for 3+ years with no panels. I put something like 700 hours on the Yamaha. I did have a couple small panels (http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200263174_200263174) hooked up through a cheap controller to keep the batteries floated during our absences, which included 3 - 4 month winter stretches with no visits for the first couple years. 30 watts worth which became about 20 after one panel suffered some damage. They were excellent for that purpose.

So I believe you could get everything but the PV panels and the charge controller and add them later if you can't buy it all at once. I would say that would work as long as you don't have any prolonged periods where the batteries would just sit there self discharging. I would recommend a disconnect switch so you can easily remove all loads when you are gone. Our RV had some phantom load I could never find; the disconnect fixed that when we'd leave.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 02, 2009, 06:21:54 PM
Appreciate the info, thanks Don.

I'm just trying to slap something together to provide a minimum amount of power for a few months while I learn more about solar, and come up with cash to pay for a larger system.

I was thinking that I would still need a charge controller, but if the alternator regulator would work that would be great to save the money on the charge controller.

In a full system the generator hookup is through the inverter, and then back into the batteries?  Looking at inverters it looks like only the higher dollar inverters are set up for generator use.  So with a cheaper inverter you still need a charger like the Iota to have a generator backup? 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 07:25:39 PM

In a full system the generator hookup is through the inverter, and then back into the batteries?  Looking at inverters it looks like only the higher dollar inverters are set up for generator use.  So with a cheaper inverter you still need a charger like the Iota to have a generator backup? 

Depends on where you draw the line for becoming a higher dollar inverter, and how much power and what wave form you want/need.

Xantrex, for example does have a square wave inverter/charger, 1500 watts inverter, priced at something like $800. To me that's not cheap, nor is it overly expensive; model TR-1512 (also in 24 VDC models I think). A unit like that has three stage charging and an equalization charge setting. I looked or quite some time for a stand alone charger that had equalization capability and never found one that made economic sense. It was better to go with a combination unit, IMO.

You should have an equalization setting if you are using flooded lead-acid batteries. If you go with AGM batteries you don't need equalization capability, AGM's don't like the higher voltages.

I had some other thought rolling around and it got away on me... maybe I'll be back in a bit.   ???   d*


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 07:44:29 PM
Oh!

It was simply to note that inverter/charger units operate in a pass thru mode, when the AC generator power comes online. When generator input is sensed, the inverter section switches off basically, and the generator power is passed thru to the house/cabin power circuits. At the same time the battery charger section will accept incoming generator AC power and begin to charge the batteries.

If a big AC load in the cabin comes on the generator input into the charger may be reduced until the AC load is removed. I only mention this as I found it interesting. I've watched the generator power automatically split and change between charger and AC use on my Outback Mate monitor, as Karen used the toaster or microwave while the generator ran.

Since my generator is smallish I have my inverter/charger programmed to accept only up to 20 amps generator input. The inverter on the other hand can pump out 30 amps continuous. I've seen the situation where all 20 amps (2400 watts) from the generator goes into the cabin AC loads and the inverter supply an additional 800 watts from the batteries. Then with the big AC loads removed the inverter/charger goes back to charging.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 02, 2009, 08:38:00 PM
Arizona Wind-Sun has excellent information on batteries (http://www.windsun.com/Batteries/Battery_FAQ.htm) available.

Beavers, you've seen it, but I mention this for others. According to them "At approximately -22 degrees F (-27 C), battery AH capacity drops to 50%. At freezing, capacity is reduced by 20%."

My battery bank was sized taking this into account. I also thought long and hard about insulation.  :-\ In the end I decided against the bother of insulating. I may have mentioned my reasoning before; I don't recall. So will the reader please forgive me for boring them if I am repeating myself.

My cabin is seasonal use. Mid-May through August we are up there virtually full time. In winter (December through March) the cabin may sit for 2 to 3 weeks (hopefully never longer  ;) ) with nobody there. My collected data shows that in periods of inactivity the PV system puts 300 watt-hours maximum into our 15,120 watt-hour total rated capacity battery bank. That may change upwards as the batteries age. That is so little input I seriously wonder there would be any measurable warming effect? I believe it is so insignificant an amount that there would be no benefit to the trouble and expense of insulating while still providing ventilation. That's how I see it. Others may have differing opinions.  ???

If, on the other hand, our cabin was used continuously through the winter months there would be much more power flow in and out of the batteries; with the resultant internal battery heating byproduct, it would most likely be worth the effort involved to provide insulation. As with so many things regarding homes and cabins there is no "one size fits all" answer.



One thought I have had is that it is a shame to be wasting all that solar power when the system sits idle. It would be cool to be able to use that excess power in the manner of a diversion load as used in wind generation. The excess power could be used in a resistance heater to either warm the batteries or perhaps to keep the temperature inside the cabin from falling as low as it does. The Outback FlexMax charge controller has an auxiliary function that I'm sure can be used for something like that.
other brands may have similar features. I have not taken time to check it out. If anyone has any thoughts on that I'd be happy to hear about it or carry on a discussion.





Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 03, 2009, 07:30:39 AM
In our cabinets in MNN we installed battery blankets.  These are DC powered blankets that are designed to keep the batteries from freezing in serious sub zero weather.

I'm wondering if something like your ap Don, would benefit from that?  specially since it could be used as a diverter for the unused power :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 03, 2009, 08:22:40 AM
Something like that would help keep the battery temperature up with the excess power. It would be akin to Glenn's use of excess power being used to pump water.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 03, 2009, 08:26:19 AM
Something like that would help keep the battery temperature up with the excess power. It would be akin to Glenn's use of excess power being used to pump water.



I could look for who the manufacturer was if your interested.  We use them for Cellular backhaul sites where we've got SONET transport nodes and MW transport gear  [cool]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 03, 2009, 08:28:56 AM
cool.  see if their are 24 VDC models. Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 03, 2009, 06:58:24 PM
 :o :o  d* d*

This place is a great source for info, and I really appreciate the help!  But man...the more I learn the more I realize how much I don't know!

I got my copy of the NEC in the mail today, and after skimming through it, I realize I have WAY more to learn than I thought!

Oh well...a year ago I didn't know the first thing about building a house, but with a lot of studying and the help of this forum, I've managed to figure it out.  :)

Guess it's time to get serious with studying up on the NEC first.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 04, 2009, 11:42:39 AM
http://www.watlow.com/literature/specsheets/files/heaters/colfrzs0407.pdf

Comes in 12vdc, 48vdc, 120vac and 240vac


But at 12vdc you might be able to work it no?

Check them out :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 04, 2009, 02:20:06 PM
Those guys have a whole world of available heaters. They would be able to supply whatever was needed by the looks of it. Whether or not their equipment would be cost effective is the thing.    

This will need some more thought and research.


The first step will be to come up with a realistic estimate of how much excess PV power there is in summer and winter......   more to come.


I'm going to park this link to those guys website here as a handy thing.

http://watlow.com/products/heaters/ht_flex.cfm

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Pritch on December 04, 2009, 02:41:25 PM
Well Don, now you have to start planning your battery box insulation retrofit!    ;D d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 04, 2009, 02:42:23 PM
Those guys have a whole world of available heaters. They would be able to supply whatever was needed by the looks of it. Whether or not their equipment would be cost effective is the thing.    

This will need some more thought and research.


The first step will be to come up with a realistic estimate of how much excess PV power there is in summer and winter......   more to come.


I'm going to park this link to those guys website here as a handy thing.

http://watlow.com/products/heaters/ht_flex.cfm



We use them to keep the batteries from freezing when it's -40 in MNN  ??? d*  But they do work.  I'd also like to check and see what the cost is (I ought to find out who our rep is -- *chuckle* maybe I can get a deal on some ;) )

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 04, 2009, 04:17:03 PM
Well Don, now you have to start planning your battery box insulation retrofit!    ;D d*


something to think about over the winter.    :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 07, 2009, 09:54:38 PM
Okay, if anyone has been holding their breath on this "excess PV power" idea you may as well take a breath now. This has become very low priority for me right now. I've done some research and more thinking. Here's my reasoning....


First let me say that the procedure to setup the Outback inverter to use the excess power is straightforward. Matching the load to the available excess would be the main trick. Too large a load would have the system continually cycling the diversion load on and off too much.

Standard Test Conditions (STC) in the PV industry are based on an irradiance of 1000 watts/ square meter. In summer we get 6 - 8 very good hours of sunshine a day with 2 to 3 hours over 1000 watts/m*m, the balance over 700 watts/ m*m. In summer I don't have much use for that extra power. We could use it in winter, though and that was what I was hoping to do.

In winter we get about three real good hours of sunshine, 11:30 AM through 2:30 - 3:00 PM. Real good in winter meters out at 450 to 550 watts/m*m. Much less than summer.

Let it be noted there are three stages in charging the batteries, bulk, absorb and float. During the bulk stage all the power from the PV panels is used to charge the batteries, assuming an MPPT charger. In absorb and float there is waste, some power from the PV panels is wasted. On a day after typical loads the day/night before, it takes until 1 to 2 PM for the bulk stage to be completed. This past weekend we didn't even make bulk on Sunday; very cloudy.

So if I say the winter maximum output is about one half that of the summer, that would be approximately 624 watts total rated panel capacity x 50% = 312 watts.... round that up to 325 for good measure.  325 x 3 hours is 975 watt/hours, lets call it 1 KwH. That's like running one of my electric heaters on medium for an hour. Not much warmth for the trouble. 1000 watts = 3412 BTU


In summer though there may be enough excess to run something like two of these pads:  12 volt / 30 amp / 370 watt  from solarseller.com ....  scroll down the page about 2/5 the way.

http://solarseller.com/diversion_load_heating_air_water_wind_hydro_solar_loads.htm

They could be wrapped on the water heater tank and the foam insulation replaced. I'd have to do some calculations to see if it would be practical or not; cost vs benefit.

Thoughts welcome.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: rick91351 on December 08, 2009, 03:45:54 AM
Don: I am tossing a dream or two but if you went to a tracker system.  How much more output do you feel you would see from your panels?  The literature I am seeing is all over the place everywhere from 25% to 50%.  25% would hardly be worth it cost wise I would think.  However if you could achieve even 35 to 40% that would really be getting into the more doable lets take a look at this would it not?  Especially if it were in more of a every weekend to full time residence application or say a remote pumping application? 

In your location do you have any problems with ice accumulation on your panels and cutting down your output that you have noticed?  I would think they would be dropped down now to almost no chance unless you have a lot off freezing rains mixed with snow.

 rlr

     
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 08, 2009, 06:54:51 AM
A tracker system would increase power or sure, how much though, I don't know. Glenn built his own tracker and I believe he has the bugs worked out, but I don't know if he has quantified what the power output increase is.

In our case the tracker would have to be "bullet proof" as we are not on site all the time to catch a problem.



Snow/ice. I've been up there during and after snowfalls. Even with the winter angle there was a covering of an inch or so. It did melt off within a few hours of the sun coming out bright though. If we were on site we would be able to sweep the snow o with a long handled broom, or tilt the panels to vertical and cause it to all that way. The slight amount of ice melted off too but took a little longer.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 08, 2009, 07:15:24 AM
The tracker was working until the seals went out of the cylinder - it was old. 

I replaced the seals, and I think the only problem is that I have to recharge the west side of the tracker - filled it once but I think the liquid went down to fill the cylinder so I have to fill it again.  Meanwhile it is just aimed south.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on December 17, 2009, 04:41:49 AM
Don and Glenn,

Or anybody who wants to put his or her two cents in on the question.

I've been playing around with the generator for charging our battery bank and have learned that if I allow the bank to drain to about 24.2 volts, which should be around 50% discharge, it takes roughly four to five hours to bring the bank back to float. If I recharge at 24.8 to 25 volts, however, it only takes one hour to return to float. Am I better off recharging once a week for about an hour, or every other week for a four to five hour run on the generator?

I understand this is really a personal choice, but I was wondering what you guys think about running the generator more frequently for less time and what this might mean for battery life.

Thanks.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 17, 2009, 06:18:05 AM
The deeper you discharge the shorter the battery life! The manufacturer (good ones) will specify the number of discharges that the battery will take. There are dozens of strategies for charging and some are definately better if you are trying to get 10 to 15 years out of a battery.

You should also be checking specific gravity to calibrate your own strategy!  Good Luck!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 17, 2009, 07:46:15 AM
Ditto what Dave said.

I'd be charging them every 2 - 3 days
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 21, 2009, 04:07:11 PM
Found some pretty good battery info from Rolls Battery.

Might be kind of basic for some folks, but for a guy like me who is just learning it was educational.  :)

http://www.rollsbattery.com/files/userfiles/Rolls_Solar_Instructions.pdf
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 22, 2009, 07:08:26 AM
Beavers,

Yes the Rolls info is very handy.  I have most of my 32 customers now on them offgrid.

You must keep in mind that they are in the business of selling batteries! Some of their info is geared for that. There are definate strategies to get 10 to 15 year lifespans and they are, let us say not always going to steer you that way!

Good Luck!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on December 22, 2009, 08:17:31 AM


They could be wrapped on the water heater tank and the foam insulation replaced. I'd have to do some calculations to see if it would be practical or not; cost vs benefit.

Thoughts welcome.



I saw no one responded and I haven't been around much
1 BTU will raise 1 pound of water 1 degree from 60-61.  I usually drop the 60-61 for rough estimates.
So if you have a 20 gallon hot water tank you have 166 lbs of water.
If you have 600 watts power you could get 2000 btu a day in a perfect world with no losses.  
2000 btu/166 lbs of would raise the temperature around 12 degrees by my math.
In a small tank you would see a significant rise.  In a 30 gallon tank you would get 8 degrees a day change.  You would probably lose that overnight.  

On the other hand you could probably build a drain back solar hot water panel for under $216.  At 3400 Btu per square meter per hour you could get 10,400 BTU (3kw) of power in heat even if you only had a 50% absorption rate.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 23, 2009, 02:22:54 AM



[/quote]

I saw no one responded and I haven't been around much
1 BTU will raise 1 pound of water 1 degree from 60-61.  I usually drop the 60-61 for rough estimates.
So if you have a 20 gallon hot water tank you have 166 lbs of water.
If you have 600 watts power you could get 2000 btu a day in a perfect world with no losses.  
2000 btu/166 lbs of would raise the temperature around 12 degrees by my math.
In a small tank you would see a significant rise.  In a 30 gallon tank you would get 8 degrees a day change.  You would probably lose that overnight.  

On the other hand you could probably build a drain back solar hot water panel for under $216.  At 3400 Btu per square meter per hour you could get 10,400 BTU (3kw) of power in heat even if you only had a 50% absorption rate.

[/quote]

If they are getting below 40F and your using the batteries you would have to do both or use an exchanger on a generator for bad weather.
I go through this from time to time and try to get people to build the battery house/room very close to the house so it can be conditioned from the house. Lot's easier!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 23, 2009, 12:01:12 PM
Dave,

One of these days a set of Rolls batteries would be nice!  I think I'm going to start with a cheap bank to learn and practice with.  :)

What in the Rolls manual do you think reduces life span?  Their suggestion for what seems like infrequent equalizing (based on other stuff I've read)...or something else?

I'm thinking of mounting my batteries attached to the house in a set up like Mountain Don has.  If the batteries need to be vented, how do you condition the space using the house without sucking all your heating or cooling out through the battery box vents?

Thanks,
Beavers
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 24, 2009, 08:25:43 AM
Beavers,

I am still laughing from a Crash Test Dummies xmas album about Beaver pelts. I will try to take this seriously. On the Rolls life or avoiding end of life there are many things that over the years they have sort of changed. Some of these things I keep close to my chest for my customers but the one pearl that I will add here is to design so that you "complete" charge most every day. On their site I have seen them say once a week, once every 2 weeks, on and on....  The charge system should be big enough to daily charge and bulk charge at the exact rate or slightly less. If you drag this out too long during the day, you just use more water, expose the terminals to more acid, creat more maintenance.

Yes Don's is similar to the goal and remember that the gas is really only there during bulk near the set-point and during absorption. There are things here that are close to the chest also but one way is to use the AUX on the inverter or the CC's AUX to contoll a very small fan based on voltage set-points. Charge during the middle of the day, use solar, and avoid wind or hydro that has 24 hour gassing, or make these other sources float during the hours that it is really cold. There are other ways and you might pry them out of me over time. You could become #33?, Nah, you can do this!

Merry Chrristmas
Title: Re: OFF GRID POWER; various thoughts on...
Post by: RainDog on December 28, 2009, 05:24:18 AM
Amorphous-Si PV vs. Crystalline-Si PV modules?

Is this a deal? http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=543 (http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=543)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 28, 2009, 06:17:29 AM
Amorphous-Si PV vs. Crystalline-Si PV modules?

Is this a deal? http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=543 (http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=543)



It might be, if they listed snow loading specs and explained more about who provides the warranty. For Offgrid the high voltage controller you would need may be out soon but is not yet! No problem for a grid-tie batteryless though. I do like the high voltage for long distance applications. Sun has great prices but sometimes poor service!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on December 28, 2009, 09:53:56 AM
Thanks Dave!

I've seen those powered battery box vents you mentioned.  With the cold winters I have, I like the idea of keeping the batteries warm. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 28, 2009, 10:56:41 AM
I saw a movie called off the map and it had a line in it like your quote.

"working for someone else is expensive,
you spend so much time there that you never have enough time to do things for yourself"

There is a nice way to do the battery venting passively in a very cold garage and keep them warm!  Do you want to guess how?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 29, 2009, 09:31:26 AM
Can you compare this system to say, the one you built with separate components?

I'm looking for an idea of the price difference when doing the work yourself versus the convenience of buying a completely put together package versus the component reliability etc in both.

Thanks
http://sunelec.com/index.php?main_page=600_watt_off_grid_system
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on December 29, 2009, 10:01:56 AM
Can you compare this system to say, the one you built with separate components?

I'm looking for an idea of the price difference when doing the work yourself versus the convenience of buying a completely put together package versus the component reliability etc in both.

Thanks
http://sunelec.com/index.php?main_page=600_watt_off_grid_system


Sure you can compare! The problem doing this is the intangible questions and their answers.

Like what is it for? How long? Do you expect to add on to it? There are many more questions like how much effort you will put into it? Budget? And the big one, how much energy will you need? If this is for living offgrid keep in mind that there is a very high incidence of failure on these first systems. Half of my customers are someone else's deign that I help the owner design and use properly.

Where did Don go? Snow cabining?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on December 29, 2009, 12:33:56 PM
Can you compare this system to say, the one you built with separate components?

I'm looking for an idea of the price difference when doing the work yourself versus the convenience of buying a completely put together package versus the component reliability etc in both.

Thanks
http://sunelec.com/index.php?main_page=600_watt_off_grid_system


Sure you can compare! The problem doing this is the intangible questions and their answers.

Like what is it for? How long? Do you expect to add on to it? There are many more questions like how much effort you will put into it? Budget? And the big one, how much energy will you need? If this is for living offgrid keep in mind that there is a very high incidence of failure on these first systems. Half of my customers are someone else's deign that I help the owner design and use properly.

Where did Don go? Snow cabining?



Good points (and I've heard them all but tend to get over excited and forget to include them)....

Off grid cabin -- not living -- with minimal usage (like Don's).  12vdc pump (that may actually be 24vdc) pumping water out of a 205' deep well into a cistern about 80 feet above it (don't know if that matters at all but I haven't checked amps yet)...maybe some 12v lights and a 12v ceiling fan (or maybe 24vdc) with some 120v outlets for small TV (maybe), DVD player (maybe), toaster, maybe even a small MW oven...who knows really?  After all it's a vacation cabin and not a home.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 29, 2009, 07:40:05 PM
Don (c'est moi) is in Colorado for a few days, to see some real snow (quantities).

We should be back home tomorrow PM sometime, as long as it doesn't snow heavily in or around Raton Pass. 


I'll catch up then.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: RainDog on December 30, 2009, 05:23:48 AM
Don (c'est moi) is in Colorado for a few days, to see some real snow (quantities).

We should be back home tomorrow PM sometime, as long as it doesn't snow heavily in or around Raton Pass. 


I'll catch up then.

 Snowing on Raton

 http://video.google.com/videoplay?docid=-6717780685002939476&ei=F2I7S6nVJY6-rALRiOm-Cg&q=snowing+on+raton&hl=en&client=firefox-a# (http://video.google.com/videoplay?docid=-6717780685002939476&ei=F2I7S6nVJY6-rALRiOm-Cg&q=snowing+on+raton&hl=en&client=firefox-a#)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 30, 2009, 05:04:28 PM
Well, it did not snow on Raton, but it was cloudy and windy and threatening snow north of Santa Fe (south of Raton). Now it's snowing at home.  I'm glad the roads were dry for driving; it is hard dangerous to do 82 mph in snow.


Is that system any good? How does it compare to what you would put together yourself?

You have not answered the question; how much power am I going to use in a day or a week? That has to be answered first, before trying to see how much it's going to cost or if system "xyz" will do the job.

It's tedious, yes. I made my best guesses several times over many months. You must be honest about expected hours of use for each light, microwave, etc. Make two lists, one that you need AC for (microwave type stuff) and the other DC things you might use. Use watts rather than amps and volts as you can change the DC watts into 12 or 24 VDC based systems at any time.  Make the list, round up any odd numbers.

Once you know how much you will use, then the battery bank size can be calculated and from that and the number of sun hours the total PV panel wattage can be determined. Then the charge controller can be picked. The amount of AC power will indicate how large an inverter is needed.

A note on the inverter: you mentioned a small microwave. Be aware that a microwave that is marketed as an 800 watt unit will likely consume 1100 - 1200 watts while operating. That 800 watts (or other advertised number) refers to the cooking power, not the amount of power used.Maybe you knew that, maybe you did not. As it makes a big difference I wanted to be sure on that.

One size does not fit all. You will likely need more PV panels than I would for the same size battery bank, for example because of our different latitudes.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 30, 2009, 05:49:48 PM

There is a nice way to do the battery venting passively in a very cold garage and keep them warm!  Do you want to guess how?

I'm trying to guess, but my imagination is failing me, Dave.    ???

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on January 06, 2010, 07:00:27 AM
One more clue! The very cold 30F garage is attached to the house. :o
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 06, 2010, 01:58:44 PM
Hmmmm....

Is the battery box up against the warm wall?

Insulate the battery box, vent it at a high point and remove any insulation from the house wall where the battery box is located? 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 07, 2010, 09:16:35 PM
Can you compare this system to say, the one you built with separate components?

I'm looking for an idea of the price difference when doing the work yourself versus the convenience of buying a completely put together package versus the component reliability etc in both.

Thanks
http://sunelec.com/index.php?main_page=600_watt_off_grid_system


OK point has been lost in translation.  The amount of power required or desired is in fact irrelevant to the question asked :)  So let me try again.

If you built a system yourself (so Don, you have what?  a 900 watt system?) then go out and find a 900 watt (or similar) package (anywhere is fine) and then compare it to yours.

Why?  let me explain:

I used to build PC's.  I went out and found the Motherboard I wanted, the processor, the fan and heatsink, the hard drive, disk drives, CD Drives, graphics cards etc etc etc.  My systems cost less then the big box systems and were better.

To this day my home built PC, while old and outdated, still is a better system then what you can buy in a few ways.  For example, I have more memory slots then most box systems do, I have more PCI slots, more drive bays, more room overall, more fans, bigger power supply, the list goes on and on...and it cost me less (at the time) then something similar from Hewlett Packard.

Now, today, I'm not sure since I no longer go out and buy parts to build a PC -- though I may yet again -- and I've seen a lot of CHEAP box systems that would probably suit me fine today (I probably won't try to stuff in half the things I used to)...

So from this kind of perspective, can you compare one of these 'kit' systems to your home made system?

I'm specially interested in Don't set up becuase I think it's a very similar situation/scenario to mine.  Cabin in remote location for part time use.

I will probably build my own system using what I'm learning here and have a good friend -- who's probably reading this post now ;) -- who's been educating me on the technical side of things (electrical) that I don't know.  I've built Microwave Transport Node sites to back haul Cellular traffic to the MSC (mobile switching center) which includes installing DC power controllers, rectifiers and batteries (series parallel) so I'm not new to the construction aspect of what we're discussing -- might even have a lead on some good batteries to use and will be checking into that since we install them in all of our sites to provide battery backups for the MW gear (-48vdc systems).  Anyway, I digress :)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 07, 2010, 09:46:16 PM
The computer analogy may still be still valid. I used to build desktops too. It was always a lot of fun selecting the components and the machines did usually come out cheaper than store bought. I'm not sure about today; when we last needed a new desktop I went to Dell. I wouldn't even think about building a laptop, though, which is what the last two computer purchases were. However, there's still a ols desktop in the corner of the office with an overdriven AMD 900 Mhz CPU that serves as a backup media storage unit.

Anyhow on to the PV system question. If one measures the system size by the panels, our system is 624 watts; three 208 watt panels. We have a charge controller that is higher quality and more versatile than what is offered most any pre-packaged kit. Ditto the inverter. My batteries are only golf cart GC2's. From Sam's Club they are dirt cheap compared to any other battery. Picking them up locally I saved a lot on freight costs. So far they are working well, and my past RV experience with them leads me to believe they will be cost effective.

I did spend a lot more money on our system than that one you referenced. Looking at it, I see we have more panel watts and more battery capacity. We also have a lot more inverter. And I have a lot more cable from panel to charge controller.  :D  

Tell you what... you should now have my prototype almost-ready-for-prime-time   ;D  PV system sizer tool. Run some numbers through the probable power load sections and send me the file, and let's go from there and have a look at alternative equipment choices.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 07, 2010, 09:48:26 PM
What are the specs on those batteries that are used in the cell communications trade?  Those could be great to have when priced right.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 08, 2010, 12:31:30 PM
Nice sheet -- one thing is for sure, I've got a LOT of thinking to do...just running lights for 10 hours a day can change a plan from 6 panels to so many you might as well run and hide!  Sheesh!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on January 08, 2010, 03:45:31 PM
"What are the specs on those batteries that are used in the cell communications trade?"

Yes this could be very interesting.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 08, 2010, 07:50:30 PM
These aren't the exact models we're using but pretty much the same sort of thing.  They are used in sites which must provide a minimum run time for the MW gear (transport nodes, routers etc) of 8+ hours.

What this means is that it should take at least 8 hours to go from -56vdc to -46.5vdc (where most systems die)....though sometimes the equipment will run around -46vdc they are usually dropping like flies then.

I can log into my controllers (in 5 states) right here :) 

http://www.sbsbattery.com/category_desc.php?cPath=3

We get ours from "Telecom Battery Solutions" more or less -- actually from Magnatek.

But I don't know that they are any better...I would just expect them to be since we're carrying E911 traffic which is well, kinda critical :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 26, 2010, 07:39:06 PM
Wish I had that reliable grid power, eh.  [ouch]

Hundreds out of power since last week - power not expected back for days to come.  I'm so glad the state forced me to hook up to that reliable grid...  OK so they told me I had to and I didn't... [waiting]

http://abclocal.go.com/kfsn/video?id=7238715

http://abclocal.go.com/kfsn/story?section=news/local&id=7240825
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 07:57:21 AM
Wish I had that reliable grid power, eh.  [ouch]

Hundreds out of power since last week - power not expected back for days to come.  I'm so glad the state forced me to hook up to that reliable grid...  OK so they told me I had to and I didn't... [waiting]

http://abclocal.go.com/kfsn/video?id=7238715

http://abclocal.go.com/kfsn/story?section=news/local&id=7240825

Too bad we all weren't rich enough to fight them in court over these kinds of things.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on January 29, 2010, 08:05:26 AM
I have an DC electrical question.

We have a Sundanzer DC electric fridge and we're planning on moving it a little farther away from our power supply. The manual says we should use 12 gauge cable for the distance we'll be at and the fridge comes with a fairly short 14 gauge cable. Should I just get 12 gauge to run from the DC box to the 14 gauge fridge cable, or should I replace the 14 gauge with 12 gauge for the entire distance? To be perfectly clear, do I remove the 14 gauge from the fridge and wire in the 12 gauge directly to the fridge?

Thanks,
Dave
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 09:07:20 AM
http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=255
Found these and was wondering if they sounded like decent panels for the money?

I want to put together a system for as little as possible but that will be reliable (within reason)...basically I can't afford $10k in solar power and budgeted $2k but could go a little more.

I need 2 of these 18Vmp panels, 4 Trojan L16RE-B 6v batteries, not sure what kind of inverter but my corrected watt hours per week is 6347 as calculated right now.  Also need a charge controller for the panels.

Since those panels list at $348 that's $696 in panels
Those batteries run about $330 -- so that's $1320 (ouch -- I think I might take Don's approach -- heck, 12vdc deep cycle RV/Marine batters aren't that expensive.  In fact I could get Optimas and save $400 at least and they've got to be decent...maybe I'm thinking wrong?)

http://store.solar-electric.com/xaxwmp60amps.html
I'm still learning (have a long way to go) but this appears to be what I would need for a controller?  I know I could go cheaper but I thought I read the MPPT's were the way to go???

That's $529

http://store.solar-electric.com/xatr15wa12vo.html
$760 for this inverter which has the charger plug in for the generator.

OK so if I went this route then the cost looks like:

$3305 for a 400 watt system with 1500 watt inverter and MPPT controller as well as 4 good batteries.

Hmm...also I have a 3000 watt generator that peaks at 4000 watts and will use that as a back up for the batteries as well as running saws and such (for construction at the cabin).

Thoughts?  Am I choosing the wrong components?  Did I miss something?  Could I reduce costs by going with 6v golf cart batteries?  Is the contoller/inverter combination incorrect?

It's kinda fun mind you, doing this.  I'm using Don's spreadsheet and trying to figure out what kind of power we will need at the cabin since all we've done to date is camp out in the trailer with ONE battery (except one time I had 3 becuase it was very cold) and the main thing that used the battery was heat which we've solved by buying the wood stove :)  And better insulation.

Anyway, thanks in advance.




Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 09:13:15 AM
WOW!  Just read that the Sams Club GC-2 is $66 at most places and can be found for $44 in some places (Costco maybe?)...in any case that changes my above cost considerably if I went that route.

So, 8 (need 8 due to the lower amp hour rating) x $66 = $528

Overall cost reduced to $2313 for the system I put together
Title: Re: OFF GRID POWER; various thoughts on...
Post by: muldoon on January 29, 2010, 09:49:55 AM
I'm interested and learning here also.  I have not built a system, just read on it, my input does not come from experience. 

I went to google Sams GC-2 for power storage and the first link I found was pretty clear that the lifespan of these is in the ballpark of a year.  While saving money (up front) is great, it might not be soo great to replace them every 12 months. 


http://www.power-talk.net/golf-cart-batteries.html

Our Experience with Golf Cart Batteries

  The third set of batteries to store power for the Ranch was a set of Sams Club GC-2's.  We had two sets of eight hooked in series and then each bank was connected to a buss bar for a 420 AH capacity.  These lasted 12 months.  Thinking that maybe we just got a bad batch, we tried the same thing again.  Twelve months later we were again looking at 16 depleted little batteries. 

  We kept them charged, watered and clean and didn't abuse them with microwaves and such.  The largest DOD they were subjected to was 35% with the average more like 20% - 25%.  Even if you considered each day for a year as a "cycle" that would be only be 365 which is short of the average 500 which we see on a lot of charts.  If we had been hammering them daily with high load devices, this might be understandable but the typical draw we have is in the 3 - 10 ampere range.  One thought was that we should have added another bank of 8 the second time around, for a total of 24 to ease the average load per battery. 

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on January 29, 2010, 09:55:07 AM
It depends on how off brand you are willing to go and how much risk you are willing to take.  There are many 40 Amp charge controllers on ebay made by smaller wind and solar energy companies that can be had for under $100.  Many have good feed back.  Here is one I have been looking at.
http://stores.ebay.com/Coleman-Air-Parts

Personally for such a small system that doesn't get regular use, I probably wouldn't go so high end, but that is just my personality.  A 1500 watt square sine 12V inverter can be purchase for $150.  You could by 4-5 of them for the price of the Xantrex.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 10:23:56 AM
It depends on how off brand you are willing to go and how much risk you are willing to take.  There are many 40 Amp charge controllers on ebay made by smaller wind and solar energy companies that can be had for under $100.  Many have good feed back.  Here is one I have been looking at.
http://stores.ebay.com/Coleman-Air-Parts

Personally for such a small system that doesn't get regular use, I probably wouldn't go so high end, but that is just my personality.  A 1500 watt square sine 12V inverter can be purchase for $150.  You could by 4-5 of them for the price of the Xantrex.

Do they have the Generator hook up to provide a charge on the batteries when the gen is running?

Good points all -- this is a limited use cabin which I hope to eventually improve to the point that we could spend a lot of time there -- maybe 5 to 10 years later but certainly not as long as I'm working as much as I do!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 10:26:10 AM
I'm interested and learning here also.  I have not built a system, just read on it, my input does not come from experience. 

I went to google Sams GC-2 for power storage and the first link I found was pretty clear that the lifespan of these is in the ballpark of a year.  While saving money (up front) is great, it might not be soo great to replace them every 12 months. 


http://www.power-talk.net/golf-cart-batteries.html

Our Experience with Golf Cart Batteries

  The third set of batteries to store power for the Ranch was a set of Sams Club GC-2's.  We had two sets of eight hooked in series and then each bank was connected to a buss bar for a 420 AH capacity.  These lasted 12 months.  Thinking that maybe we just got a bad batch, we tried the same thing again.  Twelve months later we were again looking at 16 depleted little batteries. 

  We kept them charged, watered and clean and didn't abuse them with microwaves and such.  The largest DOD they were subjected to was 35% with the average more like 20% - 25%.  Even if you considered each day for a year as a "cycle" that would be only be 365 which is short of the average 500 which we see on a lot of charts.  If we had been hammering them daily with high load devices, this might be understandable but the typical draw we have is in the 3 - 10 ampere range.  One thought was that we should have added another bank of 8 the second time around, for a total of 24 to ease the average load per battery. 



Pretty good points -- but Don seems to have done well running his -- so I'm wondering what he thinks? Could be that they over used them more then they admit??

I thought about RV batteries and even Optima's (I have an Optima Yellow Top in my jeep) which run about $200 but figured at that price I might as well get the Trojans -- of course, I might instead try to get some cell site batteries ;)  Since I could probably get them direct from the factory :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on January 29, 2010, 10:41:40 AM

Do they have the Generator hook up to provide a charge on the batteries when the gen is running?

No.  That is definitely a higher end very user convenient feature of this model. 
If cost is in issue, and you are looking to lower it.
http://www.samsclub.com/shopping/navigate.do?dest=5&item=429487
You could probably find an equivalent 40-50 amp battery charger at most automotive stores.  If you are willing to spend the money up front for a more full time system, Xantrex is always a good brand.  I have had good experiences using their marine units.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 10:41:56 AM
I have an DC electrical question.

We have a Sundanzer DC electric fridge and we're planning on moving it a little farther away from our power supply. The manual says we should use 12 gauge cable for the distance we'll be at and the fridge comes with a fairly short 14 gauge cable. Should I just get 12 gauge to run from the DC box to the 14 gauge fridge cable, or should I replace the 14 gauge with 12 gauge for the entire distance? To be perfectly clear, do I remove the 14 gauge from the fridge and wire in the 12 gauge directly to the fridge?

Thanks,
Dave

Ideally you'd run the 12 ga the entire distance. But if the 12 is 'fairly short', I'd probably just use the 12 for the extra length needed. If I already had enough 12 gauge laying about, and if changing the cord at the fridge was easy, then I'd likely change out the wire to all 12 gauge.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on January 29, 2010, 10:45:28 AM
The 12 gauge will be running roughly 10 to 12 feet, if I don't change out the 14 gauge. If I change it out the total for the 12 gauge will be about 16 feet. I guess I'll have to pull the fridge out and see how difficult it'll be to change out the 14 gauge.

Thanks,
Dave
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 10:49:43 AM
WOW!  Just read that the Sams Club GC-2 is $66 at most places and can be found for $44 in some places (Costco maybe?)...in any case that changes my above cost considerably if I went that route.

Sam's Club has great pricing on their GC-2's nationwide. My Costco does not sell auto/truck/RV/marine batteries at all.

I believe it is normally impossible to beat the Sam's club GC-2 pricing.

Whether or not they are as good as the trojan, I have no idea.

Once you have the battery capacity required calculated, you can do price comparisons. Most likely the GC-2's will be the least amount of money spent. They likely won't last as long as any L-16, but if you estimate life and factor in $$ spent I believe the GC-2's are a good bet on a small system.

I'll at those other questions you posed later.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 10:51:40 AM
The 12 gauge will be running roughly 10 to 12 feet, if I don't change out the 14 gauge. If I change it out the total for the 12 gauge will be about 16 feet. I guess I'll have to pull the fridge out and see how difficult it'll be to change out the 14 gauge.

Thanks,
Dave

Dave,  You could also take the quick and dirty route and simply cut off the 14 gauge close to the fridge. Then spilce the 12 gauge to it. As long as you make good connections and tape/insulate well, you'd never tell the difference in power use or loss.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 11:00:56 AM
I'm interested and learning here also.  I have not built a system, just read on it, my input does not come from experience. 

I went to google Sams GC-2 for power storage and the first link I found was pretty clear that the lifespan of these is in the ballpark of a year.  While saving money (up front) is great, it might not be soo great to replace them every 12 months. 


I have a set of 4 of the GC-2's from Sam's Club in the RV. They are now coming up to the end of their 4th year of use. I have no idea if that is typical or if the other guys experience is. One variable that was not mentioned in that article was temperature. ANY wet cell battery will have a shorter life when used in a high temperature environment. Most of my RV batteries lives have been in a cool to cold environment. They spent their first year in the typical desert summertime 90's, but the last 3 in the cool/cold of the mountains.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 11:25:25 AM

 even Optima's (I have an Optima Yellow Top in my jeep) which run about $200 ....

This is my personal opinion... I love the Optima for a vehicle battery. I have two red tops for the Cherokee. The plan is to replace them one at a time on a 2 year cycle. That way there will always be one battery that is at most two years old.

I believe the yellow tops are a good battery but too expensive for a stationary battery. Optima's big selling point, to me, has been their construction which is pretty much vibration proof. That's a big point in a 4WD that sees off road use.

AGM batteries are used successfully in many off grid applications. They will cost two to three times as much as a flooded wet cell battery, more if you compare to the Sam's GC-2. They don't require maintenance (watering). IF they are charged at too high a rate or overcharged they can be damaged. Overcharging can cause them to out gas and since any lost water can not be replaced that will shorten their life. For that reason AGM's are not run through any equalization charging. 15.5 volts (on a 12 VDC system) is about the absolute max charge voltage.

AGM's also have a much lower self discharge rate than a flooded wet cell battery. Lots of plus points for them. AGM's, by their nature, can only have their state of charge tested with a voltmeter.

Do not confuse a gelled cell battery with AGM. You do not want a gel cell for off grid power systems.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on January 29, 2010, 12:24:24 PM
Thanks for the insights, Don.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 29, 2010, 02:06:23 PM

http://store.solar-electric.com/xaxwmp60amps.html
I'm still learning (have a long way to go) but this appears to be what I would need for a controller?  I know I could go cheaper but I thought I read the MPPT's were the way to go???

That would work but might be more than you need.

Another choice could be the Blue Sky SB3024iL MPPT.    http://store.solar-electric.com/blskysbchco3.html
With it you could wire those panels in series to the charge controller. The controller can charge 12 VDC or 24 Vdc batteries. It has enough capacity for up to 540W (12V) & 800W (24V) panel output.
http://www.blueskyenergyinc.com/uploads/pdf/BSE_Product_Line_Overview.pdf
<$350 or just over $400 with meter.

As for the inverter, that Xantrex appears to be good... the charger section offers loads of power and offers the three stages plus equalization. 10 - 70 amps charger output.     http://lib.store.yahoo.net/lib/wind-sun/TR-inv.pdf

A lot of folks forget about the charger they will need at some point if they buy a cheap inexpensive inverter. Most, if not all, automotive chargers will not have an equalization mode. Something to keep in mind.


Question: Do you already own the small microwave you might want to use off the inverter?  I ask because our small 800 watt (1100 watt draw) microwave will not run on the square wave inverter I own. It hums (louder than on sine wave) but does not produce cook power. I don't know of any way to predict what will happen short of plugging one into a square wave inverter and trying it. In fact I don't know enough people with square wave inverters large enough to know if there are microwaves that will run on square wave. No idea. Maybe someone will know.  ???  I think I recall seeing some people using microwaves on cheap square wave inverters. I'm pretty sure my neighbor in the mountains runs a microwave; I know they have a square wave Xantrex inverter. Again, something to think about.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on January 29, 2010, 04:12:58 PM
Thanks Don -- no microwave and I beleive I removed it when the wife told me we didn't need one :)

I removed the battery charger and some other items and reduced usage based on guestimations made on my last trip.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 11, 2010, 08:40:18 AM
http://www.infinigi.com/renewable-energy-charge-controllers-c-2_37.html?page=6&sort=2a

this might save you a few bucks on the Xantrex
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on February 11, 2010, 11:40:16 AM
http://www.infinigi.com/renewable-energy-charge-controllers-c-2_37.html?page=6&sort=2a

this might save you a few bucks on the Xantrex

Thanks :)

If all goes well we will be making our solar power purchase within the next couple months :)  Gotta get a roof on and some walls done etc first though!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on February 25, 2010, 04:08:58 PM
Well finally got started on my off grid power system.  This going to be gradual build, starting with a battery bank being charged by an alternator, with solar panels added as we have the cash for them.  I figure we can still use the alternator down the road to charge the batteries on cloudy days.

I got a cheap Harbor Freight 6 1/2 horse motor, and ordered the mounting plates and direct drive coupler from the The Epicenter (http://theepicenter.com/cgi/order.cgi?page=power_sources_generators_and_batteries.html&cart_id=%%cart_id%%).

Buying the mounting plates from them saved a bunch of work.  They are well made, looks like they cut them with a plasma cutter, they bolted right up to the motor and alternator.   [cool]

So here is the meager start of my system...
The motor generator combo, and the Exeltech inverter I got from Considerations.  I removed the small gas tank, going to hook up a 6 gallon marine tank.  With the quick release fittings should make for easy fuel changes.  Also have to come up with some kind of enclosure to mount the setup in...something along the line of what Mt. Don built for his generator.


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv682%2Fadbeavers%2FHouse%2FP2250009.jpg&hash=fdb9531650c7890216dcd792ae198f88)


Close up of the couplers.  The direct drive really makes for a nice looking unit IMO...almost looks like store bought, not redneck engineered!  :)  


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv682%2Fadbeavers%2FHouse%2FP2250014.jpg&hash=9ae6eee5c95b89bc28355a954b52970e)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 25, 2010, 04:17:38 PM
That looks nice; rubber insert shaft coupler by the looks of it.   

I see the engine has a cast iron sleeve; that's good too.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Solar Burrito on February 25, 2010, 06:10:17 PM
Well finally got started on my off grid power system.  This going to be gradual build, starting with a battery bank being charged by an alternator, with solar panels added as we have the cash for them.  I figure we can still use the alternator down the road to charge the batteries on cloudy days.

I got a cheap Harbor Freight 6 1/2 horse motor, and ordered the mounting plates and direct drive coupler from the The Epicenter (http://theepicenter.com/cgi/order.cgi?page=power_sources_generators_and_batteries.html&cart_id=%%cart_id%%).

Buying the mounting plates from them saved a bunch of work.  They are well made, looks like they cut them with a plasma cutter, they bolted right up to the motor and alternator.   [cool]

So here is the meager start of my system...
The motor generator combo, and the Exeltech inverter I got from Considerations.  I removed the small gas tank, going to hook up a 6 gallon marine tank.  With the quick release fittings should make for easy fuel changes.  Also have to come up with some kind of enclosure to mount the setup in...something along the line of what Mt. Don built for his generator.

Great looking motor. Is this setup cheaper than a Champion 3500w generator for $299? Or is this more of a fun project by building it yourself?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 25, 2010, 06:32:55 PM
I'll bet it cost a little less, depending on the alternator output and not counting the 6 gallon marine fuel tank.

The advantage being that for battery charging purposes (12 VDC) it puts out the required DC and has a built in regulator obviating the need for a 120 VAC to 12 VDC charger.    On the downside it only puts out 12 VDC.

Close?  ??? 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on February 25, 2010, 07:11:14 PM
I got the motor on sale for $150 from HF, and the alternator, mounting plates, and couplers were $150 minus shipping.  Not any cheaper, but like Don said it doesn't need a charger to charge batteries.  I'm hoping that I will be able to idle it down and use less than full throttle to charge the batteries to cut down on noise, and fuel use.

I actually have one of the Champion 3500w generators.  For just running power tools ect. on a jobsite the Champion would be the way to go.  With the motor/alternator you still need an inverter and a battery to make 120v power.  Once you factor in those it's much more expensive than the Champion.  If you are looking to charge batteries though, the alternator would be better as far as I can tell.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: diyfrank on February 25, 2010, 07:17:09 PM
One thing to keep in mind, A car alternator puts out about half its rated current at an idle 600 rpm"s or so. The ratio from the crank to the alternator is about 3 to 1.
 At 1800 RPM's you'll be at half power output. at 3600 RPM'S to reach full output.
Either gear that sucker up or burn a lot of fuel to reach maximum output.

I like the mount though, It has a clean look.
If you could separate the two and mount something in between to increase  the alt. speed.  
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on February 26, 2010, 01:21:24 PM
I think its a 65 amp alternator.  I can't remember where I read it but, you aren't supposed to charge the batteries at too high of amps.  I'll have to dig back through all my info, but I think 30 amps or so was the most I would want to charge the batteries that I'm planning on getting.

I calculated that I should only have to run the motor a couple of hours a day to keep things charged up.  If I can run it a half throttle I hope it won't be too bad on gas.  It's definitely not a long term solution, but I think it should work for a couple of months until we can get some panels.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 26, 2010, 02:13:29 PM
The maximum charge rate for a typical flooded cell deep cycle battery is usually given as C/8, where C = the battery capacity in amp-hours. If batteries are parallel connected C is the total amp-hour capacity of the battery bank.

So with a 210 amp=hour battery, that is 210/8 = 26.25 amps maximum for a sustained period.

I've also seen C/5 listed as okay for flooded batteries that are deeply discharged, and a rate of C/10 listed for batteries that are 85% or greater charged.

There are special rules for gel cells and some brands of AGM allow higher rates. Best to check with the battery manufacturer when in doubt.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Beavers on February 26, 2010, 02:27:34 PM
Thanks for the number Don, saved me from digging through all my bookmarks to find it.  d*

My calculated load for the house is 49.5 amp hours a day.  Keeping under C/8 and charging at 25 amps would only have to run the motor 2hrs a day.  I think I could live with that for the short term.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Solar Burrito on February 26, 2010, 08:51:28 PM
Hey guys, I have an battery related charging question i've been wondering for a while.

Right now I have a 75watt panel and Xantranx c40 charge controller charging a single Deep Cycle group 31 battery. The problem is we keep a Honda 4x4 quad on our property and the battery dies before we get back to use it.

Any way I can connect the much smaller ATV battery to the Group 31 deep cycle being charged from our solar setup?

I've never heard of dissimilar battery sizes being charged together but It would be really convient if I could! The ATV battery is $50!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 26, 2010, 09:07:47 PM
How long does it take for the ATV battery to go dead? Many months or a shorter period?


Rather than try to hook the ATV battery into the existing PV system it might be easier to use a small PV panel just for the ATV battery. If the battery is fully charged, or close to full, a small panel should be able to retain them in full charge. We use 22 watts worth of panels to keep the RV batteries full over the winter.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Solar Burrito on February 26, 2010, 09:17:48 PM
It will go dead in 2 weeks. I have a crappy 1 watt panel but it's not meant for being outside so I don't want to leave it up there.

We obviously don't have AC power up there either, only our small PV system.

Can a small 12v battery be connected to a large 12v battery?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 26, 2010, 09:27:15 PM
If it goes dead in two weeks I think the battery is "dead meat" already and there is no hope for it OR there is a "phantom" drain that is sucking the power. No battery, if in decent shape, should go dead that fast.

Have you tried disconnecting the battery from the ATV system?  (pull the neg or pos lead off the battery)  You could install a battery switch or an Andersen connector to make that easy. I have a disconnect switch in the RV "house" system because there is an unknown small load that sucks the house batteries down if left connected during prolonged absences.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 26, 2010, 09:31:31 PM
I am not sure if there is any danger to one battery or the other if the ATV was to be connected to the PV system.   ??? :-\
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on February 27, 2010, 07:39:21 AM
Hmmm...did you check www.rockymountainatvmc.com

I think I got a battery for our Yamaha for half that there...mine was doing the same thing so I replaced it -- no point in messing with it beyond that.

http://www.rockymountainatvmc.com/productDetail.do?navType=type&webTypeId=19&navTitle=Electrical&webCatId=20&keyword=BATTERY&prodFamilyId=8926
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Solar Burrito on February 27, 2010, 05:14:41 PM
Thanks but it's still $50. Some are $100! That seems really high for an ATV battery! It's for a Honda Foreman 400 ES. The ES stands for electric Shift and it has 3 lights on it and a cigarette lighter so I suppose it uses lots of juice...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 05, 2010, 09:54:50 AM
http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=255
Found these and was wondering if they sounded like decent panels for the money?

I want to put together a system for as little as possible but that will be reliable (within reason)...basically I can't afford $10k in solar power and budgeted $2k but could go a little more.

I need 2 of these 18Vmp panels, 4 Trojan L16RE-B 6v batteries, not sure what kind of inverter but my corrected watt hours per week is 6347 as calculated right now.  Also need a charge controller for the panels.

Since those panels list at $348 that's $696 in panels
Those batteries run about $330 -- so that's $1320 (ouch -- I think I might take Don's approach -- heck, 12vdc deep cycle RV/Marine batters aren't that expensive.  In fact I could get Optimas and save $400 at least and they've got to be decent...maybe I'm thinking wrong?)

http://store.solar-electric.com/xaxwmp60amps.html
I'm still learning (have a long way to go) but this appears to be what I would need for a controller?  I know I could go cheaper but I thought I read the MPPT's were the way to go???

That's $529

http://store.solar-electric.com/xatr15wa12vo.html
$760 for this inverter which has the charger plug in for the generator.

OK so if I went this route then the cost looks like:

$3305 for a 400 watt system with 1500 watt inverter and MPPT controller as well as 4 good batteries.

Hmm...also I have a 3000 watt generator that peaks at 4000 watts and will use that as a back up for the batteries as well as running saws and such (for construction at the cabin).

Thoughts?  Am I choosing the wrong components?  Did I miss something?  Could I reduce costs by going with 6v golf cart batteries?  Is the contoller/inverter combination incorrect?

It's kinda fun mind you, doing this.  I'm using Don's spreadsheet and trying to figure out what kind of power we will need at the cabin since all we've done to date is camp out in the trailer with ONE battery (except one time I had 3 becuase it was very cold) and the main thing that used the battery was heat which we've solved by buying the wood stove :)  And better insulation.

Anyway, thanks in advance.






http://sunelec.com/index.php?main_page=615_watt_off_grid_system

This system is very close to the one I priced out -- but has what might be better batteries, 3 panels and all the other goodies I hadn't added.

Thoughts?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 05, 2010, 08:45:38 PM
Well, the panels ARE made in the USA, nice to see. It's okay being blemished. No UL approval could be a problem if there were an electrical inspection.

Other thoughts in no particular order:

What is the shipping on the batteries going to be?  They have a marginally higher rating than the Sam's Club batteries but cost more to begin with, plus shipping.

Xantrex states the amperage draw on that inverter is a max of 77 amps at rated power. Allowing 25% for a surge that means a 100 amp input breaker to the inverter is large enough. They are selling a 250 disconnect, which appears to be a breaker. You need a breaker, or fuse, in the inverter feed, but not one 2.5 times the calculated likely maximum current.  Way too much breaker for the inverter. At least I'm assuming that the 250 amp disconnect/breaker is meant for the feed from batteries to inverter.

Their package offers no discounts over buying each item picemeal from them.

Another assumption is that they mean the panels are to be connected in series. I say that as the charge controllers I am familiar with all want/need an input voltage that is greater than the battery bank it is going to charge. A 24 V battery is usually powered by 48 volts input from panels. So that fits with the 20 amp breaker being used at the combiner as a disconnect/breaker.

IF the panels are in series, and if your system is not going to be inspected, you can likely come up with a substitute box and disconnect for less than 79 + 15 = $94 as with the panels in series you really have nothing to combine. Parallel panels would be different.

I'm confused why they include two 60 amp breakers. Xantrex recommends 50 amp for the charge controller output breaker. You only need one breaker in the positive line if you have the system properly grounded. 

I can tell you where you can get the C40 for $104 instead of $145

Anyhow that's some thoughts about their "kit"





Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 06, 2010, 08:33:09 AM
:D

Thanks Don,

I asked mostly becuase I wanted to get some thoughts on their package vs. the one I put together with your help.  I was curious why they did some things and at the time hadn't looked closely at the batteries which I then discovered were golf cart batteries too -- interesting.

Anyway, I was also curios about the voltage and wanted to see if the package we came up with compared.

I see that with your assistance my package has more thought into it (thanks to your spreadsheet too) and price wise is very competitive :D  I like that.

Still learning a LOT/TON and am excited becuase we may be starting our buys REAL soon :D  [cool]

I plan to stick with what we came up with actually and was going to ask about running the panels in series for a 12 vdc system and I think you just answered that!  Series to 24vdc to charge the 12vdc battery bank for the cabin right?

One other thing, I'm considering trying to run a 24vdc feed to the well pump (but I need to check the pump out first) if it's actually 24vdc rather then 12vdc and the panels will be closer to it if I put them where I plan, but the batteries further away (I need to do a drawing) -- what are you thoughts about that?

By the way, this is an amazing resource and at times I just smile becuase I know I'm going to learn something!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 06, 2010, 08:52:00 AM
The inverter Sun spec'd is meant to run on 24 VDC.  That's why the 24 v battery system.

The panels in parallel would not be able to charge the 24 V system. At least using equipment I am familiar with, that would not work. I have not used the Xantrex or looked heavily into their specs and operation. BUT the ones I am familiar with require a higher voltage INTO the charge controller than the battery pack voltage. This is partly because the panels may not be putting out much voltage on a cloudy day... not enough to push the current into the batteries. So with a 24 VDC system you need more than 24 VDC output from the panels to be able to have sufficient power to charge the batteries on cloudy, low voltage panel output days. Those panels singly put out a max of something like 18 VDC.

I'm being wishy-washy, waffling, on that answer because I doubt that Xantrex has any magic power boost built into the charge controller but I don't know for sure.

OTOH, with a 12 VDC battery system the panels would be okay in parallel, but the cables etc need to be bigger, and that inverter would not work.


Re: the pump. Yes, you need to verify it's voltage and current requirements, or volts and watts.   Add a nice diagram with distances between components.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 07, 2010, 11:35:05 AM
I might be wearing out my Honda eu1000i.  It seems that for the last few days that when the charger on the Prosine 2.0 inverter is enabled, it just keeps cycling back and forth every 10-15 seconds from standby to charging.  Nothing's changed recently.  When the inverter cycles to the charge mode, the generator "lugs" for a second, recovers, and the charge phase on the inverter cycles back into standby mode. 

It's like the gen isn't responding with enough power soon enough to keep the inverter in charge mode. 

I'm careful about the maintanence on the gen, change the oil once a month, add some every 5 days, etc. 

I'm a little worried about all that cycling....all I need is for the inverter to go boots up as well.. :(       

Tomorrow is Monday and I'll be making some calls to see what sort of tech support I can drum up.   
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 07, 2010, 12:17:04 PM
Have you tried using the generator to power some regular AC loads, like a power tool or toaster?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 08, 2010, 08:39:41 AM
"Have you tried using the generator to power some regular AC loads, like a power tool or toaster?"

Yes, the power from the gen is still going into the inverter and then into the house and still running the whole house and the electric fence, I just have the charging mode on the inverter turned off. 

I think that rules out the possibility that the quality of the sine wave being produced by the gen is inadequate, or I don't think I'd be able to run the house on the gen through the inverter. 
 
If I turn on the charge mode, the inverter switches to charge for 7 to 10 seconds, the engine lugs down, then the inverter switches back to standby, and the gen revs back up to normal, then the inverter switches to charge mode and the aforementioned repeats until I turn the charge mode off.

I tried shutting off the house to eliminate all AC loads and then turning on the gen and the inverter's charge mode...no dice.

I get the gen serviced each summer....but there have been 4 summers and there are a lot of hours on it.  I wonder what the life expectancy is.   Having a "spare" so I could take one offline as servicing is needed is a goal. 

I have a 5500 watt B&S gen but it won't run the house through the inverter, I'm pretty sure its the type of sine wave it produces.
 
Anyway, the PV panels are keeping the battery bank charge in good shape, and I just shut down every nonessential electrical item at night.  As the days lengthen and the sun shines more, and I get another job (always helpful), I'll be able to explore the issue further. 

In the meantime I think I need to figure out how to hook the big gen directly to the house in case the Honda goes completely gunnybags. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 08, 2010, 08:51:56 AM
considerations,

Your Honda generator is 1000 watts? Did the Prosine charge controller work fine with the Honda prior to these events?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 08, 2010, 10:55:37 AM
I do not know your inverter/charger and only use the Outback and Xantrex (SW's XW's) but your inv/chg has to be able to limit the charge current to run a small generator. You could have other problems also but this first step has to be adjustable in the programming of the inv/chg.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 08, 2010, 02:34:37 PM
A long distance diagnoses is more a guess.

I too am not familiar with your inverter/charger.

It more or less sounds like the inverter is drawing more current than the generator can produce. That could be why the generator lugs as if overloaded and then goes back to normal, only to repeat the cycle. It could be the inverter circuitry sensing the overload or the generator itself. I'm not familiar with the little Hondas either.

The only generator failures I've experienced are total failures to produce power, never a partial failure.

Have you tried pulling all the AC power to the cabin distribution system to see if the charger alone will repeat the scenario? Is the charger section programmable as to maximum AC current use or maximum output? I'd try limiting either of those if possible to slightly below the generators maximum continuous output rating.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 08, 2010, 08:32:33 PM
"Your Honda generator is 1000 watts?" Yes

"Did the Prosine charge controller work fine with the Honda prior to these events?" Yes

"Have you tried pulling all the AC power to the cabin distribution system to see if the charger alone will repeat the scenario?" Yes, I shut off the big breaker in the power shed...no AC going out at all, and the scenario repeats.

"Is the charger section programmable as to maximum AC current use or maximum output?" Ummmm..There are default settings, and there was a setup programming sequence that I had to go through.  The setup programming was ridiculously complex.  I haven't changed the settings since the initial programming...and I don't remember....so back to the book, that is next.  A cursory reading says the Prosine won't charge if the input voltage drops below 95.  I have to go back to the programming sequences to see if that can be altered...just seems logical that if it was working before I shouldn't have to change anything.

Today I also got an "instant" readout voltage meter on the gen to see what happens when the inverter switches to charge mode.  It's only sucking about 6 amps from the gen when the charge mode comes on.  The trouble is that it won't wait for the gen to get back up to speed before it kicks out of charge mode.  A week ago it did, and was working just fine since December 20 until the last few days. 

I also plugged a 7.8 amp drill into the gen, revved the drill up and put it to hard work several times.  The gen didn't mind and although there was a short (1 second or so) initial period when the gen's rpms dropped, they came right back and the drill didn't notice...held its performance steady. 

So now I'm going to find out something like there are different kinds of amps....thought I understood (mostly), but maybe not.  ???

I enjoy electricity because it makes so many things so convenient, but...this is probably the most difficult part of the entire project for me to get my head around. 








 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: pagan on March 09, 2010, 03:54:58 AM
If it worked fine at some point within the last few months and you've changed no settings on your inverter/charge controller I'd say the problem is with your generator. Not that it's in the throws of death, but that something is interfering with the power getting to the charge controller before the charge controller kicks it off.

Maybe try putting a load on the generator before the charge controller so the generator is already running at a higher RPM. It might just be the time it takes the generator to rev up and increase the power output is too long for your charge controller.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Redoverfarm on March 09, 2010, 09:42:08 AM
OK People this is completely out of my realm of comfort.  ???  I need to get busy and develope a system to operate at the cabin.  My main power and charging source will be a 12KW propane generator.  I would like to operate the generator as a charging system for a battery bank and run the cabin when the batteries are depleted.  Here is a list of what will I will be using.  Some of which are not listed as watts but rather amps and some I am not sure what they draw.

1100 watts of lighting.  That is a total but only a portion will be used at one time.
9.8 amp 110/120 well pump
1100 watt Microwave
2- exhaust fans. One is a bathroom exhaust and the other a 600CFM kitchen fan
1- Sure flow DC pump
3- ceiling fans

I know nothing about sizing the inverter or charging system or even the size or the amount of batteries.

Any information will be greatly appreciated.  If you have any sites that list the equipment that you feel are a good buy that would also be useful.

Thanks  
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 09, 2010, 10:09:28 AM
Dilemma time.

When I began playing with Don's spreadsheet I was able to put together what I envisioned as a minimalist remote cabin off-grid system.  400watts delivered via 2 200watt panels through a Blue Sky SB3024iL Charge Controller into 8 Golf Cart batteries and then feeding both 12vdc items as well as a Xantrex TR1512 1500 Watt, 12 Volt Inverter.  This would power some lights, a well pump, maybe a radio and a composting toilet fan.  Not much, but perhaps with enough reserve to make use of some other things (like maybe charging an ipod, or a cordless drill etc).

However, I may (may being a very operative word here) be able to afford to go with a little more...so I'm playing with the following:

3 of these panels:  SUN ES-A-210-fa3 210 watts, 11.48 Imp, 18 Vmp
I'm wondering if running them in series at 3100 feet in altitude would be too much for this controller:

Blue Sky SB3024iL Charge Controller 30A 24V MPPT

With 8 batteries as originally planned (need 8 in the winter and 6 in the summer except for at the coldest time of year when I'd really need 10-12 and probably more panels -- it's a trade off right?)....

And....

Xantrex Prosine 1800 Watt HW 12V Sine Wave Inverter w/transfer Switch

That would give me 1800 watts of AC and no modified sine wave so if we did decide to add a small MW oven we could.

Cost? 630 watts for about $3136 plus shipping and of course all the wiring etc.

vs. 400 watts for about $2328

A little more charging juice in t he winter might be nice I'm thinking and true sign wave may be handy at some point.  This doesn't really change my system much I think (1500 watt inverter vs. 1800 watts) except that it will produce a lot more power in the summer (north country -- could get more then double the sun I'd get in winter!  In fact, in the winter I'll get maybe 3 solid hours of sun but in the summer I could see 12!  ???

I doubt we'd need the generator for anything but heavy tool use in the summer but in the winter can imagine that we might need it during longer stays if the clouds are out and we can't get good sun exposure.

Anyway, please fire away!

Also, Don, you mentioned something about using higher input voltage to charge the batteries.  I took that to mean that on a 12 vdc battery string you would want 24+ vdc coming into the charge controller?

Also also :) ;)  I'm looking at wiring needs to the panels and was thinking that running the three panels in series triples the voltage to 54.9vdc right?  (if they are 18.3Vmp) and that Blue Sky charge controller is rated at no more then 57v I think....would I be better going with a slightly more robust controller?

I was thinking this is where the Xantrex XW MPPT 60 Amp Solar Charge Controller would come into it's own since it allows a higher input voltage to charge the 12vdc battery bank.

Thoughts?

THANKS!  [cool] c*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 11:43:42 AM
John,

No PV panels, no wind, right, IIRC?

If that's correct you should seriously reconsider, or choose an inverter/charger unit that is smart enough to be able to sense battery voltage and then automatically start the generator. Otherwise you will drive yourself and your wife batty with constant monitoring the battery state of charge and/or deplete the batteries past the danger point too frequently and shorten their life.

The only inverter/chargers I have knowledge of, with that capability are Outback and the better Xantrex. There are others though. An auto start kit (relay & stuff) is required as well. There are 2 wire and three wire types as far as the generator connections go, I believe 3 wire can be considerably more expensive. I haven't looked into this much as for the present I'm not doing an auto start system. It's also handy to have an interior control for manually starting the generator.

The system is programmed so when the battery voltage drops to a certain value and for a certain length of time, the generator will start.

Note that the better units have the charger and inverter in one unit. The batteries normally supply the current needed for the AC demands placed on the inverter. The generator can be used to supply extra power when the inverters capacity is being overloaded.


Okay, what is the panel setup for? 120 VAC only or a 120/240 VAC?  That will determine the inverter setup. If you need 240 VAC in most cases you will have to have two identical inverters that are designed for stacking in series, to produce two 120 VAC legs. Also if 240 VAC is required the generator must be 240 VAC split phase.  Better inverters can also be installed in parallel to increase available current. Series/parallel also is used at times in larger systems.


As for how much inverter output required yo will need to make a list of everything that is likely to be used at the same time.  You can use the PV sizing tool   http://countryplans.com/smf/index.php?topic=8192.0 (http://countryplans.com/smf/index.php?topic=8192.0) for doing the load and battery calculations.  You need to enter watts, so just remember amps x volts = watts

For the well pump:  9.8 amp 110/120 well pump, that is more like 10 x 120 = 1200 watts with a starting surge.  ??? on that

The manual/literature for the various fans should indicate power consumption. Or try the internet resources.


I hope that helps some.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 12:04:42 PM

...... you mentioned something about using higher input voltage to charge the batteries.  I took that to mean that on a 12 vdc battery string you would want 24+ vdc coming into the charge controller?

...... I'm looking at wiring needs to the panels and was thinking that running the three panels in series triples the voltage to 54.9vdc right?  (if they are 18.3Vmp) and that Blue Sky charge controller is rated at no more then 57v I think....would I be better going with a slightly more robust controller?

A quick partial response, no time at present for more.

The voltage going into the battery must be higher than the rated voltage of the battery system.  

That also generally means the voltage going into the charge controller must be higher than the battery voltage.  As a rule of thumb that working voltage input to the charge controller should be 1.5 times the battery bank/system voltage. That provides a safety factor for cloudiness as well high temperature voltage losses. Having the input to the CC even higher is fine with most of them. There is an upper limit listed in any good CC specs. You can not exceed that without (a) damaging/destroying the CC and (b) voiding the warranty.

When calculating the theorteical maximum voltage from the panels the Voc (voltage, open circuit) value must be used. Than fudge factors must be applied. Multiply the Voc x 1.25 x 1.25, That's right multiply by 1.25 once and then a second time. That will supply the likely maximum voltage that could ever be produced on a very cold, but very sunny morning as the first rays of the sun strike the panels. If that calculated value is near, at or greater than the charge controller maximum input do not use that panel and CC combination.

I'm pretty sure that Blue Shy model would smoke with that proposal: check the specs.

There is a PV panel string sizing tool available at Outback. It uses a database of hundreds of panels. Of course it is only 100% useful for system sizing when using Outback Charge Controllers, but it can give you the panel values and combination values that may be handy. It is also temperature compensating so you can dial in your own conditions and see how the outputs change.  Placing the mouse cursor on a colored square produces the cold Voc as well as other data.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Redoverfarm on March 09, 2010, 12:36:04 PM
Don you are correct No solar or wind (not at this time).

The generator that I have and posted a picture earlier is a standby generator which will monitor the incoming power and when it notices a depletion it will automatically start.  So my thinking was to utilize the inverted power as my primary feed (just as grid power is normally used with the generator) and let the generator determine when it needs to start. I guess I need to contact the manufacturer and determine if this configurations with a inverter can be made.

The panel is completely 110/120 now but I did reserve a couple 220/240 breakers for future use.

The pump is a slow start and supposeably does not have a surge. 

The fan paperwork does not list any of the technical information only the installation guideline.  They used to put that in there was it's not on the particular fans that I have.

I guess the load and battery size will determine the inverter size?

 

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 04:59:06 PM
John,  The total simultaneous loads will determine the inverter size. How long you want the batteries to supply those loads without the generator running will determine the size and number of batteries.

I’m having some trouble trying to get what I want to say condensed into a compact coherent paragraph or two. What I’m trying to clarify why what you propose could have problems because that’s not what the standby generator designers nor the inverter designers had in mind when they set out to build their products.


First, a standby generator will sense when there is no 120 or 240 VAC present at the house service panel, as in a grid power failure here at my home. That loss will cause the generator to start to replace the grid power. When the grid power returns the generator will shut down. A proper grid setup like this will also include an automatic changeover switch to be certain there would be no feedback from the generator into the grid. A standby generator itself has nothing to do with the batteries or an inverter.


Inverters. The better type like the Outback and Xantrex include a charger in the inverter. Inverters have a low battery voltage sensor and a circuit that turns the inverter off when a certain low battery voltage is reached. On the better ones that LBCO (low battery cut off) voltage is user programmable. There is, or should be, a battery voltage setting that will turn the inverter back on when the battery is recharged to a higher voltage; the LBCI low battery cut IN) voltage.

Every inverter has a pair of DC input connections as well as an AC output connection. An inverter/charger also has an AC input connection. When AC voltage is applied to the AC input terminals that current is passed through the inverter and split between powering the house and charging the batteries.

Inverters also consume a small amount of power just sitting there at your beck and call. It’s not much but adds up. Over time the batteries will be drawn down to the LBCO and the inverter will shut down. To get around this waste the better inverters have a search function. Virtually no power is used until something is turned on to demand power. At that point the inverter clicks on and things light up, hum or buzz.

These inverter/chargers are meant to be the main supplier for the AC house power. They are wired up so that when there is AC input to the inverter/charger they can charge the batteries and seamlessly continue sending AC power to the house panel.




It’s the charging connections I have trouble when trying to use the existing auto start system that is built in to the standby generator. Specifically where to hook the AC input of the charger up to. If the AC from the generator is connected to the AC inputs of the inverter/charger, that will charge the batteries. However, that will also send power through the inverter/charger (via the built in “pass though” that is a part of such units) to the service panel. There the AC power would be sensed as a return of the “grid” power and shut down the generator. At least that’s how I see it. I could be wrong, be misinterpreting something.

If you want the system to run without user intervention I believe it gets more difficult than need be.


If you used a separate inverter and a separate charger it might be easier, but that also might cost more than a single unit.


With all that in mind the first thing to do is determine the capacity required for the inverter output and the capacity required for the battery bank.

While you do that check the standby generator specs, or call the supplier. You would want to know if the remote start capability of the generator is a two or three wire setup. Also see if there is a delay system built into the generator. That is when it is called to start, is there a preset or a programmable delay between engine starting and connecting AC power output. I would think so, but not having worked with generators that were designed as a standby I’d like to know. It think there should be.


I hope I did not muddy the waters with that.  d*

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Redoverfarm on March 09, 2010, 05:21:09 PM
Yep clear as mud Don.  But no fault of yours.  Just a mental block on my end.  

I do have a automatic transfer switch and seperate breaker for the generator supplied by the manufacturer.  Normally there is a 60 amp wires ran from that transfer to the house panel box.  Normally the circuts for the house are wired to the 12 circuit generator panel (transfer switch).  I know it does have 3-4 smaller wires which I think are the monitoring wires which detect the power failure from the grid (via generator transfer panel)to the generator and that activates the generator. The transfer switch has two modes which are automatic or manuel.

I know I could probably just go with a battery charger from the generator to charge the batteries once the inverter shuts down and it would remain deactivated until the batteries are restored. I think that then the power would be restored to the panel and the generator should shut down after it detects power. Or at least in theory. 

You have given me a good bit to digest and I was aware that it would not be easy but I still think it can be done.  This is just one area that I am completely lost and it will take me a while to get it figured out.

Maybe someone has crossed this bridge before and may enlighten me some.

Thanks.    
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 05:36:25 PM
Dilemma time.

A..... I'm wondering if running them in series at 3100 feet in altitude would be too much for this controller:

B..... Xantrex Prosine 1800 Watt HW 12V Sine Wave Inverter

C..... I doubt we'd need the generator for anything but heavy tool use in the summer but in the winter can imagine that we might need it during longer stays if the clouds are out and we can't get good sun exposure.

D..... 54.9vdc right?  (if they are 18.3Vmp) and that Blue Sky charge controller is rated at no more then 57v I think....would I be better going with a slightly more robust controller?



A.....  Altitude has small effect on increasing the amperage output of a PV panels. No effect on voltage. Hot temperatures decrease voltage output, cold temperatures increase voltage output. Clearer skies, no clouds or less atmosphere sue to higher elevations increase the amount of sunlight that reaches the panels and that increases amperage output.

B & C..... No battery charger in that and you will need one.

D..... I think we covered that already. bad idea for those 3 panels and that charge controller. But do remember use Voc and those correction multipliers when totaling the input voltages.

Hope that makes sense...

 :D

My head/jaw hurts tonight.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 05:44:13 PM
FYI, on the cold weather and PV panel voltages.

The Outback online calculator predicted a Voc from the panels in series, at the lowest temp I've recorded up there this winter, of 129 volts. The Outback FlexMax charge controller recorded a peak voltage of 127 volts for that time period. Pretty close, although I should add that I have also recorded 125 volts at temperatures that the calculator predicted would be 10 volts lower. ??? Goes to show there can be real world variance from theory. However, I have enough safety factor that even using a worst case scenario everything should be safe.  

Take that as a hint to not cut theoretical peaks too close to the stated hardware maximums.



Note: if your panels are not listed in the Outback calculator you can enter your own data. I believe Xantrex has a similar calculator with their equipment listed.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 06:07:17 PM

I know I could probably just go with a battery charger from the generator to charge the batteries once the inverter shuts down and it would remain deactivated until the batteries are restored. I think that then the power would be restored to the panel and the generator should shut down after it detects power. Or at least in theory. 

I believe that is correct. That system though will have to be finely tuned to allow the generator powered charger to bring the batteries up to an absolute true full charge, before the inverter kicks back in and causes the genny to shut off. It should be possible but may require fiddling.

I now remember there was something I wanted to add. Beware of cheaper inverters that have the LBCO voltage fixed at something like 10.5 to 11.0 volts. As far as I'm concerned that is too low a voltage to use. The LBCO and LBCI shoiuld be adjustable by the user.

The charger you select should have the three types of charging; bulk, absorb and float as well as an equalization option. The EQ is not available on a number of stand alone chargers. You will need to be able to disable the generator start/run when you want to do an EQ or even treat the the battery to a complete full charge.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 09, 2010, 08:31:36 PM
Dilemma time.

A..... I'm wondering if running them in series at 3100 feet in altitude would be too much for this controller:

B..... Xantrex Prosine 1800 Watt HW 12V Sine Wave Inverter

C..... I doubt we'd need the generator for anything but heavy tool use in the summer but in the winter can imagine that we might need it during longer stays if the clouds are out and we can't get good sun exposure.

D..... 54.9vdc right?  (if they are 18.3Vmp) and that Blue Sky charge controller is rated at no more then 57v I think....would I be better going with a slightly more robust controller?



A.....  Altitude has small effect on increasing the amperage output of a PV panels. No effect on voltage. Hot temperatures decrease voltage output, cold temperatures increase voltage output. Clearer skies, no clouds or less atmosphere sue to higher elevations increase the amount of sunlight that reaches the panels and that increases amperage output.

B & C..... No battery charger in that and you will need one.

D..... I think we covered that already. bad idea for those 3 panels and that charge controller. But do remember use Voc and those correction multipliers when totaling the input voltages.

Hope that makes sense...

 :D

My head/jaw hurts tonight.



Thanks Don -- so the Xantrex contoller if I want to run series then.

I was thinking the transfer was for the gen -- guess I need to re-read that.  Is there a decent true sine wave inverter for similar cost that also has the battery charger?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 09, 2010, 08:41:18 PM
Yikes!  Just looked up true sine wave inverters with charge controllers and got shell shocked!  Guess it's back to modified sine wave for now.

With the Xantrex controller and the Xantrex inverter charger I should be set anyway, I was just toying with the idea of true sine wave becuase if we wanted a MW oven it might matter.....I think we ditch the MW idea *chuckle* and stick to the propane stove and cook fires!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 09, 2010, 08:50:52 PM
  Is there a decent true sine wave inverter for similar cost that also has the battery charger?

Xantrex Pro-Sine 2.0..... 2000 Watt Sine Wave Inverter/Charger


Magnum Energy.....  2000 Watt Sine Wave Inverter/Charger

More bucks though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 10, 2010, 03:34:31 PM
"OK People this is completely out of my realm of comfort." Roger that

Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 10, 2010, 03:41:43 PM
"With the Xantrex controller and the Xantrex inverter charger I should be set anyway, I was just toying with the idea of true sine wave becuase if we wanted a MW oven it might matter.....I think we ditch the MW idea *chuckle* and stick to the propane stove and cook fires!" 

I have a microwave and a Prosine (Xantrex) inverter.   I still use the franklin stove and the crock pot for cooking.  The most use the MW got is popcorn (it was a load test).  I heat rolls, melt butter, that's about all....My system is small for a "real" house and an MW is a wattsucker.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Redoverfarm on March 10, 2010, 04:57:59 PM
"With the Xantrex controller and the Xantrex inverter charger I should be set anyway, I was just toying with the idea of true sine wave becuase if we wanted a MW oven it might matter.....I think we ditch the MW idea *chuckle* and stick to the propane stove and cook fires!" 

I have a microwave and a Prosine (Xantrex) inverter.   I still use the franklin stove and the crock pot for cooking.  The most use the MW got is popcorn (it was a load test).  I heat rolls, melt butter, that's about all....My system is small for a "real" house and an MW is a wattsucker.

What size microwave do you have?  I looked at a 700 but there is just enough room to warm a cup of coffee.  But hey that's about all I will use it for. Not a big fan of cooking in one anyway. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 10, 2010, 06:16:57 PM
We have an 800 at the cabin. It serves us well for warming things. Keep in mind that the rating you see in the ads is cooking power. Our 800 draws 1100 or so when working.   That may seem like a lot but when it's only for 2 minutes that is almost 37 watt hours which is like an 18watt lamp burning for 2 hours. It doesn't seem like so much when I look at it like that.  Maybe it's me.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 10, 2010, 07:06:40 PM
John, looking over that list of power loads you provided, I had a thought. You listed a pump that draws 1200 watts and a microwave that draws 1100 watts. (That was the power use on the microwave, or was it the cooking power?) Add those: 1200 + 1100 = 2300 watts. Or if the 1100 was cooking power the actual use is likely around 1650 (ours in the house is that), so 1200 + 1650 = 2850 watts. Unless you want to have to check if the pump is running any time you want to use the microwave (and hope it doesn't start while the microwave is in use), you need an inverter that will handle a load of 2300 or 2850 plus some extra in case there are some lights or whatever in use at that time.


Does that make sense?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Redoverfarm on March 11, 2010, 03:15:31 AM
Completely. Thanks Don
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 13, 2010, 07:06:11 PM
"With the Xantrex controller and the Xantrex inverter charger I should be set anyway, I was just toying with the idea of true sine wave becuase if we wanted a MW oven it might matter.....I think we ditch the MW idea *chuckle* and stick to the propane stove and cook fires!" 

I have a microwave and a Prosine (Xantrex) inverter.   I still use the franklin stove and the crock pot for cooking.  The most use the MW got is popcorn (it was a load test).  I heat rolls, melt butter, that's about all....My system is small for a "real" house and an MW is a wattsucker.

What size microwave do you have?  I looked at a 700 but there is just enough room to warm a cup of coffee.  But hey that's about all I will use it for. Not a big fan of cooking in one anyway. 

The inside of the MV oven is about 12 x 12 x 9 inches.

The little label on the back says .95 Kw, but just like someone on this forum said, it pulls 1100 watts (I have a Kill-a-Watt) when running.  I don't use it if the gen is on and unplug the fridge and the freezer till I'm done.  Almost not worth the trouble, but I don't always have a fire going with spring coming. 

My mother gave (force fed) it to me recently, and I felt compelled to make her feel good by reporting that it works, she cannot imagine life without one...and it does, just have to be sure nothing else is going to tax the system when its in use  [waiting] 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 13, 2010, 08:06:14 PM
The microwave uses a lot of watts but only for a short period of time, so it is not all that bad on the batteries if they are decent sized.  It all depends on the system though.

We have a 1250 watt inverter microwave.  It gets the job done fast.  I am still not convinced that it will kill me.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 13, 2010, 08:34:46 PM
I am still not convinced that it will kill me.... [waiting]

Only if you can figure out how to get your head inside and turn it on.    [crz]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 15, 2010, 02:44:26 AM
"The microwave uses a lot of watts but only for a short period of time, so it is not all that bad on the batteries if they are decent sized."

I'd love to have a battery bank that is double or triple the current size as well as 3 times as many panels.....its on the "list".
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on April 04, 2010, 06:08:28 PM
I am still not convinced that it will kill me.... [waiting]

Only if you can figure out how to get your head inside and turn it on.    [crz]


I heard it's hell on cats.... Note to self... do not dry Fluffy in the microwave....

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi302.photobucket.com%2Falbums%2Fnn110%2Fdragon_4_life_05%2FFunny%2Fcat_microwave.gif&hash=203a71a716e4a29c33f9c762055acb88)

The extra capacity is handy, considerations.

Nothing like a delayed response, eh? [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 04, 2010, 07:12:01 PM
Who is using what for 12v sockets?

I'm curious because I thought there was a typical household receptacle for 12vdc but um, not so much.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on April 04, 2010, 07:52:40 PM
I don't mess with 12v.  I invert everything and run 120 or 240 full sine.  Others have done some though I know.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 04, 2010, 08:03:05 PM
There is no such thing as an off the shelf quality low voltage DC receptacle or plug.

However a NEMA 6-20P configuration receptacle or plug makes a good choice. They are 20 amp 250 VAC rated and accepted by the NEC for use in DC circuits as long as there is no 220/240 VAC in the same structure.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.homedepot.com%2Fcatalog%2FproductImages%2F300%2F10%2F10dbd6ee-3725-43b9-8c30-eb4ce031f032_300.jpg&hash=c7e0ffb3d098253c62ca2630e747357c)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.homedepot.com%2Fcatalog%2FproductImages%2F300%2Fe0%2Fe0b41290-3e36-4e84-aae3-b571bdb43fdd_300.jpg&hash=043e5cb678b01beb88524242df88da31)

I use them.  I wire the 'vertical' connector + and the 'horizontal' one negative. That's with the units oriented as pictured.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 04, 2010, 08:24:23 PM
Thanks Don -- just saw that also at BackWoodsSolar.com

I'm not sure how much 12vdc stuff I'd need (or 24vdc for that matter) but want to plan to run some lines for it incase I find a use (or buy a chest freezer or fridge in 12 or 24vdc).

Just in the planning stages right now. 

Saw COSTCO has 6v Golf Cart batteries for $78 ea.  220 ah rating.  Didn't buy them becuase I wasn't ready but I wonder if maybe I should have just got them anyway.

Need to look around more though.  But Walmart doesn't carry them so that's out.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 04, 2010, 08:32:50 PM
And remember common wall switches areAC only.

My SamsClub has 210's for $68.   $9 core.   I pa7d no sales tax either as in NM everything used in PV or wind is tax exempt. Check on WA state.

Those are what I bought. They've been the same price for over a year. Don't buy too early as they age just sitting there.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 04, 2010, 08:34:37 PM
check...

http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=WA04F&re=1&ee=1
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 04, 2010, 08:38:22 PM
Thanks

Was playing with the PV calculator again and am wondering about something:

If you run a 24vdc bus / battery bank -- what do you do for 12vdc appliances?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 04, 2010, 08:53:13 PM
1.  Run a center tap to take off 12 VDC with a hot wire tap.   bad.

2.  Use a 24 VDC to 12 VDC converter. They are solid state, high efficiency, and usually work in either direction. 24 to 12 or 12 to 24. I have one made by Solar Converters.

http://www.solarconverters.com/product_frame.html     
Select  Battery Equalizers/DC Autotransformers

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 04, 2010, 09:46:53 PM
1.  Run a center tap to take off 12 VDC with a hot wire tap.   bad.

2.  Use a 24 VDC to 12 VDC converter. They are solid state, high efficiency, and usually work in either direction. 24 to 12 or 12 to 24. I have one made by Solar Converters.

http://www.solarconverters.com/product_frame.html     
Select  Battery Equalizers/DC Autotransformers



Great!  Thanks.

I'm thinking 24v might be better to use and have noticed some differences when using the calculator (which I found interesting).

My solar panels (by the way) will be 46 feet from the cabin when I plan to install the batteries (assuming I plan to put them where I've chosen).  The well head is 125 feet from the solar panels and over 150 feet from the spot where the batteries should be.

My cistern is 446 feet from the cabin corner (24 feet from battery corner) and about 50-70 feet above the cabin in elevation.

I'm thinking that the 46 feet from the panels to the cabin won't be a problem for 24v given that yours are MUCH further away.

I have planned a 400 watt system but if finances allow I'll probably do 600 watts.  If I did that I'd be running something like 54+vdc from the panels (3 in series) which again will have no problem with the 50 foot run I'm thinking.

I also plan to run 8 of the 220ah batteries.

With all my current calculations this is more then I need but I suspect that once we start using it we'll want more...we're human after all!

I also found some 60 watt CFL's that run about 12watts so that will help a bit too and I read that it's better to use more direct lighting to reduce the need for lots of overhead lighting.

My next thing to check is LED's.  I might like to install some DC LED's in the kitchen and in areas where reading might be done.

The bathroom should have a fan too so I have to add that but all in all I think we'll have a great system
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 05, 2010, 07:54:05 AM
I have a wire size calc if you to run some numbers. Need max amps, distance, voltage.....


We have no ceiling lights at all, mostly table lamps with 23 watt CFL... 100 watt incan equiv


We have provision for bath fan, but no fan. Window opens.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on April 26, 2010, 08:31:15 PM
I'm designing and installing my electrical and solar setup right now. I'm trying to work out what sort of panel to get - a "main lug" (without breakers on the power feed) or "main breaker" (with breakers).  The feed to the panel will be protected already as there will be a pair of linked 30A two-pole breakers forming a transfer switch between the inverter and a direct generator feed.  The cost difference isn't huge - I'm more worried about doing what's gonna work best and what the inspectors expect to see rather than saving $20.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on April 27, 2010, 03:26:30 AM
"I'm thinking that the 46 feet from the panels to the cabin won't be a problem for 24v given that yours are MUCH further away."

My panels are 75 feet from the cabin, and it is a 12v system, but the inverter is in the power shed (panels being on the roof of the shed) and the cables from the panels to the inverter are only about 8' long. 

I think where the distance issue comes up is with DC...not so much with AC....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 27, 2010, 05:28:21 AM

I think where the distance issue comes up is with DC...not so much with AC....

AC or DC does not matter.
Long wire runs become a concern with higher loads (amps or watts) running on low voltages. Powering a 1200 watt device on 12 volts, AC or DC, requires heavier wire than the same load on 240 volts, AC or DC.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 27, 2010, 05:35:09 AM
I'm more worried about doing what's gonna work best and what the inspectors expect to see rather than saving $20.

I like to think of the electrical as being made of two parts; the regular AC portion from the main service panel into the rest of the cabin/house and the alternative power portion. That would mean there should be an AC mains breaker in the main service panel.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 10, 2010, 08:40:07 PM
We are finally nearing the point that we will be buying all of our solar power stuff and this is what I'm contemplating:

1 -- it is most likely we will use the cabin on weekends only with maybe 2 or 3 one week trips per year.  Thus a large store of battery power may not be required.  So 6 batteries should suffice if using the calculator is any indication.

2 -- 1500 watts is plenty of AC power for our application (I'm thinking 1000 watts would be adequate but couldn't find a decent inverter/charge in that range.

3 -- due to winter conditions and the possibility of low sun exposure due to trees and the north west climate (actually we probably get 275-300 days of sun there but it can also be cloudy for a while) and the desire to possibly run the well pump longer or use the heater on the composter 600 watts is more desirable then 400 watts -- this gives us better charging in low light conditions.

So this is what I am thinking of doing:

3 SUN A-200-fa3 (11.05imp) panels in series (600 Watts)

6 Costco 220ah Golf Cart batteries
SUN-1012 Sinewave Inverter (if it will work but I think it should)
http://sunelec.com/index.php?main_page=product_info&cPath=6_40&products_id=788

And the Xantrex C40 charge controller.

That puts me around $2000 :)



Title: Re: OFF GRID POWER; various thoughts on...
Post by: NM_Shooter on May 11, 2010, 05:18:41 AM
Something to keep in mind when designing the system, is that many of the electronics (inverter, DC-DC converters) consume electricity even if you are not applying them to a load. 

Note the Sun 1012 inverter... it has a MAX efficiency of 85%.  This is almost always calculated at full output power.  So if you are using a full 1000 Watts, you are burning 150W just to run the inverter.  Same with DC/DC converters.  There is a quiescent power draw for all of these devices, even if you are not using the power that they are putting out. 

If possible, find a way to supply power to these converters only when you need to use power.  Many of them have an enable input that allows you to turn them on and off. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 11, 2010, 05:51:10 AM
That inverter does have a Loading Sensing (Power Saving)mode listed in the specs. That means it can be set to put itself in a standby mode. What they do not list is the power used while in standby. They do list 150 to 220 watts next to the Loading Sensing (Power Saving) line. That seems to be very high. My Outback will do it's standby thing and be using 24 watts while waiting. It will sense down t0 something less than a 3 watt load to go out of standby to working. It would seem that the Loading Sensing (Power Saving) feature of the Sun may not be very useful.

It would be nice to be able to get a download of the manual someplace. Perhpas it would explain the Loading Sensing (Power Saving) better. Another thing that would be good to know is is there is a connection point to have a remote on-off switch for the inverter. I have one with the Outback and a cheap Cobra I used to have had provision for one as well, though I never used it.

It's nice to see the charger built in, but it would be nice to see if it was capable of equalizing. The spec sheet lists 2 modes, so I'd guess that could mean no equalizing, but that's a guess. . Again it would be nice to read a manual.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 11, 2010, 06:51:39 AM
That inverter does have a Loading Sensing (Power Saving)mode listed in the specs. That means it can be set to put itself in a standby mode. What they do not list is the power used while in standby. They do list 150 to 220 watts next to the Loading Sensing (Power Saving) line. That seems to be very high. My Outback will do it's standby thing and be using 24 watts while waiting. It will sense down t0 something less than a 3 watt load to go out of standby to working. It would seem that the Loading Sensing (Power Saving) feature of the Sun may not be very useful.

It would be nice to be able to get a download of the manual someplace. Perhpas it would explain the Loading Sensing (Power Saving) better. Another thing that would be good to know is is there is a connection point to have a remote on-off switch for the inverter. I have one with the Outback and a cheap Cobra I used to have had provision for one as well, though I never used it.

It's nice to see the charger built in, but it would be nice to see if it was capable of equalizing. The spec sheet lists 2 modes, so I'd guess that could mean no equalizing, but that's a guess. . Again it would be nice to read a manual.

I've requested more information.  My thinking was that the cost is so much less then comparable inverters by Xantrex etc that it might be worth the expense to try it out and see how it lasts.

It's possible it will be junk and need to be replaced in a year or two but then who knows really and at about $500 cheaper.....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 13, 2010, 06:31:58 AM
No reply -- I've had this problem before :(  I hate it when people don't reply.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on May 14, 2010, 06:21:12 AM
I'm trying to decide on what's the best way to connect my solar panels to my 12:12 standing seam (clip-style)  metal roof.

The obvious way is to use the Unirac standing seam clips (http://www.unirac.com/pdf/ii220.pdf) but the guy who is selling me my system advised against them as they are fiddly to install.  Given our 100psf snow loads, it also seems somewhat lightweight of a connection.

The alternative is to use a Unirac rail system (http://www.affordable-solar.com/unirac.smr.stuff.htm), which has L brackets to connect the rack to the roof (#6 on the diagram).  Apparently I can just screw through the roof panels into the framing with lag screws and caulk (or butyl tape??) in the hole and under the bracket will make it waterproof.  My worry here is that the movement of the metal during hot/cold cycles will lead to water leaking through the penetration and/or buckled roof panels.

Does anyone have any experience with either of these approaches?  Any opinion on what would work best?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 15, 2010, 06:41:06 PM
I meant to comment sooner but got side tracked.

Was eliminating all those holes that you'd have with a ribbed panel roof one of the reasons you selected standing seam metal? If so it seems a shame to drill even a few holes to mount the rail system.  On the other hand there would not be many holes and the use of self sealing butyl tape would go a long way to help prevent problems. Fasteners with synthetic rubber washers tightened properly (= not too tight) are a must.

Another thought of mine. Panels need to be spaced high enough off the roofing to allow for good air circulation behind the panels. As the panel temperature rises their output falls. Most panels manufacturers should be able to supply that info. It becomes even more important to ventilate the panels properly in warmer/hotter climates. Almost any knid of a roof will radiate a lot of heat  around the panels elevating the local microclimate temperature.

The panels, being dark colored, get hot anyways. Restricted air circulation can make that worse. On a bright sunny day the panels can get hot enough to be uncomfortable to touch.

Something to keep in mind..

(someplace I have (had?) the typical highest temp a panel in full sun can reach on a roof. It's higher than one might think. I can't find it though.   ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on May 18, 2010, 10:04:47 AM
Come-on Don! Tell him to put them on a top of pole mount and be done with it! It is the only sane way short of what the trogledite did. d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 18, 2010, 10:47:04 AM

Yeah Dave, poles are actually king in my book.    :D  I was thinking of expanding on the original thoughts, but I was rushed and concerned my response with the original roof question. I do like poles a lot more than roofs though, for PV panels, no doubt on that.

No scrambling on the roof required.
No penetration problems (with the roof)
Excellent circulation of air around panels.
Easy to adjust the angle, see my quickee adjuster with the month positions marked.
         http://countryplans.com/smf/index.php?topic=2335.msg97225#msg97225 (http://countryplans.com/smf/index.php?topic=2335.msg97225#msg97225) scroll down one image
          I am happy with the way that turned out. 1x1, 11 gauge (1/8" for those who don't do metal gauges) steel tubing
Easy to adjust left-right to pick the best sun orientation line.
On roof panels seldom have perfect sun orientation lines.
Easier to clean when necessary. I have a long handled (extended with PVC pipe) broom and a long handled mop.

Buy old drill pipe. I got 4" ID 1/4 inch wall quite cheaply, compared to new. THe Uni-Rac mount is sturdy and well made, easy to mount the panels to. I added my brace arm for two reasons, ease of adjustment to as a wind brace.

Personally, I would not want to have to access panels, or anything else, on a 12:12 roof if I didn't absolutely need to. As a last factor, a special GFCI may be code required for panels on a metal roof. Not sure if that in for Grid Tied only or if for Off Grid as well? I'd have to check in that.

Ground level racks are also usable in some place.  



Dave knows a little bit about solar.   ;)     http://www.sierratel.com/offgridsolar/ (http://www.sierratel.com/offgridsolar/)


Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on May 18, 2010, 12:05:37 PM
In retrospect, pole mount sounds good.  Or, more to the point, working on a 12:12 roof sounds anything but good!  Unfortunately I've got a lot of 100ft high trees on my lot and only two open areas - one where I put the house (positioned so the S facing roof gets the most Sun!) and one 200ft from the house right on the road (if you can call our dirt track a road).  I guess I could put something by the road, but it would definitely distract from the otherwise wilderness feel of the approach (and would be more likely to be stolen).  Cutting down trees is also an option, but it would be hard to clear out enough space without changing the feel of the lot.

A pole-mounted system would also need to be pretty solid (or very easy to tilt) as we get a lot of snow (100 psf snow load).

Re the thermal issues - I'd think there should be pretty good circulation thanks to convection on a 12:12 roof.  There has to be at least an inch of space due to the seams, and there should be plenty of temperature differentials to get air moving.  And the roof itself has an inch of ventilation underneath it too.

I was planning on using a GFCI on the panels as my supplier (Sierra Solar - very helpful company) said that I'd need one.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 18, 2010, 12:24:38 PM
 Unfortunately I've got a lot of 100ft high trees on my lot and only two open areas - one where I put the house (positioned so the S facing roof gets the most Sun!) and one 200ft from the house right on the road

Trees up to 75 feet with us. Same sort of situation. That's why our cabin is where it is and the panels where they are; 300 feet away. Works well, but it needed all that copper wire (#2AWG) and conduit.

The Uni-Rack site gives wind loads on their model of racks, not sure about snow. The panels would have to be raised enough to allow for clearance height with all the snow that slides off. Our experience has been that the snow has little problem sliding once the sun comes out. If we;re there at the snow time I usually snowshoe down to them and brush them off. I keep the broom and washers tied vertically to a nearby tree rather on the ground so I can find them in winter.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: intelijoc on May 19, 2010, 09:36:52 AM
I'm spitballin the idea of setting a solar array on my vacant property ( currently structureless).
Will I first have to connect to the "grid" utility company?
If I did this, would I be able to sell electricity back to the utility company for cash?  Or would they simply issue credits to an existing account.. am I making sense?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 19, 2010, 10:08:48 AM

If your possible building plans include being grid tied you should check with the local power company before doing anything. The power company we use at home has a great plan for grid tied residential customers. With them it's possible to select from a plan that just gives credits to your account when you produce more than you use. They have another plan where they will pay credits by monthly check. The company we could connect up in the mountains by the cabin has no such buy back offerings at all at this point. So it not only varies state to state, but it varies company by company.

Being grid tied can save you the cost of the batteries needed to be fully off grid. That has the drawback of leaving you in the dark when their side fails.

Note that even if your location is remote enough to be lenient on building codes, or maybe no codes at all, if you connect to a power grid, they will almost certainly have rules that need to be met, including minimum equipment standards. They may also require a professional electrician for part or all of the PV installation and actual grid connecting.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: intelijoc on May 19, 2010, 11:15:17 AM
I did not know about the minimum standards, rather; never considered it. Sounds like a permit may be in the future.  I'm a pole away from power.  Can I get power dropped to my parcel, (without ant site plan or building plans?)say to use for temporary 3-4 weeks stays in a travel trailer. I could always boondock
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 19, 2010, 11:35:44 AM
Once again that is sometimes a local thing. To get a permanent hookup here in the suburban area one needs a building permit first. But up in some more rural areas here you can get a power pole and meter by simply asking and paying for it. There will likely be a monthly fee, just for being connected, even if you do not use power. Ask on that. If they have a good buy back PV program the energy made when you are not there could pay for that and leave money left over. But as I pointed out the way the companies do that is all over the place, good to bad and worse.

G/L   It would be nice to have checks coming in the mail when you aren't there.  :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: intelijoc on May 19, 2010, 12:52:45 PM
Checks coming in the mail when I'm not there would be ideal.  I'm doing a recon trip out there in July. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 19, 2010, 01:03:08 PM
If you know the name of the power company you might be able to find all the info online. My city company has everything available online, all the rules and docs that are needed. Then again the mountain coop has nothing.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: intelijoc on May 19, 2010, 05:04:30 PM
That was my heading: online search, phone calls and documentation.  The July trip is for information gathering from a real world perspective.  I like to be hands on and meet/greet as many people on the mountain as possible.  The owners behind my parcel have spent considerable time clearing deadfall,etc.  I want to meet them. I also discovered 2 lots with driveway, septic and electric for sale on my road.  FWIW- one piece or land for sale has the drive, septic and electric with a log home kit bundled and sitting there. It's been like that for at least 2 years- the bundles of precut ready to go logs laying on the property at 10,000ft-snow, and all the elements.  I actually remember seeing this debacle in the summer of '07 so that's pushing 3 years.  What a shame.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MikeOnBike on May 20, 2010, 08:54:52 PM
Hope this is the right thread for this.

We plan to start a 20'x32' cabin this summer.  The first task is to build a 10x12 shed to camp in and store materials and tools.  We will eventually have solar power and the solar panels will either be on the shed roof or next to it.  The shed is directly behind and to the north of the cabin.  Both the shed and the cabin will have have their roof ridge oriented east/west.

We are at ~43.5deg lat.  Our sun altitude alternates between 23deg and 70deg.  I need to make sure that the solar panels on the shed roof will not be in the shadow of the cabin.   I need the angle A between the ridge of the cabin and the eve of the shed to be less than 23deg.  Any more than that and the solar panels will be in the shadow of the cabin in the winter.


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Flh6.ggpht.com%2F_YXA0QhaNyCg%2FS_YPixwg6TI%2FAAAAAAAAD2c%2F5EfZ0sQHyf0%2Fs800%2FSunAngleCalc.JPG&hash=c2a17d45c077e8029d9ff58537b6532d)


First a few numbers to work with:
Cabin to Shed Distance  33ft.
Cabin Depth to Roof Ridge 10ft.
Cabin Base Elevation  0ft.
Shed Base Elevation   3ft.
Cabin Max Height    24ft.
Shed Height to Eve  10ft.

We can use a little trigonometry to find the angle A between the cabin roof line and the shed eve.  The tangent of an angle is defined as the opposite side divided by the adjacent side.

Op
---- = tan(A)    The inverse tangent or arctangent will give us the angle A which is the slope from the cabin ridge to the shed eve.
Adj

The cabin height is the base cabin elevation + the max cabin height or 0 + 24 = 24
The height of the shed eve is the base shed elevation + the shed height to the eve or 3 + 10 = 13
The Opposite side is the difference between these two or 24 - 13 = 11

The distance between the ridge line of the cabin and the shed is the distance between the shed and the cabin + the cabin depth to the roof ridge or 33 + 10 = 43.  This is the Adjacent side of the triangle.  Now reach for a calculator with trig functions or find a web calculator.

11
--- = tan(A) = 0.255814   The arctangent or inverse tangent of 0.255814 is  atan(0.2555814) = 14.34 deg.
43

14.34 deg is less than the minimum winter sun angle of 23 deg at my location so I don't have to worry about a shadow on my solar panels in the winter.

Hope this might help someone with a similar situation.  It should be useful if you have a cabin or trees due south of your solar panels.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on May 21, 2010, 05:33:59 AM
Mike,
That was a nice post and I am sure helpful. One of the other ways is basically using posts and being at the site during the winter solstice. Kind of the no math version. I think it is best to always live thru a year at the site! It is amazing how many different things will occur to one. Hey Don! c*  What time is happyhour?

Oh yea, the reason I posted was to tell you guy's that some of these long runs of cable we have to do, will be getting easier. Magnum energy has a 250V charge controller out this summer and there is another that I can't talk about that will enable some very, very long runs with small wire.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 21, 2010, 05:35:11 AM
That's cool. Good of you to share this trig lesson. It goes to show there are good reasons to pay attention in class.   :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: intelijoc on May 21, 2010, 04:32:30 PM
I've done due diligence part 1.  Contacted county planning, power company and mapping.  Seems like the bottom line is to get power on my property I need a rought site plan, driveway, septic and well and an engineer to coordinate all.  Sine the lots is less that 2 acre it need to be wetlands free.  What I did not ask was if I could get power dropped to the lot for use with a travel trailer- yikes!  I want to be able to use my place sooner than later.  It may be 5-7 years before I have the financial bump ++ to get a permanent structure built.  I was considering extended stays.  The solar was a way to maybe get cash when I am not present. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on May 24, 2010, 11:50:36 AM
14.34 deg is less than the minimum winter sun angle of 23 deg at my location so I don't have to worry about a shadow on my solar panels in the winter.

I was just thinking about similar things myself.  One thing to watch out for with this calculation - you need to have an angle that's quite a bit less than 23 degrees (as you have), otherwise you'll get Sun in the middle of the day but only for a minute or two!

We're at a latitude of about 39.5 degrees north, so I think the Sun gets up to more like 27-28 degrees mid winter.  Looking at some graphs (http://www.gaisma.com/en/location/reno-nevada.html) I found on google, if you have a 20 degree vertical angle to an obstruction, with at least 30 degrees each way horizontally to the SE and SW, then you get Sun from 2 hours before midday to 2 hours after.  It looks like this'll probably cover almost all of the solar energy you're gonna get at that time of year.  Time to get out the inclinometer I bought from John (http://www.jshow.com/sunkit/listings/7.html), stand on top of a step ladder and see if Don's suggestion of pole mount panels is gonna work...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MikeOnBike on May 24, 2010, 06:58:52 PM
David, you have a good point.  My model is a fairly simple representation.  It does not consider the varying angle of the sun from sunrise to sunset.  It is only 2 dimensional, a snapshot in time. 

If we use the middle 5 hours of the day, the sun at our site alternates between 15 deg. and 23 deg.  I can probably get by with making sure the angle between the cabin ridge and the shed eve is at least 15 deg.

Since the angle in my example is 14.34 I will just barely be clipping the panels with a shadow during that 5 hour window.  At my site the 4 hour window that you suggest is 18 deg. so that period would be shadow free.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 13, 2010, 10:04:25 AM
Having considered my dilema of the well being located too far from where I plan to install my battery bank (about 150 feet) I've thought seriously about buying a Costo 60 watt system which includes 4 15w panels, a 7am charge controller and 200 watt inverter.  It's $269 and a deep cycle Marine battery with 85 amp hours of reserve runs about $62.

My thought is that I can install this system on the small pump house I plan to build and put a switch in it so I can turn on the pump easily (today I have to clamp the battery to the pump using the alligator clamps coming out of the well head).

What do you all think? 

I plan a 600 watt solar system for the cabin with 1000 watt inverter but thought perhaps this would be a good second system for the pump and perhaps someday a small shed can be put there also with some lights running off the inverter (or 12v).  Also I was thinking I could use the inverter to charge my Ryobi drill batteries.

Thoughts?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 13, 2010, 02:07:43 PM
OK I took the plunge and bought the Costco system and a Deep Cycle 12v battery (85 AH) for the well.  Once home I tested it all out and found each panel kicked out ~20-22 vdc and the Charge controller ran about 20vdc (it tells you 5-10% of panel output).  The panels are in parallel and produce a combined 60 watts in optimal conditions according to the booklet that comes with it.

I hooked up the battery which was running ~12.5v and in about an hour the controller kicked off.  Which, according to the booklet happens at 14.2v.

When we get to the property I'll build a small pump house to house the battery and controller as well as the inverter and set up a station to charge a second 12v battery (I like a back up battery and keep my old jeep battery for the well) and a station fore the Ryobi charger (need to check wattage).

I'll let you know how this works out for us but I'm hopeful we can run the well pump at least a couple hours a day and not have to use the generator any longer to charge a battery to pump.

We used to run a trickle charger (2amp) during the day while working on the cabin and then hook it up for a few hours (the battery) on the well -- then repeat in a couple days.

This last time we got busy and forgot to charge the battery for the well and the cistern ran pretty low (pressure at the spicket was way down)...so I need to get 1000 gallons (or close to it) back into the cistern and keep it up there for the summer months of cabin work.

It's VERY nice having ice cold water in the summer!

This investment was ~$330 and I'm hopeful in the end that it will save generator usage and gas as well as the need to plumb electric from the cabin solar (12vdc) to the well.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MikeOnBike on June 14, 2010, 07:47:42 PM
OlJarhead,

I'm really interested in how this works for you.  I have a similar situation.  Our main cabin's solar/battery is about 250ft from the spring.  I was thinking about the same kind of setup you are using.

We will have three cabins on our property.  Mine is the furthest and highest elevation gain from the spring.  I'm about 1200ft. away and 150ft. above the spring.

I'm considering this pump to give me a couple of gallons/min to fill the water tanks in each cabin.

Solar Pump
http://www.firemountainsolar.com/waterpumps.html#solarslowpump (http://www.firemountainsolar.com/waterpumps.html#solarslowpump)

Elevation/GPM Chart
http://www.firemountainsolar.com/pdf/solarslowpump.pdf (http://www.firemountainsolar.com/pdf/solarslowpump.pdf)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on June 14, 2010, 09:29:13 PM
In retrospect, pole mount sounds good.  Or, more to the point, working on a 12:12 roof sounds anything but good!  Unfortunately I've got a lot of 100ft high trees on my lot and only two open areas - one where I put the house (positioned so the S facing roof gets the most Sun!) and one 200ft from the house right on the road (if you can call our dirt track a road).  I guess I could put something by the road, but it would definitely distract from the otherwise wilderness feel of the approach (and would be more likely to be stolen).  Cutting down trees is also an option, but it would be hard to clear out enough space without changing the feel of the lot.
After wandering around the lot for a while I've found a point by the driveway that's a fair distance from the "road" and that has a decent view of the Southern sky.  The trees to the South are about 25 degrees above the horizon, so it's not gonna get much sun December and January, but I guess that's what backup generators are for.  What's more I can put the generator/inverter shed and propane tank near by, and run LPG and 240V side by side for the 200' to the cabin.

This is good news, as I thought my cabin was facing almost South, but it turns out it's facing roughly magnetic South, not true South.  What's more it's the wrong side of magnetic South too, so it's almost 25 degrees off.  I guess it's a good idea to check the magnetic declination before you have the whole cabin built....

So goodbye scary chicken ladders and fussy roof clips, hello solid and dependable schedule 80 steel tube.

Now all I need to do is find out how much pole and concrete I need to hold up 50 sq ft of panel centered 10ft off the ground in a fashion that the building inspectors don't object to and the snow won't destroy...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 17, 2010, 11:30:28 AM
Now all I need to do is find out how much pole and concrete I need to hold up 50 sq ft of panel centered 10ft off the ground in a fashion that the building inspectors don't object to and the snow won't destroy...

UniRac, manufacturer of pole mounts and so forth, has info on pole sizes, depths, etc for various combinations of panels and expected wind loads. Sorry, I have no link at hand but have a printed brochure someplace.  Google UniRac Albuquerque
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Bob S. on June 17, 2010, 06:02:02 PM
I have been watching this topic for guite a while. And it has accured to me that you could build a coverd patio/out door kitchen ect. with a shade made from solar panels. Not protected from rain but protected from the sun, should work well.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 17, 2010, 06:43:00 PM
Sure. The Intel Fab here has an array that is the shade roof for parked cars, I believe.

(They have it I'm not sure on the parked cars....   Car shades are common in the SW)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 19, 2010, 01:52:18 PM
OlJarhead,

I'm really interested in how this works for you.  I have a similar situation.  Our main cabin's solar/battery is about 250ft from the spring.  I was thinking about the same kind of setup you are using.

We will have three cabins on our property.  Mine is the furthest and highest elevation gain from the spring.  I'm about 1200ft. away and 150ft. above the spring.

I'm considering this pump to give me a couple of gallons/min to fill the water tanks in each cabin.

Solar Pump
http://www.firemountainsolar.com/waterpumps.html#solarslowpump (http://www.firemountainsolar.com/waterpumps.html#solarslowpump)

Elevation/GPM Chart
http://www.firemountainsolar.com/pdf/solarslowpump.pdf (http://www.firemountainsolar.com/pdf/solarslowpump.pdf)



Just got in but the first trial has been a good one, albeit a learning one!

First off, it rained almost the entire time!  I'm not sure how much that hurts solar panels but I DO know that it's a calculation that you must take into account when designing a system.  Cloud cover means poor performance.

So, having experienced rapid charging in full sunlight (rapid is a subjective term of course) I was surprised at how slowly the panels charged the battery in cloudy rainy weather.  But not really ;)  I was actually surprised how well they did despite the clouds though I did move them to track the sun to maximize the solar power generation.

I hooked up the 85ah deep cycle battery to the well when we arrived and began pumping water right away.  Once we had 26 gallons in the tent trailer I let the pump run until the battery dropped (without panels) to 12.3v.  I then shut it down.

The next day I assembled the panels and let the battery charge to 12.9v by making 3 adjustments to the panels -- 7:30am they faced East (to catch the morning sun) and by about 1PM I faced them South and finally around 5PM I faced them West -- however, it was raining and pretty dark with clouds most days.

I pumped the well enough to drive the battery down to 12.3v again on Wednesday and it really down-poured!  The weather was foul but the battery seemed to almost hold under the strain as long as the panels faced the sun.

Thursday after letting the battery hit 12.9v again I let the well pump and drive it down to 12.4v again then disconnected  it.  I did notice however, that in light clouds and almost sunlight the battery hovered around 12.4v as long as on the charge and didn't seem to drop lower.

On Friday the sun poked out a little more and the battery climbed about 13v for the first time :D  It was working!  I pumped more water and continued to track the sun with the panels.

I've now decided that a lazy susan would be a good way to track the sun -- just assemble on big enough to sit on top of a well house and then rotate it during the day to catch the sun...after all, why spend $1000 on a tracking pole for a $269 set of panels?

All in all I'm impressed with how well they worked and am certain that if the sun were out all day I'd have a full cistern.  As it is it rained so much that when the sun finally did come out it was nearly a shock!  Most days were in the 50's (is this really June?) and very cloudy and wet.

Last night it dropped to about 39 degrees and was clear....and we came home today.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: davidj on June 21, 2010, 03:46:33 PM
I have been watching this topic for guite a while. And it has accured to me that you could build a coverd patio/out door kitchen ect. with a shade made from solar panels. Not protected from rain but protected from the sun, should work well.
This was actually our second-from-last plan - a "solar gazebo".  I was gonna build a timber-frame 10'x12'x10' structure, put a steel tube across the middle of it and mount a tiltable panel.  In Summer we'd drop the panel flat and put the picnic table under it.  In winter we'd rotate it near vertical and it would catch the low Sun and shed snow (and not be in the way at that time of year - "hanging out in the yard" isn't really gonna happen when there's 4' of snow on the ground!).  It all fell apart when I realized that "cabin South" and "true South" were actually 25 degrees off from each other and hence it wouldn't get as much Sun as I'd hoped.

The Sierra Nevada brewery in Chico also has a parking lot shade structure made of solar panels.  But I prefer their "recycling" - the brewing mash gets sent to a local cattle farm in exchange for (very tasty) steaks which they server at the restaurant!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 22, 2010, 07:53:10 AM
http://www.theinverterstore.com/the-inverter-store-product.php?model=pwric150012s#

Found this today and wanted input.  It's a little more then the inverter/charger I found on the sun site but this one has more information on it and is a 1500 watt inverter.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 22, 2010, 02:16:06 PM
SunElectric tells me they will remove the batteries and inverter from the 615 watt system and sell it as a package including discount.

That system is so close to what I am building that I'm thinking it might work for me.  Then I go get the Costco batteries and a different inverter and I'm in business :)

We're so close to making this buy that my fingers are getting itchy!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 23, 2010, 05:44:26 AM
SunElectric tells me they will remove the batteries and inverter from the 615 watt system and sell it as a package including discount.

That system is so close to what I am building that I'm thinking it might work for me.  Then I go get the Costco batteries and a different inverter and I'm in business :)

We're so close to making this buy that my fingers are getting itchy!

I should note that I'd like the Xantrex inverter but can't afford it.  Perhaps someday I can afford a much better inverter but with me not working I've got to be cautious of the bills in order to complete the cabin.  So I'm looking at saving $300-$400 on the inverter with the hopes of someday getting a True Sine wave inverter in the future (when I get work etc).

In the meantime, this package is basically what I had been trying to put together to begin with so it might work out.  I don't save much money on doing cables myself but hey, every little bit counts!  The only other area might be the boxes??  I've been looking at Home Depot and wondering if I could make some of the Square D's do the job.  Would save me a couple hundred if I can I'm sure.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 23, 2010, 11:39:11 AM
Ok Here goes!  I hope I've not beed too rash!!!!  But I was convinced to go a different route on my inverter/charger and decided it made sense.  Not being an electrician I'm not 100% certain but it seemed like a good idea...so here goes:

55 AMP Charger: http://www.theinverterstore.com/the-inverter-store-product.php?model=chg-dls-55
2500 watt Modified Sinewave inverter:  http://www.theinverterstore.com/the-inverter-store-product.php?model=pwrinv2500w-top-rgb

The thinking is that lower priced inverter/chargers often only have 3amp chargers which could take a week to charge up a 660ah battery bank (assuming the math is close to 660/3 and the batteries are basically dead and you've got 220 hours of charging to do :o ??? )  on the other hand this charger gives 55amps and should do the same job in 12 hours....my thinking is that I don't mind running the genny for 3-6 hours at a time if I have to but don't want to rely on it for days on end just to have to do it all over again in 3 days if the weather  is bad!

The inverter is modified sine wave but with 2500 watts is more power then I felt I needed.  On the other-hand it's got a lot of features and apparently AIM has been making them for over 10 years....let's hope I don't need the 1 yr warranty :P  But honestly, at $229 if it doesn't work out I can take a look at a xantrex with no charger on it in the future :)

I also ordered 3 205watt panels from Sun Electric plus boxes, lightning arrestor, breakers and some cables.

Next I'll get the batteries from Costco and make the battery cables and get with a friend to plan, prewire what we can, plan some more and then hopefully by the end of July we will be powered at the cabin! :D  [cool]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 25, 2010, 09:14:33 AM

55 AMP Charger: http://www.theinverterstore.com/the-inverter-store-product.php?model=chg-dls-55

I have had that exact charger for several years in the RV. I bought the optional IQ Smart controller for it. That allows the unit to switch between two rates of charge automatically. There's a plug/jack on the charger that allows one to change the rate manually. The only thing that charger does not do is an equalization charge. It's a well made unit. Mine was made in AZ, I think they still are.

http://www.iotaengineering.com/ (http://www.iotaengineering.com/)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 25, 2010, 09:47:05 AM

55 AMP Charger: http://www.theinverterstore.com/the-inverter-store-product.php?model=chg-dls-55

I have had that exact charger for several years in the RV. I bought the optional IQ Smart controller for it. That allows the unit to switch between two rates of charge automatically. There's a plug/jack on the charger that allows one to change the rate manually. The only thing that charger does not do is an equalization charge. It's a well made unit. Mine was made in AZ, I think they still are.

http://www.iotaengineering.com/ (http://www.iotaengineering.com/)


Cool :)  The one I bought appears to have a controller in it which allows it to adjust the charging rate from a bare trickle to full 55amps automatically.  So perhaps an updated version?

Either way it sounds like I've learned a thing or two from you Don! hehe even if subliminally!

Erik
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 25, 2010, 10:12:31 AM
Yes, they sell a model with the IQ built in.


Just a side note; same outputl Iota chargers can be paralleled to double the current output. They sell a plug in controller for that.

The Iota people were very helpful when I had several questions a few years back.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: NM_Shooter on June 25, 2010, 12:31:15 PM
Make sure to check the operating temperature range on your inverter!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 25, 2010, 12:48:34 PM
Make sure to check the operating temperature range on your inverter!
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FCabin%2FInverterandCharger.jpg&hash=ed96e9972b5bbaed41aa57d3af8238a8)
I'll go check but I thought it was something pretty extreme on both sides of the fence.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 25, 2010, 12:57:48 PM
Quote
# No load minimum operating temperature: -15 degrees Celsius
# Full load maximum operating temperature: 55 +/- 5 degrees Celsius (automatic shutdown)

The books says 30 degrees F to 150 F operating range.

Kinda surprising because running below 30 degrees will just keep it cooler.  Not sure why they would suggest that actually - though laptops have issues down there but that's more of a Hard Drive thing I suspect.

It sounds like I should probably install this in the wall below the service panel INSIDE the cabin.  I can bring in the battery cables to a Square D or similar box (cheapest one I can find) which I can insulate the back of with fiberglass and/or foam and then run from there to the service panel above it.

That leaves the Charger and batteries in the battery box outside.

Has the added benefit of making it harder to steal the inverter.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on June 28, 2010, 07:08:49 PM
Just a comment about batteries.  I just went through the spaghetti lines and checked all of my battery cells for specific gravity.  A good indication of bad cells.

About 6 months ago when refilling the batteries water I added EDTA - I found it at a chemical supply for mining and had read that it would chemically desulfate with some pretty good testing that I posted somewhere here earlier.

To my surprise, nearly all of the cells aside from 2 bad batteries, were over 1300 - top of the scale - and that has never happened before.  I had one marginal one - added EDTA and threw threw pulse charger onto it - it also came up to over 1300.  I have two that seem to have shorted cells, but not bad out of 12 batteries dating back to 2004.

I swapped out batteries to get 8 good ones running together - two sets of 4, and even using extra pumping, my power is better at night than it has been in ages.  I also have 8 new batteries in another bank so running 16 batteries - L16's right now.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 11, 2010, 03:45:29 PM
Went through my system today and did some diagrams etc but one thing I have to figure out still is where to install the Iota Battery charger (55a)?  I'm assuming that I can't run it in parallel with the solar power so need to figure out how to disco the solar when running the genny and Iota charger.

Otherwise, I'm pretty good to go :)  The 10amp cables I bought will be within spec for a 45 foot run from the panels to the PV box which will be mounted next to the load control box (not sure if that is what it's called -- it's the one with the main disconnect and connections to charge controller and inverter).

I'm planning something similar to what Don put in.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 11, 2010, 06:24:04 PM
I'm also looking at installing the panels in a fixed installation until I can afford something else.  So, here is my thought:

Build Carport Roof over Camper that we use on the Property and install Solar panels on a steel frame that I can tilt between 63 degrees in the summer and 33 degrees in the winter (we are at 48 degrees latitude and I read somewhere that you can add 15 degrees in the summer for more efficiency and subtract 15 degrees in the winter).  My thinking is to install two different length 'legs' to the top of the panel rack and stack the panels one above the other (so three panels laying sideways -- I'll draw it).

I'm hoping this will have the added benifit of being somewhat secure and even hidden a little from view at ground level).
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 11, 2010, 06:26:43 PM
I just hook it to the + and - of the batteries, OJ.

As long as you are using a proper charger the other stuff should take care of itself, just as multiple charging sources - wind , more separate solar etc. can be hooked to the batteries.

Now I use a welder for a charger - running 160 amps sometimes - haven't blown anything yet but I try to be careful and keep my overcurrent device handy.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fovercurrentdevice.jpg&hash=0a3fdbf565fe9164edd30f305e7ffd2c)

That should be steeper in the winter as the sun is lower - I guess that depends on where you are measuring your angle from.  About 45 degrees works pretty well for fixed.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 12, 2010, 06:36:11 AM
I'm also looking at installing the panels in a fixed installation until I can afford something else.  So, here is my thought:

Build Carport Roof over Camper that we use on the Property and install Solar panels on a steel frame that I can tilt between 63 degrees in the summer and 33 degrees in the winter (we are at 48 degrees latitude and I read somewhere that you can add 15 degrees in the summer for more efficiency and subtract 15 degrees in the winter).  My thinking is to install two different length 'legs' to the top of the panel rack and stack the panels one above the other (so three panels laying sideways -- I'll draw it).

I'm hoping this will have the added benifit of being somewhat secure and even hidden a little from view at ground level).

Got them backwards.  63 degrees in Winter and 33 Degrees in Summer.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 12, 2010, 06:38:50 AM
I just hook it to the + and - of the batteries, OJ.

As long as you are using a proper charger the other stuff should take care of itself, just as multiple charging sources - wind , more separate solar etc. can be hooked to the batteries.

Now I use a welder for a charger - running 160 amps sometimes - haven't blown anything yet but I try to be careful and keep my overcurrent device handy.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fovercurrentdevice.jpg&hash=0a3fdbf565fe9164edd30f305e7ffd2c)

That should be steeper in the winter as the sun is lower - I guess that depends on where you are measuring your angle from.  About 45 degrees works pretty well for fixed.

So you just connected your charger straight to the battery buss?  Thinking about this I'm wondering if when you begin charging the Xantrex C40 detects that the batteries are 'charged' and backs off?  Also the Xantrex is supposed to be able to protect the panels from power being backfed into them at night...I'm wondering if that works the same way when the charger is on?

I saw this today: http://www.interlockkit.com/squareDmain01.htm -- seems like it's $150 for a $5 part???  Probably approved by some bureaucrat but I'm thinking I could make the same thing for a few bucks...anyone make there own?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 12, 2010, 07:51:56 AM
I called Xantrex customer support and this is what I was told:

"The Xantrex C40 Charge Controller will sense the voltage of the buss at 13.6vdc (supplied by the Iota) and shut down charging from the Solar Array as it will detect a 'fully charged' condition.  It should be fine in this application and I don't see any reason it would be damaged."

So seems like Glenns idea will work nicely :)

I may toss in a break (60amp ought to do it I think) for the Iota charger so I can disconnect it positively when not in use but otherwise I think directly wiring to the battery bank is the answer!  WhooHoo!

Now to get some wire, some batteries and start powering our cabin....oh wait, first things first, Chimney, Roof, siding and wiring THEN bring the solar and install....*chuckle* if I could do it all in one week I'd so be there!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 17, 2010, 08:43:25 PM
The DC current can makea much longer arc than an AC current normally would hence only a few of the smaller AC breakers work on lower DC loads.  So therefore the higher price tag for the breakers.  There are some battery disconnect switches that may not be approved for solar but would be effective to their rated amp level - not automatic though.

I have been doing the welder charging in conjunction with the inverter charger for around 6 years now - many of the same 2004 batteries still in my bank - I haven't blown them yet.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on July 21, 2010, 05:42:10 AM
Glen is right, of coarse! The DC arc also tends to burn thru the contact much faster! An AC arc is reversing polarity and the contact area can be smaller and of a lower quality alloy. The Square D type QOU line is what you want for low voltage solar. It has a din rail mount to allow you to fabricate your own panel or modify an existing. They also have wiring set screws on both input and output. They are harder to find than the type QO. There are series tricks for QOU's to get them over 100vdc also.

It hurts to hear about "blowing batteries" but you are that kind of guy! How about the inverters Glen? They are getting harder to fix (no parts) My repair guy in Oakland retired so I am looking for spare SW's. A replacement XW is near $3K now. It is all I would use though if pushed that way.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 21, 2010, 08:29:15 PM
I haven't had any problem with the inverters at all, Dave, but in constant current, the welder voltage drops to some rate near but above the batteries.  24v systems and DC welders (on Constant Current)  are a pretty good match.  The massive amount of batteries buffer the charge current from the welder protecting the inverters.  The problem with the DC welder is that it is not a tapering charge thus as the batteries continue to come up in charge, the welder still keeps pumping full amps into them therefore I monitor the charge on meters and only do it when I am there to monitor them.

There is a DC, Constant Voltage mode but it is a bit more scary as if the batteries are low it could put up to 300 amps into the batteries as the amps go full blast to bring up the voltage.  I prefer CC and have spent a lot of time monitoring with meters to learn how to do it. I started around 60 amps and worked my way up to what I feel is a good combo of Inverter charger to provide tapering charge and welder at 160 amps for horsepower in bulk charging.   Use meters and understand the system and what you are doing if you are dumb enough to try to do what I am doing......    By that I do not mean to imply anyone is dumb.... I mean that a screw up could have serious consequences even for me...... [ouch]     :)

Without a pretty good knowledge of what is going on and what you are doing I am afraid I would have to say, Don't try this at home, kids...... [waiting]

Considering that I am charging 16 - L16 batteries, I have a bit of room to play.  To equalize I am planning to disconnect sets of batteries and do them offline.  Sparks are a big no-no around heavily charging batteries.  They could fly all over spewing sulfuric acid and plastic shrapnel on anything within reach of their hydrogen/oxygen explosion.

I haven't screwed up and blown anything up on my system that I recall, but I do take great care to keep sparks away from the batteries.  Connections are done at the other end of the cables away from the batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 24, 2010, 08:19:39 AM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FCabinSolar.jpg&hash=2aa11b1bc60a5c47eba43b25a9745bd5)
This is my proposed cabin solar power system.

Thoughts?

Note:  Done in visio, the bus bars don't show actual connections.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 24, 2010, 03:43:04 PM
Nice job -I was too cheap to buy Visio- :)

A couple things come to mind - make sure the charge controller you get is capable of taking the higher voltage from the panels and dropping it to 12 volts - not all controllers will do that.  BZ MPPT will.

Some of the automotive modified sine wave inverters commonly only last about a year -

Possibly a Harbor Freight one with their added warranty could be a solution as I have had them fail in less than a year and some don't fail. [ouch]

If spending more then a good name brand inverter is best for reliability. 

I only use sine wave inverters for the house and limit modified sine (really modified square wave)  to automotive and field power uses.  I have blown up a lot of things that don't like modified (square) wave.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 24, 2010, 04:04:01 PM
Nice job -I was too cheap to buy Visio- :)

A couple things come to mind - make sure the charge controller you get is capable of taking the higher voltage from the panels and dropping it to 12 volts - not all controllers will do that.  BZ MPPT will.

Some of the automotive modified sine wave inverters commonly only last about a year -

Possibly a Harbor Freight one with their added warranty could be a solution as I have had them fail in less than a year and some don't fail. [ouch]

If spending more then a good name brand inverter is best for reliability. 

I only use sine wave inverters for the house and limit modified sine (really modified square wave)  to automotive and field power uses.  I have blown up a lot of things that don't like modified (square) wave.

Visio was a perk from my work :)  I didn't have to pay for it!  Or I wouldn't have it.

The Xantrex C40 is rated to take up to 125 volts in and kick out 12/24/48 as desired :)  Xantrex tells it's the right one for the job and will shutdown during auxiliary charging off the Iota.

I'd like a True Sine inverter but cost was a factor so I went with the AIM (American Inverter Manufacturing I believe) -- they tell me that's all they do but I don't recall the warranty.  However, for $200 I figure it ought to do -- one thing I wonder about is whether CFL bulbs will be OK with Modified wave?  They don't like dimmers and I wonder if the square wave might blow them -- guess I'll find out!

I mostly only intend to run small appliances (TV radio maybe a toaster) on it.  My neighbor runs Modified (has for 30 years) and tells me it will run a fridge and freezer and small MW but the MW will run slowly....if it gets me by until I can afford a True Sine Wave inverter I'll get a Xantrex probably :)

Got my batteries and was hoping you could tell me what you used to recondition yours (I know it's in here somewhere)....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 24, 2010, 04:48:04 PM
I have a pulsing charger that will recondition them if they are not too bad.

Best thing I did I think was to use EDTA to chemically break down sulfation.  There are methods draining - charging and refilling them, EDTA added in the make up water was enough to bring them back decent.

I think the Xantrex charge regulator is already a pulsing charger so it should work with the EDTA to stop sulfation.  I have a C40 but have not checked the input specs on it - got it before I studied up and added MPPT controllers.

My batteries from 2004 have been on the C40 since that time.  Most of them are still alive and well.

One thing I do know about the C40 is that it does have an equalization mode that is pretty decent so when you want to equalize at a higher voltage, set it to equalize and tune up the batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 25, 2010, 06:41:14 AM
I have a pulsing charger that will recondition them if they are not too bad.

Best thing I did I think was to use EDTA to chemically break down sulfation.  There are methods draining - charging and refilling them, EDTA added in the make up water was enough to bring them back decent.

I think the Xantrex charge regulator is already a pulsing charger so it should work with the EDTA to stop sulfation.  I have a C40 but have not checked the input specs on it - got it before I studied up and added MPPT controllers.

My batteries from 2004 have been on the C40 since that time.  Most of them are still alive and well.

One thing I do know about the C40 is that it does have an equalization mode that is pretty decent so when you want to equalize at a higher voltage, set it to equalize and tune up the batteries.

Thanks -- do you wait a few years to ad the EDTA to bring them back or is it something you run all the time now?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 25, 2010, 06:50:58 AM
I just added it this year with my oldest batteries being from 2004.  I lost one from 2004 and one from 2005 I think.  Possibly a bit of EDTA added earlier may have prevented that loss.  The two had shorted cells and I haven't recovered them - but I just pulled them out of the lineup, and haven't tried to do any more serious work with them.  

I left the EDTA in them once I added some.  I put a couple tablespoons in a gallon of water and just used it to replace water as the batteries needed it.  I went back to normal rainwater or distilled water after that except if a cell still showed signs of low specific gravity then it got another dose of EDTA water added.  I monitor battery condition with the hydrometer and that is when I found that the EDTA had improved the batteries.  I had never seen the specific gravity that high consistently before the EDTA.

Title: battery care
Post by: OlJarhead on July 26, 2010, 10:05:09 AM
I just added it this year with my oldest batteries being from 2004.  I lost one from 2004 and one from 2005 I think.  Possibly a bit of EDTA added earlier may have prevented that loss.  The two had shorted cells and I haven't recovered them - but I just pulled them out of the lineup, and haven't tried to do any more serious work with them.  

I left the EDTA in them once I added some.  I put a couple tablespoons in a gallon of water and just used it to replace water as the batteries needed it.  I went back to normal rainwater or distilled water after that except if a cell still showed signs of low specific gravity then it got another dose of EDTA water added.  I monitor battery condition with the hydrometer and that is when I found that the EDTA had improved the batteries.  I had never seen the specific gravity that high consistently before the EDTA.



Thanks again for that post -- I plan to make use of this info :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on July 27, 2010, 08:05:45 AM
My pleasure, OJ.

On another note Sunelec messaged me that my new panels are on the way and I see that they once again dropped their prices with a sale.

http://sunelec.com/

I haven't found anything to beat them so far.  They have thin film a lot cheaper too if you have lots of room for panels.  Freight may cost more than more expensive panels though - I haven't worked that out - just went for the 190's
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 03, 2010, 02:51:05 AM
I put this post in the Off Grid section because the panels glenn and I ordered have the MC3 connectors. According to what I have read they are legacy connectors and the new standard is the locking MC4. For warranty purposes I read also that the factory ends must be left intact. Do you order the adapter cables and then cut the ends off of them to do your series or parallel connections into a combiner box??? Thanks in advance for all the info. Also, Mtn Don and Glenn if you have time to do a layout diagram like OJ did, that would be great for us first timers. God Bless
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 03, 2010, 03:29:09 AM
If connecting in parallel the connection to the combiner box is usually done by purchasing a premade cord with a female plug on one end and a male on the other. The cable is cut at the appropriate spot. The plug end attaches to the panel connector and the cut end wired into the box terminal like any other electrical box connection.

For series connections the panel plugs simply are plugged together in a series pattern.

You can also order custom made cables with an MC3 on one end and an MC4 on the other  if needed. Places the TheSolar.Biz can do that.

You should still be able to use the MC3 panel connections. If you tape them with silicone tape they will be more weather resistant as well.

If in doubt and faced with an inspection, ask the inspector what he wants to see.


If you'd like to see a wiring schematic I can draw one and post in in a week or thereabouts. (off to the mountains today).

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 03, 2010, 07:07:30 AM
Tickhill, the way to keep your warranty intact is to order an extra cable and cut it in half using one end for the connection at the end of your string and same  for each set of panels you must parallel.

I live in the boonies - such things are not available here - they didn't have them when I ordered my panels, so I take my chances and chop off the ends hoping the company has enough faith in their panels that it likely will not fail.

Likely you will have to void the warranty on at least one panel if you take the cut off end and put it on the other panel (cut off the female - plug it onto the male at the opposite end of the string or opposite way) for a connector....why didn't I think of that earlier..... [ouch]

Combiner box I guess is ideal and probably required for code, but I use wire nuts most of the time.  Seems any box with a cover should meet code.  I haven't checked it out.

Free Code suggested practices.

http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PVnecSugPract.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 03, 2010, 08:13:31 AM
Tickhill, the way to keep your warranty intact is to order an extra cable and cut it in half using one end for the connection at the end of your string and same  for each set of panels you must parallel.

I live in the boonies - such things are not available here - they didn't have them when I ordered my panels, so I take my chances and chop off the ends hoping the company has enough faith in their panels that it likely will not fail.

Likely you will have to void the warranty on at least one panel if you take the cut off end and put it on the other panel (cut off the female - plug it onto the male at the opposite end of the string or opposite way) for a connector....why didn't I think of that earlier..... [ouch]

Combiner box I guess is ideal and probably required for code, but I use wire nuts most of the time.  Seems any box with a cover should meet code.  I haven't checked it out.

Free Code suggested practices.

http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PVnecSugPract.html


Glen I use the Mariposa True Value hardware store!  They have everything!!!  ??? Fuse your parallel strings gentleman! We don't need a wildfire caused by a bad panel.  It is rare but possible! Ow on the wire nuts for DC
but I like the spirit...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 03, 2010, 09:05:40 AM
Thanks, Dave.  Wire nuts... I guess they are not the best, eh?

What would you suggest as best? Crimp butt connectors?  Terminals in the combiner box? Always a combiner box?  Exceptions to a combiner box?

I'll check out the True Value - they have solar stuff too?  The special cable end adapters for the panels?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 03, 2010, 09:17:01 AM
Looks like I found some of the answers in the code I posted above - Though I haven't read it all, what I did read was both clear and interesting.

I highly suggesting downloading it.  Looks like the big file and small one look the same - maybe resolution difference as far as I have seen.  Many pics included.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 03, 2010, 12:09:46 PM
If I could double the money i have recieved from troubleshhooting wire nuts I would get a newer vehicle. That is truck for you guy's in the trailerhood! New song for me!

I crimp or use the torqued square driver/slot terminals. You can buy them at home depot in a 10 or 20 screw strip. Just hack saw cut what you need, tape them, and pass inspection. I like the midnite combiner boxes if I am billing and build my own out of the weather tight comex boxes also H depot.

Oh yea, True value has it all ! They try! They have had some good people in there, at times! :-\
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 03, 2010, 03:36:10 PM
Thanks for the tip on the nut problem, Dave.

I'll look for the items you mentioned.  I stayed away from True Value for a long time as things there were costing about three times what they were at Coast but they are better now I think under the new owners.... most of the time.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 05, 2010, 12:36:46 AM
Mtn. Don, I would like to see a drawing/layout of your setup. I patterned my inital setup after yours, although I will probably go with the SUN 3024 inverter/charger when sunelec gets them in. The panels and Outback FM60 arrive this afternoon, I have camera in hand to document. Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 05, 2010, 07:34:25 AM
That is sure a deal on price for a pure sine wave inverter, Tickhill.  I note a pretty good efficiency difference between it and a Xantrex, but there is no comparison in cost if it holds up well.  I would go with it over a modified sine myself if money was a consideration (I don't mean that it is not for me---  [ouch].  I haven't seen any reviews yet.

http://sunelec.com/index.php?main_page=product_info&cPath=6_40&products_id=791     87% efficient max.   $525

http://www.xantrex.com/web/id/47/p/143/pt/18/product.asp    94%  efficient  (peak)  $2773
http://sunelec.com/index.php?main_page=product_info&cPath=6_40&products_id=583


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 05, 2010, 01:27:42 PM
Glenn, just got the panels and the FM60. No damage, now the work begins by removing the old panels and building a frame for the 190's. Also Elizabeth with sunelec emailed me today and said that the SUN 3024's have arrived and ready to ship out. I wish I could download a manual first, and yes $ is definitely a consideration!
I took one panel out and set it in the sun for a quick voltage check and it was 30.0 vdc just leaning against the shop. If prices stay this low, I will probably get another 3 this fall. I am going to build my frame to hold 6, it will just look a little empty till I fill it up with the other 3.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 05, 2010, 07:15:42 PM
Cool.  I have been having a bit of a communication slow down with Phoenix.  Maybe Miami is better - I emailed Miami today. 

Parts have arrived on time once I got the last order in, but getting it ordered if you have a question seems to be a bit slow.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 06, 2010, 06:45:17 AM
http://www.alphapower.com.au/aps_ProductsContent.php?mid=2&lid=6&nid=104

Would you use these?

Specification
AlphaCell Gel GXL
> Service Life: Long
> Runtime (minutes): 210, 180 & 165
> Sealed VRLA: Valve regulated lead acid
> Heat Resistant: High
> Hydrogen Emission: Low
> Terminals: L-type with .28" hole

> Silver Alloy: GXL-HP (on 210 and 180GXL)
N/A (on 165GXL)
> CA/SN Alloy: GXL
> Cells Per Unit: 6
> Voltage Per Unit: 12.8

Operating Temperature Range
> Discharge: -40 to 71°C
(-40 to 160°F)
> Charge (with temp compensation): -23 to 60°C (-9.4 to 140°F)
> Float Charging Voltage: 13.5 to 13.8VDC
> AC Ripple Charger: 0.5% RMS or 1.5% of float charge voltage recommended for best results. Max. allowed = 4% P-P

A friend has a pair for sale (to me) for $75 (total).....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 06, 2010, 07:03:41 AM
Not me.  I won't touch a gel cell. 

Lead acid for me.  L16 or Golf Cart only pretty well.

Gel cells will not take any abuse.  Charge them wrong - they are toast.  They can also lose the moisture in the gel rendering them useless unless you pop them open if possible and try to work in the proper amount of distilled water to restore them - only practical in small aplications such as my gold detector... and even then they may not come back.

A special charger is required to keep from damaging them.  Equalizing may damage them.  Too unforgiving for me because I am a bit of an abuser.....[waiting]

One golf cart battery should be in the area of $90 to $100.  Two are necessary for 12v
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 06, 2010, 08:49:02 AM
Cool.  I have been having a bit of a communication slow down with Phoenix.  Maybe Miami is better - I emailed Miami today.  

Parts have arrived on time once I got the last order in, but getting it ordered if you have a question seems to be a bit slow.

Still no response to e-mail questions on prices and sizing so apparently they are too busy to check e-mails or respond.  

They still have the best pricing and selection for my needs for the solar pump for a customer so I put the order in with their automated online system.

Rec'd their (www.sunelec.com) automated response receipt with the following note: 8-6-10 appx 10:30 am

Quote
Thank You! We Appreciate your Business!
Your Order Number is: xxxxxx

Checkout Success!...

Your order will be processed and shipped out to you shortly. For Solar Panels

Please allow up to 3-4 business days for your order to be processed and prepared for shipment
Thank you for shopping. Please click the Log Off link to ensure that your receipt and purchase information is not visible to the next person using this computer.
Log Off

Please notify me of updates to these products
SUN-75 $2.48/Watt

Recorded this to report to you on their follow through.  I have never had a problem with order fulfillment from them.  It looks like you mostly need to just figure out what you want from their in-stock items and order online.  With lowest pricing available that I can find, they are probably too busy for the small stuff.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 06, 2010, 11:19:47 AM
Forgot to mention that I got the Grundfos SQ Flex from the Solar Store in Bend, Oregon.

They have had every shipment of parts to me in about 2 days - maybe one on some of it.

http://www.thesolarstore.com/grundfos-m-50.html

Their e-mail and backorder notifications have been near immediate even to taking care of the Grundfos level switch I missed ordering. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 06, 2010, 02:36:35 PM
So... received notice that UPS rec'd information to pick up the panels from Sun for shipping 3:23pm - about 5 hours elapsed time on this order.  Not bad.

Looks like no problems with the online ordering and shipping if you know exactly what you need.  Nice that they post complete panel specs online.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 07, 2010, 04:16:24 PM
Cool.  I have been having a bit of a communication slow down with Phoenix.  Maybe Miami is better - I emailed Miami today. 

Parts have arrived on time once I got the last order in, but getting it ordered if you have a question seems to be a bit slow.

Call Tucson :)I found that talking to them was completely different!  Very nice and curtious and very helpful.

I could never get through to Phoenix.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 07, 2010, 07:44:38 PM
Thanks OJ - I was thinking Phoenix would be the one with their stuff together.  I think I have it handled now.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 08, 2010, 08:42:52 PM
FWIW, as requested, a schematic of sorts.  The drawings are not my best, most careful and neat work, but I believe it gets the idea across. Feel free to ask questions make comments or laugh....

It's in two parts, the first all the stuff down at the PV panels in the meadow...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fjemezmountainproperty2010-1%2Fpart1.jpg&hash=232435abb351e90297c48b8da894d71d)

... and the rest up at the cabin, 325 feet distant...

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fjemezmountainproperty2010-1%2Fpart2a.jpg&hash=d6e87beb7bd5b06ac55873208f3334b7)

Please note that if the panels and the balance of the system had been closer together like most systems will be, there would have been a #2 AWG ground wire running from the panels combiner box to the balance of the system.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 08, 2010, 11:52:48 PM
Thanks Mtn. Don! Easy understood drawing, it helps greatly. What is the voltage/amp rating of the CB in the combiner box. I am only 30' max from where the panels are mounted to the FM60.
I currently have a 4 conductor 10 AWG SJ cord buried from the shop to the panels.
Thanks for the drawing,  God Bless
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 09, 2010, 04:31:07 AM
The breaker at the panels is rated 150 VDC.

Also note I made an error on the second drawing and corrected the values for the breakers listed there. I got most of the breakers from solarseller.com; some from affordable-solar.com
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 09, 2010, 06:34:23 AM
That drawing is a beauty, Don.  I like it.

I use black for all of my DC grounds because I am used to automotive DC having a black ground and all other colors are hot.  Just easy for me to remember - maybe not right.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 09, 2010, 09:49:54 AM
I'm looking at getting 4 40 watt PV panels from Sunelec specs are below and wiring them in series to a MPPT charge controller.  Any thoughts as to these panels in this application, dealing with Sunelec or the quality of their products?

Thank you.

Model     SUN-40
Power (W)    40 Watts
Open Circuit Voltage (V)    21.90 Voc
Short Circuit Current (A)    2.54 Isc
Maximum Power Voltage (V)    17.50 Vmp
Maximum Power Current (A)    2.28 Imp
Dimensions    22" x 21 1/4" x 1 3/8"

$120/ea
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 09, 2010, 11:23:17 AM
I'm looking at getting 4 40 watt PV panels from Sunelec specs are below and wiring them in series to a MPPT charge controller.  Any thoughts as to these panels in this application, dealing with Sunelec or the quality of their products?

Thank you.

Model     SUN-40
Power (W)    40 Watts
Open Circuit Voltage (V)    21.90 Voc
Short Circuit Current (A)    2.54 Isc
Maximum Power Voltage (V)    17.50 Vmp
Maximum Power Current (A)    2.28 Imp
Dimensions    22" x 21 1/4" x 1 3/8"

$120/ea

They've done me well but for the $440 why not buy a 200 watt panel?  I bought 3 205 watt panels for $364ea a month ago.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 09, 2010, 11:48:00 AM
OlJarHead,

Do you have the SUN-40's?  I'm curious if these are a quality or low end panel.

As far as going with 4 small panels instead of single large panel,  my challenge is mounting them.  My cabin is in a wooded area and I expect I'm going to have to get creative with placing the panels to avoid shade.  The small panels give me more mounting options and using 4 wired in series allows me to go 48V to my charge controller to cut down on the size of the wire.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 09, 2010, 12:08:23 PM
I am a believer in series wiring to raise the voltage and reduce the necessary wire gauge. When sizing things though, remember to use the Voc (open circuit voltage, the highest voltage the panel would be likely to put out) and then muliply that by 1.25 and 1.25 a second time. Use that figure as the maximum peak spike voltage you would likely encounter in the coldest of weather and size everything to be able to handle that voltage. Those multiplication factors will pretty much ensure nothing will blow.

There is a handy tool at Outback Power that is a great help sizing arrays when using the Outback charge controllers. It has high and low temperature adjusters.    http://outbackpower.com/resources/string_sizing_tool/ (http://outbackpower.com/resources/string_sizing_tool/)    I believe Xantrex has one for their equipment as well.   ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 09, 2010, 01:11:12 PM
Also not illustrated is the single connection from the neutral (white, Glenn   ;D ) and the ground within the 120 VAC service panel.   If I was doing it over, or with more time available, I would have placed units in better positions to eliminate or reduce wire crossing in the diagram.


As far as what's hot, positive, neutral or negative, as long as one's system is not going to be inspected by a code nazi all that matters is not confusing oneself. My head seems happy to use white as neutral and negative within the confines of a non mobile unit (cabin, house...)  It would be nice if there were distinctive colors used to tell AC wiring from DC wiring.  So I label a lot of stuff that in my younger days I would not bother with.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 09, 2010, 01:54:03 PM
I use white for neutral on A/C, Don.  Seems I saw something about black for negative on DC systems once so have always done that - but as you said - if nobody is looking then lack of confusion is important  too.   Dave may jump in here and tell me I am all wrong though and I'd say listen to him - not to me. [ouch]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 09, 2010, 02:32:32 PM
Just keep the emergency disconnect tool handy in case of confusion.  ;D



FYI, for those who are looking to pass inspections, the NEC does state white is to be used for neutral and negatives.



BTW, I also keep a jug of a baking soda solution handy in the battery chamber as well as a dry box. I haven't figured out what to do when winter temperatures arrive though. Last winter I placed the solution in a couple half filled plastic jugs. It did freeze at one point. Perhaps a more concentrated solution would have a lower freeze point. Some research and experimentation may be called for.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 09, 2010, 02:45:12 PM
... I do that also - or mix it once in a while for cleanup and I try to be sure I do not confuse it with rain water or distilled water for filling the batteries if I set it down.... [ouch]

A magic marker helps.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 09, 2010, 08:09:55 PM
OlJarHead,

Do you have the SUN-40's?  I'm curious if these are a quality or low end panel.

As far as going with 4 small panels instead of single large panel,  my challenge is mounting them.  My cabin is in a wooded area and I expect I'm going to have to get creative with placing the panels to avoid shade.  The small panels give me more mounting options and using 4 wired in series allows me to go 48V to my charge controller to cut down on the size of the wire.

Actually mine is a Sun 205 watt panel (or is it evergreen?  have to go check now)....but I have 3 of them :)  I got them from sunelec for my system...I was just thinking that one panel would be easier to mount and provides more power for less money (mine was $1.82/watt).  Something to consider.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 10, 2010, 01:10:00 PM
Don,

I'm trying to decide on a MPPT charge controller for 48V PV array charging a 12V battery bank.  I'm looking at 200watts of PV panels wired in series for 48V.  I think I have it narrowed down to the:

Outback FM 60 $525 + $30 battery temp sensor
BZ Products MPPT250HV $120 + $30 case
Morningstar TriStar TS-MPPT-45 $415 + $80 display + $30 battery temp sensor

The BZ Products is by far the cheapest but has no data logging or other enhanced features. 

I have a question about the Outback, does it completely power off when the PVs are in the dark or does it stay running off battery power?

Any other thoughts from anyone on my charge controller options would be appreciated.

Thank you.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 11, 2010, 09:06:02 PM
I am sure the controllers will have a very minor draw when powered down so that they will know when to wake up.  They need a little power to know when to work for you.

http://www.oynot.com/files/flexmax-product_catalog.pdf

Found it - standby - less than one watt.  It will gain you much more than it uses on standby.

Here is the way I see it, Jerry.

If you want the cheapest with no equalization or other bells and whistles the BZ will work.

If you like gadgets, equalize and other capabilities then it is one of the more expensive ones - both are good.

If you plan to expand the bigger ones have room but you need to be able to get and use the same panels.  If not planning to expand, you have one of the best but a lot of wasted capacity.

The BZ is not highly rated but most of them work and are guaranteed.  I have had one failure out of three and did not try for warranty although they are supposed to take care of it.  I jumpered around it but may have to change it when I hook up the new panels.  $14 return shipping for repair plus sending it in.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 11, 2010, 11:58:42 PM
This may be an advertising scheme but I looked at sunelec.com today and the price glenn and I gave for our panels have gone up a .10 cents since yesterday and they are saying "PV Industry Shortage is Happening Now!"
I wish I had done like glenn and went ahead and got 3 more.
Just thought I would put that out there that there may be something to this and that $$ may start on the way back up.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 12, 2010, 12:00:05 AM
I meant to say .10 cents a watt increase....
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 12, 2010, 08:21:28 AM
This may be an advertising scheme but I looked at sunelec.com today and the price glenn and I gave for our panels have gone up a .10 cents since yesterday and they are saying "PV Industry Shortage is Happening Now!"
I wish I had done like glenn and went ahead and got 3 more.
Just thought I would put that out there that there may be something to this and that $$ may start on the way back up.

I'd call it inflation -- I've seen it in many places and with Uncle Sam printing money like rain falling from the sky it's only a matter of time...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 12, 2010, 09:29:33 AM
I heard it may go up - quite a few solar projects going on.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 13, 2010, 03:37:50 AM
Anyone have any experience with Rasmond solar panels?  http://ramsond.com/solarprod.php (http://ramsond.com/solarprod.php)
They sell on their site, Amazon & Ebay.  The Ebay auction prices are competitive with Sun Elec.
I'm looking at their 80W Mono-Crystalline.

I really had to look at our property to find a spot that wasn't shaded by trees.  I also didn't want to take down a lot of trees to gain solar exposure.  Finally found a spot that should be good for 6-8 hours of full sun a day.  Its the corner of the cabin.  I'm looking at installing about a 16' pole that will get the panels above the eve of the cabin.  I would attach the pole to a base on the ground and midway with a heavy bracket attached under the cabin's eve.  Anyone know of any information on sizing a post with a certain square feet of PV panels mounted on it?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 13, 2010, 05:15:32 AM
A standard wall  three inch or 4 inch should work braced as you mentioned.  Guys could be added to the top if in doubt.  Trees you mention nearby should kill most of the low level wind.

There are lots of different voltages on different panels so if you are adding to your sun-elec panels you should get the same ones  to keep your charge controller working most efficiently for all - otherwise you will be working at the most efficient level of an innefficient mix.  If all from the new source then no problem.  I haven't heard of them but that doesn't mean anything - - check their specs and compare them to sun - also check the vendor and see if it looks like they may be around for warranty.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 13, 2010, 06:03:37 AM
Thanks OJ - I was thinking Phoenix would be the one with their stuff together.  I think I have it handled now.

These folks are as bad as it gets!  But, there prices are usually the best!  I said that 15 years ago BTW.
It usually helps if  you spend 15 minutes each day thinking happy thoughts about Sunelec! Well it might help, OK, it has the potential to help.

When GEL's first came out and now the AGM's it was 2 X the price for 1/2 the cycles, 1/2 the capacity and unknown lifespans over 5 years.

That never bothered me as I would pass it on to the customer ( But I always talk them out of it!) What really would bother me is losing one of the best tools in my box, the specific gravity measurement! Now that would really be a loss living offgrid!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 13, 2010, 08:44:56 AM
Don,
I have a question about the Outback, does it completely power off when the PVs are in the dark or does it stay running off battery power?


The Outback FM60 has some very small power draw even when it's not charging the batteries. For one thing, the display indicates that it in silent or sleep mode. That costs something in power use, but is negligible as far as I am concerned. It's nothing to be concerned about. Even a brand new lead-acid battery sitting there doing nothing likely has more loss due to self discharge than what the FM60 draws.

FWIW, I have the FM60 charge controller plus the VFX3524M Outback inverter/charger plus the Outback Mate and Hub 4 and two battery temperature sensors. (see note below) When we leave the cabin for a few days I pull the breaker disconnect between the batteries and the inverter. I do that just because I feel more comfortable knowing all the AC power to the cabin and outbuildings is completely off. As an experiment I have also left the system sit there for two weeks with the inverter still powered and in its normal standby mode. I can not discern any difference in power use between leaving the inverter disconnected or in standby.

(note below)  I have two battery temperature sensors, one connected to the FM60 and one connected to the VFX3524M. It is possible to have only one temperature sensor in the system when an Outback Hub and mate are used. However Outback told me that IF I depowered the inverter/charger I needed to have a temperature sensor connected to the FM60 inorder to have the FM60 read the battery temperature. IF I left the inverter/charger powered up, even in standby, I could use just one temperature sensor connected through the Hub and it would supply data to both the FM60 and/or the inverter/charger as required. If that's not clear don't worry about it unless you have an Outback Inverter/charger as well as an Outback Charge Controller.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 13, 2010, 08:52:42 AM

Outback FM 60 $525 + $30 battery temp sensor
BZ Products MPPT250HV $120 + $30 case
Morningstar TriStar TS-MPPT-45 $415 + $80 display + $30 battery temp sensor

Thank you.

I think the BZ is great for those who are needing to stick within a tighter budget. My opinion on the Morningstar is "why bother with it when you consider the price is close to the Outback?" I'm sure it's good but I like having the system all Outback.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 13, 2010, 09:00:56 AM
 Anyone know of any information on sizing a post with a certain square feet of PV panels mounted on it?

UniRac (http://www.unirac.com/) has information on pole sizing, depth, etc available n their website. I believe it is in their downloadable catalog pages for their pole mount racks. Of course their info is centered around using their mount kits. Their info takes wind loads into account on various combinations of panel sizes and numbers of panels. They supply the required depth and concrete volume for a safe installation.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 13, 2010, 09:02:54 AM
What really would bother me is losing one of the best tools in my box, the specific gravity measurement! Now that would really be a loss living offgrid!

Absolutely!!!!!!!!


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 14, 2010, 04:53:12 AM
OK, here is the Visio produced wiring diagram. Thanks very much to Tickhill for his fine rendition of my pencil sketch - MD

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fjemezmountainproperty2010-1%2FSolarLayout.jpg&hash=72cd94c4046a70521225d1955f5c38df)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 14, 2010, 05:32:19 AM
That's pretty much got it.   :) :)

Thanks very much for the great work.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Shawn B on August 14, 2010, 05:44:39 AM
MtDon,  I see the Outback inverter has a generator connection. Is it a hard wired or plug in type connection? Does this also supply a/c power to the house, as well as equalize the battery bank? 


Thanks Shawn.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 14, 2010, 06:16:25 AM
MtDon,  I see the Outback inverter has a generator connection. Is it a hard wired or plug in type connection? Does this also supply a/c power to the house, as well as equalize the battery bank? 
Thanks Shawn.

The connection for the generator inputs at the inverter/charger is hard wired. I use a locking three prong plug to connect at the generator end to make it simple to disconnect if and when I want to move the generator. After all it is a portable generator. The generator also has its own ground rod.

The AC input at the inverter/charger is a pass through system. When AC input is applied to the inverter that causes the charger section of the inverter/charger to kick in and apply DC power to the batteries. Like the FM charge controller the inverter/charger can be programmed for different charge rates; bulk, absorb and float. There is also a manually activated equalization cycle.

AC input at the inverter/charger also causes the cabin AC requirements to be drawn from the generator rather than the batteries.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Shawn B on August 14, 2010, 06:49:42 AM
Thanks Don...That was exactly what I wanted to know. That Outback system has quite a few features.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 15, 2010, 02:22:39 PM
Did some searching but did not find any definitive answers, can you deduct 30% of the cost of a off-grid solar power system from your taxes?  Or is this only for grid tied systems?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 15, 2010, 03:18:26 PM
Regarding getting a 30% federal tax rebate on off grid solar & wind systems:

Found this on the Federal Form 5695 (2009) http://www.irs.gov/pub/irs-pdf/f5695.pdf (http://www.irs.gov/pub/irs-pdf/f5695.pdf)

"Qualified solar electric property costs. Qualified solar electric
property costs are costs for property that uses solar energy to generate
electricity for use in your home located in the United States. This
includes costs relating to a solar panel or other property installed as a
roof or a portion of a roof. The home does not have to be your main
home" 

From this it appears we can claim 30% of materials and labor cost our taxes even on off-gird and vacation homes.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 15, 2010, 03:47:12 PM
Yep.

Note that with most things done by owner-builder your own labor costs do not count; only labor costs paid to someone else. 

Credits start at the PV panels or wind generator and stop after the inverter though. The balance of the wiring, etc after the inverter is just like a regular home connected to commercial grid system.

Also if you are going this route check into your state rules. Some states, like NM, do not tax the purchase of the alternative energy equipment or contracted labor. However, you need to know how to make that work for you when dealing with companies that are not alternative energy specialists.

http://www.dsireusa.org/incentives/index.cfm?State=US&ee=1&re=1 (http://www.dsireusa.org/incentives/index.cfm?State=US&ee=1&re=1)

http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=US37F&re=1&ee=1 (http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=US37F&re=1&ee=1)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 15, 2010, 04:25:11 PM
Quote
They've done me well but for the $440 why not buy a 200 watt panel?  I bought 3 205 watt panels for $364ea a month ago.

Oljarhead,

I'm leaning towards bigger panels as you suggested. What 205 watt panels did you buy, how much was shipping?

Thank you,

Jerry
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 15, 2010, 04:43:58 PM
I have had my 2kw ProSine inverter and 4 -GC batteries running well for 2 years charging them with a generator.  Now I want to make the next move to solar charging.

Here is what I'm looking at:

2 - Sun 190 watt PV B grade panels with a max power voltage to 26.7V $338ea.
http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=816 (http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=816)

1- Outback FM-60 Charge controller $508
http://sunelec.com/index.php?main_page=product_info&cPath=22&products_id=36 (http://sunelec.com/index.php?main_page=product_info&cPath=22&products_id=36)

Outback Battery Temp Sensor,

MOC 3 Connectors

$330 freight.

Any comments on any of my choices, better alternatives, issues with B grade panels would be appreciated.

Thank you.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 15, 2010, 05:15:13 PM
They do not carry the UL or any other approval. That means they will not pass inspection. There could also be a problem with insurance, maybe after a fire if they caused one and the adjuster was sharp. Non approved may simply mean they skipped on that process and the expense to be able to sell cheaper.  ???  Not approved may also mean the wiring is not good enough for the high temperature insulation rating.  ???  Approved panels will usually have connecting wires rated up to 600 volts. One of the Sun panels I searched out a year or more ago had wiring only rated to something around 50-60 volts. That could make series connections iffy. Or maybe not.  ???  Thing is we don't know from what they tell us. Non UL approval could also mean the glass surface is not up to impact (hail) standards.  ???  Again, maybe not; maybe the panels are every bit as good as a UL, CE Tuv, approved panel and Sun is just saving us money.  ???  I have no idea, but you asked for an opinion.

Cosmetic blemishes do not bother me at all. Other unknown or unseen possibly important things do. But that's me.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 16, 2010, 07:08:12 AM
Quote
They've done me well but for the $440 why not buy a 200 watt panel?  I bought 3 205 watt panels for $364ea a month ago.

Oljarhead,

I'm leaning towards bigger panels as you suggested. What 205 watt panels did you buy, how much was shipping?

Thank you,

Jerry

Disclaimer:  I'm remote, Libertarian and don't give a rats behind.....*chuckle*

The panels I bought were $1.82/watt  Sun A-205-fa3 205W Solar Module -- I basically bought their off grid system without the Inverter and batteries.

I was able to get a better deal going that route.

But as I see Don mentioned these panels aren't UL listed because they are blems -- though I see no reason to call them 'blemished'.  They seem perfectly fine to me though I haven't had them in the sun yet...should do that today.

Anyway, I'll be 24 miles from the nearest town, 3 miles from the nearest county road and hidden in the trees where only planes and google earth can see me :)

Of course Google Earth has to update it's maps first too :P
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 16, 2010, 10:04:15 AM

But as I see Don mentioned these panels aren't UL listed because they are blems --

Hold a sec....  No, no, no, that is not what I said.   I said "They do not carry the UL or any other approval. That means they will not pass inspection".

The fact that the panels are being sold as blemished has nothing to do with UL approval. UL doesn't care if they are pretty. Mostly UL tests for electrical and mechanical safety. Things like does the wire used have insulation that is rated for high enough temperatures, does the insulation have UV resistance, is the conductor large enough to carry the maximum expected amperage, can the module handle high voltages when series connected, and other stuff.

Other brands of panels are also sold as blemished from time to time. I missed out on some Sharp panels by a few weeks when I was looking. They had some kind of scratches on the aluminum frames. They still carried the UL, CE, Tuv approvals. Some Sun panels are simply not approved. Period. Doesn't matter if they have a perfect or blemished finish. On some models they come right out and say yes or no on UL. On others one has to search and sometimes still can not determine if the label indicates UL approved or not.

Maybe I worry too much. I wonder why the manufacturer has not had the panels tested and approved. Maybe there's nothing at all wrong with them. Maybe the panels are deficient in some way? I have no way of knowing. I see them as a long term investment and that's why I bought a "name brand". I'm not saying that the Sharp are better or that the Sun are crap. However, as with anything from soup to nuts I do wonder how two products similar in nature can vary so widely in price.

What I do know is that I have bought many things over the years. Sometimes I have gone for the low ball price just because I don't like to spend a lot of money. Sometimes that has been money foolishly spent when problems have developed prematurely. Sometimes I buy the cheaper thing with full knowledge that it is not going to be as durable as a more expensive item, but that's okay as it is being bought for a one time specific task. Sometimes the cheaper thing is wonderful and is at least as good as the more expensive brand name item. Costco's Kirkland brand AA alkaline batteries come to mind there.

Anyhow, I just would like to be quoted correctly.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 16, 2010, 10:15:03 AM

But as I see Don mentioned these panels aren't UL listed because they are blems --

Hold a sec....  No, no, no, that is not what I said.   I said "They do not carry the UL or any other approval. That means they will not pass inspection".

The fact that the panels are being sold as blemished has nothing to do with UL approval. UL doesn't care if they are pretty. Mostly UL tests for electrical and mechanical safety. Things like does the wire used have insulation that is rated for high enough temperatures, does the insulation have UV resistance, is the conductor large enough to carry the maximum expected amperage, can the module handle high voltages when series connected, and other stuff.

Other brands of panels are also sold as blemished from time to time. I missed out on some Sharp panels by a few weeks when I was looking. They had some kind of scratches on the aluminum frames. They still carried the UL, CE, Tuv approvals. Some Sun panels are simply not approved. Period. Doesn't matter if they have a perfect or blemished finish. On some models they come right out and say yes or no on UL. On others one has to search and sometimes still can not determine if the label indicates UL approved or not.

Maybe I worry too much. I wonder why the manufacturer has not had the panels tested and approved. Maybe there's nothing at all wrong with them. Maybe the panels are deficient in some way? I have no way of knowing. I see them as a long term investment and that's why I bought a "name brand". I'm not saying that the Sharp are better or that the Sun are crap. However, as with anything from soup to nuts I do wonder how two products similar in nature can vary so widely in price.

What I do know is that I have bought many things over the years. Sometimes I have gone for the low ball price just because I don't like to spend a lot of money. Sometimes that has been money foolishly spent when problems have developed prematurely. Sometimes I buy the cheaper thing with full knowledge that it is not going to be as durable as a more expensive item, but that's okay as it is being bought for a one time specific task. Sometimes the cheaper thing is wonderful and is at least as good as the more expensive brand name item. Costco's Kirkland brand AA alkaline batteries come to mind there.

Anyhow, I just would like to be quoted correctly.



Sorry -- mistyped on my part.

Let me try again ;)

The panels that I purchased are 'Blems' and while you can buy the EXACT same panel that IS UL listed the manufacturer doesn't bother with the blems and dumps them on the market.

This isn't uncommon actually.  When I worked in a food plant (pickles) the company made other brands then their own -- these other brands varied in quality assurance.  The ones with the least QA were generally sold as generic brands but were actually the same recipe etc as the name brand -- just less concern over the quality of the product.

In this case the manufacturer (to my understanding) doesn't really want to sell their blemished panels as a 'normal' product and rather then get them stickered etc they dump them cheap to get rid of them.

They are supposed to work as described etc but weren't put through the same testing standards as those sold with the UL sticker on them.

make sense?  You can actually buy the exact same panel with the UL sticker for around $800 rather then the $364 I paid :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 16, 2010, 11:24:27 AM
Not to initiate a flame war, but my understanding of the UL system is as follows.

A manufacturer submits a product for testing. They pay for the testing process up front. If the item passes the UL scrutiny the manufacturer gets permission to have labels printed and applied to the products they then can sell as an approved item. The manufacturer supplies the products to be tested and pays for the testing and approval process. The manufacturer then buys labels from authorized sources. Yes, the labels have to be approved too. The manufacturer also pays subsequent fees for follow up testing on items selected at random as they are produced. Not every item labeled is actually tested.

In other words, the manufacturer does not pay a fee based on the number of labels applied. If they get something approved and then don't sell any they have the up front costs paid. With the above being my understanding of the UL process I do not think it likely that the exact same products are sold as approved and unapproved and with such widely divergent prices.


Maybe I'm misinformed.    If so point me in the right direction.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 16, 2010, 04:57:23 PM
Not to initiate a flame war, but my understanding of the UL system is as follows.

A manufacturer submits a product for testing. They pay for the testing process up front. If the item passes the UL scrutiny the manufacturer gets permission to have labels printed and applied to the products they then can sell as an approved item. The manufacturer supplies the products to be tested and pays for the testing and approval process. The manufacturer then buys labels from authorized sources. Yes, the labels have to be approved too. The manufacturer also pays subsequent fees for follow up testing on items selected at random as they are produced. Not every item labeled is actually tested.

In other words, the manufacturer does not pay a fee based on the number of labels applied. If they get something approved and then don't sell any they have the up front costs paid. With the above being my understanding of the UL process I do not think it likely that the exact same products are sold as approved and unapproved and with such widely divergent prices.


Maybe I'm misinformed.    If so point me in the right direction.

No worries at all Don -- perhaps I'm mistaken in this case???

In truth, I think you know tons more then I do on the subject (actually millions of tons -- thanks for all the help!) so I suspect that in this case I'm wrong.  I'll go see if I can find out where I got the impression I did.

Thanks
Erik
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 16, 2010, 05:16:51 PM
Can't find what I was looking for so quite possibly I got it wrong Don. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 16, 2010, 06:25:53 PM
Gosh, shopping for solar panels can get tiring.  ??? The shipping can be a big factor, up 50% of the PV cost, so that must be taken into account.

Per Don's concerns, I looked for an alternative to my first choice (2 - Sun 190 watt PV B grade panels with a max power voltage of 26.7V $338ea.)
$1.78/Watt panel or $2.66/Watt delivered.

The alternative I found was (2 - 165W BP Solar A grade panels UL rated SX6165N with a max power voltage of 35.2V $361ea.)
$2.19/Watt panel or $2.98/watt delivered.

Any feedback on the BP panels?  Doesn't Glenn use Sun panels?  If so can Glenn give his $0.02 on them.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 16, 2010, 06:39:33 PM
BP has been producing panels for some years. They should be good ones.


Transportation costs were one reason I purchased my panels from a local supplier. I guess I was lucky in that respect.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 16, 2010, 07:07:04 PM
I have my first set of Sun Panels running  - No problems.

I have my second set - 1000 watts + but have not set them up yet.  I'm not worried about them.

Third set for the pump for a customer arrived today 5 x 75 watt panels.  I can take readings on them when I get working on them in the next couple weeks.

Sun has been in business for - what - 37 years, and they are not staying in business by ripping people off I am assuming.

I am taking them at their word and so far they have not given me a reason to doubt them.

"These modules are made available exclusively to Sun Electronics by one of the world's largest manufacturers. Made in USA! Identical Power specifications as A grade modules, complete factory light tower test is available. These modules have slight cosmetic blemishes. Sun modules are non-UL, Tuv or CE listed. Unlike most other brands which have power specifications within +/- 10%, these modules have power specifications within +-5%!"

I have BP panels too with no problem.  I have BP panels made for Enron also - thin film - low watts (40) for a large area but no problem.  I see watts as being watts.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 16, 2010, 09:03:33 PM
Cost to ship my panels from AZ to WA was about $220 -- that's 3 panels, midnight solar boxes, breakers, some MC cables and more.

I was pretty happy with that actually.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 18, 2010, 02:55:06 PM
I pulled one of the Sunelec 75's out of the box and put a meter on it yesterday.

VOC was listed as 21.7  measured at about 10 am on a hot day showed 20.52  - I think within reason

ISC was listed as 4.89  measured ~5.25  so a bit higher than advertised.

I don't think that there will be any problem with them performing to higher than the industry standard as they claim.

The wire was PV1F and rated at 1000 VDC, and the terminal box was rated at 1000 VDC.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 18, 2010, 06:42:55 PM
I bought the 2 - 165W BP Solar A grade panels UL rated SX6165N with a max power voltage of 35.2V $361ea, Outback FM-60 and a Unirac 5001 pole top mount.  Waiting for them to come in.  :-\ Any ideas about where to get 20' of 3" pipe on the cheap?  Does anyone know if galvanized rigid conduit is the same as schedule 40 pipe?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 18, 2010, 07:09:56 PM
Look for a used pipe dealer. I bought my pole material from a nearby (50 miles) dealer in used drill pipe. It was a bargain compared to new steel, even with the drive to get it.


EMT (rigid metal electrical conduit) is not the same as schedule 40 pipe. Sch 40 has a wall thickness of 1/4 inch in three inch size pipe, EMT is much thinner.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 19, 2010, 12:34:35 AM
TheWire, I put my panels on 3" rigid galvanized conduit. I have ~4' in the ground with concrete and I welded a piece of 2' long by 8" wide 3/8" thick plate on top of the threaded coupling that comes with the conduit. This acts as my swivel for turning the panels to the sun (manually right now). I have had no trouble with wind, I do have a hole drilled through both coupling and conduit so I can "pin" the panels in place if need be. I will be removing my old setup and putting the 3- 190 watters in place very soon. Blessings, Tickhill
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 19, 2010, 05:13:36 AM
Listen to Don on this one! Conduit is not schedule 40. These mistakes were made decades ago by folks like myself so that you guy's can move forward!  :(
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2010, 06:39:17 AM
It's relatively easy to get confused with pipe/conduit/tubing

 EMT (electrical metallic tubing): very common light thin wall electrical conduit. This is never threaded as the walls are too thin. Sold in standard 10 ft lengths

 RMC and GRC (rigid metal conduit and galvanized rigid conduit): has a thicker wall than EMT, but not as thick a wall as PIPE. Used in industrial and commercial applications more than residential. Sold in standard 10 ft lengths

 IMC (a thinner wall version of RMC): approximately 1/3 less metal than RMC. Sold in standard 10 ft lengths

 PIPE (made in a variety of wall thicknesses or schedules; schedule 40 is most common) used for fluids and gases, etc.: thicker wall than RMC/GRC. The threads are the same number of threads per inch BUT pipe threads are cut with a taper whereas conduit threads are straight cut, non tapered. Taper thread is required to make fluid and gas tight connections. Sold in standard 21 ft lengths as well as shorter lengths called nipples.


For comparison, 3 inch RMC and GRC has a wall thickness of 0.13 inch and schedule 40 PIPE has a wall thickness of 0.216 inch
                      4 inch RMC and GRC has a wall thickness of 0.13 inch and schedule 40 PIPE has a wall thickness of 0.237 inch

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 19, 2010, 07:55:36 AM
Just a note on battery recovery - I had one bad cell in one battery in an old group of four of my 2004 batteries.  I rehooked them to my system a week or two ago.  The EDTA recovered a second one in the group that I thought would not come back.

The other battery was shorted and nothing I could do was bringing it back.  I ran a pulse recovery charger on it day and night for several days.  I didn't want to put a new battery in the string so started thinking about some scrap batteries that were given to me.

Dave - you know these batteries .... some very used Trojans..... [ouch]

I had one out of the eight that has been sitting about 6 months or better that it looks like I have been able to fully recover.  It had significantly higher voltage than the rest -about 4.62 as I recall.

I mixed up a quart of rain water and a couple tablespoons of EDTA and split it among the three cells in the Trojan.   I put the Xtreme Recovery 20A pulse charger on it and a companion battery for 12 v.  The companion is the one that had a bad cell and returned from the dead.  By bad cell I mean two cells were 1300 or more SG and one was below 1100.  Point spread in SG over about 25 is not good.  

The point here is that the SG measured with a hydrometer is a measure of cell health and all should be near 1300 on a fully charged battery with little difference in SG.  If a cell is low compared to the others it is time to equalize all cells keeping water levels up above the plates during the process when the good cells will bubble profusely as the bad one is coming up.   Once it is also bubbling profusely and the SG is up then equalization is done.  Refill with rain or distilled water - do not overheat the batteries.  I use the welder to do the equalization but if you are not aware of the procedures (mine) and dangers then again - don't try this at home, kids. [crz]

After 24 hours on the Xtreme Recovery charger both the old battery and the used Trojan are over 1300 in all cells.  :)

As a substitute for the Xtreme Recovery charger, I think that any PWM solar charger will pulse the battery back breaking down the sulfation, or use a desulfator with the charger - just at a slower rate.    Note - just a link that has it - Mikey B of our forum sells them also.  http://www.chargingchargers.com/pulsetech/xcr-20.html

Battery and charging info...     http://www.chargingchargers.com/tutorials/charging.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 19, 2010, 08:45:05 AM
 The only pipe I use is 6 inch  with an OD of 6 5/8". A 9 foot section of either the sched 40 or well pipe which is even thicker/stronger is between 200 and 300 pounds.  I say this because offgrid people often want more power over the years and this is a reasonable way to add on over the years. 6 inch sched 40 will support 125 square feet of panels BTW. The 8 inch pipe is only for people like Glen who have heavy equipment service facilities!

I have sent folks down to Costco to buy a golf cart battery for emergency repairs to an L16 bank Glen. It has been very rare with Surrettes.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 19, 2010, 12:53:53 PM
The best solar exposure I could find is pointing over the roof on one edge of my cabin using a pole top mount.  My plan is to put up a 3" or 4" pipe pole from the ground up along side the cabin and attach it near the eve with a heavy bracket tied back into the studs of the in cabin at multiple points.  If I used a 20' pipe, about 14' of that would be below the attachment near the eve.  6' would be above the eve on top of which I would put PV panels with an area of about 25 sq ft.  I was also considering the possibility of using 2 10' sections of pipe with a coupling as the coupling would be between the eve attachment point and the ground.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2010, 05:03:32 PM
The eve attachment would need to be quite robust. With a maximum wind speed of 90 mph there would be approx 30 lb per sq ft force. Times that by 25 sq ft = approx 750 pounds force total.

I'm not an engineer but I suppose the threaded coupled joint would be okay in this case although I'd want to securely connect the pipe to the wall just above the coupling to reduce bending stresses on that point. I would not want to use a threaded coupler an not have the pipe and rack above the joint supporting much weight.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 19, 2010, 08:51:34 PM
I have 4 threaded couplers on maybe schedule 30 pipe (lighter than standard ) 85 feet tall for my wind generator.  The catch is that I have 4 guy wires every 20 feet to take the side stresses.  My design is based on what I could glean from Bergey Wind Generators information and phone conversation with them.

Good idea on slipping a golf cart battery in there to save the rest of the bank, Dave.  I knew I didn't want to buy a new L16 but the recovered Trojan looks to be doing good now.

20 feet of heavy wall 8" - small potatoes.... :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 20, 2010, 06:46:09 AM
http://www.amazon.com/ERICO-611380UPC-Copperbonded-Ground-Rod/dp/B002KAU1X4/ref=pd_sxp_grid_pt_0_1

Looking for ground rods and I found this (as well as others).

The only thing I know about ground rods is that I've had to pound several into the ground (when in mobile switching in the military) and that they provide the 'earth ground' for the system.

From Don's posts and pics it looks like he used two at each location?  Is this required?  We only ever used one in the military.

Anyway, I need to get a couple (or 4) of these and was wondering what your thoughts were?

Also, I have VERY rocky ground and am not certain that I can even get a ground rod down 8 feet!  In fact my well report shows topsoil for FOUR FEET and then granite.  So ya, this might be a little tough.

In that case could a person run several 4 foot rods and make a 'halo' ground system instead?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 09:44:12 AM
Lowe's and HD also stock ground rods as should any other supplier who stocks service entrance equipment.  My local stores carry them in the 5/8" diameter, sometimes the 1/2" Cheaper than that one that was posted.  You'll also need a clamp to connect the ground wire to the rod.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fimages.lowes.com%2Fproduct%2Fconverted%2F084644%2F084644071053lg.jpg&hash=4c60a46d64e2c4db580d90bcad806d65)

According to NEC driving the entire 8 ft length is required, to the point where the clamp on the upper end is actually buried. NEC has alternate grounding methods using a buried perimeter wire. Off hand I do not recall what lengths are required.

I did use two rods at the pole and panels to be sure I had a good solid ground. The soil down there gets quite dry at certain times of the year. Two rods ensures a better ground. See the following post for more....

http://countryplans.com/smf/index.php?topic=6059.msg95643#msg95643 (http://countryplans.com/smf/index.php?topic=6059.msg95643#msg95643)

At the cabin and equipment I could have likely got away with a single rod as the grey water leach keeps the earth moisture content higher. But a second rod, clamp and wire was less than $25 and provides extra 'insurance'.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 09:45:25 AM
Does your well have a metal casing?  Good ground there.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 20, 2010, 11:00:35 AM
Does your well have a metal casing?  Good ground there.



I was wondering about that Don.  Though the well is about 100 feet from where the panels will be.  How far away can I put the rod (s).

I also have dry ground in the late summer and fall so having two makes sense.  My biggest problem is that where I put the cabin and want to put the solar is quite rocky.  Just digging two feet in some of these areas is nearly impossible without a hoe!  We had to use the winch on the jeep to pull some of the rocks away from the area we dug up for footings and composter.  Was tough.

If I could use the well casing that would help, but again it's a long ways away.

I think I can get a rod or two in within 25 feet of where I'd like them, and perhaps closer but have to explore more.

Thoughts?

Erik
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 11:17:29 AM
My quick search finds nothing on the distance between the ground rod and the balance of the system.

I did find it listed that a metal well casing on a private well can serve as a ground.

I also found that the 8 foot ground rod can be driven at an angle up to 45 degrees (Cailifornia code item). No mention of angle driving in the NEC or IRC.

I found two grounding systems allowed as alternatives ...

Plate Electrodes
 
A plate electrode that exposes no less than 2 square feet of surface to exterior soil shall be considered as a grounding electrode. Electrodes of iron or steel plates shall be at least 1⁄4 inch in thickness. Electrodes of nonferrous metal shall be at least 0.06 inch in thickness. Plate electrodes shall be installed not less than 30 inches below the surface of the earth.
 
Ground Ring Electrodes
 
A ground ring encircling the building or structure, in direct contact with the earth at a depth below the earth’s surface of not less than 2.5 feet, consisting of at least 20 feet of bare copper conductor not smaller than No. 2 shall be considered as a grounding electrode.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 20, 2010, 02:43:34 PM
Picked up a 5/8" ground rod at Home Depot for under ten bucks :)  Thanks Don!

I also picked up 20 feet of solid copper #6 (bare) to run from the box to the rod for $11.60.  I figure I can try to put the rod in near where the battery box will be and will have plenty of copper to get to it even if I have to move it 5-10 feet from the box location.

I'll be wiring up the receptacles, lights and switches this trip and installing the main AC load center (bought a Homeline 125amp 8 position 16 circuits) at the same time and landing the circuits.

I pan to run seperate breakers for each area of the cabin limiting each run to 3 boxes and one light or less.  This will give me a breaker for the lower sleeping area, kitchen, refrigerator (assuming I run the camper fridge on AC), 'living' area, small loft, bathroom (1 GFCI -- man those are spendy! and a light) and left and right side of large loft.  Also running one breaker for ceiling fan and one for outdoor porch light.

I figure I can get away with 15amp breakers since these will be light loads and small areas (no more then one overhead light and 3 boxes per breaker) but plan to install 20amp breakers for anywhere that might have a heavier load (kitchen and bath).  12-2 w/ground romex for all but single box runs for desk lamps or clock radios -- which means I can upgrade the breakers to 20amp breakers if need be (which are the same price).

I plan to install at least one outdoor circuit while I'm at it and run a GCFI to the compost unit for the dehydrator and fan.

I've been told that DC likes stranded wire better then solid romex -- any thoughts on that?  The reason I ask is that I was hoping that if the inverter died and I wanted to just change a circuit to 12v I could land the wiring into a seperate box for DC under the AC box.  If not then I'll have to add a run of stranded for the DC circuits if I should want some.

DC lights are spendy but I've read that they are very efficient and draw low power (LED's) so might be a good thing to make use of on my small system.

Any thoughts?

Thanks again!
Erik
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 03:47:58 PM
First, solid vs stranded wire.

1.  In automotive uses, stranded wire is preferred. Not because it might be better able to carry the currents, but because it is flexible. Being flexible it will not fatigue and break from vibration as readily. It's also easier to run the wires in an auto when they are more flexible.

2.  There is very little difference in the resistance of a solid vs stranded wire in DC applications. So little it is negligible. Solid wire has slightly better performance, less resistance, than stranded wire in DC applications.

Example:
SOLID WIRE
conductor size      12 AWG
area             3.309 mm^2 (square-mm)
area              6530 CM (circular mil)
diameter          80.8 mil (1)
diameter         2.053 mm (1)
DC-resistance   0.00521 Ohm/m


STRANDED WIRE
conductor size      12 AWG
area             3.309 mm^2 (square-mm)
area              6530 CM (circular mil)
diameter          93.3 mil (1)
diameter         2.371 mm (1)
DC-resistance   0.00532 Ohm/m


Notice I stated DC applications. In some AC applications that use high frequency currents, stranded wires offer less resistance and cleaner power.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 04:24:23 PM
MY thoughts on DC lighting, as in MY Opinion.

Let me start by stating that my original cabin designs included a lot of DC wiring for DC lighting. I did that because I wanted to avoid the losses involved in using an inverter to supply low currents for AC fluorescent lights. It's true that a large inverter supplying a small amount of AC power to one CFL light may waste a lot of power. Inverters are generally more efficient when working near their rated capacity. My mind was set on using every watt-hour of hard won solar PV power to best advantage. I was not going to throw any power away!

However, by the time I was finished I also had several AC circuits so we could use a variety of AC items, TV, CD player, radio, vacuum, microwave and so on. I had a horrific amount of copper wiring designed in. Some of those AC devices could have been supplanted with a DC device. That would be cool, but they would only be usable on DC. There is also much less selection in DC devices. Plus some of them are crap. (my opinion).

Added to that was the higher cost of DC devices. Add to that the fact that ordinary AC wall switches don't last long on DC power. They fail before the light bulb fails. Add to that if the DC light fails it may be more difficult to obtain a replacement.

So I decided to go virtually all AC. This choice was also made easier because I wanted to have an inverter large enough to run power tools, microwave, etc. without having to worry/think about whether or not anything else was on at the same time. Choosing the 3500 watt Outback inverter provided oodles of power and many frills such as a power standby system that really works well. (Okay, true I spent a bundle on the inverter; more than what I saved on eliminating the 'extra' DC wiring. But that's okay, I feel I won in the trade offs by having the extra AC power available. To my mind I won. ??? )   I used fewer feet of wiring. My AC  CFL lamps are available everywhere and a great pricing. We do have three DC lights. Two are under the kitchen cabinets for counter lighting. I chose them because I wanted to have a couple DC lights inside the cabin just in case the inverter crapped out. Being at the kitchen counter they are more or less centrally located. They are Thinlite RV type Fluorescents. I know they are not NEC approved but so far no inspector has come round.  ::)  We also have a DC ceiling fan with electronic speed control.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 20, 2010, 05:05:08 PM
BUT, I'll add that if I had built a smaller cabin, with less intended use, I very well might have gone with a system that was predominately DC powered with a provision for lesser SC use. maybe I would have done without the microwave, the largest consumer of AC that we have in regular use. Or maybe the generator would be used more?  ???  The way things are are we could pretty much do without the generator at all. Since our solar system went active last year I have only run the generator to

(1)  equalize the batteries (I have also run an equalization cycle once last summer using the PV panels as the power source. That was a great solar day!)

(2)  run the generator just because it had not been run for a month or so.

(3)  assist in heating up the RV interior once in cold weather. The generator ran 2000 watts worth of electric heater for an hour or so.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 21, 2010, 05:44:30 AM
In my opinion, DC is more trouble than it is worth unless it is a very small system ... except I can't think of anything I would want to mess with it for - oh yeah..... tail lights on my truck.... [waiting]

We need to face the facts..... we are sold out to convenience... throw in a few extra watts to support the slight inverter inefficiencies and quit bothering ourselves with jumping over a dollar to save a dime.... [ouch]


OK - so I'm funnin you a bit but I don't want to mess with DC...  :)



Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 22, 2010, 11:18:52 AM
I'm contemplating moving my inverter and batteries out of the rolling cart (See http://countryplans.com/smf/index.php?topic=4640.20 (http://countryplans.com/smf/index.php?topic=4640.20) for pics) under the stair landing and into a more permanent location in the cabin's utility room.  The cart with its AC & DC umbilical cables makes it hard to access the batteries to check the fluid levels.  

My plan is to place each series set of 2 GC batteries on a shelf and run bus bar up the back of this vertical set of shelves to where each pair of GCs would tie to the bus.  I currently have 4 GC batteries total, but will design for 4 shelves for a total of 8 batteries.

My inverter is a 2kw Prosine with 12VDC input.  I currently have everything tied together with 4/0 copper cables.  I have a couple questions.

I like the use of the copper bar jumpers between batteries the Don & Glenn have used.  I was also thinking of using bus bar from the batteries to the bus.  Aside from having to use wrenches to remove the batteries, does anyone see any issues with this?

Don used insulators on his bus.  My + & - bus bars would about 2 feet apart.  Would screwing bus bar directly to kiln dried wood be a problem?

The batteries would be in a room with potential ignition sources, RV water pump, macerator relay, light switch etc.  Should I enclose the battery shelves put a door on it and run a vent out the top the outside, consider a fan for venting while charging, which the Outback charge controller can control or just vent the room to the outside?

I seen mention here of Storm Copper for copper bus, do they sell small quantities or are there other sources?

Lastly, Aluminum bus bar is less than 1/2 the price of copper even though it needs to be bigger than copper for the same current carrying capacity.  Any reason I shouldn't consider using it for the 2 main  buses? 

Thank you!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 23, 2010, 11:23:16 AM
In no particular order...

Storm copper: their prices on the web all include shipping. They sell any size listed. They will also cut to size, I had them cut the sheet for under the wood stove to the exact size I wanted.  They also have a 800 number and were very helpful over the phone.

I had thought of running bar straps from the battery to the buss, but it seemed like more work to make the connections line up.

Aluminum bus bars. I wouldn't myself, but it can probably be done. Remember there are certain things that must be done when using aluminum in power circuits.

Insulators behind bus bars. For one thing I needed standoffs so I could get the wrench under the bar to tighten the nut and bolt for each connection. A wood block would likely do.

Batteries mixed in with other equipment. I (my opinion) do not like the idea. Batteries do give off hydrogen and oxygen. As well there may be some acidic vapors if the batteries are undergoing a serious charge. I would want to keep the hydrogen away from any potential spark or other ognition sources. Ditto on acid fumes. That's why all my electronics, switches, fuses and breakers are totally separated from the batteries.

Stacking the batteries vertically on shelving does not appeal to me. I want to have enough space above each battery so I can get in there with a hydrometer easily and read the calibrated float easily. I (again, just me) would like to idea of having to lift batteries up above chest or belt level.

You need to minimize the possibility of a wrench, watch band, necklace, whatever from causing a short circuit. That's why I insulated the bus bars over much of their length. I am not sure what the NEC has to say on this. I was/am more comfortable with the insulation since my bars are only inches apart.

If you are playing with different ways to lay out the equipment be sure to not put anything above the batteries. That's NEC as well as common sense.

You could use a positive vent fan for battery venting, but H rises so as long as there is a vent at the uppermost area they should be fine. The Outback CC can also be used to activate venting fans.




Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 25, 2010, 10:37:06 AM
Forgive me if I missed it Don!  Having two ground bars or two ground sources is the only way to know if you even have a good ground. The code is 25 ohms or less! I like alot less in the winter and accept that my Kharma will get me though the dry months. I tell my customers to pour 5 gallons of water on it if it looks like a big storm! Set it up so you can check resistance now and then if your area is prone!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 25, 2010, 11:37:26 AM
I measured between the steel pole, some 5 feet in the ground and the first ground rod and I had quite low ohms. But since the rod and pole were fairly close together I didn't think it counted. I decided two rods would be good/better. Two rods are about 9 -10 feet apart and gave something like 16 between the two rods.

So I guess I ended up with "good" even though all I knew was to aim for 25 ohms or less. I can check by disconnecting the ground wire at one rod and metering between them.  I should probably run a check next time to see what it reads with the ground well saturated, then again in November after things dry out.   

Thanks, Dave. I try hard but am not in the professional league. I appreciate any and all assistance to give to clarify and help keep things safe.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on August 26, 2010, 06:30:17 AM
I measured between the steel pole, some 5 feet in the ground and the first ground rod and I had quite low ohms. But since the rod and pole were fairly close together I didn't think it counted. I decided two rods would be good/better. Two rods are about 9 -10 feet apart and gave something like 16 between the two rods.

So I guess I ended up with "good" even though all I knew was to aim for 25 ohms or less. I can check by disconnecting the ground wire at one rod and metering between them.  I should probably run a check next time to see what it reads with the ground well saturated, then again in November after things dry out.   

Thanks, Dave. I try hard but am not in the professional league. I appreciate any and all assistance to give to clarify and help keep things safe.

Most all homes and commercial have never had the ground connection checked even when new. Offgrid we always exceed code because we are the power company! The cutting edge of all electronics has always been from from marine and space systems. Offgrid is where we benefit and test it in my opinion!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 27, 2010, 03:40:14 AM
I just got this in an email concerning the 2011 NEC Code:

2011 NEC® Changes

The 2011 NEC marks an important milestone—100 years of NFPA sponsorship. Throughout its 114-year history, the Code has continued to keep abreast of the state-of-the-art in technology. Major changes to the 2011 NEC focus on the major issue of the day, which is alternative energy. These changes recognize the demand for alternate energy by providing installation requirements that facilitate safe installations.

Covering solar, fuel cell, and green technology is not new for the NEC, but these latest changes in the 2011 edition keep the Code updated to reflect field experience and current technology.

The 2011 Code has revised Article 625 to include plug-in-hybrid vehicle charging systems as equipment that must meet the electrical protection and ventilation requirements of Article 625. In the future, plug-in hybrid vehicles may not only serve as a source of transportation, they may also be able to serve as a power source.

Article 705 is a key article in alternative energy system requirements for systems that interface with a utility source. It covers interconnecting generators, wind turbines, and solar and fuel cells with utility and other power sources. A number of editorial changes were made to improve its usefulness.

Another change to the 2011 NEC is the addition of new Article 694, which provides new requirements for the installation of small wind electric systems. This new article also covers requirements for individual generators that are limited to 100 kW or less. Multiple wind turbines can be used in accordance with this article, as long as no single turbine exceeds 100 kW. This article is patterned in format after Article 690 for photovoltaic systems.

Tickhill
Title: Re: OFF GRID POWER; various thoughts on...
Post by: TheWire on August 29, 2010, 03:23:40 PM
Started generating solar power at the cabin this weekend.  :)  Albeit temporarily.  I took the 2 new 165 watt 35volt panels and set them against a trailer in the sun.  Ran a temporary wire to the Outback FM-60 charge controller.  220 watts max, in a wooded area.  Its amazing to watch the MPPT controller adapt to squeeze the most power out of the panels even when partially shaded.

Don was right, its hard to not keep checking the solar power gen. status on the Outback.

Next weekend the panels get permanently mounted on a 20' 4" post along side the cabin.  Lucked out with the post, stopped by a local welder to ask about having bracket made to brace the (yet to be purchased) post to the cabin and he said his neighbor had a bunch of galvanized 4" schedule 40 pipe for $30 a 20' length.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 29, 2010, 04:53:37 PM
Reasonable price on the used pipe.



Don was right, its hard to not keep checking the solar power gen. status on the Outback.


It took about a year and now I glance at it only once in a while. But I do check the daily stats using the Mate inside the cabin.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 30, 2010, 11:12:51 AM
Has anyone thought about mounting a voltmeter in the combiner box so you could actually fine tune the array for max voltage periodically? I mounted my combiner box and am seriously considering mounting a voltmeter that I can switch in/out of circuit to maximize voltage. Just wondering,
thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 30, 2010, 11:29:44 AM
When it comes to this question my philosophy is "don't sweat the details".

If by fine tune you mean to optimize the horizontal angle and solar south for a particular day/time, what about tomorrow and the day after? What about the day that's cloudy until 4 PM and then the sun comes out for a couple hours? If the power needs were that critical a reliable tracker might be worth looking at.

Our solar system exists to serve us, not the other way around. I make an adjustment a few times of the year to the horizontal angle, maybe 4 changes maximum. That's it. As for pointing it where the sun should be in an east to west sweep, I picked more or less solar noon. We haven't had to run the generator tp make up for it yet.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 30, 2010, 11:31:15 AM
Not sure I follow you, Tickhill.  Wired in series gives the max voltage or if too high for the MPPT then series parallel cuts it to a usable voltage.  The MPPT controller constantly samples and matches voltage amp draw of the load allowed to get the most watts out of the panel / load compination for whatever way it is wired - within it's capacities and specs that is.

I check with a handheld voltmeter for most testing specs or wire to the panel specs from the manufacturer for proper system design voltages.

Oh - now I understand you were talking about angles and max output.

As Don mentioned - seasonal changes are probably all that is helpful.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 30, 2010, 04:06:36 PM
I see ya'll's point. Probably more trouble than it is worth then. I have been trying to do too much with 155 watts of PV, so maximizing has been a way of life for nearly a year. Dad and I hope to get the new panels up on the mount by the weekend. Glenn, the SUN 3024 inverter/charger came in today and I got it in the system this evening. Looks like one of China's finest but it has all the bells/whistles. It favors a Xantrex on the outside. Will definitely know more once the panels are up. Thanks for your input, blessings
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on August 30, 2010, 04:57:55 PM
Cool, Tickhill.  Looking forward to seeing how it works.  If you get a chance see if soft start or variable speed drills run on it or let us know about any odd things about it. 

My Bosch soft start variable speed rotohammer will not start on my Trace 4024 sine inverter the first time unless I have a regular motor such as a saw running but after the first time it will restart subsequent times as long as it is kept plugged in.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on August 31, 2010, 10:59:35 PM
Thought I would post a picture of the SUN SL-3024 inverter/charger. Mounted in vertical position.
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FP8310164.jpg&hash=566c2957324620aecfbeef2cfe45b2b6)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 01, 2010, 05:50:27 AM
Thanks, Tickhill.  Much fancier than I expected.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on September 02, 2010, 01:50:16 PM
This thread is packed with useful info and I've learned alot reading through it. I'm also planning on being off grid for a while, until such time enough new parcel owners come along to share the costs of bringing in power. I've been looking at inexpensive travel trailers to live in while I'm cabin building and noticed all the RV appliances I see are made for 12V. It seems if I were to keep the battery bank in a shed abutting the cabin, the run could be kept minimal and maybe eliminate the need to run a higher voltage. I'd be charging with a few panels while I'm not visiting and plan enough power for a 3 day stay and using propane for stove/hot water. Considering the RV appliances are all low wattage, geared to 12V, small in size, and come with a nice set of matching oak cabinets made to maximize on space, it seems gutting the inside of a $3000 RV whose equipment was in good shape would solve all appliance/aircon/heating/cabinet issues for a while, no? Has anyone done this and run into any unforseen issues?

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 02, 2010, 02:09:13 PM
Just guessing that the cost of bringing in power even shared could buy you a nice off grid system.

If you are going to be a full time resident you may want to get away from the 12v stuff for more flexibility.  Inverters are pretty efficient and regular stuff has more choices as well as usually being cheaper.  If part time it could be a toss up.

We bought a high end three burner RV cook top and it is excellent - Magic Chef made for Airstream.  Quality varies  but it could be all you need too.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 02, 2010, 05:53:25 PM
I was originally going to use the propane range, fridge, furnace, water heater and the roof top A/C, and lights from an old RV in the cabin we were going to build. Oh, even the shower unit.   In the end we wanted a bigger fridge. We decided we wanted a range with a bigger oven. We decided to use wood stove for heat and supplement that with propane. I decided against the RV furnace as those things are power hogs. The wall propane heater we use as backup can work without a blower; the RV furnace can not.

The roof top A/C was going to need more work to install than I figured it was worth. And the RV lights were fine in the RV, with a low ceiling and lights quite low over the table, sofa, all seating areas. Lifted to a higher 8 ft ceiling that wasn't going to work as well. 

Also after working out the wiring for 12 volt and having some 120 VAC for microwave, etc, the total wiring cost was getting out of hand. You need bigger wires for low voltage, higher amperage.

We wanted to use a regular 120 VAC TV and DVD player. We wanted occasional use of a toaster, a blender. I wanted to be able to use power tools and recharge batteries for them, the laptop and the cell phone. A lot of those things could be done off 12 VDC, but in many cases not with the same carefree ease. Another factor for me was my desire to make our cabin more user friendly in not requiring special things like 12 V light bulbs. I wanted CFL lamps. I would like LED lights but still have not met any that I really like.

So for me, for my wife, I decided it was simpler to build the cabin in a more normal fashion using 120 VAC power for almost everything. That makes it easy to take things from home and use them in the cabin. We have a few 12 VDC Thinlite fluorescent under cabinet lights and the water pressure pump is a 12 VDC Shurflo. We also use an RV water heater (propane w/pilot flame).

That works best for us I feel.  I know there are others who have made a 12 volt DC system work for themselves. It can be done.



One factor not yet mentioned, is whether or not your build will have to meet the conventional building codes. RV appliances are not approved for a conventional style residence. If code gets involved it does not matter if the structure is off grid or not.


When looking at what will work best for you in your cabin I'd begin with performing an energy audit, an honest evaluation of what your power use will likely be. I used a Kill-A-Watt meter to measure actual use on many things. Once you know that, add in a cushion for growth. There is an Off Grid Calculator available for download in the General section of the forum.



Anyhow that's how it all shook down for us. We use the RV we lived in before beginning cabin construction and through the first year or so of the build, as a guest 'house'. It actually hasn't been used as much as we thought it might be and unless that changes we may decide to sell it if we can get a minimal amount for it.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on September 03, 2010, 08:36:01 AM
Thanks for the info. The code requirements are one thing I hadn't really considered. The cabin will be something in the order of 18 x 24, seasonal only. A local said that the town has different requirements for a seasonal cabin and year rounder, but I've not verified that, only that anything over 144sq ft needs various permits.

As for energy requirements, I came up with a rough estimate based on compact refrigerator, TV, microwave and up to 5 CFLs at 7 watts per, and occasionally the well pump. Heat is woodburning stove with propane backup. Hot water will be propane. I figured most of that would be along the same wall the battery bank would be up against, limiting the length of the wires.

I'll need to check in with the local building department to see if a full electrical system is necessary. Thanks for the good advice, and the heads up.

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 03, 2010, 09:46:04 AM
Hey Doc,

Your 7 watt CFL's have my eyes going nuts, but this may just be me.  :(   However, I like to mention this as at one time I could have done with 7 or 11 watt CFL's. But no longer for reading, unless the lamp is 'right there'! My 64 year old eyes don't handle dimmer light and lower contrast very well anymore. There are a number of factors at work, but the bottom mline is that is how it is.  Younger eyes like our son's could easily do with half that. Possibly by the time he is older and may develop problems there will be lighting technology that will be as bright as toidays 23 watt CFL, but more efficient and very cost efficient to boot.


I have 23 watt CFL lights, more or less equivalent to 100 watt incandescent output.


Check on the code requirements. Local officials do have a lot of leeway when it comes to things like being off grid in the boonies. Here, even tho' we're off the grid and lost in the forest the state construction division was not going to approve any electrical unless it was code compliant right down to the spacing of receptacles, etc. Everything. I built according to the code that was in effect at that time, but never invited them to the party.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on September 03, 2010, 02:41:01 PM
I hear you, Don. I gained my distance vision with Lasik surgery 10 years ago, but at 45, I'm holding everything an arms length from my eyes now. Hello reading glasses.

I wonder if LED bulbs will soon be as cheap as the CFL's. They tend to be more of a focused beam and need reflectors to spread the light cone but draw amazingly little. That's a nice type of light for reading. I'd imagine lights being a negligable part of our energy plans in the future, cabin or otherwise. That leaves the microwave and pump. No way around that, I'd guess.

Now from my experience in the last few years of looking at land and camps in upstate NY, it seems that many landowners have put up sheds and garages, not advertised as cabin or home. Once inside, it's clear from the bathroom and small kitchen they are cabins indeed. They're way off grid, and in questionable state of repair. Doubt any of them could get a CO. Maybe it's a wink wink, nod nod thing, but the brokers always say, it's a hunter's garage, with the ability for an "overnighter". Anyway, I'll call the building department on Monday and get more info on all that.

And speaking of off-grid, Long Island escaped Hurricane Earl tonight, along with the usual power outtages that follow. Nice to be online here using power to ponder the lack thereof.

Cheers,

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 04, 2010, 04:25:48 AM
Here is a link to some of the stuff I am doing with my new Sunelec panels and Morningstar MPPT controller making about 7 kwh per day from 1140 watts of panels stationary mounted to the roof.  I didn't want to duplicate the post here.  I'm happy with the new panels.  :)

They are grade B but it seems all that makes them that way are - No UL listing and minor cosmetic chips around most of the edges  of the solar cells in the panels.  They fully perform to spec.

http://countryplans.com/smf/index.php?topic=151.msg121308#msg121308
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on September 04, 2010, 12:23:57 PM
Dad and I got the 3 SUN HS-190-RL panels mounted and they really woke the batteries up! I have included some pictures showing the panels, also the new Tyco solklamp ground clamps for PV and the Outback FM60 in action.
I used an existing 3" rigid conduit and Unistrut for my mounting framework. Will bury conduit and run 8 AWG wires from shop to panels, only about 25' away.
Blessings

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FSolarPanels004.jpg&hash=63b25ddf703e286cfcd28dd312f07e2a)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FSolarPanels003.jpg&hash=5051df7bd1d4c7168068ce5b4da32ac4)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FSolarPanels002.jpg&hash=ba69a4ad5a8de56cb1a3382a20cd3720)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FSolarPanels012.jpg&hash=4769de82e80c3cfac6eed78363ab1fcf)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2FSolarPanels006.jpg&hash=4fb633557c74c8365050f5204352fbb6)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 04, 2010, 12:51:27 PM
NIce job, Tickhill - much fancier than mine.  The Outback would have been my other choice for a controller but I have wanted to try Morningstar for a long time too so got it.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on September 04, 2010, 12:59:12 PM
Thanks Glenn, I called Tony with Sunelec this week and asked when he thought they might have some more of the 190's in because they were no longer listed on the website, he asked how many I wanted, they had 24 left over so I have 3 more coming next week.
I will have to do some more bracing, probably will make them stationary at solar noon. Those panels weight alot more than the ones I took down.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on September 04, 2010, 05:20:53 PM
Wow, Glenn you got 7 Kw-hr from 1100 watts of panels per day !!

I was projecting about 10 KwHrs per day from 2460 watts of Evergreen panels (12 205 watt panels from Sunelec)

based on zone 5 and this calculator

http://www.wholesalesolar.com/StartHere/OFFGRID/OFFGRIDCalculator.html

You are doing good !



I think I have talked myself into the Xantrex XW series charge controllers and inverters -- the charge controller can handle a max of 60 AMP DC (the panels should give about 50 A max)and the XW6048 inverter (6 KW output with 12 KW surge) should handle even the largest shop tool I can think of....)

Now if I can just get a winning lottery ticket for a bank of Hup batteries (or Rolls/Surrettes)

nice job on the  mounts tickhill  (and you too Glenn :) )


I almost have the solar panel mounts for the Red Rider "low speed vehicle" completed (4 50 watt panels and a Xantrex C-40 contoller...pics to follow ) and yes we did get the $5335 tax rebate and cashed the IRS check imediately, too -- lest they change their mind --

It did my heart good to know that our tax dollars helped to save the jobs of those Chinese slave laborers that built the LSV -- God bless our insane congress critters -- at least the batteries were built in  North America (Canada) (NOTE: some sarcasm here)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 04, 2010, 09:00:09 PM
I reset the counter again this morning - still having a hard time believing that myself, Windpower.  Todays count was 7.310 kwh. [ouch]

I was not expecting over 5 or a bit more myself.  That Morningstar is really grabbing all the watts.  This is the first time I have bought a big enough batch of panels at one time to warrant getting the extra good controller.

Thanks for the compliment on my mounts, Windpower.  I know I did a real professional and craftsmanlike job... heh 

It is the kind of quality I have come to expect from myself.... at least they will probably not blow off the roof. 

At about $10 for boards and $5.00 for screws, costs were getting a bit out of hand but I figured ...Hey lets splurge on this project....  Can't take it to the grave with me... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on September 05, 2010, 01:35:43 AM
Actually Glenn I really did like your mounts

I am big on practical and inexpensive solutions to problems

Maybe this has been covered here already but

I am trying to find a place for the batteries --what are the practical low temperature limits for winter operation

I have a cement "pump house" on the property I think it would be not too difficult to keep it at 50 F in the Wisconsin winters and of course in the summer it probably never sees much over 80 F

It is also right next to the windmill tower where I plan to mount the wind generators that may use the same battery bank or another bank

There is also a cistern about 15 feet deep that is very temp stable probably 50 to 60 F year reound -- not sure I want to put a bazillion pounds of lead that deep though  or climb down there just to check and water the batts once a week

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 05, 2010, 05:01:07 AM
I think Dave Sparks mounted his extras in a similar fashion also as I recall.

Others have mentioned using wood also.

My batteries get into the thirties in the winter (air temp).  As I recall it is harder to freeze a fully charged battery - I think Mtn Don is up in the cold weather and cars often sit out in the cold.

I think we fill our batteries ever three months or so but check them in between.  Old batteries require more filling -use more water.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on September 05, 2010, 09:33:29 AM
Glenn, I checked this morning and the new panels, according to the Outback, produced 4.0 kwH yesterday. Dad and I adjusted them most of the morning so they tracked with the sun. This morning I pinned rotation at solar noon and I will check in the morning to see what they get in a fixed position. There is not a cloud in the sky here in North MS today and a little wind. I'm just not used to so much power being produced because all we had last year was an 80 and 75 watt panel. Right now my Dad's shop lighting and storm shelter are being supplied by the PV's. We couldn't even keep the batteries fully charged til now. I really tried to make the wind work for us but we have breezes not wind here. PV just sits there and hammers out the juice.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 05, 2010, 04:39:27 PM
That is great, Tickhill.

Note that with wind you need to be a minimum of 30 feet above the tallest obstacles - trees etc, in your area, but 80 to 100 feet is better and will have at least 3 times the wind you will on the ground.  Surface friction - turbulence at ground nearly stops the wind.

I got another treadmill yesterday at the SPCA yard sale for $10.   This one has a 130 volt 2.5 max DC motor in it.  That will make a good wind generator with proper gearing.  Some of them I have see have a multi-v belt running on a small and big pulley.  I think that may gear it fine and the thin multi-v belts don't use much power.  Haven't built one yet though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: uncle on September 05, 2010, 05:40:34 PM
I've read the entire thread and I've hurt my brain trying to follow all the useful info here.
I do have one question, I have seen on other boards where they promote forklift batteries for the pv system. I did not see any reference to this type of battery so here goes, Will a forklift battery work for a solar system?
Brian
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 05, 2010, 08:20:18 PM
It will...... but.... [waiting]

L16's are like a forklift battery - golf cart batteries are like a forklift battery but smaller - used in many manlifts etc.  Most all have the lead antimony plates that are very durable like a forklift battery.

6 volt batteries in series or series parallel= the voltage and amp hours of a forklift battery.

If one in a set of 4, 6, or 8 in series (24, 36 or 48V) gets a bad cell you can replace it by itself with a used one if they are older , or a new one if they are newer for from $100 to $300 or so dollars.

Usually you will be running more than one set of series batteries on a larger system so you are not out of power while you get it fixed.  

As Dave mentioned, you could go to Costco and get a golf cart battery to keep your system running -even putting it in with the old L16's  

If a forklift battery loses one cell, you replace a multi-thousand dollar battery all at once. and likely you will not have backup until you get it fixed.

L16's and golf cart batteries are easier to find and not such a big expense all at once.  One man can move either of them.  It takes a crane or forklift to move a forklift battery.  Can be done but not real practical.  Possibly consider it if someone gave you one, but likely it would not be in great shape or have much storage capacity.  :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: uncle on September 06, 2010, 02:26:38 AM
That makes sense.
Brian
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 06, 2010, 04:16:58 PM

I am trying to find a place for the batteries --what are the practical low temperature limits for winter operation

Battery capacity is rated at 77 degrees F, 25 C. The chart below shows how the temperature affects the capacity. At freezing temperature the capacity is reduced by about 20%. At the same time that capacity is falling the probable life span is increasing, so cool temperatures can be good as long as the battery bank is large enough to avoid over discharging.  Cold temperatures also require an adjustment in charge rate which is the advantage to a charge controller equipped with a remote (battery) temperature sensor.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2FBatt_temperature1.gif&hash=0318ea8c9225fec90c84b11cebe327d7)

Higher temps offer increased capacity while cutting projected lifespan.

I would think that if you can house those batteries where they would run between 50 and 80 degrees F you would be doing good, getting good lifespan and being able to make pretty close to maximum use of the rated capacity.   The batteries at our cabin run quite cold in the winter. Because it was rather oversized we've not had any capacity problems.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Headed for the Hills on September 06, 2010, 04:18:11 PM
OK, have been struggling with my solar power.  I have seven (7) 15 watt Northern Tool panels connected in parrallel and connected to a Sunforce 30 amp charge controller.  However, even under the best lighting conditions I have only been able to produce .6 amps and usually only .2 amps to charge my battery bank (running a 12 volt system).  Have used the connectors provided when I wired the system, but am wondering if I should cut the connectors off and use wire nuts to connect the wires or even soldering all the wires.  No addditional wire has been added, so I don't think power is lost in the wire length.  Shouldn't I be producing much more than that?  Any help would be appreciated.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 06, 2010, 04:34:28 PM
Nice looking installation tickhill.



Forklift batteries. My own opinion is that if you have a forklift go ahead. At 115 lbs apiece a Trojan L16 is already heavy enough.


My dream battery bank would be 12 Surette/Rolls S-1380 2 volt cells in series. More capacity than we now have; probably want some more panels too and then we could use an electric fridge most likely and save propane.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 06, 2010, 04:54:44 PM
7 x 15 = 105 watts,   divided by 12 volts = 8.75 theoretical amperes at panel rated output.  

How are you measuring that amperage? Test meter wired into one of the wires between panels and battery, like in the + lead. Are the batteries fully charged when metering the charge rate? If they are full then the charge controller is doing its job and keeping the current to a float rate.

I have 1  1/2 of those panels hooked to the RV batteries to maintain their charge over the winter. (1  1/2 as one panel is cracked and the output has fallen   ;D )  It's been a while since I metered them as the batteries stay up fine. But IIRC on a sunny day I was getting about one ampere from the one good, unbroken panel.

So with them all parallel connected you should be getting much more than the 0.2 to 0.6 amperes. Either the panels are not putting out or there is excessive resistance somewhere. With loses like that I would expect to find a warm to hot connection someplace (full sun and battery needing to be charged).

Wire nuts are a poor idea for DC circuits. If it was me I'd cut the leads so they are only a bit longer than required. Leave some extra length in case you have to reconfigure them someday. With a good terminal lug crimped or soldered on each lead you could make up your own combiner with some strap copper, a drill, S/S bolts, washers and nuts (in a weatherproof plastic box). Crimp connections are fine; better in those cases where joints end up being poorly soldered. Connect the charge controller to the bus bars with adequately sized wire. With each panel wired to a bus bar like that it is easy to remove a panel at any time if needed. Plus you would have less resistance with shorter leads and better connections.

Have you tried metering the output from each panel separately?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Headed for the Hills on September 06, 2010, 05:13:02 PM
Thanks for the reply.  I'm measuring the amps thru the charge controller.  Checked each panel with volt meter during install and all read between 12 and 14 volts (didn't check amp reading though thinking back, probably should have).  The connectors provided were plugs and with either cigarette lighter ends or just bare leads.  Took the ones with the bare leads and crimped them all together.  Plugged the panels in and ran wiring to the charge controller.  Checked voltage at charge controller and got the same reading as directly from the panels.  Purhaps a charge controller issue?

Do you think creating the bus bars inside a weather proof box would work better? 

Also, can you separate panels to where half are in the sun during the morning and the other half during the afternnon?  Or would you lose power to those panels not charging while the others were?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 06, 2010, 05:47:02 PM
If your panels are like the ones I have on the RV they came with a "trailer light" connector, into which you can plug the 'extension' with the bare leads or the cigarette lighter plug. I would cut those connectors off. Before doing that I would carefully mark the positive and/or the negative leads.  I use white tape on negative wires. Any system you can remember works.

If you have all the positive leads (7) connected together and then all 7 negative leads connected together (parallel connections) and measure the voltage in bright sunlight you should have something like 18 volts, maybe more with nothing at all connected to the panel outputs. This would be the same as the output from one panel.

With the charge controller input connected to the panel outputs and the charge controller output connected to a partially charged battery, in bright sunlight, you should likely see something like 13.5 to 14.something volts at the battery. Measure the amperage in either the positive or the negative lead from the charge controller to the battery. That will be the current the charge controller is passing to the battery. The battery needs to be partially discharged in order for this to be accurate. Theoretically the charge current could be up to 8.75 amperes, but most likely your real world result will be a little less.



As for half the panels facing one direction and half another direction, everything in parallel, and feeding through the same charge controller I'm not certain on the outcome. I think that should be okay with the equipment you have. I'm not convinced that will result in any better total power output for the day if the weather/sun conditions were the same all day.   ???  You could improve the output of the set that was directed for best AM power but at the reduction of the power from the ones that were directed for PM output. With everything pointed the same direction, most likely south, I believe it will all average out, given the same weather/sun conditions.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on September 07, 2010, 02:22:46 AM
Thanks for the temperature info, Don


I am thinking the 'pump house' is going to be a perfect location for the batteries and inverter and charge contoller
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Headed for the Hills on September 07, 2010, 03:18:38 AM
Thanks for the input Don.  Next time I go to the Cabin, I think I will try and re-wire using your suggestion.  I was suspect of the "plug-in" connectors and had thought about wiring differently from the start.  I am new to solar power (as you can tell), but am eager to have an operational system and staying off the grid.  Nothing major, just lights and a ceiling fan.  At the most, 3 or 4 CFL's and a small fan.

My panels are wired to a small battery bank (2-35 amp hour batteries) and then to a small inverter.  Doing my rough calculations, the 7 panels should easily keep the batteries charged.

Am open to an suggestions and will post later with more questions I'm sure.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 07, 2010, 05:06:09 AM
With a small system like yours a fan that runs right off the batteries might be nice. DC lights too so you save the inverter loss. As much as I like my own inverter powered system, for something very small I would think about strictly DC.  Just a thought. You can get DC powered CFL lights with the screw in edison base if you do not like the type of light LED's put out, or their cost.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 07, 2010, 05:43:24 AM
Here's some info from the Trojan battery company. This may be specific to their batteries, or in other words, if you have some other brand of batteries this data may not be what the other guys recommend. This data is also for flooded lead-acid batteries, not any type of sealed or non lead-acid battery.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Fbatterychargevoltages.jpg&hash=845d1bd5aadb860bd4aba1af59801e29)


http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx (http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 07, 2010, 05:59:17 AM
The Morningstar takes the L16's a bit higher to 32v on their special L16 battery setting which agrees with my experimental findings and info I  rec'd from an knowledgeable solar dealer in Lake Powell area.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 07, 2010, 06:57:11 PM
A question regarding Equalization was asked in another topic. I thought it might be best to copy it to here and respond here as well...

Flooded lead-acid batteries, imperfect things that they are, will develop inequalities between cells over a period of time. They may start out with more or less the same specific gravity (state of charge) but this may wander over time. The goal of equalization is to eliminate these variances between cells. This is done by applying a higher voltage than what is normally used, and at a low charge current. Equalization charges will cause excess gassing to take place, therefore the fluid levels must be watched. Equalization voltages also causes the "stirring up" of the electrolyte. Tall batteries may be more affected by stratification than shorter batteries. The rapid bubbling mixes things up.

Equalizing produces large quantities of hydrogen and oxygen. Good ventilation under equalization is necessary. I open the battery enclosure doors and leave them open.



Regular battery charging has three stages. All good battery charging equipment will have the basic three, Bulk, Absorb and Float. A better or best charger will also have the equalization capability. Whereas the bulk, absorb, float charges are programmed in and will automatically progress as the battery charge builds (in the best units they are user programmable), the equalization charge is usually initiated manually.

In the bulk stage, current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level.

In the second stage, absorb charge, voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage.

The third stage is float. After batteries reach full charge in absorb, the charging voltage is reduced to a lower level to reduce gassing and prolong battery life.

If battery power is being consumed during the charging the charger can shift back and forth between stages as needed.


Equalization should only be necessary a couple times a year. Too frequent use of the equalization cycle could reduce battery life. If the specific gravity readings show irregularities with increasing frequency that may be a sign of a batteries impending demise. Glenn had had some good fortune with desulfating processes.

Here's another chart with slightly different values....

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Fbatteryvoltages.jpg&hash=11805c42b3aa4bd22a6d2a0217780f4c)

That one is from TheSolar.biz  http://www.thesolar.biz/Battery_charging_article.htm (http://www.thesolar.biz/Battery_charging_article.htm)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 07, 2010, 07:12:34 PM
It probably can not be stressed too much that equalizing applies to flooded lead-acid batteries. AGM and gel cells are not the same. Flooded lead-acid means the type of battery with removable caps, ones you can add water to.  Other battery types can be damaged.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 07, 2010, 09:45:30 PM
Also, mentioned before but again....Keep water levels above the plates during equalizing or permanent damage may result.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: diyfrank on September 08, 2010, 04:29:22 PM
Got it, Thanks  ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on September 10, 2010, 02:40:48 AM
Glenn, got the other 3- 190's yesterday and hope to get them online this weekend. Will probably add another set of batteries also. Then it is time to bury conduit and run the power to the barn. Dad and I will probably wait for some rain to soften up the ground.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on September 10, 2010, 07:34:21 AM
Don and others!  here is a link from a ways back where folks at the outback forum were trying to use energy wasted after the battery was mostly charged offgrid. They basically are heating water with a coil. It does work but I have always thought it was a big time waster as it is so much more efficient to use the sun to heat water directly. It is far better to use an electric heat pump for excess energy.  It might give you some insight on your experiment Don. Let me know and I can get you a model number for and SCR.

http://outbackpower.com/forum/viewtopic.php?f=29&t=2865&hilit=electron&start=25
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 10, 2010, 10:57:51 AM
Thanks Dave.

Well.... I haven't posted the reason for what Dave just referred to before this. Here goes as succinctly as I can.

The PV panels don't need to do much when we are not at the cabin as there is no electricity used for anything. The PV system simply has to keep the batteries at full charge. So there is "wasted" power. Anyone with a PV system hates to waste a single watt, let alone a whole days worth.

What to do with the excess power?  Heat something comes to mind.

One of the drawbacks to a cabin in the boonies is that during freezing weather, December to April, more or less, water freezes. Dry/dried foods such as beans, pasta, rice, flour, etc. goes only so far. You can only eat so much peanut butter. Frozen glass jars (spaghetti sauce) break. Metal cans (beans, meats, fish, veggies, fruit) may have seams crack and spoilage set in when it warms. Freeze dried food varies from so-so to okay in my opinion, with okay being a euphemism for "at least I won't starve to death as long as I have this."

So it occurred to me that possibly there was sufficient excess PV produced power to use with a resistance heater, in conjunction with an insulated box to provide a storage space that would remain above freezing.

I asked Dave if he could recommend a solid state relay to use with the diversion capability of the FlexMax charge controller. That would allow the excess power to be used for heat after the battery state of charge was assured to be full each day.

Obtaining an appropriate SSR is no problem. PV cells are the real problem. PV cells are still grossly inefficient.  

I have collected weather data, including solar watts per square meter. Winter sun angles sure kill what's hitting the panels. I've run my figures a few times over a long period of time. Without getting into the actual numbers let's just say that maybe IF we had three to four times the number of PV panels, then maybe we'd have enough excess PV power to heat a small food storage locker. A well insulated locker with lots of mass to help make it through the night.

This needs some more thought. As Dave has suggested, it may be much more advantageous to use a solar water heater and storage tank with a small solar driven pump. The collector could be set up as a drain back type and used antifreeze as the liquid. More of the suns energy would be used. The downside, in my case, is the solar situation at the cabin is poor. That actually depends on the season. It's actually great having all the shade in the summer.

With some more thought this could be used to provide warm/hot water for domestic use. (In the winter we usually do not even use the water heater as the water system is left drained for freeze prevention. In summer this could save a little propane, not that we use a lot for water heating.)

If anyone wants to get into my numbers, calculations and theorizing, just say so.

Thoughts, comments, arguments, encouragement, discouragement, etc. all welcomed.  
Spin off to a cold weather food storage topic?  Or leave it here are it is related to Off Grid Power? Or perhaps an Off Grid, non electric power topic?


Title: Re: OFF GRID POWER; various thoughts on...
Post by: Bob S. on September 10, 2010, 07:42:58 PM
Don: Do you think some sort of root cellar would work?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on September 12, 2010, 09:01:35 AM
Got the extra panels up, here is a picture. Will post kwH sometime tomorrow. We went from around 19 amps charging to 35 as soon as I brought the panels online.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi877.photobucket.com%2Falbums%2Fab335%2FTickhill%2F6SolarPanels1.jpg&hash=fe8fc7acd46935e68b308e619173f838)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 12, 2010, 01:20:59 PM
Don: Do you think some sort of root cellar would work?

I'm sure that would work. I simply don't want to dig a big hole and all the rest that would be required. It would have the advantage of being a place I could leave some potatoes, carrots, but considering that it is just to allow us to go up there for maybe a total of 20 nights from mid December thru March I'm not sure that's what I want to do. I may change my mind over time. Thanks for taking the time to respond.

I/we did more thinking about this while we were at the cabin the past couple of days. Some more thoughts, ideas and questions to come. Likely in a new topic.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Bob S. on September 12, 2010, 03:13:20 PM
I think you could keep a root cellar from freezing inside with a light bulb.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 12, 2010, 03:37:09 PM
I think you could keep a root cellar from freezing inside with a light bulb.

There are many places where that could be a solution. However, resistance electrical heating can be too big of a drain on small off grid systems. Thanks though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 13, 2010, 07:00:26 PM
A new off grid problem and solution.

DSL modems seem to be highly susceptible to power surges and resets as loads change on inverters.  Nearly every pump start our DSL resets and then it is 2 minutes more to stabilize.  A real pain when posting on the forum.

Apparently it is a common problem in countries without stable power.  I often wondered but found the answer on a forum from Pakistan.  The tech there said that the DSL modems were not made to handle the instabilities in inverter power.  He recommended a UPS.  Before that I was not sure if they smoothed out the surges or not.  They do as the tech said.

A good quality UPS (un-interruptible power supply) takes whatever power there is available and smooths it down sending out stable power to the battery and surge protected outlets.  I got one from Amazon and it arrived today.  I have been running today through multiple pumping cycles without one interruption.  Hooray. :)

This is the one I got  - it was the most value and biggest for the money as well as being a good brand and having high recommendations - note that there are some that others would never buy again.  Read the reviews before you buy anything.

http://www.amazon.com/APC-Back-UPS-Outlet-550VA-120V/dp/B0019804U8/ref=pd_ys_iyr1


I did read of one person trying to stabilize a cheaper UPS as he had problems with it, but good ones are pretty cheap and take care of the problem.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 14, 2010, 08:24:47 AM
Today - second day of the UPS -

I can hear it switch over to battery (relays click) as the pump starts cause system surges.  No internet DSL loss.  It just happened.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 14, 2010, 08:44:47 AM
That's cool!  Another use for the old UPS we don't need.  :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 15, 2010, 07:09:23 PM
Question for Glenn:

Glenn, does your Bergey dump directly to the diversion load when the controller says the batteries are full? That is the power is NOT fed to the batteries and then bled off. The excess power goes directly to the diversion load, a pump in your case IIRC. twin 12 volt ford starter relays.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 15, 2010, 07:11:22 PM
Glenn's answer....

I did the above question originally via IM, then realized maybe someone else might be interested in his response. So here it is....


It dumps to the relays in my case

But now that you mention it... making me think here - The red light comes on - I assume it is dumping the power generated directly to a heater etc - or my relays, but the wind generator cannot stop producing and it is hooked to the batteries so I don't exactly know how it is done.  My pump bleeds the load off of the batteries but not sure what the bergey does with the gen power.

The manual is available from the Bergey site I think for free download - XL1 wind generator.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 16, 2010, 06:37:09 PM
The answer to this seems to be that the common diversion method is to charge the batteries but bleed or skim the excess off the batteries.

As the battery bank voltage approaches the battery
regulation voltage, the PowerCenter controller
will first try to restrain this voltage by applying the
5
optional Extra Load (or “dump load”). The Extra
Load function diverts current from the battery to
an air or water heater.


I've also found references to dump loads that indicate similar operation. It seems there is a reason for this method. Dump loads are made to operate within specific voltage ranges, such as 24 volts with a range of maybe 24 to 30 volts. A 24 volt wind gen could be putting out 80 volts at higher wind speeds. Without having a battery to even or smooth out the voltage the heater would burn out.

Similarly, and thanks to NM_Shooter for this, things like heater elements can behave strangely at voltages far from their design specs. The design impedance, resistance in other words is reached when the coils or nichrome wire reach operating temperature. At lower temperatures they may be quite different from their design point values. I verified this on two different electric heater elements. This can make it difficult to use a heater coil designed for one voltage at another that is significantly different. The calculated ohms at the design voltage can be very different at lower volatges where the element will not be able to reach design temperature.

Why am I bothering with this?   I was looking into using the excess, the un-used power from my PV modules as they sit there in the mountains with the cabin vacant. I wanted to use the power for heat; perhaps an air heater, perhaps a water heater. I also thought it preferable to divert the power before it was processed by the charge controller. It seems more efficient to use it right away, rather than feed it through batteries. But that seems to have problems or issues.

Maybe this'll be of interest to some other tinkerer.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 18, 2010, 08:32:08 AM
We probably have covered this already, but a reason for the dump load to be applied for a wind generator is that if the generator is not allowed to continue charging, ie: is disconnected from the batteries, it will or may  increase in rpm's until it possibly destroys itself.  

It must not be unloaded during overcharge conditions but rather furled or the load burned off in one way or another.

Keep in mind that anything you run off of your AC inverter will pull the battery power down also.  Relays can be hooked to the dump load to run a water pump, heater or many other things also indirectly.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Shawn B on September 19, 2010, 07:16:07 AM
Can anyone recommend a good thorough book on residential solar systems.  In particular I'm interested in the pro's and con's of grid tie versus off grid systems. I *think* I have a decent understanding of the wiring required for a off grid system. I haven't been able to find a decent schematic for a grid-tie system or the extra components required.

Is it worth it economically for a grid tie system? (spinning the meter backwards to reduce electric bills or even get a rebate?)
By grid tying is there any extra tax or fees from the power company or local gov't?

I live in N.W. Indiana and we get plenty of sun year round, except for a few short day stretches in the winter.

Thanks,
Shawn
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Shawn B on September 19, 2010, 01:24:12 PM
After more research I don't think I would want a grid-tie system.

according to the below site a grid-tie system won't operate when the "grid" is down ???  What the heck, why buy a expensive PV system then be in the dark like everyone else during power outages? This does answer the question in the back of my mind, " What prevents the system from back feeding and possibly injuring a lineman when the grid is down?" Now I know....it doesn't produce voltage at all. I was thinking that there would be a auto-transfer switch disconnecting the grid from the house ???

http://solar.smps.us/grid-tied.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 20, 2010, 02:54:36 PM
Most grid tie systems do not have batteries. That's why they go down when the grid goes down.

Automatic switches prevent feedback, the same sort of thing is required if one has a generator backup with a normal grid only home.

It is possible to have a grid tie system with batteries for backup. Also possible to do grid tie with a generator for automatic backup if the grid goes down. Frequency of outage would be one factor to consider.

Sorry, I can't recommend any books.

Not all power companies offer the same payback deals for grid tie. NM's major supplier has an excellent payback. No guarantee they will always offer the same deal though.

Is it worth grid tieing? That depends on personal needs and wants. No batteries means money saved and less bother. Not everyone wants to tend the system. Of course some folks pay guys like Dave to do that.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on September 21, 2010, 05:13:21 AM
Not quite right Don, but thanks for the plug! We only go where the power lines don't!  I would be go bonkers otherwise!  ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: rick91351 on September 21, 2010, 05:48:54 AM

Is it worth grid tieing?  That depends on personal needs and wants.  No batteries means money saved and less bother.  Not everyone wants to tend the system. Of course some folks pay guys like Dave to do that.


I am thinking about tieing in some solar or maybe wind to our next phase in our 'moving to the ranch' build.  We are on the grid, and at this time have no intentions clipping the power cord.  However it would be nice to have back up.  Talking to some of the ranchers and a store owner up there, it seems as if there is a major outage there are three places at this time they have to come and reset manually.  Summer time this takes about a hour to an hour and a half.  They are close to the road and easy to get to.  In the winter  [waiting].  Hey it is Idaho winter.

That said how much time is involved in tending to a system that is large enough to tend to the basic needs of a home in the winter time?  Very easily heated with wood but would have some propane back up if need be so there would be a fan there.  We would need to run a well pump, few lights, refrigerator and a couple computers up and going and what else am I missing?  We have a wood cook stove for the winter time, electric or propane in the summer.

Any ideas?        

 

 

    

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 21, 2010, 06:52:59 AM
Time; once everything is up and running. With quality hardware (inverter, charge controller, panels, etc.) there should be no real maintenance there. Keep the dust off.  Wet cell lead-acid batteries require maintaining the electrolyte level. I have not had a lot of experience other than our own system. Our batteries use very little water. I've only added water about every 6 months. Batteries that are used more, discharged more deeply and then recharged more than ours probably use more water. BTW, water should only be added to batteries that are fully charged if at all possible. That's because the fluid level falls as the charge is depleted. If the plates are not covered they should have water added to just cover them and then charged. As batteries age they may need more frequent watering.

I take and record hydrometer readings every month or so. Mainly just to keep an eye on things, look for low cells. So far it has simply been an exercise in record keeping.


I bought golf cart batteries as a trial. I was worried I might do something stupid and ruin my first set. ???  I don't know what, but there it is. If I was doing this again for a cabin I'd give more thought to maybe buying L-16 batteries instead. If I was setting up a primary off grid residence I would like to have Surrette batteries.


As to whether or not to grid tie... ???   As with all solar generated power, the place to start is with an honest evaluation of power needs, not power wants.  At present many power companies offer great buy pricing on user generated excess power. Who knows how that will play out in the future. Here in NM the main reason, as I see it, for the high buy prices on PV or wind power is that the state government has mandated that certain percentages of a power companies power must come from renewable sources. A grid tied home counts towards that figure. So they gain without having to spend any money for equipment. In fact they charge the home owner a hookup fee before giving anything in return.

In a similar vein, the local water utility has pushed water conservation heavily for years. Many people use less water today than a few years ago. The water company revenue has fallen and they have increased rates because we've saved water. OK, maybe the price would have gone up even more if we had not conserved. My point is, that if too many people installed grid tie systems would the incentive be reduced when they reach a point of too little demand from them?   


One nice thing about looking at this early in the design stage is it would be relatively easy to divide the wiring up into "mission critical" things that one would like to have on some sort of a backed up power system, plus all the other stuff. Properly planned it could be fairly painless to switch circuits around down the road.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on September 21, 2010, 06:34:11 PM
Watch that your grid tie system is designed to be used off grid also.  There are many up here who only bank power with the grid and do not have batteries so if the grid is down they still do not have power - no storage - pretty useless in my opinion but it does knock their bill down.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on September 28, 2010, 09:57:56 PM
Our 'neighbor' who's been on solar power for 30 years...ya 30 years....uses, get this, caterpillar batteries now.  He says he's got almost 1000ah of batteries and his old 500ish watt solar panel array can keep the batteries charged reasonably well Monday through Friday in the summer.  They run the generator on weekends for higher demand stuff and he tells me they run way to much as it is.

Anyway, he was telling me that he's tried nearly every kind of battery imaginable over the years and for some reason settled on these caterpillar batteries and likes them.

Personally, not being knowledgeable about these things (sure I've built cell sites in remove location but the engineers chose the batteries) I'd go with something recommend by those who do seem to know -- thanks to Don I'm using Golf Cart Batteries and see no reason why it won't work :)

Anyway, back to the point about power in Idaho, I don't see why you couldn't have a small system in place to provide backup.  Since running a small 60 watt system for our well I'm very impressed and having installed (ok it's not complete yet but it's a start) a 615 watt off grid system I'm realizing the hardest part is the figuring out of what you can or might run and for how long -- but once the figuring is done and the system is in I figure we'll know soon enough what 'too much' is  d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on October 28, 2010, 08:36:15 AM
I've been told by a solar installer that the golf cart batteries are best because they are designed for repeated discharges to fairly low levels followed by a nightly recharge. They have thicker plates and stand more abuse. The car and diesel batteries have plenty of amps but were designed for massive discharges over a moment or two, followed by extended periods of charging never cycling more than a few percent from full. Could Caterpillar be using heavier batteries? They may not be the run of the mill diesel engine batteries since their equipment may lay still in a field for months, then be called upon to start in frigid weather without fail. I'd love to see the specs.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on October 28, 2010, 09:44:42 AM
I would say that gold cart batteries are better for off grid energy storage than a battery designed for engine cranking, but not best. Better than golf cart batteries would be the L-16 type. Best would be something like a Surette.  

Also remember battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD (depth of discharge). If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%.

I like golf cart batteries  for a few reasons, their weight is one. Very cost effective when bought at warehouse (Costco, Sam's Club) prices, though they will need to be replaced more frequently than other types. Great batteries to learn your off grid battery maintenance skills.

I would love to have a set of Surette 2 volt cells, but price got in the way. We'll see how that goes in maybe 5 years.


Re: CAT batteries; links to applications and specs...
http://www.cat.com/cda/files/90229/7/PEGP7801_05.pdf (http://www.cat.com/cda/files/90229/7/PEGP7801_05.pdf)
http://www.cat.com/cda/components/fullArticle?m=37407&x=7&id=241185 (http://www.cat.com/cda/components/fullArticle?m=37407&x=7&id=241185)
http://www.cat.com/cda/files/1386197/7/PEHJ0073-02.pdf (http://www.cat.com/cda/files/1386197/7/PEHJ0073-02.pdf)
Just bigger versions of good quality car and truck batteries, more than likely.  ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on October 29, 2010, 11:48:19 AM
A too-small bank of batteries has obvious drawbacks. But is there any reason not to buy and assemble an array somewhat larger than my expected needs.. sort of a "just in case", scenario?

I've been told by others that it's a bad idea to add new batteries to older. Is that to say used and unused should not be mixed, or is it the age of the battery? I was thinking to soften the outlay, I'd buy 3 or 4, then another few each month, until I had enough to set up my system. They'd be unused of course, but would the shelf life be different in this way?

Cheers,
Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on October 29, 2010, 12:39:02 PM
This is timely

I am shopping for a 48 V bank

I think I have settled on the Surrette CS 6  17 PS

they are pricey (~$800 times 8  :o) but of a new design that allows replacement of individual 2 V cells 

shipping is another PITA

and unloading them without a fork lift  (OK the JD end loader will help alot) they weigh in at about 220# each

the SolarBiz seems to have the best price but again shipping is uncertain .... maybe another $500

the other option is to get a pallet of 18 Surrette S-530 (older design) but at 'only' $329 a piece and free (or nearly so) shipping from (below link)
would give me 16 for the 48 V bank and 2 spares (is there a 'shelf life' on batteries that have not been filled with acid ?) for about same money maybe a bit cheaper

  https://solarconduit.com/shop/batteries/batteries-accessories-flooded-batteries?p=2t

plus they would give more capacity ~ 26500 Watt hours @ 50% discharge compared to the cs 6 17 PS at ~ 19250 Watt hours @ 50% discharge

and prices seem to going up too

 
Tough decisions ...


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on October 29, 2010, 01:09:17 PM

I've been told by others that it's a bad idea to add new batteries to older.

Depends what older is.  If they were all put into service within a few months it's no big deal. Over a year older it is not advised, but people do it.

To go a little bigger is more than likely a good idea. When you are calculating was depth of discharge are you considering as your aim point.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on October 29, 2010, 01:17:15 PM
I am certain that if you buy dry lead acid batteries they can sit in storage for years. The lead has nothing but air to react with and I doubt anything bad will happen. The cells are closed, any O2 will get quickly used up, and that should be that.

Seems to me I recall there being no discount for dry purchase, but shipping and handling is easier as they are not hazardous when dry. Unless you drop one on a foot.  ;) 

The handling weight sure is something to think about.

Way back when I was a lot younger service stations stocked all their batteries and added acid only when the customer bought it. It was easy to find the acid in 5 gallon collapsible plastic containers back then. Probably a little harder now.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on November 02, 2010, 11:58:24 PM
Glenn, just wanted to pass on info on the SUN SL 3024 inverter/charger. I sent it back to sunelec yesterday. It was giving constant over voltage alarms and would not reset properly without having to completely disconnect the unit from the dc bus. I contacted Tony with sunelec and he said to ship it back to his attention, should be there by Friday. I have since rolled back to a backup HF 1200 Modified Sinewave inverter for lights/gargedoor opener.
The price on the inverter/charger was great but I guess you get what you pay for. Will probably be looking for Xantrex or Outback model after final dispostion.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 03, 2010, 01:27:06 PM
I notice a number of folks in this thread have opted for 120V inverters, or 24V over 12V. How long a run of wire can I use before 12V either becomes ineffective cost-wise, or loses voltage? I plan to either run 12V appliances or use an inverter to 120V if its more cost effective. My cabin will be 20 x 36 with ceiling lights and the like, maybe 2KW/day with three days reserve. Batteries would in a small shed pushed up against the wall of the house, and 500W PV on the south facing roof. I'm pondering 120V versus 12V in terms of simplicity, cost of appliances, need for inverters or other add-ons, and wire costs. Any thoughts guys?

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 03, 2010, 01:32:09 PM
Thoughts, yes.

1. What sort of appliances would you like to have available for use?

2. Have you done any shopping for them in 12 VDC?



More later on wiring.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 03, 2010, 06:40:36 PM
Have shopped but not yet bought:
12V ShurFlo Well Pump to cistern,
12V ShurFlo classic to fill pressure tank
12V RV Microwave
12V 10cu.ft. SunFrost Refrigerator
12V LCD TV/DVD Combo.
max of 8 15W LED lightbulbs
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 03, 2010, 07:49:44 PM

I'll state right up front that I do not believe a 12 VDC electric system is advisable in any but the most basic situations. Basic = a few lights and that's about all. But that is me and I wanted more than a few basic lights. I recognize this is my personal bias.

Note that when designing low voltage circuits it is desirable to keep the voltage drop to 3% or less over the run of the wire when under load.
Also note that standard home 120 VAC switches will fail after a very short time when used on DC circuits.

12 VDC RV microwave. Wow! The smallest microwaves are usually around 600 watts or so. That's cooking power. Most back of the case nameplates on a 600-650 watt m-wave will indicate a draw of about 800 watts at full cooking power. 800 watts / 12 VDC = 88 amps!   :o  That's what the math says, unless there's some kind of magic they've discovered or I don't know about.  I am amazed. I must be missing something. But if there was a draw of 66 amps, 12 VDC a person would need #4 AWG wire ti run just under 9 feet and keep the voltage drop at or less than 3%.

If it's the item I saw on a Walmart ad it draws up to 20 amps at 12 volts and the reviews I read are mostly by customers disappointed with the speed; 8 minutes to make 10 oz of cold milk hot.  Anyhow, 12 VDC, 20 amps, 3% max drop, #10 AWG wire, maximum length of wire = 7.44 feet. #10 is heavy wire. Solid Romex type is hard to work with.   :-\


A 15 watt LED light would be drawing a theoretical 15 / 12 = 1.25 amps. For a 3% max drop that would mean...
 2 lights total on circuit, #12 wire, 2.5 amps, a run of 37 feet is okay
 3 lights, total on circuit, #12 wire, 3.75 amps, a run of 25 feet is okay
 4 lights, total on circuit, #12 wire, 5 amps, a run of 19 feet is okay.


7 amps, like the max on the Shurflo Classic pump:
#12  3% drop  14 feet     5% drop  22 feet
#10  3% drop  22 feet     5% drop  35 feet
#8   3% drop   34 feet     5% drop  56 feet

How many lumens does the 15 watt LED put out? The 26 watt CFL's I have and like as they make it easy for me to read a book are rated about 1600.

Links for those 12 VDC items would be nice. Maybe some of them would sway my personal bias. ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 03, 2010, 08:57:08 PM
One of many available online voltage drop calculators.

http://www.windsun.com/Hardware/Voltage_Calc.htm (http://www.windsun.com/Hardware/Voltage_Calc.htm)

Select if you wish to solve for Distance or Conductor Size
For calculating wire runs in a cabin use the "overhead" in the Installation field.
Use "single phase"

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on November 04, 2010, 02:28:12 AM
Totally agree Don

the cost of an inverter will be paid for quickly by savings in wiring and 'special' appliances

a 12VDC system is useful for only very basic situations -- like maybe a popup camper -- and probly not even then if you are considering microwave or entertainment systems

Tesla was right Edison was wrong
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 04, 2010, 03:42:43 AM
Wow, I knew there would be voltage loss with 12V but hadn't really considered just how big a challenge it would be. A game changer was also a voicemail this am from the code enforcement officer who told me that my cabin would need to have conventional wiring even if "off-grid".

My assumption was that an inverter would rob some power while, um, inverting, and add to the expense of the setup. In light of what you have said, I'll plan around a 110V system. I'd venture to guess the appliances will be cheaper too. Moreover, running a considerable length of wire out to the well pump will be far easier in 110V. I figure 30-50ft to the well, then down 50-100ft. That's a long stretch.

Now if I run an inverter, are there any appliances that are better at 12V such as the ShurFlo, or can it just as well be all 110V?

Thanks for sharing your wisdom, guys.

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on November 04, 2010, 05:18:04 AM
Glenn, just wanted to pass on info on the SUN SL 3024 inverter/charger. I sent it back to sunelec yesterday. It was giving constant over voltage alarms and would not reset properly without having to completely disconnect the unit from the dc bus. I contacted Tony with sunelec and he said to ship it back to his attention, should be there by Friday. I have since rolled back to a backup HF 1200 Modified Sinewave inverter for lights/gargedoor opener.
The price on the inverter/charger was great but I guess you get what you pay for. Will probably be looking for Xantrex or Outback model after final dispostion.

Hmmm,   well I guess that settles that....

It was nice to think something good might be available for a low price.  Looks like we have to stick with the standards who care about their name.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on November 04, 2010, 05:25:14 AM
I'm with the rest, Boc. 

Even a small good quality, FULL SINE wave inverter is better than running DC in my opinion. 

Your list has way too much stuff that would be better on AC in my opinion.  Not modified sine wave though. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 04, 2010, 05:43:46 AM

Now if I run an inverter, are there any appliances that are better at 12V such as the ShurFlo, or can it just as well be all 110V?


The Shurflo is available in 12 and 24 VDC and 115 VAC. I run the 12 VDC version of the Shurflo cabin interior water supply pump. My reason was that it is easy to find a replacement 12 VDC pump if the need ever arises; any good RV dealer will have one on the shelf whereas the 24 VDC or 115 VAC would need to be ordered. Plus I could also pull the one out of the RV. Or vice versa.

Running the 12 VDC pump required additional expense to be able to hook it up as my DC system is 24 volt. I have a solid state voltage converter, 24 to 12 VDC.   Shown Here (http://countryplans.com/smf/index.php?topic=2335.msg65662#msg65662)  That is better (for the batteries) than running a tap off them for 12 VDC.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on November 10, 2010, 10:31:10 AM
I'm very happy with my AIM 2500 inverter.  Cost was about $200 and I've run a sawsall and jigsaw off it as well as a TV and playstation, CFL lights, incandescent lights and the Composting toilets dehydrator.  We also used it to charge my cell phone and Ryobi batteries for the drill :)

With 6 GCB's my reserve power is limited but with the SunElectric 205 watt panels (3) I'm getting the bank charged to 13.5vdc even on low light days.  With full sun it goes up to 'fully charged' which is 14vdc according to the inverter lights.

All in all I'm very happy but have already thought about adding two more batteries and perhaps a 4th panel in the future.  Of course the Iota charger will work fine to get the bank charged up more but I haven't wired it in yet.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on November 17, 2010, 12:45:50 PM
Just got the quote from the Solar Biz for the batteries
(thanks for the Solar Biz tip,  Don)


going with the 6V 546 AH   6-CS-17PS Surrettes @ $710 each

(8 of these for the 48 V bank)


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.dcbattery.com%2Frollssurrette_6cs17ps.jpg&hash=9c5dd9adbc0321e79531fc51efe27d5d)


the shipping is only $120  (at least that is the quote -- I think I better grab it before they change their mind)

at over 1700 pounds (220# each) I know I could not get them with the truck for that

This is exciting !

eta

I just noticed there is no handle on these things -- but it looks like there is a molded 'hook' on the side -- anybody know where to get a handle ?




Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 17, 2010, 02:27:27 PM
 [cool]  nice batteries, good choice     8)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 22, 2010, 10:00:10 AM
Wow, moving those around is going to either take some sweat or some thought. I'm not a burly sort and if I had those, I'd slice the bottom off a dolly and spot weld two blades extending forward like a forklift to catch those grooves. You could roll up, tilt back and away you go.

As my wind project finally comes to completion, can someone tell me whether there is any difference in load on an alternator for a single 12V battery and an entire bank of them? My father says a larger bank of batteries discharged to, lets say 70%, will take more torque at the alternator rotor than one or two. I say once the voltage exceeds the battery's, it pours in like water into a tank, regardless of how many there are. Of course it would take much longer, but at the rotor, I can't imagine you'd know the difference? What say you?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 22, 2010, 10:29:47 AM
The alternator has an upper limit as to how many amps or watts it can deliver. If the alternator is rated at 70 amps output (840 watts) that is the maximum it can deliver whether it is connected to a single 12 volt battery or to a hundred 12 volt batteries(in parallel).  It would take 100 times as long to charge the 100 batteries but the alternator can't tell any difference.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 22, 2010, 11:15:05 AM
You mentioned a discharge of 70%. I hope this is not your planned aimpoint for depth of discharge, but rather just an example.  I would aim for no more than a 50% discharge (DOD).

If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fconstruction%2Fcyclelife2.gif&hash=4e48b1239da3427a11ea2833af872859)

The graph is for a Concord Lifeline battery, but others will follow a similar pattern


Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 22, 2010, 06:44:58 PM
Sorry for the confusion, guys. I meant as an example, and my plan, that the batteries are discharged 30% leaving a 70% charge. I was hoping not to discharge to 50% if can help it.  d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 27, 2010, 02:41:04 PM
Ok, it's been a gusty day and I've finally come to the close of a wind turbine project. Cost was $96 for an aluminum high torque five blade 5ft radius design, $130 for the all-weather alternator. The 34 ft Rohn telescoping antenna mast ran $160. Building the frame and furling tail section proved frustrating at times, but the time spent with dad, priceless...parts, maybe $15 at Lowes. At 15ft up and in turbulent wind, today's gusts pushed the unit to average 20-60 open volts. With discharged deep cycle battery, between 1 and 4 amps or current. 15-50 watts isn't much and I'm not thrilled with the output for all the effort. Nonetheless, I wanted to get in cheap and test it's feasibility before taking the plunge on a much larger and expensive setup. I'm thinking no one single source will suffice. Now, back to microhydro and hello solar..

Doc
http://theadirondoc.blogspot.com/p/elements-running-with-wind.html (http://theadirondoc.blogspot.com/p/elements-running-with-wind.html)



wrapping up the frame: http://www.youtube.com/watch?v=OCMoJZ0kCcM (http://www.youtube.com/watch?v=OCMoJZ0kCcM)
today's open voltage test:http://www.youtube.com/watch?v=Jxep24RXgvg (http://www.youtube.com/watch?v=Jxep24RXgvg)
alternator vs. 12V dead battery:http://www.youtube.com/watch?v=3C3hxWOjK8U (http://www.youtube.com/watch?v=3C3hxWOjK8U)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on November 28, 2010, 03:28:09 PM
Do you have equipment that would permit the collecting of data for a period of time, day, week etc? A little bit of power over a whole day can add up.

It was good to see real blades, not carved up PVC pipe.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on November 29, 2010, 09:33:13 AM
I have no equipment for that yet but I did manage to find a good deal on a bank of batteries. I'm the proud owner of 8000 watts of potential energy..  ;)

The 50ft bluff on my Adirondack camp is likely to be windier than my "testing grounds" out on Long Island, NY. We'll see what it will put out over a week or two when spring rolls in and I hoist it up. I need to find a good charge controller with load diverter this week. Oh yes, a dump load as well.

Cheers,
Doc
Title: ultralife batteries? Hmm
Post by: AdironDoc on December 01, 2010, 04:40:32 AM
Found a great online deal on Centennial 6V 220AH batteries, $89/each. After shipping, not so great. I was told by them that the Trojan T-105 is a much beefier battery and offers better lifespan. I appreciated their candor. They offered a local distributor location so there would be no shipping but there will be state sales tax. Unfortunately, locally they carry neither Centennial nor Trojan but the following:

6V 210Ah UltraLife $125/ea
6V 235Ah UltraLife $135/ea

There is a CORE fee of $15/battery

I've never seen any reviews of this brand. Can anyone tell me anything about them? I'm looking for an inexpensive entry-level set of batteries. Plans are for 24V so 8 in total.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2010, 05:59:49 AM
No nearby Sams Club or Costco?  My Sams stocks golf cart 6v 210 amp for $79 + $9 core.  MTL the same as those Ultralife
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 01, 2010, 06:41:22 AM
No nearby Sams Club or Costco?  My Sams stocks golf cart 6v 210 amp for $79 + $9 core.  MTL the same as those Ultralife

I have both but have never seen the batteries available. A visit to their websites yields no "6V batteries" or references to "golf cart". If so, I'd have bought 8 of them today....bummer
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 01, 2010, 09:28:22 AM
I've noticed that my Sams does not list the batteries on the web, but does carry the batteries in stock. My Costco does not carry batteries but the one across town does. ???  puzzling
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 01, 2010, 05:50:11 PM
That's good to know. The cheapest interstate and  energizers I found on the web are $120 and up. I'll call the local Costcos and Sams' and scout around.

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 01, 2010, 06:20:23 PM
Hey Doc, Nice experiment on the wind turbine.  Thanks for posting it.  I think you will be a lot happier when you get it up higher and away from turbulence.  Wind at 85 to 100 feet is about 3 times that at ground level but anything over 30 ' above treetops is better than near the ground.

I built my 85 foot tower and put it up by myself with a gin pole but it was a real chore.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 02, 2010, 03:52:28 AM
Thanks, Glenn. I extended the telescoping rods up near their 34ft max to see how hard it would be. Lift the mast sections vertically, with the unit on top, and cables hanging is really at least a two person job. The gin pole method with a winch suddenly seemed attractive. I guess there's no easy way, huh?

Im really impressed that you build your own mast. That's no small feat. What's your turbine put out? I'm considering the windy nation 750 which is on sale this week only at $899. It's ratings are real world, the support has been great, and the unit has impressive stats. My Delco will never measure up to my energy use.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 02, 2010, 07:44:51 AM
I have a Bergey XL1 - 1000 watts rated although I have seen more in a storm.  I am a dealer but haven't sold others due to the fact that we are not in a great wind area and peoples unrealistic expectations could cause me problems.  Last I checked it was over $2000.

My install was really rough as I did not want to cut my Oak trees so I had to work the side cables around them too.  Took me about 10 and 1/2 hours to get it stood.

I based my design on the materials in the Bergey mast after I conned a few answers out of them.  I used 20 foot sections of light weight 4" blow pipe I had left over from well drilling - threaded and coupled on the ends - I made a cable attachment collar to slip on top of each coupling so guy wires every 20 feet and  I roughly copied their base tower and gin pole mount.  Anchors are 3 foot long steel stakes driven through the base into the ground.

I want to build my own wind generator next time using PM motors - likely gearing up with a multi-v belt.  I now have 3 off of treadmills.  I have plans for a well designed carved PVC set of blades and commercial PVC -green - water pipe to make them from.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 02, 2010, 09:22:42 AM
Wow.. that's a great plan. I saw someone on the web who also did their own and it worked out very well. Carved his own wood blades which, if I'm not mistaken, were 8 or 9ft in length. In the end, he was putting out over 1.5Kw consistently and said he had more power than he could use at that point. That's everyone's dream, I suppose.

I liked Hugh Piggot's diagram for a tower and might use that concept. His guy wires lie on the ground already taught, side to side, the one in the rear, slackened. It prevents any problems laterally while hoisting. I'd like to attach a hand winch to the gin pole, which when fully erected, would fit in a groove atop a cement block and get locked down. That would potentially be a one man operation if done right.

I'm intrigued at the idea that the swept area of the rotor has a great effect on the power as it is squared. That makes for an exponential curve upwards for radius increase. The loss of torque from gearing, however, is a simple ratio of teeth to teeth making the curve of loss linear. I'm thinking, capture a large swept area, then make up for the loss in tip speed by a simple two cog gearing at say, 1:3. Maybe we can capture the benefits of a large swept area and still stay in a high RPM range for optimal PMA output. I'd love to experiment with that.

I'm on the fence today about taking advantage of the windynation 750 one week sale. They tend on the conservative side and back up their claims with videos demostrating under real loads. After a tax rebate, the complete system runs me around $650. The alternative is to put in a bit more and do the solar now. Ah..decisions.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 02, 2010, 09:29:48 AM
Just weighing this against intro solar kit. Wind is...well, sporadic and unpredictable. Solar, on the other hand is...well, same ;)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fwww.windynation.com%2Fsites%2Fdefault%2Ffiles%2Fpowercurve750final.jpg&hash=176c344482fff45696afeaadf0f48d2a)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 03, 2010, 09:07:39 AM
I find the hybrid system to be the best, Doc.

Some of each - wind works at night and in storms.  Solar on cloudy days is about 10% or less of the total panels.  Micro hydro could be good in the winter but doesn't work well with ice.... [ouch]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 03, 2010, 09:17:03 AM
I think you may be able to do better piecing your own solar together than buying a kit - however there could be good kit deals too.

Sunelec - panels sometimes under $2 per watt plus shipping.  Various good full sine wave inverters out there - sometime Ebay if you are careful. 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 04, 2010, 08:12:15 AM
Hey Doc, I doc-umented a bit of my wind generator installation for you.  [ouch]

I took a few pix of it yesterday before I went off to work.  Here is a pix of the whole thing - 85 feet tall.  I forgot to mention that I did do the thing with keeping the side cables tight and tilting with a gin pole and come-along anchored to a tree, with a couple exceptions.  In that area my ground averages 20 to 30% grade and I did not want to cut trees so the side cables had to be alternately extended or routed around trees as it became necessary ie: the west cables were  anchored at roughly 6 feet lower elevation than the east cables and the south cables were at roughly 10 feet lower than the north cables.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen1.jpg&hash=8c03e9b38d08b1f0a936526b6660d223)


A telephoto shot of the generator at 85 feet elevation from the ground in front of my shop.  Note that the Bergey uses slip rings and the cables hang down inside the tower - #4 wire to appx 150 feet to the controller.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen2.jpg&hash=c2a593eb3c5420706f11a418044e2862)


I cut out plates to the diameter of the pipe plus about 1/16th inch to allow them to rest on top of the pipe coupler but still rotate.  I welded chain links to the plate to attach the cables to and prevent wear.  Tight collars would not have allowed for screwing the pipes together and would not self align with cable tension.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen3.jpg&hash=46f63eb7fbe982fe73762c4a026832d4)


Here I drilled a hole in an existing natural rock with a roto-hammer and epoxied an eyebolt with a welded loop (can't unbend in a wind storm) into about a 6 inch deep hole.  I wanted that much embedment to hopefully get past any chance of fracture.  The hole was completely filled with epoxy (Hilti HY150) to prevent intrusion of water and freeze fracturing the rock causing a failure.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen4.jpg&hash=841cb654fc521fdffd4b863f276c2f23)

Here is a natural rock I moved to location with my John Deere trackhoe loader bucket - estimated weight 6000 lbs.  Note that I calculated cable lengths then added about 10 feet due to the uneven terrain.  At install I ran the cables through the eyes and cut the cables with the extra length as needed.  Tower elevation at the base was not the same as any of the anchor points, hence the problem with changing lengths.  pull on any of the cables when standing is not over 50 lbs.  Raising is another story.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen5.jpg&hash=ae7b2cd99c2b287baf9b23c33febc03e)


Here is my base plate and hinge for the tower - the round stakes are probably 7/8 sucker rod about 3 feet long - at least 4 of them there as I recall.  The cable from the tower there is a ground and the gen cables are in the grass - not visible.  I got the gin pole a little close to the tower pivot - it was removed when done and was mounted in a hole this side of the tower pivot.  No worries about the loose nut there --- it is really just a pin retainer - no other function.  

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen6.jpg&hash=57c044c75a453a18d56e689d3186cab6)

And last - a shot looking from the base level up to the generator at the top 85 feet up.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi778.photobucket.com%2Falbums%2Fyy62%2Fthe_troglodyte%2Fwindgen7.jpg&hash=a0c891327b17f774a3f1de20f61d221c)

Cable clamps... "Never saddle a dead horse" - put the saddle over the live side of the cable and the u section over the cut off end - less chance of cutting the live side with clamping pressure over the years.

I hope that demonstrates the ease with which one can do it yourself and save money..... [waiting]    




:)




Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 05, 2010, 06:45:09 AM
Sorry for the late reply, Glenn. I've been up one last time to the camp to see how it's been cleared, and to take a water sample from what I believe to be a springbox. 6ft x 3ft concrete. The timbers and roof have fallen in, but I've poked a stick down over 3ft. Don't know how deep it is once it's cleaned out, but it's an interesting find nonetheless.  Not even sure what use I'd have for it.

Your mast installation is great! I can't believe the height you achieved on your own. Is that sched 40 pipe you used? It looks larger than 1.5". I'm not sure what the local zoning is, but I hope to come up to at least 50ft to 60ft for cleaner wind. Hope since I'm on 35 fairly remote acres, nobody would say much in any event. Only thing is, the highest point (up on a ridge) is 150ft from my neighbors cabin lot. I'll scout around for a suitable location as far from him as possible.

I just bought a Superwinch portable winch in a bag to help out hoisting. Rated at 2500lbs and runs 12V. My Windtura750, with rotor and frame weighs in at 66lbs, so not too bad. They recommend sched 80 1.5". I'll more than likely go with common HomeDepot sched 40 galvanized instead, which is what many other wind turbine manufacturers recommend. Unlike your welds, I figure on using simple plumber's connectors and T-fittings. My welding needs some practice! Like you, I'll use a tree as a winch anchor and later remove the 30ft gin pole.

Thanks for the tips on solar panels. I've been browsing Sunelec's site and think a 480W setup on a pole will be perfect. You've inspired some new ideas, Glenn.

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 05, 2010, 07:44:36 AM
No problem, Doc.

My mast is using blow pipe I had left over from well drilling - actually it is a 4" tubing a bit heavier than 4" exhaust tubing - maybe 1/8 to 3/16 inch thick.  Bergey uses a similar material on their tower.  You can go to their site and download the tower manual for clues on building and installation.  Downward loading is very low so heavy pipe is not necessary with the guy wires.

Wind generators do make a bit of noise but usually not unpleasant as the blades sweep through the air.  Not too far from your batteries on distance or there is a lot of line voltage loss.  I asked the county here if a permit was required and they said yes so I put it up without one anyway - my story was going to be that the installation was experimental and temporary with the stakes in the base, but that was 8 years ago and still no one has said anything at all.  IN the meantime the county guy was fired for corruption and the second one was fired for messing with the citizens too much- lots of un-permitted buildings up here by public officials families.  :)

I tested the Sunelec grade B panels  - they are every bit as good as the more expensive ones in my opinion and meet all specs.

Glad I could kick in so useful info.  [idea]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 05, 2010, 11:56:34 AM
I was looking at some of your threads, Glenn. Really remarkable. oI think you should write a book.

I wonder if you'd make a recommendation on gin-pole length. Pipe lengths come in 10' here so I'd be at 40-60ft depending on final site inspection. Can I figure on roughly 1/2 of the mast height? Do you put a pulley on the end of the gin-pole or fix it securely and then on to near the top of mast? Did you find it necessary to double guy the gin pole to the mast at more than one point, such as near the top, and 1/2 way between?

Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 05, 2010, 12:06:30 PM
I've noticed that my Sams does not list the batteries on the web, but does carry the batteries in stock. My Costco does not carry batteries but the one across town does. ???  puzzling

Don, your advice paid off. No local batteries on the web, but I called around and found them at Sams. A $30 membership and a one hour drive later and I found myself now a member of 3 warehouse clubs. I did it to score 6 Energizer GC6 220AH batteries at $72 each. After opening a charge card so I could pay (all I had was visa and amex), I got an additional $20 off. After I put in for a 30% tax credit for all my solar project receipts, that's $48 per battery! Awesome!

Just wanted to say thanks for your advice!

By the way, my project calls for the batteries in a couple months. Until then, I don't want to harm them over the winter. Should I cycle them already or can I leave them be?

Doc
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 05, 2010, 09:59:27 PM
If you have them near power just keep a small float battery charger on them - series 2 6's if necessary and  parallel the sets to use one charger for 12 volts.  If they go down and stand while low they could sulfate.

A good charge once in a while could do also.  Don't ask me if I take care of my batteries that well.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 05, 2010, 10:26:10 PM
I was looking at some of your threads, Glenn. Really remarkable. oI think you should write a book.

I wonder if you'd make a recommendation on gin-pole length. Pipe lengths come in 10' here so I'd be at 40-60ft depending on final site inspection. Can I figure on roughly 1/2 of the mast height? Do you put a pulley on the end of the gin-pole or fix it securely and then on to near the top of mast? Did you find it necessary to double guy the gin pole to the mast at more than one point, such as near the top, and 1/2 way between?



I have thought about a book a couple times - looked into it a little but it seems I am a bit too lazy to do it so far..... [waiting]... but thanks anyway.... maybe someday.

The longer the gin pole, the easier it goes up - but be sure to lay it out so that when pulling it up it doesn't hit the gin pole pulling point/anchor.  I used 25 feet on my 85 footer as there was a tree at about 27' as I recall.. so about 1/3 length of tower should do it.  The gin pole hinges on a separate anchor at the base  about 6 inches away from the tower and a bit higher than the tower anchor bolt would be good to allow it to lay down over the tower pole for hooking cables.  A snatch block could be used at the top of the gin pole for more reduction or just a tough come along or chain hoist - truck winch etc.  I try to think about whatever will work - - go through the steps in my mind - sketch it if necessary to think of possible problems.  I use whatever I have to do the job safely - multiple ways it could be done.

I put a stake in the ground to the side of the tower at 90 degrees from it's base mount to temporarily find proper cable length then transfer them to the gin pole as proper length is found.  Generally I figure 3 cable clamps for full cable strength but it varies a bit depending on size if I recall correctly.  Note that the gin pole will attach to the cables temporarily somewhere around the top 2/3 of the cable length depending on anchor spacing.  Seems mine were about 50 feet from the base in 4 directions.

Use the length of the gin pole for distance from base - shorten a few feet to keep the pole off of the ground when the tower is plumb.  I used one cable at every 20 feet on the tower and attached them at their proper length to the gin pole so that the entire tower would come up at once as the gin pole was pulled down.  Even a 4 inch tower is remarkably flimsy until properly guyed.  I think a 20 foot gin pole would do you for 60 feet.

Another caution - be sure to have the back cables attached  and not over loose or when it goes past center it will continue falling - possibly on you.  I know - obvious but thought I would mention it.  I calculated the lengths of the cables - left them extra long by 10 feet or so as I mentioned then fastened them a bit snug for when the mast was vertical , then adjusted each of them carefully until it was plumb - I used a nut driver for speed - .  Side cables can be attached snug if on level ground - if like mine they may need adjustment - I raised - checked - raised - checked - adjusted - til done.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 06, 2010, 04:47:26 AM
Great info, Glenn. On your recommendation, I've sketched out my plan for a 20 on 60 gin/mast setup. Please tell me if you see any room for changes or improvements.

Btw.. I knew the roots of cattails were loaded with starch, but after a visit to your youtube channel, I'm going to try cooking with them this spring. Now that should be interesting. Cattail "potatoes" and salted pine chips, pine nut cake, and spruce tea. I'll try anything once.  c*

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi234.photobucket.com%2Falbums%2Fee314%2Fglennjakobsen%2F60ftbase.jpg&hash=2a5759647d88599c2c2531c6488b7726)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 06, 2010, 08:49:31 AM
That looks pretty good, Doc.  

I need to try the cattails also.  Almost did but didn't quite get around to it.

I'm not an engineer so tend to go a bit on the conservative side and hope I'm good.  

I used just the stakes and a steel base that I built from what I could gather from the Bergey info - clues.  I am not worried about the concrete base and bars - you would likely want to relieve it in the area of the tee or add couplers to the short nipples  to allow more sitting on the base for a little more support as it goes up - that is likely not even critical though.

The 10 feet of 1 1/2 above the last coupler with the generator bothers me a little - also the 30 feet un-guyed at the bottom.  If it was mine I might add a 5 foot section of pipe at the top to mount the generator on cutting down leverage on the threads at the top above the guy, guy at 60', 40' and 20' and temp the three of those to the top of the gin pole for raising.  Watch for binding where the bottom pipe sits on the concrete so it doesn't bend and snap off there - again something to watch - likely not a problem.

The ten feet may be OK with the generator but some rough rule of thumb stuff - wind exerts around 30 psf at 100 mph If I recall correctly.  5 foot 5 blade  fan and about a foot generator - not sure how turning affects it -  say 10 square feet of surface - x 30 psf =300 lbs push in a giant wind x 10 feet gives us 3000 foot lbs at the 1 1/2 inch cut threads at the coupler at the top guy.  Cut threads weaken the pipe.  I'd feel better at 5 feet and 1500 foot lbs at the last guy.  Maybe I am way off and any engineers here feel free to correct me... just trying to make a good guess.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on December 06, 2010, 10:16:01 AM
Sorry If I am late to the discussion, the Off Grid thread can be hard to keep up with.  I studied the Bergey installation guide too. What I liked was how they used steel plate, angle iron, and large bolts for the gin pole design instead of the T.
 Doc,I have never seen designs for 1.5" diameter pipe that tall. Most commercial towers I have seen sold are 4-6 inch.  I have seen them as low as 2" at the top. I am with glenn in the distances of unsupported pole.  Personally I would be using guy wires every 10 ft with that thin of pipe, starting at the lowest place to clear the blades.  It might be cheaper to buy bigger pipe than more wires.  Let us know how it works out.  Otherpower.com has a great walkthrough with good pictures on tilting up towers.  On estimating the wind, I did a walkthrough on a homebuilt wind meter here.  You can find it by checking my old posts.  There are also many wind maps for NY on the web.  On the subject of permitting, anything over 16ft requires a permit in my county.  I found a loophole in NY state laws.  There are right to farm laws in almost every state including NY.  There is a provision for wind turbines for power.  This is to stop local municipalities from harassing farmers with zoning/permitting.  My recollection was that it required 7 continuous acres to be considered under right to farm laws.  I don't know if tree farming qualifies.


Edit:
Here is a link to right to farm laws:
http://www.nationalaglawcenter.org/assets/righttofarm/index.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 06, 2010, 01:07:00 PM
Doc,I have never seen designs for 1.5" diameter pipe that tall. Most commercial towers I have seen sold are 4-6 inch.  I have seen them as low as 2" at the top. I am with glenn in the distances of unsupported pole.  Personally I would be using guy wires every 10 ft with that thin of pipe, starting at the lowest place to clear the blades.  It might be cheaper to buy bigger pipe than more wires.  Let us know how it works out.  

Thanks, guys. Although my new wind unit will come with a mount for 1.5" galvanized, I could always use a larger diameter for the base and reducers on the way up. I'll guy it as suggested, at 10ft increments, or, just above each fitting and as high as possible, say half way up the final  length.

At the moment, my little 30lb setup sits atop a 34ft Rohn telescoping mast which although guyed every 8ft, is made of very thin pipe. The thickness reminds me of lightweight fence tubing that makes up the top rail of a chain link fence. Amazingly strong when guyed properly. 34ft ends up weighing only 40lbs. I figured at 60lbs, and an additional 25ft up, galvanized would be a big step up.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 08, 2010, 11:04:13 AM
That was a clever loophole, Squirl. Don't know that I'd qualify on that one, but I googled wind turbine heigh restrictions and see most upstate county zoning laws put a height restriction of somewhere around 100ft give or take. Distance from property lines seems to vary greatly from a distance equal to the height, to over 300ft with sound limitations as well. I should be fine at a meager 60ft.

Ostensibly, my land is considered unimproved being raw acreage of forest. That doesn't stop the town/county from very high taxation. My 35 acres will end up costing me as much as my home in the suburbs of NYC. Now whether a wind turbine is a permanent structure or capital improvement, thus being taxable, will remain to be seen. I'm hoisting this on the QT.

I found a loophole in NY state laws.  There are right to farm laws in almost every state including NY.  There is a provision for wind turbines for power.  This is to stop local municipalities from harassing farmers with zoning/permitting.  My recollection was that it required 7 continuous acres to be considered under right to farm laws.  I don't know if tree farming qualifies.

Edit:
Here is a link to right to farm laws:
http://www.nationalaglawcenter.org/assets/righttofarm/index.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 08, 2010, 04:12:42 PM
Seems if there are just steel stakes in the ground rather than concrete it is not permanent.  That is the official Bergey mount.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on December 10, 2010, 05:37:26 AM
That was a clever loophole, Squirl. Don't know that I'd qualify on that one, but I googled wind turbine heigh restrictions and see most upstate county zoning laws put a height restriction of somewhere around 100ft give or take. Distance from property lines seems to vary greatly from a distance equal to the height, to over 300ft with sound limitations as well. I should be fine at a meager 60ft.


Good luck.  I always hope people just leave me alone too.  The provision would be more of a backup.  Zoning and permitting are two different things.  If they want to be jerks, they can fine the crap out of someone after the fact.  Anything over 16ft needs a building permit were I am at.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 10, 2010, 06:51:27 AM
ill be looking forward to hearing more about how you do with your new turbine.  it is the same plan i have to back up some solar panels.  i guess since "fees" for permits are so high at my place, the cabin will start out at the 120 sq ft and will be off grid.  i asked them at the placer county hijacking office about a wind turbine, they said no restrictions, but they may be looking at some guidelines going in somewhere in the near future.  but at this time only need a electric permit.  i think, correct me if im wrong, that would only apply if i were grid-tied.

yep, im not going to let them get to me, im just going to do the real cabin down the road.  ill spend the time getting septic in and other things in place, at least we can spend quality weekends there with that.  the good news is also my property taxes will only be about 500 a year until we build, and it sounds like a lot of places are higher than that.

adriondoc, did you buy your set-up, or is it something you set up on your own?  i keep getting these emails from a DIY site who had plans for a homeade set-up you could build on the cheap, and it looked pretty good from an appearance stand point, but from what i am seeing they just really arnt that expensive to buy and install.  anyway, i cant wait to hear how your project is going.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 10, 2010, 07:31:32 AM
Thanks, and welcome to the forum. I'm learning something every day here from others who have walked our path before.

My first wind project was cobbled together from an alternator I bought on E-bay for $120 based on a rewound delco, blades from windynation.com, and some miscellaneous parts from Home Depot. I got a telescoping mast from Rohn for $140. All told, it's run me around $450. In a brisk breeze the delco type alternators max out at around 40-50W. Not much bang for the buck unless they run continuously.  For me it was more of a feasibility test. It worked, that's clear.

I just bought a larger unit, the Windtura 750, from windynation.com. It puts out 400W in the same breeze the delco gave me 40W in. In a real wind, the numbers are double that. Normally $999, it was marked down to $899, plus 5% off for being a member, and a 30% tax rebate left the price not much more than what I paid for my homebuilt unit. I'm not trying to sell you on any particular model, just to point out that DIY doesn't save all that much in the end. The main cost this time around is 60ft of 2" galvanized pipe with all the fittings for the mast.

As for my cabin.. I looked for months at every conceivable kit available. I finally beat all the prices by finding a local mill owner/builder who would get permits, clear land, and frame the cabin at $36/sq ft. Remember, keep it simple. You can always add on and double the size of what you build later. 

I encourage you to keep a photo journal of every step of  your journey. Post them and write about your decisions, your projects. I've done that in a blog and hope years from now my kids will look back and smile.

cheers, Doc

ill be looking forward to hearing more about how you do with your new turbine.  it is the same plan i have to back up some solar panels.  i guess since "fees" for permits are so high at my place, the cabin will start out at the 120 sq ft and will be off grid.  i asked them at the placer county hijacking office about a wind turbine, they said no restrictions, but they may be looking at some guidelines going in somewhere in the near future.  but at this time only need a electric permit.  i think, correct me if im wrong, that would only apply if i were grid-tied.

yep, im not going to let them get to me, im just going to do the real cabin down the road.  ill spend the time getting septic in and other things in place, at least we can spend quality weekends there with that.  the good news is also my property taxes will only be about 500 a year until we build, and it sounds like a lot of places are higher than that.

adriondoc, did you buy your set-up, or is it something you set up on your own?  i keep getting these emails from a DIY site who had plans for a homeade set-up you could build on the cheap, and it looked pretty good from an appearance stand point, but from what i am seeing they just really arnt that expensive to buy and install.  anyway, i cant wait to hear how your project is going.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 10, 2010, 10:30:26 AM
....only need a electric permit.  i think, correct me if im wrong, that would only apply if i were grid-tied.

Don't assume that if you are off grid you do not need a permit for electrical. For our location the county inspector still wanted to see all the requirements for inside the building to comply with code. Partly that is a safety issue. Partly is is the fee. Partly it may be because someday the grid may be connected to (they mentioned that). Partly it may be because that's the way it's always done. Even the low voltage parts have sections in the NEC.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 10, 2010, 10:45:04 AM
Quite right. I'm off grid too and when I pressed the codes department on the issue of low voltage, I was told the same. I asked if the standard wiring rule was a "suggestion or requirement", to which the code officer replied, "a word to the wise, it won't cost you much to bring it to code". Understood. Now, good luck finding a way through the 3 miles of woods to inspect it.  ;)

....only need a electric permit.  i think, correct me if im wrong, that would only apply if i were grid-tied.

Don't assume that if you are off grid you do not need a permit for electrical. For our location the county inspector still wanted to see all the requirements for inside the building to comply with code. Partly that is a safety issue. Partly is is the fee. Partly it may be because someday the grid may be connected to (they mentioned that). Partly it may be because that's the way it's always done. Even the low voltage parts have sections in the NEC.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 10, 2010, 07:48:45 PM
thanks for the additional info adriondoc, i appreciate knowing what you have done, and yes, as you say it helps to know the paths others have walked, as those steps are much easier to follow.  and i really aggree with the deal about DIY, i had already noticed i could get a decent turbine for between $900 and $1200.  and that is really fantastic!  sounds much better than micky-rigged, and wow! thats a lot of difference in watts delivered, day and night difference.

i guess being off grid wont save me with the electric permit!  real bummer!  the thing im tossing around is and that power is extreemly close to my building site.  i havent pulled out the tape measure, but i would guess only around 100'.  thats a cheap hook-up. 

so i was talking to one of my customers today.  of course their situation is very different from mine.  they have a 2800 sq ft, 2 story home.  last month they had solar installed.  today pacific gas & electric came over and installed their new meter--one that will sell back the extra to the grid.  they have 16 solar panels, i figure most times they will be making a significent excess of electricity.  its pretty smart to have your system working for you.  i had heard that in calif. you wouldnt get paidfor the excess.  but apparently you do, or maybe it depends on where you are.

as much as i dont like dealing with the local power company, maybe i should suck it up and go grid-tied up there.  there sure are alot of decisions to make when you buy land with the intentions of building a cabin!

and thank you to you and mountain don for pointing out that getting around the permit  wont be as easy as i was thinking.  they dont have to go thorugh any woods to get to my building site, just drive on up when the weather is good.  i guess i should have spent more time on the "buying land"section.
















, and next to impossible.  unfortunatly
 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 11, 2010, 12:23:39 PM
In California the last I knew and still think it is the policy, the rules were of course written to favor the power company.  They only have to pay you avoided costs which is about 2 cents per kwh.  You in the meantime will supply them with a product they can sell for a profit.  It does not pay here to provide them with excess power.   Banking and using up to the amount you use annually could be good.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 11, 2010, 01:13:59 PM
There were some changes made by the CA legislature last year. I'd check with the power company to see just what the current options are. I know PG&E at least allows one's own generation to be applied equally against any power that the customer buys from them. At the end of a year there is a settlement; I just don't know what the changes are.

Even here in NM where the company that supplies us in the suburbs pays actual cash for surplus (at a rate higher than the base rate) the power company we would be connected to in the mountains has no buy back plan at all. So it can vary.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 11, 2010, 06:40:15 PM
that sure makes it tough for people to make plans, too bad there isnt some uniform guidelines that power companies would have to follow.  but at the same time, that would create more bureaucratic bs, so maybe not.  in a perfect world everyone would just do the right thing!  nice dream...

im going to see my customer next friday, and i want some 411 from her.  by the way, she also has a cabin at lake tahoe, but not the placer county side, shes closer to stateline (where calif and nevada borders meet).  i hope new fair guidelines were legislated, but you know how likely that is.

mountaindon, thats too bad the power co by you doesnt participate.  are they a small local co?  by the way, how are taxes, and land prices your way.  my brother is in st. petersburg, fl.  he wants out of there by summer and has plans for that area outside of santa fe, a few acres, a storage container underground for emergency supplies,....  he misses NM alot, we all do.  and the fl humidity is killing him.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 11, 2010, 07:02:40 PM
mountaindon, thats too bad the power co by you doesnt participate.  are they a small local co? 
Yep. Jemez Mtn Co-Op

  by the way, how are taxes, and land prices your way. 

We just paid the taxes for the year: mtn prop; $104     city home; $1300

Land: we paid $19K an acre in the mtns. Depending on how close to Santa Fe it could be more. Or not.  Santa Fe itself is nuts!???
http://www.jemezproperties.com/ (http://www.jemezproperties.com/)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 11, 2010, 07:11:15 PM
Wow.. for unimproved (but subdivided) forest, I pay $600 per 5 acre lot. I own 35 acres. Dems' the breaks..  ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on December 12, 2010, 04:14:19 PM

in "tax 'em till they bleed" Wisconsin I pay $2889 per year on 105 acres with a small house

guess I don't feel too bad .....

the CRP covers it for now -- expires 2014

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 12, 2010, 05:10:47 PM
You are safe then -- the world ends in 2012.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 12, 2010, 07:39:47 PM
thats right, we wont have to worry about taxes and building permits after, what is that... december 21st, 2012.  glen and sassy, i hope theres a standing offer of visiting your underground cabin about that time for us forum folks,  ill bring food!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 12, 2010, 09:33:55 PM
I thought it was earlier, but yes - just checked - Dec 21, 2012.  All CP members are invited here to watch it from the ridge top.  It will of course be a pot luck event to insure that there is enough food for the occasion....that way no matter how many show up, we are covered.....  The view should be good from here.  :)

There are apparently some predictions for 2011 also but that is too early for me.... I'm going to sit that one out and wait for the Mayan one.... [ouch] 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 13, 2010, 05:41:27 AM
ABC News: "doomsayers assert that Earth will be ravaged by a smorgasbord of cataclysmic astronomical events -- everything from a Planet X flyby to a "killer" solar flare to a geomagnetic reversal, ensuring we have a very, very bad day"

Sounds like a party! But...

Huffington Post: "According to a recent study by an associate professor at UC Santa Barbara, this fundamental "end date" may also be inaccurate. It could be at least 60 days out of whack."

Better bring some extra beer, Glenn.  ;D



I thought it was earlier, but yes - just checked - Dec 21, 2012.  All CP members are invited here to watch it from the ridge top.  It will of course be a pot luck event to insure that there is enough food for the occasion....that way no matter how many show up, we are covered.....  The view should be good from here.  :)

There are apparently some predictions for 2011 also but that is too early for me.... I'm going to sit that one out and wait for the Mayan one.... [ouch] 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 13, 2010, 01:35:52 PM
OK... looks like sleeping bags will be in order with the extra beer.   [ouch]

Reminds me of when we all used to get out the lawn chairs and sit on the beach in Oregon so we wouldn't miss seeing how big the Tsunami was.  Nothing like being there in person.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 13, 2010, 01:47:42 PM
I don't know how things go on your end of things, but whenever there's a storm coming, two things go fast; water and beer. I've started stocking long ago but test for quality on a routine basis.


OK... looks like sleeping bags will be in order with the extra beer.   [ouch]

Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 13, 2010, 03:51:22 PM
ok mountaindon and adriondoc, 8) i got the message and i am stocking up on the water and the beer, tell sassy ill bring potluck with extra.  (is that bud, or coors?)

hey, was that 60 days early, or 60 days late? of course, 60 days late would put up into 2013.  some people are saying all of the numerous large earthquakes and volcanic eruptions, and a tsunami or 2 is early results of the event as the solar flares have already begun.  stay sharp!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 13, 2010, 06:09:54 PM
HAARP was accidentally left on high during some of the events.  [ouch]

I am not sure if it was early or late so it would only be prudent to stock enough beer for 120 days..... [waiting]

...truth be known, for me that would be about 4 beers......

I drank enough when I was 17 to last.... :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Sassy on December 13, 2010, 06:37:59 PM
You can all just hang out & we'll keep the gardens going if the dates are off...  and we'll put you to work on the underground cabin   c* ;D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 14, 2010, 05:11:19 AM
Being in an underground house, Glenn is most likely of all of us to survive any meteor strikes and solar flares. Maybe we should all start digging?

Also was thinking.. taxes are based on size of houes, number of bathrooms, etc. If my front door is a ladder down, good luck assessing me. Nice thought.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 14, 2010, 02:04:59 PM
..and it is all accurately documented and sent to the assessor when you contract your rights away signing the line on the permit...Note that it is not necessarily easy or reassuring if you decide to try to avoid it either.  Ex-post facto laws try to trump inalienable rights and common law (the true law of the land)  in code situations.

As I mentioned before , one of our supervisors told a friend that the permit process was not for safety, but rather for taxation.

Safe practices used to be the responsibility of the master carpenter and old buildings attest that he did a pretty good job.  Now they are given to a county inspector who many times does not really care.  The failure of our DMV carport, The County Library in Coulterville, the flooding of the building and safety departments new castle lower floor, as well as the travesty linked below all attest to the same thing.

Collected the fees - charged the taxes - went through inspection motions, yet claim they have nothing to do with insuring quality or safety... primarily a taxation tool and guarantee that you will buy from those who have paid off the system....

http://goldrushcam.com/sierrasuntimes/mariposa-daily-news/92/1265-a-failed-driveway-and-mariposa-county-claims-immunity
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Shawn B on December 14, 2010, 02:26:03 PM
Never been to California.........could visit Yosemite  :) a party at Glenn's would probably be way  [cool] Just one question are you the part of California that will fall into the Pacific or will you be the owner of new beach front property....if only for a few days?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 14, 2010, 02:46:54 PM
Beach front property.... solid rock below us for almost 3000 feet to the new sea level.... we hope.... [waiting]

We have had some cool parties here .... muldoon, whitlock, harry51, adawgk, mikeyB, PEG got close but his sister wouldn't let him leave so we went to see him......others... We all feel pretty safe here.  :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 14, 2010, 07:16:10 PM
We widened our driveway, which required a permit. Permit fee was over a grand. Later, an arborist was spotted traipsing about our land cataloging which trees they would allow to be cut. We put up $2K for a bond, "just in case", a tree got damaged. Whille 12 trees were removed, a sapling's bark got scarred by the backhoe. $2K gone. The town "owns" trees over 3 inches in diameter. Mental note: remove every gosh darned tree not yet 3". Groundcover may not be removed without permit. Mental note, stop  cutting grass on the slope in front of the house.

Our neighbor, without permits, took down over 30 trees, regraded their slope, and did their driveway. They paid $3K in fines, and got a variance a few months later.

Next time, we do it, and ask forgiveness  later. Welcome to the suburbs of Long Island.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 14, 2010, 07:22:26 PM
.... I jus' couldn't live like that.... [waiting]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: phalynx on December 14, 2010, 07:33:21 PM
Permits are almost EVERYWHERE now.  Texas is the last holdout and I don't think it will be long.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 14, 2010, 07:38:19 PM
Last weekend I cut down a few big old dead and half dead Aspens. One of them fell on a small (maybe 4 inch) pine and smashed it flat. Too bad. I was going to cut it anyways. Next week I'm planning on cutting several more dead and mostly dead Aspens. Good firewood. Then I'm going to cut a couple of national forest trees that are endangering the south fence, already leaning and tangled in the uppers.

I asked karen. She said fine. Good enough for me.  ;)

You ought to look at the West.  No on second thought don't. Too many people here already. Well I might make an exception.  ;D  


How do they decide what to cut? I take out the small crap and those others that are too crowded. But I like being able to pick them myself. There are a couple I saved for shooting at. Trying to see how many 45 and 50 cal. rounds it'll take. Try that in NY.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 14, 2010, 09:40:18 PM
Cool - stormy tonight and my wind generator is putting out about 800 watts.  :)

Extra power from a home brew one could be a nice addition.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 15, 2010, 04:57:01 AM
Cool - stormy tonight and my wind generator is putting out about 800 watts.  :)

Extra power from a home brew one could be a nice addition.

Thanks for getting me off my rant and back on topic, Glenn  d*

My upstate land is my sanctuary from the madness of living in an area of 12 million. Like, Don, I enjoy using my 30/30 or 12 to keep a few unruly trees in line.

800 watts is awesome! Imagine if we could average 200W each hour every hour of every day.. Heck, I'd settle for 100... Send some wind over here
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 15, 2010, 08:45:07 AM
I wasn't necessarily trying to get you back on topic, Doc... I just had a power related comment to make....

My grandfather was born in Dolgeville... [waiting]





:)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on December 15, 2010, 10:16:52 AM
For a moment I thought the topic of this thread was "OFF TOPIC; various thoughts on land ownership..."  ;)

I love Dolgeville! Nice town, nice people, cut through by the beautiful West Canada Creek. When I drive through, my pulse quickens because I know I'm close to camp. :)

I wasn't necessarily trying to get you back on topic, Doc... I just had a power related comment to make....

My grandfather was born in Dolgeville... [waiting]
:)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 15, 2010, 07:23:58 PM
Really..... I wasn't sure what part of the state you were in...   [ouch]

1890 - was a couple years ago....likely no one remembers us.... they went to Oregon shortly after that.  Had other relatives in W. Winfield and one died In the Cooperstown rest home.

No wind on the wind generator tonight..... rofl
Title: Re: OFF GRID POWER; various thoughts on...
Post by: altaoaks on December 17, 2010, 07:49:33 PM
 c*hi everyone, well i hit the jackpot today.  when i arrived at the customers house with the new solar install, the solar rep was there following up on the job.  i had the opportunity to ask about power buy-back and the buy-back rate.

well, our industrious public utilities commission gets the honor of setting the rate!  and at this point they have not set this rate.  we all know who the PUC reports to, the power companies!  supposedly the rate will be set around march, 2011

the rep said that the way its going to work is the homeowner gets a bill of approx. $5 monthly, which is the transmission fees/taxes.  12 months from install, and every 12 months thereafter, the power company calculates what is owed either to or by the customer (this is called the "true-up")  the customer either gets a bill or a credit.

should be interesting to see how cush a deal PG&E and SO CAL Edison get out of their buddies over there at the PUC.  lobbiests rule!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on December 17, 2010, 07:53:11 PM
Don't look for it to be anything fair.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 17, 2010, 08:02:49 PM
That's more or less what I thought the deal in CA was. It does not pay to oversize the PV system when the years use is totaled. That's the way it was here in NM until a few years back. Now the participating power companies will cut a check.

Currently  ;) our cost to buy is about 0.09 (average on December bill) and they pay 0.12 per kWh for any excess

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on December 23, 2010, 01:46:22 PM
In another thread I showed off the LED Christmas lights at our cabin. I also showed that we used 6 strings of LED C6 type white lights mounted down the cabin side and over to the shed for nighttime illumination. That works very well. Even on the darkest night we have plenty of light to see our way from the cabin to the shed and around the immediate area.

I noticed something odd though.

We use an Outback inverter. There are may programmable features. One I use is the search function. This allows the inverter to run in a standby mode when no power is being used. When a load is sensed the inverter turns on. It is adjustable for sensitivity. I have it set down to where a small LED night light will activate the inverter.

However, a single string of the LED Christmas lights or the single LED night light, must be plugged into the receptacle the "proper way". Reversing the plug the light?string will not trip the inverter on. Rather the light(s) pulse on-off in sync with the search signal. Changing the orientation of the plug resolves the issue.   ???

Just interesting. If at first something doesn't react the way you think it should analyze what changes could be made.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on January 03, 2011, 07:14:50 AM
LED's are

Light Emitting DIODES

a diode passes current in only one direction

so it kinda makes sense depending on how the inverter current sensor works

my 2 cents  $2 worth (inflation you know)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on January 13, 2011, 11:05:18 AM


The BIG RED Batteries are here !!!   

Surrette 6 CS 17 PS     6V 530 Amp Hour

all 1800 pounds of them

Ordered from the Solar Biz (very good people)  shipping was only $120


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi55.photobucket.com%2Falbums%2Fg135%2FCrockette%2FIMG_5228.jpg&hash=3765d8862c2559bd65821006e1dcc59c)



(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi55.photobucket.com%2Falbums%2Fg135%2FCrockette%2FIMG_5227.jpg&hash=fbed4771830f37dc2c2b902ad3a6b38b)



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 13, 2011, 12:11:27 PM
Way cool!  Those are the best batteries anyone on here has ever shown as their own.  There should be many years of great service.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on January 13, 2011, 12:29:16 PM


Thanks Don for the Solar biz tip -- saved me $1600 over the next best deal

they have a 10 year warranty-- hopefully we will be using them well into the next decade -- supposedly individual (dead) cells can be replaced, too


at 50% discharge we should have 10 KW-Hrs of storage

my FIL is going to FL near Miami -- I may ask him to pick up a Xantrex 6048 inverter down at Sunelec to go with these batteries


Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 13, 2011, 12:46:31 PM
Impressive savings! 

Glad you could benefit
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on January 28, 2011, 06:54:47 PM
Wow, those look almost like fork lift batteries.  Impressive.

Speaking of which, has anyone ever considered using forklift batteries for their bank?  I've heard of one instance, but never seen any discussion on the possibility, or not.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on January 30, 2011, 09:28:16 AM
At home, my two widescreen TV's sit in standby mode most of the time, and, with the added burden of cable box and DVD, add up to nearly 400W/hr or 10KW/day!

I went looking for better options for my off-grid camp and happened upon this nice 32" TV at BJ's. It's an LED by Westinghouse that takes only 54W while on. Add an 8W DVD player and your talking about as much power as a light bulb. Not bad for bringing a couple evening hours of creature comfort to your battery run cabin.

http://www.amazon.com/Westinghouse-LD-3255VX-32-Inch-720p-Black/dp/B003SZRWBO/ref=sr_1_5?s=electronics&ie=UTF8&qid=1296411357&sr=1-5 (http://www.amazon.com/Westinghouse-LD-3255VX-32-Inch-720p-Black/dp/B003SZRWBO/ref=sr_1_5?s=electronics&ie=UTF8&qid=1296411357&sr=1-5)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on January 30, 2011, 09:48:40 AM
Good, but remember, with any electronic device with a remote control, the main unit (TV, DVD player, etc) will have a constant low power demand. So there will still be a small draw, that will add up. Some like myself who just absolutely don not like to think about that wasted power will use power strips with a switch to really turn off those items. I did it a little different. I installed a wall switch with a pilot light beside the sofa/TV location. It is wired to a half outlet. When we want the TV on we flip the wall switch. The power that the TV wants then trips the inverter standby and powers up the inverter. The remote can then turn on the TV, etc. When we're done we flip the wall switch again and it all goes off. If no other devices are on the inverter goes to sleep.

The standby on the inverter does draw some power but it is far less than the TV or DVD unit.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on January 30, 2011, 06:05:02 PM
The standby on the inverter does draw some power but it is far less than the TV or DVD unit.
I've got to get around to using the new power strips I bought last week. My bill is outrageous considering I'm home only at night, keep all the lights (CFL) off and have gas stove/heat/water. I used the Kill-a-watt meter and noted my refrigerator (normally the largest household draw) uses only 1.5 KW/day. My bill says I'm using 15Kw/day. Other than refrigerator, I've got a 65" LCD TV, and a 50" LCT TV, 2 PCs, one of which is usually always on, and a hot tub. Sometimes I scratch my head and think it just doesn't add up. My pals have homes twice this size and half the bill. I've noticed I can keep my TV's off, but my cable box if turned off, takes some 5 mins to reprogram itself. Not worth the aggravation. I'll run everything through power strip except cable boxes.

My 5KW cabin inverter is on order and draws 0.9A at a rated efficiency of 90% and 95% at 1/3 load. I will turn it off unless we're using something electric. Figured if something doesn't run properly, I'll add a pure sine wave unit for that appliance alone. Can't see spending for filet mignon when most of my appliances will gladly eat leftovers. ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on January 30, 2011, 06:13:58 PM
Sounds like you have a plan there, Doc.

We have built our system up to where about 90% of the time it handles our parasite loads too, so we just pretty much run like a normal house.

You might want to contact your power company and complain or have them do an energy audit.  They had been making a mistake on reading our old meter for years.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Cowboy Billy on February 02, 2011, 01:00:26 PM
Wow, those look almost like fork lift batteries.  Impressive.

Speaking of which, has anyone ever considered using forklift batteries for their bank?  I've heard of one instance, but never seen any discussion on the possibility, or not.

My Dad Brother and I have 120 acres in Michigan's eastern UP. We got a used smaller 24v forklift battery 1100lbs. We have a 26' travel trailer with a 12'x20' room on it. We run the lights tv microwave ect for about 3 days on it before we have to charge it back up. Which usually takes 5 hrs with our home built chingfa diesel generator. We do have two small solar pannels on it but they are in the woods and generally just make up for battery losses while we are not there.

The biggest problem we are running into is that we have two cells that self discharge faster than the others. So when we use it our battery voltage drops off faster than it should and we have to charge it more often. Also the low cells are more likely to freeze and cause further damage. We have been trying to find a single cell battery charger but haven't had any luck yet. And trying to charge up the low cells and not over charge the good cells isn't working.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fsphotos.ak.fbcdn.net%2Fhphotos-ak-snc4%2Fhs243.snc4%2F39494_1282622720623_1681757389_541062_461818_n.jpg&hash=6678ba729b1ea4554b490b8486ef3ec3)

The box on the 4x4 is the charge controller for the solar pannel and the 750 watt wind-generator which we haven't put up yet. On the back wall is our 5000 watt inverter.  Once I get the the tower up for the wind-generator I want to make a underground root cellar that will hold the generator and battery near the tower and help keep it from freezing.

Billy

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 02, 2011, 03:31:07 PM
Have you tried a desulfator?  Or thought about a chemical additive?   At this point there's little to be lost.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 03, 2011, 08:40:17 AM
These chargers are expensive but I have heard good reports about them rejuvinating batteries

http://www.r-charge.com/RC-15A24-2412VDC-Industrial-Charger-Rejuvenator_p_99.html#
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Cowboy Billy on February 03, 2011, 11:01:24 AM
Thanks Don

Just looked up the desulfater. Looking at the plans I think my brother can figure out how to set it up to charge/desulfate 1 cell as well as the whole battery. Even as it is its not bad as we usually just go up for the weekend and we can run it friday nite to sunday and recharge it before we go home. But we would like to bring it back up as far as possible so we are not taking more life out of the battery than possible. Dad and I were up 10 days over new years. And only used four gallons of diesel to run the 10 days and leave the battery fully charged. For the $750 we paid for the battery 2/12 years ago it has just about paid for itself in fuel cost and not having to listen to the generator run.

Thanks Windpower

Nice looking unit but not cost effective for our use level. We are only at the farm once or twice a month for the weekend and a few weeks a year. If we were there full time it might be a different story.

Billy

Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on February 05, 2011, 04:30:26 AM
Ok, I had promised myself to exercise at a least a modicum of fiscal restraint going forward but seeing the liquidation on sunelec.com, I took the plunge. My off-grid collection now includes 2 Sun panels, 200W, and a 30A MPPT charge controller. $1.68/Watt. Not bad. At 3 peak hours minus various losses, I figure in the order of a kilowatt daily. Added to the wind turbine it should be all I need. If not, there's always the Yamaha 2300 Inverter. Now I suppose I'll be needing to buy a shed to mount the panels on and store all the goodies in. Thanks guys for pointing me to what seems to be the most inexpensive solar site around. Now, is there a reallycheapsheds.com?  :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on February 07, 2011, 08:50:07 AM
Ok guys. Let's say I've got a couple of SUN panels, 200W each. I run them through my MPPT Controller and into my 12V bank.  I know there are always losses, I just don't know how big those losses usually are. My solar map shows 3.5hrs average peak. What kind of actual power output should I expect? How large a difference between a sunny day and raining?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on February 07, 2011, 09:11:04 AM
Is that in the winter or summer?  I have found many solar maps to be unreliable because the average 365 days a year.  Some average by month and some by season.  I once found a site with the raw data of average sun hours in a given day.  This gave me the best perspective of how they came to that number. This also gave me the difference based on weather conditions.  I think the best charts are broken down by month.  Sorry, I can't find the site.  I assume that 3.5 hours is peak summer sun. I have researched the Catskill area and in the winter the sun hours are far below that.  Although I believe you said your place was seasonal anyway.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 07, 2011, 09:46:06 AM
Links to monthly solar maps are available in ther first message in the Off Grid PV Sizing Tool (http://countryplans.com/smf/index.php?topic=8192.0) topic.

Inefficiencies in lead acid batteries can be as much as 20% of what the PV modules were putting through into the batteries. That figure includes the losses that occur when the energy is withdrawn and used to light a lamp, turn a motor, etc.

Have you run your projected use, etc through the PV calculator?  Two biggest errors made with owner designed PV systems are:
1.  insufficient storage or withdrawing too much energy and
2.  insufficient wattage from PV modules.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on February 07, 2011, 03:27:41 PM
Closest city to me shows 2.5hrs by winter, and 4 in summertime, avg 3.55. I'm assuming being there in all but winter. Just wondering what a "200W" panel would be expected to put out under real world conditions, assuming direct sun, peak hour, and in rain.

I've done a energy budget and it appears I will be using on the order of 1-2Kw/day depending on how often the pumps run. I've assembled 8 220AH batteries for 1760AH at 12V. I wanted to have a discharge depth of 50% to last a 3 day weekend, so figure I have now have 10KW to spend over a three day period. To lengthen the discharge period (or shorten the recharge period), I have the wind unit, and now the 400W of PV. It seems to me I have more than enough to cover extending my stay by a few days or using a bit more than I originally figured. I've toyed with adding another two panels if need be. My MPPT handles 1200W max.

Although the rated watts on all the panels out there look impressive, I still wonder what I'll be generating each day while I sit on my porch and enjoy a cold one.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 07, 2011, 04:33:23 PM
What will 200 W panels do in the real world?   ???


Pretty good if the sun shines brightly!  :) In winter cold weather they do even better as long as the sun shines and as long as the modules are correctly tilted. Modules are generally rated at 25 C (77 F) degrees. When the temperatures rise the output falls and the opposite happens when temperatures fall. Voltages can spike quite high when the modules are first illuminated on a deep freeze day. That only lasts for a moment, just long enough to fry charge controller electronics if their over-volt point is reached. Our panels Voc is 36.1, the theoretical maximum. I've seen it as high as 42.6.

Our modules are rated at 208 watts each; three modules for 624 watts. In bright summer sun, even with elevated temperatures, our modules perform above their rating.

This past weekend we had some rather low temperatures at the cabin. Yesterday with the sun bright it was still only 15 F outside. The Outback recorded a maximum power of 701 watts at one point.  :o  I observed 665 to 678 watts myself over a period of a half hour.

Cloudy weather does drop the output, but on all but the blackest of cloudy days they still put out.

At least that's what our Sharps are doing. YMMV
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on February 07, 2011, 06:36:35 PM
What will 200 W panels do in the real world?   ???


Our panels Voc is 36.1, the theoretical maximum. I've seen it as high as 42.6.

Our modules are rated at 208 watts each; three modules for 624 watts.The Outback recorded a maximum power of 701 watts at one point.  :o  I observed 665 to 678 watts myself over a period of a half hour.

Cloudy weather does drop the output, but on all but the blackest of cloudy days they still put out.

Thanks Don, that's awesome! I expected disappointing results but it's nice to know the claimed rating is close to the real rating. My MPPT can handle up to 40W panels, and my VOC is 33.2V. Hopefully not an issue. I'm looking forward! :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 12, 2011, 07:52:34 AM

Ordered the Xantrex XW6048 Thursday


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fep.yimg.com%2Fca%2FI%2Fyhst-82241567817297_2144_10723099&hash=0105a3d030c93815827f5cc0ead1fb8a)

from Sunelec -- good price --  $2900

http://sunelec.com/index.php?main_page=product_info&cPath=6_38&products_id=54

The FIL is going to pick it up when he is down in Miami and drive it back for me

saved almost $400 shipping  :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 12, 2011, 09:20:51 AM
Will you be able to use it either on or off grid or is it grid tie only, Windpower?  Nice inverter.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: AdironDoc on February 12, 2011, 01:43:25 PM

Ordered the Xantrex XW6048 Thursday


(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fep.yimg.com%2Fca%2FI%2Fyhst-82241567817297_2144_10723099&hash=0105a3d030c93815827f5cc0ead1fb8a)

from Sunelec -- good price --  $2900

http://sunelec.com/index.php?main_page=product_info&cPath=6_38&products_id=54

The FIL is going to pick it up when he is down in Miami and drive it back for me

saved almost $400 shipping  :)

Nice unit. I hope you get great use out of it.

The cost to ship these items never fails to amaze me. My 2 Sun PV panels arrived 250 bucks later, strapped to what essentially amounted to a wall (header, footer, studs, 5/8 inch plywood). Irony was, the the other side was exposed, covered with a sheet of cardboard, and scratched along the edge leaving a jagged aluminum edge. I'll file it down but sometimes I wonder... I've got a running record of 2 returns for the last 5 items.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 12, 2011, 01:59:50 PM
I'm so happy I was able to pickup many of my items locally.  :)

Truck freight can be a killer

30-some years ago someone drove a forklift fork through our first Vermont castings stove; right from the factory to us.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 12, 2011, 02:46:46 PM


Off grid, Glenn


shipping my 1800 pounds of batteries from Canada cost me   $120    -- go figure

 
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 17, 2011, 04:15:14 PM
Doesn't make much sense but that's how it is I guess.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on February 18, 2011, 12:33:00 AM
My 3 orders from Sunelec cost $60 shipping each time. I had 2 shipments of 3 panels each and the panels were strapped to oak pallets with plastic corner spacers between the panels for stability and to keep them off of each other. This also made the job of moving them from one end of the truck to the lift gate a lot easier with the hand pallet jack. I am closer to Miami than most.
If you can pick them up yourself, you are better off. I had actually started putting a pencil to the costs of me driving down to Miami and quickly nixed that idea.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 20, 2011, 05:13:05 AM

MIL called (not FIL) and said that their friends from the Keys were going to meet them in Sarasota (IIRC)  they didn't want to drive the extra 3 hours to Miami to pick up the inverter.(they are retired and on vacation "for a month or so")

"so can you still get it shipped ?"

Sure, I guess, seems I don't have a choice

"I hope it won't cost you too much"

Oh, no problem, it is only about $400 to get it shipped

"Oh good, I was afraid it was going to be expensive"

*shaking head in disbelief*

The only reason I bought it now from Sunelec was because he said he would be happy to pick it up because he was going to FL anyway.  Otherwise I would have bought it from The SolarBiz this fall. This put a significant strain on our cash flow right now (with the Cessna annual and the $%K&***ing truck trans blowing up, real estate taxes due) 

Told my wife....


she said, yeah that is the way he is ....

 I don't get it.  He is always bragging about what he does for people, and that he is a "man of his word" --- it is a side I haven't seen about him before.

Wife is not surprised at all


I don't get it at all


*end of rant*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 20, 2011, 08:06:35 AM
Looks like the reason their price is so low might be because that is discontinued; still a good inverter but everyone else seems to be selling the new model that also does three phase.   That sucks on the reneging on doing the pickup
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on February 20, 2011, 08:37:37 AM
alot more money for the new one though

I can't think of a good use for 3 phase at the farm

If It needs that much power I'll get a gasoline motor .... ;D

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on February 20, 2011, 08:39:31 AM

I can't think of a good use for 3 phase at the farm


Most of us wouldn't. It's like Xantrex fixed something that didn't need fixing.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on February 28, 2011, 08:05:37 PM
X probably did it for Machinists and not Farmers. Hi  Don! Been to busy to lurk, that is a damn shame! :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on February 28, 2011, 08:10:41 PM
I have a couple 3 phase machines that would like it....but I also have a rotary phase converter so I think I have it covered.  Now if I would just hook them up. [ouch]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 01, 2011, 04:20:48 AM
Hey Glen,   I think we both could use a hook-em up guy....  41 inches of rain on paddy hill so far!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 02, 2011, 12:30:58 PM
I haven't kept a total this year Dave, but I'm sure we are right there with you and more rain and maybe snow on the way.

Got your rainwater tanks full already?

My little cow water pond is starting to seal pretty good now.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 03, 2011, 06:15:08 PM
SunElec -- sale on used (new year ago - reject for slight cosmetic flaws) Solar panels -

See their letter

http://campaign.r20.constantcontact.com/render?llr=cgx9b8cab&v=001cHaZO6NvI5XvL0G5057uWbnJjdiUONtACcaI_kG1I7090fRgas-nwETNgXsv2OVd9zKek8NQe7iQ9f8f2__tSvVs-gxp6zsr9hQ05-hez3DUajHfDQphkgRPMjm5esgzS5clzyZ7N2_Ou5lGqE1nOk87_-7WcQ_PUXZdlX2rknMmibCVb3baNg%3D%3D

.98 to 1.34 per watt. 

The .98s are laminates.

I got their grade B's and they produce right up to full capacity or better.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Tickhill on March 04, 2011, 12:37:31 AM
Glenn, got the email yesterday and it would be a good opportunity for someone who wanted to get their feet wet with RE to invest in some PV. I too am well pleased with the panels I got from Sunelec. In fact it is time for me to change tilt but may just wait til the summer. Tickhill
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 04, 2011, 05:51:18 AM
I think these panels would be as good as they say they are and would not worry about them at all.  Watts are watts.

If there was a problem I am confident they would take care of it.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: considerations on March 04, 2011, 07:11:41 PM
Wow great price.  Now, if I could just buy the winning lottery ticket.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 09, 2011, 05:10:36 AM
Did you folfs notice that Sun has a wherehouse in SF? As for their warranty keep in mind that it could cost you alot in shipping which may not be a problem now. I say may not because they still have a ways to go in the good service rating. Great price as long as you have time to hang on the line.

Hey Glen, do you know anyone who wants 4 of the 75V Dupont 100W panels from last year? I will beat the Sun price!  They were used for running 300V for my high voltage charge controller testing that Xantrex/Schneider is building.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 09, 2011, 05:25:16 AM
I have a couple of possibilities on a need for the panels, Dave - PM me a price or I can drop by on the weekend possibly.

On dealing with Sun, I found that knowing what you want and ordering via the internet is the way to deal with them.

I don't deal with Phoenix, AZ branch - they are the worst customer service.  I have done well with Miami.

Problem with a Peoples Republic of California office is Sales Tax.... about 9%.  Once there is a store in the state I think we are stuck for Tax no matter what.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 09, 2011, 11:37:56 AM
I would rather pay tax than shipping! ???

I also have a unused outback mx-60 in the box and an xw4548 inv/chg that I will swap for an xw4024.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 09, 2011, 01:27:03 PM
I'm not sure if the shipping would go down that much but it might.

Sometimes its worth paying extra just to keep the state from getting more tax..... [ouch]

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 10, 2011, 05:49:40 AM
OK Glen,

I get the point of not giving the state the money! Truckers are much more deserving, but those 4 panels were a dollar per watt and over 300 to ship to Mariposa.

I also think that going to the belly of the beast (SF) could be even worse than the Phoenix store. They are a funny company and the owner is the funniest! He once told me that a cracked cell was not a defect but an opertunity to sell! :(
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 10, 2011, 09:02:08 AM
Interesting....  I think those panels exceeded UPS sizes and had to ship by truck.

Seems order before last 500 watts or so, were crystalline rather than thinfilm I got from them, and fit UPS and were cheaper.  Seems truck shipments from FLA have been running around $250.

I dealt with his daughter in Phoenix and got her on the phone only once.  After that I emailed John Kimball.  Soon I heard from her but when I tried email next order I got no response.  Finally I submitted an order to Miami on the online order form and received my order but had to decide on appropriate panels on my own with no consulting with them as they just were not available.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 12, 2011, 05:50:05 AM
Sun does have some great deals but I just can't send a customer there knowing there is a very good chance that I will get blamed for issues that develope. The nightmares about racking systems and panels that don't fit from other forums would shock you.  So as long as you buy nice easy things from them all is well, some of the time...
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 12, 2011, 07:29:10 AM
Good to know that stuff, Dave. 

I only buy the panels from them.  I buy the 2x4 racking system at the local lumber yard... [ouch]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 12, 2011, 07:52:22 AM
....nightmares about racking systems and panels that don't fit from other forums would shock you.  So as long as you buy nice easy things from them all is well, some of the time...

As well as people being given info that was plain wrong... like being told it was okay to series wire too many panels for the charge controller being used. And people being unable to get satisfactory answers to their questions, so much that they try to get free answers from vendors they never bought from.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 12, 2011, 08:41:08 AM
I haven't been able to get design info from them, but tend to forget that I already know what to watch for in system design on my own.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 14, 2011, 09:37:34 AM
Hey Don,

Did you ever solve the keep the cans from freezing problem?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 14, 2011, 09:52:48 AM
Dave, everything was going just fine with the undersink cabinet insulated and a small transmission oil cooler in a thermosiphon loop using water warmed by the water heater on low. Until the pilot went out. I think the pilot may have gone out because of an issue with an extreme cold snap and issues with drawing propane from portable cylinders. I'm not 100% sure on that, but since it's never happened before am leaning to that theory. I think the propane burner kicked in and the supply tank was low and very cold. It could not supply sufficient propane and flamed out. My theory anyways. I did more propane research and now know I didn't fully realize the issues with cold and propane. We had some below zero weather coupled with a week of heavy cloud cover.

Nothing in cans or jars froze solid but water in PEX lines froze. No problems with any valves or the tank though. I think we were lucky.

I have a new solution in mind for next year that involves a hole in the ground. More on that in a new thread later.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 14, 2011, 11:58:11 AM
I was running a heat trace to keep my sewage pipe from freezing (to the composting bin for the toilet) but noticed that despite the low wattage (I think it was just 5 watts per foot and I used 6 feet) it was still too much for the 660ah battery bank and 615 watt solar power -- in the winter anyway.

I found my battery bank down to 12.0 volts when I arrived Friday and had to ration light usage despite using CFL's.  We added a freezer which uses about 15-30 watts depending on it's cycle and once the batteries were charged up it ran fine but I can see the need to add at least two more batteries to get me to 880 AH's versus the 660.

At the same time, however, I hooked up my Iota charger (finally) and made use of it for a couple hours and brought the bank back up to 12.5v because the clouds just kept the sun from doing it's job!

I plan to work on the solar power in the near future and might installed another panel and battery just for winter use with the heat trace.  I figure I can install a low voltage shutoff like Don mentioned last year as that ought to heat the pipe and then let the battery recharge and then heat the pipe again etc but I'm working on options still.

We want to add a small fridge too and I feel that it's likely ok to run the freezer and fridge (on low settings) when we aren't there to preserve things and provide cold storage when we arrive but I'm learning I need to get back to the drawing board to make sure the system can handle the usage.  God forbid I wanted to LIVE in my cabin! hahaha  I'd have to do some serious work on the solar (add a couple panels maybe and more batteries) to ensure I didn't have to run the generator very often.

However, in the end, it's just plane cool to have solar power :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 14, 2011, 01:12:24 PM
I had my concerns about that heat tape when you mentioned it.

What kind of freezer, if I may ask?


One of the issues with an unattended system is what will it do when it's cloudy for days on end? I planned for three days minimum of capacity (actually have more than that as things are). This past winter we had five days in a row on two separate occasions with continual cloud cover. The weather station records illustrated that starkly with the watts/m*m column never getting above two digits during those periods. (That is sun watts per sq meter, not the PV power output. Right now, sunny day it is at 766 watt/m*m. Summer it hits over 1000)  That would not be an issue if we were at the cabin; I could start the generator. However, if we were absent and if there was something like a refrigerator operating there could be consequences I'd rather not deal with. For that reason I'd like to have an automatic start generator if we were running a fridge/freezer. Peace of mind insurance.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 15, 2011, 07:13:41 AM
I had my concerns about that heat tape when you mentioned it.

What kind of freezer, if I may ask?


One of the issues with an unattended system is what will it do when it's cloudy for days on end? I planned for three days minimum of capacity (actually have more than that as things are). This past winter we had five days in a row on two separate occasions with continual cloud cover. The weather station records illustrated that starkly with the watts/m*m column never getting above two digits during those periods. (That is sun watts per sq meter, not the PV power output. Right now, sunny day it is at 766 watt/m*m. Summer it hits over 1000)  That would not be an issue if we were at the cabin; I could start the generator. However, if we were absent and if there was something like a refrigerator operating there could be consequences I'd rather not deal with. For that reason I'd like to have an automatic start generator if we were running a fridge/freezer. Peace of mind insurance.



I'll have to check the Freezer model -- my wife bought it at Fred Meyers.  Our plan with the Freezer is to leave it set off unless it's needed.  Once needed a Freezer can usually go without power for short periods of time (even days) if not opened.  However, I am concerned, like you, that it could somehow run without power too long -- something to ponder.

I'm also looking at this fridge: http://www.pcrichard.com/catalog/product.jsp?productId=1533&parentCategoryId=7&categoryId=1104&subCategoryId=1104010020

I was told that getting a fridge without a freezer is the key to using less energy.  I guess I'll be doing some learning!!!

An autostart generator would be very nice to have and I might have to put a small one on the shopping list.

As for the heattape, it does seem to be working nicely but uses more power then I anticipated :(  I think it's going to be perfect for use when I'm there but will have to be shut off when we leave -- which might be fine.

I may look at a timer to turn it on and off daily though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 15, 2011, 08:17:54 AM

I was told that getting a fridge without a freezer is the key to using less energy. 

Hmmm. Where did you hear that? How much less? A top load freezer or fridge will be use less electricity, so if the freezer is a top load that can be very good. I've also read and believe that a top load fridge uses less electricity than an upright. But they are the very devil itself for convenience of use.

Are you aware that residential fridges and freezers are meant for use within a temperature range of something like 60 to 100 degrees. It's obvious that when in a hotter location the unit will consume more power. But it is not obvious, in fact it is counter intuitive, to think that in a colder location (like 40 degrees) the unit may also use more power, not less.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 15, 2011, 08:36:40 AM
Hmmm. Where did you hear that? How much less? A top load freezer or fridge will be use less electricity, so if the freezer is a top load that can be very good. I've also read and believe that a top load fridge uses less electricity than an upright. But they are the very devil itself for convenience of use.

Are you aware that residential fridges and freezers are meant for use within a temperature range of something like 60 to 100 degrees. It's obvious that when in a hotter location the unit will consume more power. But it is not obvious, in fact it is counter intuitive, to think that in a colder location (like 40 degrees) the unit may also use more power, not less.



My neighbor who's been on solar for 30 years told me to look for a fridge without freezer.  Something to do with the cycling/dehydrating/antifrost of the freezer I guess.

The cabin stays VERY cool in the summer (as low as 45 at night and remains cool until well into the late afternoon) so I figured the fridge will not have to work too hard in those conditions.  I also plan to put the freezer on the North side to keep it in the shade 95% of the time (if not more).
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 15, 2011, 09:04:03 AM
I'm not sure I got my point about low environmental temperatures and residential refrigerators made. Refrigerators in cold spaces are not going to run as well as they would in their design temperature range. A fridge in a cold space may not save any power.

The common household refrigerator is not designed to operate at 45 degrees. At low environmental temperatures the internal operating pressure of the refrigerant falls below design parameters. That makes the motor run longer to do the same amount of cooling. So even though the unit might run with less frequency it will run longer than if the room was at 75 degrees. The system does not lubricate as well either and that shortens the expected life. Commercial refrigeration units that have the compressors sitting outside on a roof top have different, more complex, more expensive metering devices in the refrigerant section. They can operate in extremes of temperature without problems and with greater efficiency. A residential use refrigerator could be built to run at lower temperatures and still be efficient. That costs a little money and most people keep their residences at least at 65 - 70 degrees, so the manufacturers of residential refrigerators don't spend the few bucks.

There are refrigerators sold as "garage refrigerators" that are made for use in a cold space like an unheated garage. Expensive though.

My point is do not count on a cold environment making any savings in electrical use. I have some info saved someplace, but I don't know where off hand.

I believe the operating problems are most severe with fridges that have a cooling fan with the condenser. Units with the coils under the skin like many freezers, are more immune to the issues. Something to do with pressure head or something. ??? Low temp = low pressure = low flow = less refrigerant and less lubricant flow = trouble, is what I understood from what I read.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 15, 2011, 10:33:01 AM
Ok,  here goes.  I have a question which I have been researching.  It is about UL products in the solar setup.  I have to pass a code inspection before a certificate of occupancy is issued.  Based upon my readings of discussions here it appears that all products used in the electric system for a house must be UL approved to pass inspection.  If this assumption is wrong, please correct me.  I have been searching for products to build my system.  There are a lot of products out there from some of the big names, but when I look them up most don't advertise if they are UL listed or not.  I was searching through the Xantrex line in particular and found only 2 products advertised as UL listed and that was for UL 458 - Boats and RV's.    I am particularly looking for this in charge controllers and inverters.  Has anyone else run into this?  Am I missing something?  Also, is there a particular UL listing I should be looking for before I buy a product?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 15, 2011, 11:58:13 AM
UL listed or ETL listed satisfies NEC.  All Outback charge controllers, inverters and power panels are listed. Ditto on the Xantrx C series controllers; probably all their major inverter/chargers.

I noticed that the printed matter I have on my Outback inverter shows ETL clearly. Hidden is the fact that it is ETL listed to UL1741 standards. And if I remember rightly the label on the unit shows the UL symbol. Not everyplace I've seen the unit offered for sale makes mention of any approval.  Reading the manufacturers manual seems to always mention UL or ETL listings.

Depending on how knowledgeable or "by the book" the inspector is it may be the little things that catch you up. Automotive wire and standard welding cables are not UL listed for example. Black wire is not suitable for a negative DC conductor. Run of the mill terminal connectors are not UL listed. The common RV / race car battery disconnect is not UL listed. Some PV modules sold as blemished or seconds may not have UL labels. (sometimes that is because the cells may be placed too close together to pass the high voltage test. Sometimes it may be because of the connecting wires not having UL labels. Sometimes it may be just that they never paid to get the right to use the label).


My battery cables are not UL-Listed. But I used white tape on the ends of the negative cables just like NEC calls for. I did not invite the inspector. There is a break point, above which white tape is accepted and below which it is not.


Side note: When looking at things like breakers and switches, for example, sometimes you come across things with a UL recognized label. These are for components that are used in devices. The entire device can get the UL listed label, but any components with the UL-R symbol are not approved as individual items. Clear? I had found some circuit breakers classed as UL-R. Good price. But by themselves they were not UL-listed. They needed a UL-Listed enclosure as well. Probably more than you needed to know.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 16, 2011, 05:44:46 AM
Very nicely done Don!  If you are going to be inspected then talk with the local inspector about any quirks he has! Do the best you can about what Don has said. Yes all of the Xantrex high end gear will work for code as well as Outback. The Outback gear came from Xantrex guy's who went out the back door BTW.
Magnum as well and anything from Midnite also! Good luck!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 16, 2011, 05:46:40 AM
Thanks Don .  I didn't know about the ETL.  I found that the outback flex controller was, but it was not readily available.  I had to go and pull the user manual for the product to get the information.  After much searching I was able to find an owners manual for the C series from Xantrex to find that it is UL certified on page 23 out of 100.  What a real PITA it is to find this information.  With the cost of testing and the necessity of the certification to pass code, you would think this would be more prominently displayed.  The Xantrex website no longer has any links to any of the C series products.    Morningstar charge controllers also seem to be certified, but again, I had to dig through the manual, product by product to get the information.  Very time consuming. I spent a long time on just three controllers.  I can't imagine how long it would take for all the different inverters.   Does anyone know if there is a reason for this?  Is there just a general assumption that major brand names are certified?  Or do inspectors just not usually check?

My view is that the local hardware stores and electric supply sell the UL wires and other parts I would need, but not the off grid components. Education and design of the electric system is the next step for me.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 16, 2011, 05:49:22 AM
Thanks Dave.  Inspection is certified by any licensed electrician.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 16, 2011, 07:43:41 AM
Aw shucks  :-[  Thanks Dave.  :)



My view is that the local hardware stores and electric supply sell the UL wires and other parts I would need, but not the off grid components.

Don't forget that common everyday UL listed AC parts (disconnects, switches, breakers...) are almost always not safe to use on the DC side of the system.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 16, 2011, 10:57:07 AM
Thanks Dave.  Inspection is certified by any licensed electrician.

Actually that depends on the county, state, ect. You can do it yourself if you are the homeowner in most places.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 21, 2011, 07:18:45 AM
to MPPT or not MPPT?  That is the question.

Ok, here goes for discussion.  I am looking to upgrade components of my small portable solar setup to slowly expand more towards a cabin sized system.  These will be UL for a future electrical inspection.  The first component I have settled on is the charge controller.  Some advertisements seem to boast an up to 30% greater efficiency.  Here is the breakdown of my understanding and factors that I used to come to my conclusions.  The first factor was price.  I will use similar devices for comparison (60 amp).  The minimum price non-mppt charger I could find was a Xantrex C60 for $150.  The minimum price MPPT chargers I found were the Outback FM 60 and the Xantrex XW-60 for $500.  So what do you get for that extra $350?  My understanding from some books and articles the MPPT technology has 2 main advantages.  First it takes voltage over the necessary amount for the battery bank and converts it to current.  An example if your panels are putting out 17v and the charging volt of the batteries is 14v the 3v difference would be lost if it were a non-MPPT charger.  So on cold sunny days this would be most pronounced.  The second advantage is that this conversion of volts to current can match higher voltage solar arrays to lower voltage battery banks.  This can be a real advantage by not having to pick you panels as closely and mixing and matching panels.  This can also have an advantage if you want to run the DC solar line a long distance (like don did), because you can use a higher voltage, lower amperage line and just let the charge controller do the work of matching the voltage.  Did I miss anything?

So let me break this down into dollars and my system. 

First, my I don’t plan on running long DC lines.  My hope on integrating passive solar into my home means I will have a clearing for solar access around the house.  If I do run a line, it will be 120v AC.

Second, I believe I can shop and match panels in 12 and 24 volt and connect them in series or parallel to match the voltage of my battery bank of 24v to 48v depending on sizing and expansion.  I will reconsider this if I find a great price on an only 12v inverter, but the cost difference in 12 and 24v inverters would half to be over $200 for MPPT to start to have consideration for this factor.  I also would have to find an large difference in price between the panels that put out 100v and at 1 amp and the ones that put out 25v.

So the last factor was the power efficiency gain per $ spent.  The efficiency gain seems to be largest for systems at 12v rather than higher voltage. The panels seem to come in average voltage ratings of 17, 26, 35 Vmp.  So the tolerance of power lost seems to be greatest at the 12 v. level.  I will go with this for maximum dollar differences.  So if I have a 500 watt panel array at 12v, a 30% gain in efficiency (highest advertised gain) would be an extra 150 watts.  This compares to that I can get a 150 watt panel for $300. So with weighting the greatest panel difference and greatest average gain, it is still cheaper to get an extra panel.  This seems to change as you go for larger systems and more panels.  Then the power gain from a $350 additional cost MPPT charger is greater than the percentage gain from adding more panels.

 So for simple small to medium sized systems it seems cheaper just to add an extra panel rather than going with an MPPT charger, and for a medium to larger system the additional cost is worth it. 

What did I miss/ get wrong?  I would appreciate any critiques.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2011, 08:18:52 AM
I have the Outback FM60. The FM60 has a maximum open circuit voltage (Voc) rating of 150 volts. That means if the incoming voltage from the PV array e\xceeds 150 volts the unit may toast. My Sharp panels have a Voc or 36.1. Three in series equals 108.3 volts. However, in winter with clear blue skies there can be a cold weather induced peak. It doesn't last for long but can still damage the charge controller. I have recorded readings of 141 volts on several occasions.

The maximum Voc of the Xantrex C60 is 55 volts. That is going to severely limit any series connections with PV modules. Voc from the panels should probably not exceed 36 volts. 


Outback generally has a operating temperature range that goes to lower temperatures than many other charge controllers.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2011, 09:13:26 AM
To add to the Voc notes above.

I used the string size calculator that Outback has online (http://www.outbackpower.com/resources/string_sizing_tool/). It has sliders for maximum and minimum temperatures. It comes up with recommendations for maximum number of panels in series and parallel. There is an extensive list of PV module data to choose from. You can also enter your own data for panels that may not have made it into their database yet. Using that calculator the maximum voltage my three panels should produce is 127 volts (three in series). Looks like I hit 12% more than that. Could have been extra cold or extra bright (8800 feet altitude has less atmosphere to screen the PV modules.).

I believe Xantrex has a similar tool; I know SMA (grid tie inverters) does.

I also believe that when running the numbers to keep everything on the up and up with NEC that there may be another safety factor percentage that needs to be considered. Another 25%, BUT I am not certain of that. So that is only mentioned as a caveat, something to be checked on, no guarantees one way or the other. I may be confused. That may apply to sizing breakers or wires. Darned if I recall for certain.

Maybe Dave Sparks can set us straight on that.

Squirl have you planned out how much battery capacity you will need when all is said and done?  I think that is the place to start and then from that data work out array capacity and from that charge controller size.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 21, 2011, 10:18:20 AM
Everypanel I looked at had a 25-26 Vmp, but the Voc was around 30.  And all the 17 Vmp ones had a Voc of 23.  The Xantrex C60 can only go 12v and 24v systems.  The C40 can go up to 125 Voc, which should be more than enough if I want to go from a 24v to a 48v system.  My understanding was any voltage differences from over 2-3 above the battery bank would just be lost if I didn't get the MPPT charger.  That is just what I could glean from a few articles on it, not 100% though.

So for $100-$125 I could go for a C40 or TS-45 and a slowly expand a 24v system up to 960 watts, and if I went bigger I could switch to wiring in a series to 48v  up to 1920 watts.  If I went with a system over 1-2kw, then that it would probably be time to upgrade to an MPPT charger.  I would probably have to run the cost/benifit ration if my system was over 1kw.  So if you get 25% more power (average high advertised rate) it would be worth the additional cost at around 1kw.  Although, I distrust the advertised improved rate.  It seems like this would only be under certain conditions and would not apply some or most of the time. So if in reality, if over the life of the product,  it gave you a 15% real world gain, it would become cost effective closer to the 1.5kw range. This of course is with distance run not being a factor. These are just my thoughts so far.  

So operating temperature should be another factor to check.  The Xantrex C series is 0 degrees C.  The morning star and outback are -40 C.  That and the warranty seem to be more brand specific than between the MPPT technology/ cost difference.

Does the FM60 have diversion control for use of excess energy?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 21, 2011, 10:35:28 AM
Don,
 A building department or inspector could calculate that you are overvoltaging a controller from temp data and make you rewire an array. I doubt they would...  As far as safety, the wire is 600vdc, the breakers are 150vdc, and so if you overvoltage the controller it will record that and probably have problems, or will soon. Same with the breaker. The point here is it will not harm anything except your budget. Electrically the controller just stops working or internal circuit protection takes over. Some internal protection is one time only!
 One of the extremely nice things about a 600vdc hi voltage controller is that you widen the design range. Also the issue of long distance and small easy wire gages for ease of use is very tempting, as long as one has the wallet!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 21, 2011, 11:27:27 AM
Ok is the NEC 25% buffer down or up? Example if you have a 45 amp controller at 24v then it has a maximum rating of 1080 watts. A 25% decrease is 1080x.25 = 270 watts  or a panel array of (1080-270) =810 watts.  As opposed to X x 1.25 = 1080. Or an array of 864 watts.  Either way, it is around the panel array size were MPPT technology becomes a cost effective alternative.

I have an idea on size, but there is a lot of time and money before this is all finished.  I currently have a 100 watt 12v. single deep cycle marine battery system now.  It is great for lights and a little bit of charging.  I figure I can add a panel or two and keep it 12v, but I will need a new controller.  As I spend more time there, I figure I will expand it.  I would like to reach around a 500 watt 24v system with four T-105's by around when it is time for the electric inspection.  This would give me 5400 watt hours, and around 2kw hours production per day in the summer. Good for a weekend, but not quite full time.  If/when I am there full time, I would probably want up to 11000 watt hours capacity and maybe a 750 watt panel array.  My estimate is around 1.5-2kw hours a day (what I have used in the past).

Since I am on the very top of the mountain, I figure I will want to add a small wind system eventually.  I have read that the power output of these can vary from a little too extremely high.  I think I would give it its own charge controller.  I will probably install this type of system after I get a certificate of occupancy.  Between the two systems I have an average estimate of 3-4 KW hours per day, which is less than my current electric usage.

This lead me to kicking around the cost/benefit of MPPT technology, so I thought it would make a good discussion topic.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2011, 02:16:06 PM
on the NEC rules...
It's volts or amps.

(1.25 x 1.25 is 1.56, so rather than go through n * 1.25 * 1.25, I use n * 1.56)
 
Example. Sizing a circuit breaker to be used between the PV modules and the charge controller.

Take the short circuit current rating (Isc) of the PV module you plan to use and multiply it by 1.56, then select the next higher breaker size. So Isc = 8.13 x 1.56 = 12.68, probably use 15 amp breaker.

If the Voc is 36.1, then 36.1 x 1.56 = 56.3 volts, so the DC voltage rating of the breaker should be at least 56.3 volts.


More thoughts on selecting, or not selecting MPPT, later.


PS I never overvolted anything. I came close on two days but since it was during the coldest temperatures recorded in some sixty years it's not normal. The next highest recorded voltage was 127 which is very well within the 150 maximum. I know it would only take once.  If I get concerned I have a choice of a higher volatage controller or a cold weather panel cut out. I have toyed with the thought of a cut out.  :-\
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 21, 2011, 02:56:01 PM
I meant "you" in the same sense as "one".
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2011, 04:18:08 PM
Dave. I did not mean to imply you were picking on me. Just wanted to it clear my system got close to trouble but usually does not.


Wind generator: yes it would need it's own charge controller. One that has provision for a dump load.

FM60 and diversion. There is an Aux output. It can be prrposed for different tasks but only one at a time. The manual explains. (D/L at Outback) It could be used to trip a relay that would be sized to handle the required voltage and amperage for load diversion. I investigated that route when looking for ways to keep "things" from freezing in the cabin over winter. The conclusion I reached was that it is possible but likely not a good return on the money; not to mention the bother. I was wanting to use the excess for resistance heating. It really doesn't amount to a lot of useful heat was my conclusion. What were you thinking of using the unused PV module power for? Or were you thinking of a wind generator dump?


System planning: I get uncomfortable when discussing planning a new system and at the same time to be talking about how the system will be grown in the future. Adding a wind generator is different from increasing battery bank size or changing the system voltage. That is my opinion and may differ from that of others. Adding more PV modules in a second group as Glenn has done is fine too as those modules have their own charge controller. The absorb charge and float charge voltage points may have to be played with to keep one from interfering with the other. That's in theory; as I've never had the situation I can't say much more than that.  Adding batteries is not great practice, IMO. Sometimes not avoidable, but that is where planning comes in.


MPPT: Again, just my opinion, but I do think MPPT has advantages no matter what the system size, except for all but the smallest system where two panels in place of one may be a better buy.  Maybe the advantages are more quickly realized when the modules are wired in series making the PV array voltages much higher than otherwise needed. By that I mean 30+ VDC from the array for a 12 VDC battery, 60+ for a 24 volt battery.

In hot or cold weather I believe any system will gain in performance wired that way with MPPT. The PV output voltage always has to be higher than what is required to charge the battery. It is the PV cell temperature that matters, not the air temperature. The module temperature can be 30+% greater than the surrounding air temperature. In a system where the PV output voltage is close to the battery system voltage the module voltage may fall too low to do any charging on a hot sunny summer day. If the series voltage is higher (like 2 panels in series instead of in parallel) there will always be enough voltage and the MPPT controller will make best use of what there is.

Similarly on cloudy days. I am amazed at times that our system is still pumping out a few amps on cloudy dark days. Looking at the voltages being received at the charge controller I can see that without series and MPPT there would be no charging happening at all.


One of the things I like about what I put together is that it runs itself. I don't worry about it being cloudy anymore; I notice, but I no longer worry. My wife can "work" it too. I wrote a user guide.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 21, 2011, 06:29:36 PM
And I have had a friend run a winter temp CC at close to 148V  :o waiting for Midnite to release their 200V contoller. I am glad that you don't think I am picking on you! You would know if I was... Spring is coming! Although Glen may doubt this!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 21, 2011, 06:36:51 PM
Wow! 148... makes you wonder how well everything is calibrated.   :-\

Spring is definitely here, at least where our cabin is! A year ago we had three feet of snow in places, minimum of 12 to 24 inches everywhere, no ground or grass showing anywhere. This weekend it's all dry grass and pine needles save for north facing slopes.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 22, 2011, 06:02:24 AM
I never thought about the advantage of going further over voltage of the battery bank with the panel array.  This way when the array puts out lower voltage and would not be charging at all, it still gives it a little charge.  That is another great factor to consider.  I wonder if there is a way to quantify that.  Also upon further reading of the subject last night I read that MPPT chargers are best to maximize power gained from the panel array, while PWM are used to maximize battery life.  There weren’t a lot of articles on this.  Most of the books and articles I have read though give these as descriptions of each technology but not as a comparison.  Such as the statement "pwm maximizes battery life", but not pwm gives longer battery life than mppt. There was no quantitative data on the extended battery life of PWM over MPPT technology though.

There seemed to be a lot of "if” and "possible” caveats in a lot of the marketing and advertising of certain devices without much information as to what the parameters of the scenarios they are referring too.  I figured bringing up the topic with some like minded individuals would flesh out a the limits a little better.  Thanks don and dave.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 22, 2011, 07:22:40 AM
I've seen the claims that PWM produces superior battery life too.  ???  Claims but no data to back the claims. I have no proofs either, but I'm willing to go out on a limb and state that no matter how much good might come from a PWM charger, it is more often than not countered by batteries that...
...get discharged too deeply, too frequently,
...are not brought back to full charge pretty much every day,
...have the fluid level fall too low too often,


I don't see big name battery manufacturers giving longer or shorter warranties depending on the charging technology being used.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 23, 2011, 08:17:30 PM
Ok so here is a question:  If a piece of electronic equipment does not list watts but rather lists kwh's (I'm sure amps was there somewhere but without my reading glasses I couldn't read it) could you not do the following to get average wattage:

Given:
24x365=8760 hours in a year
1000 watt hours equals a kilowatt hour
a 100 watt bulb running 10 hours = 1 kilowatt hour or 1000 watt hours.
Freezer uses 242kwh per year with an energy star tag.

Then:
1000 watt hours divided by the wattage of the device equals the amount of hours it takes to make one thousand watt hours or:  1000/27.65=36.16 and 8760/36.16=242

This would mean that a 27.65watt Freezer would use 242kwh per year assuming it ran 24x7x365 at that rate.

Reality though tells me that it draws much less then that most of the time and some number higher then that periodically as it cycles.  SO I'm unsure if calculating this way really helps.  What I'm trying to ascertain is both if I can use this kind of conversion to convert kwh to watts for the purpose of the solar calculator and if in fact I can use this as a base for a system or components of said system?

Mostly I'm just trying to see if my 3 panels and 8 batteries will handle the freezer running 24x7 in the spring, summer and fall when outside temps range above freezing most of the time (it can get as cool as 40 at night in the summer but mostly runs in the high 40's at night and 80's during the day.

I also plan to put the Freezer on the North side of the cabin to keep it cooler when it gets hot out rather then have it in the porch where the greenhouse effect will make the porch VERY warm during the day.

Thoughts?
Erik
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 23, 2011, 08:36:41 PM
I haven't seen one that small.

Seems a lot of my stuff uses around 125 or more watts but runs from 8 (Old efficient GE) to 40 or so minutes per hour (new fridge or freezer).
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 23, 2011, 08:40:30 PM
Offhand I don't recall the size panels and batteries - Total watts panels - Golf Cart Batts?  Hours sun per day?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: glenn kangiser on March 23, 2011, 08:46:05 PM
242/365=.66 kwh per day -

660 watts of panels for 1 hour - 330 for 2 hours 165 for 4 hours sun plus another third for losses and inefficiencies and ability to store about half of that for night plus draw the batteries down only about half way.  A backup generator for cloudy days or several of them, will likely be necessary, as it is even at my place.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Windpower on March 24, 2011, 04:18:12 AM

I have found this calculator to be very handy
 you can plug in various Kw-Hrs per month and get an idea of the system size needed adjusted for your average hours of sun for your location

for mine I plugged in 300 Kw-hrs per month  (about 10 Kw-hrs per day) in zone 5 (4.5 hours sun per day) and got 2222 watts of panel required (pretty close to my 12 evergreen 205 watt panels (I hope to get them operational this year)


So if your freezer uses 242 Kw-hrs per year, then divide by 12 months gives 20 Kw-hrs per month

plug that in, find your average sun  (zone 2 = 5.5 ?)  gives 121 watts of panels required minimum

http://www.wholesalesolar.com/StartHere/OFFGRID/OFFGRIDCalculator.html
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 24, 2011, 05:30:57 AM
I think your calculations are a good start.  I don't know what the test conditions they use for determining power usage of an appliance.  If it is with normal usage and you plan on only going in it every few days, I would say that the power consumption stated is above what is needed.  If the test condition was no one going in it, and you will go in it infrequently, I would go with the assumption that you will use slightly greater power.  Also don't forget the losses to the inverter and I believe there is a slight extra inefficiency if running a msw inverter as opposed to a true-sine. (not 100% on that) Also if your inverter doesn't have sleep mode, it can drain as much power from the batteries as the freezer.
 I tend to average usage across a day.  You will be lucky that the time you want to use it is when the sun stays out longer.  IIRC you are in zone 4, so you will have slightly less than zone 2.  I assume you panels are around 600 watts total, so an average of around 2KW a day in spring? So it seems like you would get enough power per day just based on the energy star rating.  I would be more concerned with the DOD of you batteries.  What are you comfortable with?  Are they top quality batteries? My assumption is you have about 5 Kwh capacity.  I have been shopping for inverters lately and most seem to be rated for 90% efficiency.  Add in the power usage if your inverter doesn't go into sleep mode, and the freezer, you could easily be at 1kw a day based on your calculations.  So 2 days of cloudy weather could bring you below .25% DOD.  So it all depends on the level of discharge you are comfortable with.  My assumption is if you will be there during times of use so you can monitor your batteries and recharge them when necessary.
If it still has its energy star tag, I assume it is new?  Maybe buy it from a store with a generous return policy.  Put it in on Kill-A-Watt meter and see if it performs as advertised.  This would also be a good way to check your inverters usage too.  If it doesn’t perform as advertised, return it.  The only thing you would be out is the effort to move it.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 24, 2011, 06:05:51 AM
I look at those annual energy star numbers like this. The label says 242 kWh or 242000 watt hours.
8760 hours in a year
242000 / 8760 = 668 watts used in an average day, Call it 700 watts a day for good measure.
7 days a week = 4900 watts a week.

My PV calc has fields to enter the watts and the hours per week of use and is set up to calc an weeks worth of power to help average things out.
Enter 700 watts in the watts column and 7 in the Hrs/Week column and that produces the 4900.


So the first thing is to estimate how the batteries will stack up and then the array.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 24, 2011, 08:48:27 AM
Squirl, in case you haven't looked the calculator/spreadsheet has fields to enter correction factors for inverter efficiency, battery cold weather performance, depth of discharge and autonomous days.

I do have to work on the PV array section at the end though.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 24, 2011, 01:45:56 PM
From oljarhead in another thread (http://countryplans.com/smf/index.php?topic=8192.msg133658;topicseen#msg133658). Copied this part to here as it fits here better.


- I see voltage in another way   Running under 48vdc from the panels to the charge controller limits range on 10awg wire to under 50 feet (not sure the distance) where as 48vdc will run 50 feet on 10AWG according to xantrex.  In my case I'm pushing 60vdc from the panels which gives me a little better (I think) performance at 50 feet over 10awg.

I'm no electrician mind you, I'm just thinking that running 18vdc from the panels would cost me in wire size (read $$$).  

So, question:  and I should post this in the other thread, but here goes anyway:  Am I losing something by putting the panels in series and pushing out 60vdc to the controller?

Another question is this:  If I put 3 batteries in series I don't change the AH rating just the voltage so if I put 3 panels in series I'm wondering if all I'm doing is increasing voltage and not wattage?  I figured 3 205watt panels would give me 615watts of charging power.

Anyway, good topic!


I'll have some response later. Dinner prep beckons....

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 24, 2011, 02:54:13 PM
Quote
I'm no electrician mind you, I'm just thinking that running 18vdc from the panels would cost me in wire size (read $$$).

I'm not sure of the exact numbers for your 205 watt panels, but if we say 18.5 volts and 11 amps that's probably close.
so... using 50 feet for the 10 AWG copper wire length...
55 volts 11 amps computes to a voltage drop of 2.4%
60 volts 11 amps = 2.2% voltage drop

18.3 volts 33 amps = 21.8% drop
20 volts 33 amps = 20% drop

Number 1 AWG wire would be needed to get below 3% with 18 to 20 volts.

So yes series wiring PV modules is a very good thing. Not only is the smaller gauge less expensive it is much easier to handle and make connections to. I know from my experience with the 2 AWG I used in our system.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 24, 2011, 03:02:34 PM
Quote
If I put 3 batteries in series I don't change the AH rating just the voltage so if I put 3 panels in series I'm wondering if all I'm doing is increasing voltage and not wattage?

You are increasing voltage by a factor of three and the current flow remains the same.
Using the example of a module rated at 18.5 volts, 11.1 amps, 205 watts...
Place three panels in series you get 55.5 volts at 11.1 amps, 615 watts
In parallel you get 18.5 volts at 33.3 amps, 615 watts


Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 24, 2011, 03:35:59 PM
You are increasing voltage by a factor of three and the current flow remains the same.
Using the example of a module rated at 18.5 volts, 11.1 amps, 205 watts...
Place three panels in series you get 55.5 volts at 11.1 amps, 615 watts
In parallel you get 18.5 volts at 33.3 amps, 615 watts




Awesome clarification Don!  Thanks! [cool]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 25, 2011, 06:09:29 AM
From oljarhead in another thread (http://countryplans.com/smf/index.php?topic=8192.msg133658;topicseen#msg133658). Copied this part to here as it fits here better.


- I see voltage in another way   Running under 48vdc from the panels to the charge controller limits range on 10awg wire to under 50 feet (not sure the distance) where as 48vdc will run 50 feet on 10AWG according to xantrex.  In my case I'm pushing 60vdc from the panels which gives me a little better (I think) performance at 50 feet over 10awg.

I'm no electrician mind you, I'm just thinking that running 18vdc from the panels would cost me in wire size (read $$$).  

So, question:  and I should post this in the other thread, but here goes anyway:  Am I losing something by putting the panels in series and pushing out 60vdc to the controller?

Another question is this:  If I put 3 batteries in series I don't change the AH rating just the voltage so if I put 3 panels in series I'm wondering if all I'm doing is increasing voltage and not wattage?  I figured 3 205watt panels would give me 615watts of charging power.

Anyway, good topic!


I'll have some response later. Dinner prep beckons....



Yes, the C40 is a PWM charge controller, not MPPT so everything over 18v is lost power.  That is probably why you didn’t fry the controller. 615 watts exceeds the recommendation of 40 amps and a 12v battery array (40x12=480 watts).  But with your configuration you are probably only charging at 200 watts. Also check the maximum Voc of the controller, you may be exceeding that too. (could fry it)  Many of Don’s calculations work for the controller he has the Outback Flex60 with MPPT.  See my discussion above of tradeoffs of the $400 extra spent on an MPPT charge controller.  Although, I have spent the past week researching this issue through books, all the old issues of home power magazine, and internet articles since I started that discussion.  I was able to find a Morningstar mppt-45(great reviews) for $350.   This puts the price difference much closer to the PWM controllers and pushes me to the category that MPPT is worth it at any panel array over 1 panel.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 25, 2011, 06:49:32 AM
Jarhead, correct me where I make mistakes, but I took a look at your set up the other day.

You have 8 batteries at (6v?)  Wired to have a 12v battery bank.
You have a 12v msw inverter.
You have 615w panel array wired to 60v.
You have a C40 charge controller.

To get maximum power out of your setup you can change the panels to 18v, buy new wire, and get rid of a panel for a total of 410 watts.  (least expensive)
You could get a new charge controller to handle the higher voltage and amperage.  MPPT preferable and 60 amps if you are sticking with a 12v battery bank. As you saw in my calculation earlier even if you are limiting it to under 40 amps coming in, it exceeds the controller rating for amps coming out (12x40=480 watts).  So you would need 60 to get over 615 watts out. (12x60= 720 watts)  You would still need new wire for a 12v bank with a non-mppt charge controller. ($200-$360 estimate)
You could change you battery bank to 24v but you could have to get a new inverter, charge controller, and maybe an extra panel. (most expensive)

This is just off the top of my head.  I hope it helps.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 25, 2011, 02:02:18 PM
Squirrel the C40 is designed to allow up to 120vdc in and will convert to 12, 24 or 48vdc for the bank so I am in no danger there I beleive.  I'm running half what the input voltage it can take limits me to.

As Don pointed out 11.27imp and 54.60vmp should give me 615watts of power...I think I'm fine.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 25, 2011, 02:38:20 PM
Squirrel the C40 is designed to allow up to 120vdc in and will convert to 12, 24 or 48vdc for the bank so I am in no danger there I beleive.  I'm running half what the input voltage it can take limits me to.

As Don pointed out 11.27imp and 54.60vmp should give me 615watts of power...I think I'm fine.

Actually that is what I was trying to point out that his calculations were for his MPPT controller, not the C40.  The C40 does not convert the 54.60vmp to your 12v battery pack.  PWM charge controllers do not convert any power. It only uses approximatly 14.4v of the 54.6v, so 40.2 x 11.27 amps or 453 watts is wasted.  If it did convert it as you suggested, it would push the push the amperage to 51.25 amps (615w/12v), well over the rating of the controller.  Morningstar put out a good manual about the difference between the type of charger you have (all Xantrex C - series are PWM)and the type Don has (Outback Flex60 MPPT).
It can be found here:
http://www.morningstarcorp.com/en/support/library/MS.WP.MPPTvPWM.01.EN.pdf

I
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 08:00:57 AM
OK, I guess I had no idea that this is what was going on.  I saw the max input power of the C40 (125vdc) but I guess I missed the whole thing about not using the full power of the panels (or even 70%) because it can't use all the current.  I'll give Xantrex a call and confirm and then I guess I better start looking for an MPPT controller that can give me all 615watts (minus losses) instead of only 200!  That might explain some things I've been wondering about.

Thanks
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 28, 2011, 08:13:02 AM
I would just add to what Don has said about picking a battery voltage and then the contoller. You guy's are starting out and so pick an MPPT controller as it will give you flexibility down the road. You have to choose from the XW contoller, the Outbacks, the Midnite and the Morningstars. The rest should be avoided as they will not network. Actually, in my opinion it is Xantrex or Outback as they will interface well as a system with the inverter/charger. I have to do this for my customers but you folks can mix and match as long as you know the short side of having a system that will not integrate over time. Good Luck!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 08:18:58 AM
OK spoke to Xantrex's tech support and they concur.  They advised that getting a 20amp MPPT controller would do the trick as I'm only running about 11.23imp off the panels (15amps would even work but 20 gives a little room to play) and suggested I could find one around $100-$150 if I did some searching.

Has something to do with a DC to DC converter -- way beyond me now -- and that the C40, as squirrel indicated, isn't designed to utilize the power of the panels when running them in series as it's only using about 14.2vdc in bulk charging mode leaving the remaining 40+vdc unused and all that charging current  d* d*

Thanks Squirrel!  I'm off to find a new controller!  DOH!  d*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 08:30:05 AM
Trying to find a 20amp MPPT controller that can take the 615watts of power coming in seems hard.  Each 20amp controller I find seems to be limited to 200-300 watts of charging power for 12vdc battery banks.

Any help would be appreciated -- also, I want to be sure I get a controller that will not blow up when I kick on the Iota 750watt charger running off the Generator.  The C40 has no issue with it but cheap Chinese made controllers might start to smoke ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 28, 2011, 08:52:55 AM
Actually you need a 60 amp charge controller.  Yes you are right that you have 11.23 amps coming in, but it when it converts the power out you have 50 amps at 12 volts.  So you need a charge controller that doesn't only hand the amps coming in, but the amps it is putting out after the conversion.  I'm actually disapointed in the Xantrex manuals that they don't lay this out.  I read the Xantrex, Outback, and Morningstar manuals.  You can see from the product manuals the maximum array size per controller at which battery bank voltage.
Here are morningstar's mppt:
http://www.morningstarcorp.com/en/tristar%20mppt

As you can see the maximun nominal for a 45 amp controller with a 12v battery can handle a 600 watt array, and the 60 amp maximum is 800 watts .

Here is the Flex60:
http://www.wholesalesolar.com/pdf.folder/controller%20pdf%20folder/flexmax60_specs.pdf

Page 2 has the specs for the 60 amp version.
12 VDC systems 750 Watts / 24 VDC systems 1500 Watts /
48 VDC systems 3000 Watts / 60 VDC Systems 3750 Watts

Again, the "system" size voltage is the battery bank voltage, not the solar panel voltage.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 09:11:38 AM
Actually you need a 60 amp charge controller.  Yes you are right that you have 11.23 amps coming in, but it when it converts the power out you have 50 amps at 12 volts.  So you need a charge controller that doesn't only hand the amps coming in, but the amps it is putting out after the conversion.  I'm actually disapointed in the Xantrex manuals that they don't lay this out.  I read the Xantrex, Outback, and Morningstar manuals.  You can see from the product manuals the maximum array size per controller at which battery bank voltage.
Here are morningstar's mppt:
http://www.morningstarcorp.com/en/tristar%20mppt

As you can see the maximun nominal for a 45 amp controller with a 12v battery can handle a 600 watt array, and the 60 amp maximum is 800 watts .

Here is the Flex60:
http://www.wholesalesolar.com/pdf.folder/controller%20pdf%20folder/flexmax60_specs.pdf

Page 2 has the specs for the 60 amp version.
12 VDC systems 750 Watts / 24 VDC systems 1500 Watts /
48 VDC systems 3000 Watts / 60 VDC Systems 3750 Watts

Again, the "system" size voltage is the battery bank voltage, not the solar panel voltage.

Hey, I appreciate that!  I've been trying to grasp what I need and keep running into various questions but I think you just solved it.  So I need the bigger controllers (read:  spendy ones) that can take the power coming in from the panels and then convert it to the 12v battery bank and retain all the power that came in -- or as you said 60amps once converted to 12vdc.  DOH!  I guess I missed all that in the beginning when planning my system.

So I could use one of these: http://www.thesolarstore.com/charge-controllers-mppt-charge-controllers-morningstar-tristar-mppt-mppt-charge-controller-volt-wremote-sensor-mppt-p-451.html

Or one of these:  http://sunelec.com/index.php?main_page=product_info&cPath=22&products_id=35

Or the Outbacks you posted.

Now it's just a matter of which one has the best reputation I guess  d* ???

I hate to say it, but I'm kicking myself for not understanding this to start out but I get it now...and I'll be ordering very shortly!  I also understand now why I didn't seem to have the charging capacity to keep up with the silly heat tracer I was running!  Sheesh!  I should have been able to run that without an issue this winter but nearly drained the batteries in a week on it.  I've also noticed that the batteries haven't been fully charged very often when I've gotten to the cabin.

On a side note, when the Iota charger kicks on they do pick up pretty quickly but I don't like to run it if I don't have to as the whole idea is to have little use for the generator in the future....anyway, which controller do you recommend?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 28, 2011, 09:31:33 AM
I have seen many debates as to which charge controller was better the Xantrex, Outback, or Morningstar.  Most seem to agree that there is very little difference in performance.  I have not researched midnight solar.  They all seem to be priced around the same at around $500.   Most posts I read seemed to agree outback had the best customer service.  Others said they wouldn't know for morningstar, because they didn't need customer service.  If Xantrex told you you needed a 20 amp charge controller, I would start to question their customer service representatives.
Dave Sparks would have great insight into the better product.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 28, 2011, 09:44:37 AM
Like Dave stated; nice thing about Outback or Xantrex is the ability to integrate as a system. Charge controller, inverter, a central control panel for monitoring and programming. You can even hook them up to a computer with the right software and record everything the system does. I appreciate having the Outback Mate inside the cabin, mounted on the wall at a nice easy to read height, rather than poking my head into the crowded enclosure where the CC and inverter are.  

Outback and Xantrex both have good reputations. Midnight is also good and has charge controllers with 200 and 250 volt maximums. Other than that I don't know much about them. They have been around for a few years too.

On the charge controller: note the difference the system voltage makes to the array wattage capacity; higher system volts makes for the ability to use a higher wattage array. That is one of the reasons I chose 24 volts for the battery system. And I believe one of the reasons Windpower chose to go 48 volts on the battery bank.

On the generator: Normally the only reason I run my generator is to "exercise" the engine. I do that once a month or so; probably more like six weeks on average. When I do that I may also run an equalization cycle, although that can be done with the PV array and charge controller if I have the right bright sunny day.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 28, 2011, 10:03:32 AM
I did notice that one of the savings between the morningstar and outback was that the morningstar does not have an integrate LCD display standard.  I did feel that this was a little deceptive because every picture they advertise has the LCD display in it, but it is not included.  I had to read the massive manual to find that out. You can buy one separately for $100, or you can buy a remote one for around $130.  It didn't matter to me because the morningstar stores twice as much data as the outback (200 days) and can be accessed by plugging a computer into it.  (I already have some extra cheap laptops).  Also the display doesn't matter if you were going to get a remote anyway.  I think the remote display for outback was $150.  I'm not really sure the necessity of the display because it just shows you the past performance.  So, it is what it is, and many of the less expensive controllers don't record this at all.

It took me a week of researching the different components and options to figure out the difference.  Don’t feel bad for not getting it at first.

I understand the issue with the price.  It seems like if you want to have a panel array over 600 watts you have to go with the more expensive controller or up the battery voltage and get a more expensive inverter.  Seems like they get you either way.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 10:13:52 AM
Thanks and Thanks.

I'll probably get the Morningstar or the Outback.  I found the Morningstar a little cheaper and can use a laptop to get the readings from it if I want -- truth is I have only a meter on my inverter right now and have to count lights to know what the battery bank voltage is!

I won't buy the Xantrex because 1.  They really didn't make it clear in their documentation in the beginning that it wouldn't do what I wanted.  2.  They advised me to get a different cheapo controller that wouldn't work either.

I've also decided not to buy from Sunelec now because they suggested the 10awg cable and running the panels in series and then sold me the C40 controller!  DOH!  d*

All in all, I'm not happy with Xantrex or Sunelec but also have to smack myself for not making absolutely certain that what I was getting was going to do what I thought it would....ahh lessons learned.

Now I just need to find good sources, check prices again and make a final decision on the Outback vs. Morningstar and I'll be set :)  probably buy tonight so I can have it ready for the next trip to the cabin -- then I'm going to do some work on the system too I'm thinking (need to clean up cabling and equalize since i haven't done it yet).

I have a ton of other projects but this one matters the most at the moment :)  Thanks again!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 28, 2011, 10:16:34 AM
I think the remote display for outback was $150.  I'm not really sure the necessity of the display because it just shows you the past performance.  


The Outback Mate provides full control of an Outback charge controller or inverter(s). Everything from setting the charge points, time for different charge modes, turning on or off the EQ mode, present battery conditions, input voltages and amps, volts and amps into the batteries, etc.  If you have a compatible generator you can setup the auto start. The Mate is much more than a place to read past daily performance data, although it does that too.

The only thing I found slightly annoying is that a Mate is required as an extra purchase in order to program the Outback inverters. But there's a reason for that too. Their inverters can be stacked, series and parallel to increase the AC voltage (240) or the AC wattage capacity. If the Mate was included with each inverter that would be a waste.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 28, 2011, 10:21:26 AM
Here is the response I got from Morningstar just now when I asked them if the 45amp MPPT controller would work:
Quote
Hi Erik,

The TSMPPT 45 can deliver up to 600W to a 12V battery bank. Using 615W will not damage the controller, the controller will simply limit the harvest to 600W.

This, however, will be significantly more than what you will get with the C40 in your present configuration. The C40 will only be able to deliver up to the short circuit current rating of the array (likely 12-13A) in full sunlight. The TSMPPT 45 can deliver 45A with this array (in full sunlight).


Regards,

Adam Kehlenbeck
MS Technical Support
www.morningstarcorp.com
support@morningstarcorp.com

I decided to re-ask the question with the 60amp MPPT controller in mind...at least I'm getting somewhere!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Squirl on March 28, 2011, 10:34:09 AM
That is a good thing to know.  I did not know they were required to program the inverters and generator auto start.

I know this may be a little off Erik's question, but Don do you use the equalization feature of the charge controller.  I have been meaning to ask this.  It seemed like another advantage that many of the less expensive controllers didn't have.  Does anyone have any opinions on this feature?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 28, 2011, 10:51:43 AM
Yes Squirl. I normally use the equalization feature in the FM60 CC when I equalize. What works well for us is if I'm thinking about equalizing I hope for a sunny morning and afternoon on a day that we drive up to the cabin. By the the time we get there (11 AM or so) the system will have run through a short re-bulk charge and will be in absorb already. (Because there's been no use for a day or longer). I check the fluid levels in the batteries and if good use the Mate to initiate the equalization charge. It can be programmed to equalize for a predetermined length of time and the system would then go into float.

I sometimes use the equalize settings from the inverter/charger if I want to exercise the generator. The cool thing is I could most likely do away with the generator altogether. This winter at Christmas we spent several days up there and three of them were partly cloudy to very cloudy. We were in  no danger of withdrawing too much power from the batteries. I did run the generator on the third day but only because it had not been run since October.


I have discovered a variety of features, abilities, that the FM60 and the VFX3524M inverter/charger can do. I will never be sorry I spent the money for them.
http://eshop.thesolar.biz/retail/Items.aspx?code=OUTBACK_CC&key=cat (http://eshop.thesolar.biz/retail/Items.aspx?code=OUTBACK_CC&key=cat)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 29, 2011, 05:13:43 AM
Decided to go with the Morningstar 60amp MPPT controller.  Price was almost the same so it came down to the discussions here and their support which I interacted with a bit yesterday (I'll post their response to my question about the 45a vs the 60a controller but in a nutshell the 60a won't ever be near max so will always use the full 615watts - if enough sun etc - for charging unlike the 45a controller).

Hope to have it in a few days (got it from the place in Bend OR which isn't too far from me actually).  Then we'll see how that battery bank does!  I'm assuming I'll need bigger wire to the controller then with the C40 but I haven't tied it all up yet anyway so swapping should be easy and I'll keep the C40 for the well system I'm planning.  It might be overkill but ought to work fine with a 75watt panel and 12v deep cycle battery I'm thinking -- then I can plant those fruit trees! :)

Anyway, thanks again Don and Squirl for squaring me away!  Now I'll be able to hook up that freezer and abuse the system and see what the controller tells me it's doing :)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on March 29, 2011, 05:37:09 AM
http://www.thesolarstore.com/batteries-accessories-battery-accessories-desulfator-battery-life-saver-volt-desulfator-p-416.html
What the heck does this do and do they really work?  I'm curious.

I was perusing the store and well, I can see several things I want now!  Sheesh...I want a meter for the bank for a quick glance when not plugging in the laptop, those nifty caps looks like a good idea, the battery bank vent sounds like a good idea too and and and...sheesh I need to get back to work! hahahah  I worked 8:30am to 10:30pm yesterday and will likely pull long days for the next two weeks which always gets me wondering what new gadgets I can get for the cabin ;)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on March 29, 2011, 10:19:09 AM
No generators allowed at my place! So, yes the CC is used for EQ! In this industry you really need to know that most of it is dealer/installer driven. You can get decent advice from the manufactures and it can be spotty. The point is you really need to understand all that you are doing unless you can write lot's of checks.
I have huge respect for check writers! w*
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on March 29, 2011, 10:29:07 AM
I used less than 5 gallons of gas (heavy on the Stabil) in the last year.
Most of that was just to run it because it had not been run in a while.  :-\  
It was indispensable while building and pre solar system though.


Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 13, 2011, 05:53:29 PM
Help!  I was getting ready for my trip to the cabin and reading my new Controller manual to make sure I have the right cable for it (4awg sounds about right for 60amps over a short distance (2 feet)) and saw that I needed a 75 amp breaker and NOT the 60amp breaker I have in there now.

So here is the question: what will happen if I continue to use this: "60 amp 150VDC with 1/4" stud terminals. Uses one small 3/4" breaker space. Midnite Part Number: MNEDC60 Same as: OBDC-60, OBB-60-150VDC-PNL"?

I assume it will pop if there is full sun and the batteries need max charging but otherwise will be fine until I can find a 70 amp breaker? And does anyone have a line on one?  I am having trouble finding a 75amp breaker of the same size etc...but that's 25% above the rating.

Thanks in advance.

[EDIT:  changed to 75amp breaker to meat the 125% rating]
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 13, 2011, 06:01:17 PM
http://www.midnitesolar.com/productPhoto.php?product_ID=197&productCatName=Breakers&productCat_ID=16
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 13, 2011, 08:22:15 PM
http://www.midnitesolar.com/productPhoto.php?product_ID=197&productCatName=Breakers&productCat_ID=16

I found this one there: OBDC-80 though no 75amp ones...I'm thinking 80 would be ok?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 18, 2011, 10:28:01 AM
Did a little reading on the GC2's and it seems I can use the Trojan settings for the T-105's for my charging profile.  Listed here: http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx

So that means I need to set the voltages to the following:
Absorption:  14.80v
Float: 13.20v
Equalize: 15.50v

They are currently set at (setting #5 for flooded cell):
Absorption:  14.60v
Float: 13.50v
Equalize: 15.30v

I can custom set those using their software to build a custom profile but will have to leave as is for the next 10 days -- hope I didn't goof that up too much.  The controller has only two flooded cell settings (in their canned settings) so I chose the lower of the two and left it.  What I'm wondering is if it will make much difference?

I'm also wondering if the controller's telling me that it was down to 0-30% charge has anything to do with these settings?  I'm looking to see if there are others I can change now, but the controller shows a min voltage of 12.62 for the day I saw the lights indicating 0-30% charge...I'm trying to figure that one out still.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FCabin%2Fsolar2.jpg&hash=5d2909bf80df380af6a1a66bdbe4f013)
This shows a min voltage of 12.62 which according to Trojan is only a 10% discharge or 90% charge....thoughts?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 18, 2011, 02:10:14 PM
There is likely little effective difference between those charger settings.

I don't know or understand where the 0-30% and "lights" you refer to are coming from? 

On the low voltage reading.... don't forget that the voltage reading will drop lower faster when large loads are applied. If I microwave something for several minutes the instantaneous reading falls precipitously but then climbs back up to where it was. Also remember temperature effect. Hydrometers give most accurate readings for state of charge, and also require temperature corrections.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 18, 2011, 06:28:39 PM
There is likely little effective difference between those charger settings.

I don't know or understand where the 0-30% and "lights" you refer to are coming from? 

On the low voltage reading.... don't forget that the voltage reading will drop lower faster when large loads are applied. If I microwave something for several minutes the instantaneous reading falls precipitously but then climbs back up to where it was. Also remember temperature effect. Hydrometers give most accurate readings for state of charge, and also require temperature corrections.

Thanks Don,

On the controller are 3 lights:  Green, Yellow and Red.  In the book it says that if the Yellow and Red are on then the batteries at 0-30% of charge.  This confused me when I saw that the recorded lowest voltage was in the 90% range...maybe a glitch in the controller?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on April 18, 2011, 06:52:49 PM
Could be.  A hydrometer reading would clinch it. I use the voltmeter as a handy quick indicator to what's happening, but the hydrometer never lies when corrected for electrolyte temperature.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on April 19, 2011, 01:09:50 PM
Could be.  A hydrometer reading would clinch it. I use the voltmeter as a handy quick indicator to what's happening, but the hydrometer never lies when corrected for electrolyte temperature.



I'm going to have to get one and a new Multimeter I think.  Just found some 6awg 90c wire (THHN) that I can use in my install instead of the 4awg stuff I installed.  I'm so NOT an electrician but the book says that as long as I use 90c wire I can use 6awg and I think it would make a cleaner install and since the controller isn't more then 2 feet from the battery bus I don't think the bigger wire will make a noticable difference (if any).  Now I just need to get some conduit so I can put all the wiring in conduit next trip out and then I might just be nearing that point in which I can be proud of the install! :D
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 03, 2011, 07:53:20 AM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FController.jpg&hash=972aa388f39a19e34c28bbfa9bb8e9b2)
Here are the last two weeks of data from the controller.  I've noticed that the lights still indicate a low charge on the batteries when they shouldn't and I'll have to call Morningstar on that.  I think, actually, I just need to download their software and make some changes to the settings.

Meanwhile, thinks seem to be working nicely.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: PlainsMontanaPower on May 17, 2011, 07:59:57 AM
So im new to these forums and fairly new too offgrid power :) so hello everyone.
id like to first say i really like your cabin setup and detailed build especially your power center mountainmandon.
i liked the box setup you built so much that i built one this last week at my cabin in montana. its not quite finished yet but its getting there im down to running a vent out the roof and putting all the equipment in there and some paint.

that said i have alot of questions lol

1. where can i find the copper bar material you used for your bus bars i love that its sooooo clean.

2. at what voltage should i get scared when batteries drop too ?? 11.7?

and many other question i have but first ill tell ya myt setup

we started our cabin 20 years ago and started with a very small solar panel and 2 batteries well when i brought my kids over a few years back they brought all there gadgets and almost killed the batteries so we ordered a new kyocera 130 watt panel a ts-45 morningstar controller and 2 more golfcart 6 volt batteries.....my dad hooked it all up............not good he got a lot of wrong information so as of last week we had a 80 watt panel and the 130watt panel hooked together in parrallel and then running 55 ft with 8 awg large strand wire to the morning star controller needeless to say as far as the controller was telling us we were never getting past a 35% soc even on a nice sunny day so yeah i figured the wire had a lot to do with that i called a few place like montana solar out of misoula very good guys and  arizona solar and wind which is who we bought most of our stuff from they both said to noit hook the 2 panels together and that it would make the 130 panel work like a 80 watt panel so now ive unhooked them im going to run 2 awg just for the 130 watt panel to the morning star  controller and then hook the 80 watt panel to our old mark 15 controller with the existing 8 awg and both in parrale to the batteris (4x 6 volt cart batteris is series-parralell) Does this sound right ? and what percentage of gain do you thjink ill get from this ?

right now i think the biggest problem is not enough voltage is going to the batteries to ever get them even close to topped off.

oh and also again love your power center ill have to post pics of the one i built very similar to yours  but not enough room for 3 seperate compartments so for the batteries i built a box over them in the big box and am running a vent just from the battery box throug the roof and the bigger room is also vented with eve roof vents.

any help here is greatly appreciated :) im so glad im found these froums so much great info my brain is going to burst lol
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 17, 2011, 09:43:40 AM
Copper from Storm Copper.  
http://www.stormcopper.com/Copper-Landing1.html?gclid=CIDi1bbQ76gCFcgZQgod2H8MCw

Here's a voltage vs state of charge chart
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Fvoltages-charge.jpg&hash=7d92fbda0b82b29a5b8f7596321985c9)
I would find 11.7 volts very worrisome..  We generally don't drop below 80%

Also note that a hydrometer is the best method to determine SOC.


If the panels are very mismatched as those two are you will be much better off with them having separate charge controllers. I did not take time to run the numbers but the change in wires should make for a better more efficient system.  There are a number of voltage drop calculators online. We have some links here for them someplace, but I have to run right now.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 17, 2011, 12:31:57 PM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FCabin%2FSolarPower_may2011.jpg&hash=28170ca255eb7114c10937f8aa11d4dd)
The last 7 days (up to Sunday) that I recorded.  Found the voltage on Friday to be interesting as it was the first day I ran the Freezer much -- I did not run it all day mind you, just ran it a few times to keep it cool enough to use as a Fridge (I know that's not the best thing for it but it works until I get the Fridge installed).

Thoughts?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 17, 2011, 12:34:31 PM
I should add that Friday (-2 on the chart) we arrived about 1PM and used the Freezer (to cool it down) and then ran lights and battery chargers a lot.  Wasn't much sun out either.

Saturday (-1) we ran everything and then some all day and had very little drop by the looks of it -- it was a heavy use day as seen on the chart -- I think adding the two additional batteries will be wise if I want to run the Freezer and Fridge all the time....guess I'll find out!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 17, 2011, 01:25:12 PM
My question is; is that watt hours row the watt hours going into the batteries from the panels? That's what I think it is. That indicates your system plowed 1140 watt hours into the batteries on Sat because your Friday use dragged the batteries down to a low point of 12.27 volts.  And Friday you can tell you either arrived after the best sun had gone or it was a lousy sun day; 420 watt hours.

Saturdays absorb time was very low (70 minutes) which would lend itself to a long bulk charge before the sun went away or a day with clouds or a combination.

Then Sunday when you took the snapshot the system had not yet recharged much as the max volts were still down from where iy usually peaks. Also the watt hours are still low and the absorption charge only just reached 1 minute.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 17, 2011, 01:52:07 PM
My question is; is that watt hours row the watt hours going into the batteries from the panels? That's what I think it is. That indicates your system plowed 1140 watt hours into the batteries on Sat because your Friday use dragged the batteries down to a low point of 12.27 volts.  And Friday you can tell you either arrived after the best sun had gone or it was a lousy sun day; 420 watt hours.

Saturdays absorb time was very low (70 minutes) which would lend itself to a long bulk charge before the sun went away or a day with clouds or a combination.



Then Sunday when you took the snapshot the system had not yet recharged much as the max volts were still down from where iy usually peaks. Also the watt hours are still low and the absorption charge only just reached 1 minute.

We arrived Friday just before the panels were in the shade (I need to remove that tree and make it into planks!) and the weather was mostly cloudy.  I was also surprised by the heavy usage the next day and am guessing that charging batteries (18v Ryobi's) and running the freezer, lights, etc all must have really sucked the power.

I'm still so new to all of this I'm mostly doing this:  ???

I think the watt hours are the amount of charge going into the bank.  One thing I noticed is that the draw down to 12.27 still put me around 60% I think (haven't done the math) which would be ok I think.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on May 17, 2011, 01:53:52 PM
One thing I've noticed is that my fully charged bank runs about 12.9v rather then what Trojan indicates 100% should be (12.7)...thoughts on that?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on May 17, 2011, 02:23:12 PM
Do you have a meter you know for certain is properly calibrated?  Maybe the meter in the CC is off?

Hydrometer check?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on June 02, 2011, 04:09:08 AM
Time also! Trojan will have hidden away in there spec a resting period before you make the measurement.  Not to worry on this one!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 03, 2011, 08:17:48 AM
http://www.walmart.com/ip/Danby-9.1-Cubic-Ft.-Frost-Free-Refrigerator-in-Black-with-Stainless-Steel-Door/11368635
Using the calculator I see that running this fridge (at about 1030 watt hours per day) and the freezer I previously mentioned (about half what the fridge will use theoretically) then my system with 3 panels, 6 hours of sunlight per day (summertime I can probably get more then that but in general I should be able to get 6 hours of pretty much direct sunlight at 33 degrees for the time I'm running these both) and 8-10 220ah GCB's with the 60amp MPPT controller should do it.

That's taking it to 50% of discharge according to Don's spreadsheet.

Now, am I doing something wrong?  Does it look right?  I set it to 4 days without sun which might suck if I get 5 or 6 without it but the region only gets about 15 inches of rain a year and has around 300 days of sun.....so I'm hoping anyway.

Last 44 days of monitoring the MPPT controller and I've seen only 3 days where it had little to no charging.  Rest of the time it seemed to do fine.

Also, I may not need to run them both at the same time but want to be able to.

My worry is mostly because I'm often gone ten days in a row so there will always be at least 10 days where I cannot put the generator on the system to get it back up to charge.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 03, 2011, 08:50:34 AM
http://www.uakc.com/energyguides/dar1102we-danby.jpg
Found this for a fridge I'm looking at that doesn't have a freezer -- uses almost 200 watt hours less per day.

This http://www.refrigeratorexpert.com/danby-DAR1102WE.html fridge may do the trick as it's all fridge which is ok since we have a freezer already and I've been told that these use less energy (which appears to be possibly true from what I'm seeing).

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 03, 2011, 08:54:50 AM
I should also add that with this unit I was able to drop hours of sunlight down to 5 hours per day which still left me with 3 panels and 8-10 batteries (at 50% discharge).

It is most likely that I will only run the Fridge until late August or early September (deer season starts).
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 09, 2011, 08:37:53 PM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FMPPTlog.jpg&hash=0e3ed7f1c05bb1468fd0e5544aa5dd95)
Here is the latest log from my controller.  I've hidden the days we weren't at the cabin unless they showed recovery from when we were there (more watt hours despite out no longer being at the cabin which I assume is recharging the batteries).

I have not yet checked water levels or equalized the batteries which I plan to do this weekend.

We seem to average above 600 watt hours per day which I assume is replacing energy we used while at the cabin (though the one day we used a lot more which I think is due to using the freezer more and not having much sun).

THis weekend it is supposed to be cloudy and raining so might be interesting.

I've noticed that absorption seems to run about 3 hours while float can run 7 to 10 hours -- which I assume is just as long as the sun is hitting the panels.  On days that we were at the cabin it tended to be cloudy and I'm wondering if the float times were lower because of this??
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on June 10, 2011, 03:02:16 AM
Both the bulk stage and the float stage duration can vary widely in time spent in either stage. Too bad the data display does list bulk charge as it could help explain what is going on. You may understand the following. If so good and this is for anyone else.

Bulk charge is the first stage, the state the CC begins every day with. Duration of the bulk charge stage will vary because of factors such as; how deeply the batteries are discharged, the intensity of the sun on the PV modules (clouds, smoke, snow, etc.) as well as how much power is being used at the same time the batteries are being charged.

Absorption charge is next. This is the only charge state that can be programmed for duration. The manual shows 150 or 180 minutes, depending on battery type (page 36). Those times may be modified by the CC under certain circumstances.

Then the unit will switch to float charge.

So, on a cloudy day the CC may remain in bulk charge for a longer duration than "normal". Since the length of the absorption charge is fixed, on a bad day the CC may never even reach float. That occurred three times in that chart.

It is also possible for the CC to reach absorb and switch back to bulk if some heavy demand is placed on the batteries. That is determined by the battery voltage falling below a certain value and remaining low for a period of 30 minutes. There is a low voltage point that will actually cance; the float charge for that day
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on June 10, 2011, 07:39:42 AM
Thanks Don, I even went and double checked about the Bulk charge period which lead me to call Morningstar -- I've not yet had a reply yet but will bug them until I do -- also want to understand the lights and why they don't repflect the charge correctly but I think that may be a setting and I'm planning on working on the setup when I get there this weekend.

Thanks again for the response, it helps me a lot!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 05, 2011, 06:30:11 AM
I have figured out the lights :)

It seems that while you can make changes to the controller via their software and tell it exactly what you want it to do, it will not do those things unless you switch the dip switches to 'optional' which sets the controller to run on your specific programming.

Thus the lights were showing stock indicators rather then my trojan adjusted ones.  So that's solved :)

I'll post another set of data collected off the controller, what is interesting is the 'input' and 'output' power.  Neither of which appears to be raw panel power.  I do get array voltage and amps but if I want to see the actual 'wattage' of the panels I have to do some math (which is ok of course).

Anyway, so far I've seen pretty good production from the panels and my only weak point might be the batteries.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 05, 2011, 08:29:45 AM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FJuly42011.jpg&hash=70e8344c36717459be535af4377c9e2d)
One interesting thing is the voltage on 6/30.  I see no reason why this is so low???  The ONLY thing running during that time was the 12vdc fan on the composting toilet and the Charge Controller.

However, I've also noticed that the controller is set to a time that does not match my time zone and I have not discovered the mystery of how to change that just yet -- hmmm.....

Beyond that I've noticed that 'Max. Output Power Watts' appears to be the amount of power produced by the controller and sent to the batteries and not the power coming off the array (that may sound silly as one cannot be different from the other, but in fact it can.  After all 60vdc off the array at 11amps is ~660watts where as 14.8vdc from the controller at 45 amps is ~666watts right?).

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on July 07, 2011, 09:46:51 AM
Output Power Watts' appears to be the amount of power produced by the controller and sent to the batteries and not the power coming off the array .....

The difference between power from the array and the power into the batteries is the loss in the charge controller. There are small losses usually noticeable at the CC heat sink fins. I think that into the batteries figure may also reflect some of the battery charging loss inherent to lead-acid batteries. Not + on that though. ???  IMO, what goes into the batteries, and what is taken out is what is most important.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 19, 2011, 05:19:23 AM
Turns out I have a Surflo 9325 Well pump that with 24vdc power can pump as much as 100 gallons in an hour or more.  It's down ~80 feet into the well which puts it about 40 feet below the last known water level (when the well was drilled).

So, I'm now in the market for a ~100 watt solar panel to power the well with as the 60 watts of 12vdc solar I was using is inadequate -- though I could rewire it to give me 24vdc it's just a tad shy of the recommended size and I could use it elsewhere.

So, if anyone finds a sub $200 panel that might work please let me know!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 19, 2011, 06:01:52 PM
http://www.sunelec.com/sun-laminate-118-watts-2430-vmp-p-785.html
I'm hoping to get this panel for my well solar...if I can get close to the price they were offering for 10 of them.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 20, 2011, 06:58:34 AM
http://www.sunelec.com/sun-laminate-118-watts-2430-vmp-p-785.html
I'm hoping to get this panel for my well solar...if I can get close to the price they were offering for 10 of them.

Didn't notice the 'Laminate' part and didn't really understand it.  These do not have frames so I won't want them.  Looking at other options now.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on July 20, 2011, 07:35:01 AM
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi998.photobucket.com%2Falbums%2Faf102%2Femcvay%2FJuly18th_log.jpg&hash=be52316cbb856537729acbec582daa6c)
Another weekend another log ;)

This one is broken up a bit because of my messing with the controller.  Each time it is reset it restarts the log (I was doing firmware updates and programming changes).

With the new Fridge running full time, running two battery chargers, a DC fan and 3 lights at night we used a lot of power!  Drew the batteries down around 65% of charge (which isn't bad I think) and exercised things a bunch. v:)

I'll see what it's doing when I get there this weekend (I think) to see what happens when no lights or chargers etc are running and the fridge is on #3 setting (we had it on #4.5 when we were there).

All in all though, I couldn't be much happier!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2011, 08:07:23 AM
Am I correct in taking the 65% to mean you drew the batteries down to have 65% capacity remaining? That's not bad but doesn't give much wiggle room for clouds if that was a typical single day.

Regarding the refrigerator. One thing I've noticed with our propane fridge is that while we are using the cabin the fridge maintains 35 to 40 F on our number 5.5, but when we leave the cabin for several days the fridge will freeze some things. So then our number 4.5 seems to work best. It would be interesting to see how the temperature in yours runs.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2011, 08:12:00 AM
Random thought, sort of, directed towards those who are contemplating installation of a alternative power system.

 From talking with people with PV systems already in use, both here, other places on the web and in person, the biggest single "failure" item seems to be insufficient storage capacity.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2011, 10:27:19 AM
Temperature Compensated Battery State of Charge Chart, 12 volt. Being temperature compensated this might save someone some time and math.

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Ftemp-comp-01.jpg&hash=a3a5fd9739d1110b1fbf8370c0c1e958)


or for 24 volt (below)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Ftemp-comp-02.jpg&hash=b247862d1b88ec3054dbb03baf56782e)


EDIT 09/25/2011    Made the spreadsheet the pictured charts were taken from available for download. Also expanded the flooded wet cell charts to include a 48 volt system. Separate download for AGM batteries.

... for 48 volt (below)

(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2F48voltSOC.jpg&hash=9153a4ac77d8281bf2aa73bbdc65b4e7)

Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2011, 10:35:07 AM
The above images are from a spreadsheet. It can be downloaded from below.

There are two flavors, flooded cell batteries and AGM sealed
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 19, 2011, 10:44:08 AM
The AGM charts
12 volt
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Ftemp-comp-03.jpg&hash=efa99ebffb435aa826b7a4dfc8870a8f)

24 volt
(https://countryplans.com/smf/proxy.php?request=http%3A%2F%2Fi139.photobucket.com%2Falbums%2Fq305%2Fdjmbucket%2Fsolar%2Ftemp-comp-04.jpg&hash=7d09b07f69abf4b05c1cd16f882f28ab)
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 23, 2011, 03:14:35 PM
Am I correct in taking the 65% to mean you drew the batteries down to have 65% capacity remaining? That's not bad but doesn't give much wiggle room for clouds if that was a typical single day.

Regarding the refrigerator. One thing I've noticed with our propane fridge is that while we are using the cabin the fridge maintains 35 to 40 F on our number 5.5, but when we leave the cabin for several days the fridge will freeze some things. So then our number 4.5 seems to work best. It would be interesting to see how the temperature in yours runs.





Yes 65% remaining.  The lowest I've seen the system get to so far is 12.2vdc which I believe (I'll have to check) is around 50%.

Our fridge seems to run cold enough around 4.5 on the setting and that can cause some ice formation (droplets) on the back wall of the unit (inside it of course)...when we leave we adjust to 2.5-3 and that keeps a couple gallons of water quite cool/cold.

I could shut it off when we're gone but I want to see just how the system performs.

As for battery power, I'm concerned also.  I used the calculator to plan the system and my calcs suggest 880ah is enough power to run the fridge and lights the way we do and not draw the system down but it appears to be incorrect.  I'd not really expect an overnight drop of greater then 20% if it is to last 3 days without sun...let alone 4!  So, perhaps 440ah of battery power ought to be added before it's been a year to ensure I can indeed run the freezer and fridge full time as I have not even tried that yet!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 23, 2011, 03:23:44 PM
12.2 is about 50% with a big BUT.... but that can be thrown off by recent battery charges or discharges and needs temperature correction. Hydrometer is best, but needs temp correction too.

As far as fridge temperature, leaving a few gallons in it if there is not much food is a good idea; helps keep the cool working right. 40 degrees or lower is needed for best food preservation, BTW.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 23, 2011, 03:32:34 PM
12.2 is about 50% with a big BUT.... but that can be thrown off by recent battery charges or discharges and needs temperature correction. Hydrometer is best, but needs temp correction too.

As far as fridge temperature, leaving a few gallons in it if there is not much food is a good idea; helps keep the cool working right. 40 degrees or lower is needed for best food preservation, BTW.



Thanks Don,

I have to get a Hydrometer pretty soon!  I've been relying on gauges and meters so far but it's a learning curve.

This past weekend I had a strange thing occur:  the 60a breaker on the disco box that the panels are run to tripped.  THe midnight solar 60amp breaker did not trip but this one did  ???  Then the MPPT controller showed a Green and Yellow LED which should mean that I was down to 60% of charge but I knew that wasn't right since everything said 100% otherwise.  So I reset the MPPT controller and it went back green...BUT it was during the main part of the day when I normally get a lot of my charging...so I double checked and the panels were giving decent power and the controller was indeed charging the string...something isn't right.

I logged into the box via serial cable becuase the Ethernet connection would not work...so at this point I'm not sure what happened.

Daily I'm getting a HVD alarm (High Voltage Disconnect) but I'm not seeing voltages high enough to trip that...another thing to try to resolve.

Lastly, my well solar tripped also!  My Xantrex C40 was not running and the batteries (two group 27's in series) were dead!  One was at 2.2vdc and the other was at 8vdc...something smells.

I checked the system and couldn't figure it out, removed and replaced the batteries (I had two spares) and everything worked fine again...then the sureflo pump shorted out (I think) and the bank went to 1.0vdc!!!  Yikes!  I disco'd the pump and the batteries were back to 25.6vdc.

So, I came home and ordered a new Surflow pump and did a little more of this:  ???
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 26, 2011, 10:31:47 AM
What about night time temps versus day time temps?

Currently it can get to 85+ during the day at the cabin but drop to 40 at night...everything cools down.

So, if I figure my battery banks out at 40 degrees I suspect I'll need more batteries.  No?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 26, 2011, 10:54:40 AM
Our batteries are cool to cold all the time. In summer the cases may warm on a hot day but the fluid still measures colder. EG: When I checked the sp gr about a month ago when we were having 85 F highs in the afternoon, the fluid was still only about 62 F. Very few actual hours of the hot summer day have the high air temps; most of the day/night is spent below 65. I don't measure much in the winter but the last time I did the fluid was hovering somewhere around freezing. So yes, that does diminish what's available for use.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on August 26, 2011, 11:13:04 AM
Now if I was to dig another, bigger hole in the ground and have the batteries down there, they would stay warmer in the winter.  :D  Perhaps the charging and discharging might even produce some heat that could be trapped? Probably not worth my effort though considering winter use is only for a few days at a time and a couple weeks apart.
Title: Re: OFF GRID POWER; various thoughts on...
Post by: OlJarhead on August 26, 2011, 11:33:41 AM
This is actually why I decided to build the porch and put the batteries inside of it.  I can use the windows for solar heating and found that even without insulation I can keep the porch 10-12 degrees warmer then outside.  When it's -10 degrees that's probably a good thing!
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 16, 2011, 09:14:18 AM
Question for Dave Sparks....

For someone with an Outback FM60 charge controller and an Outback VFX 3524(M) inverter, what would you suggest as spares? Listed from most likely to less likely to be required.

Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on September 16, 2011, 11:04:05 AM
Any MPPT controller needs a spare MPPT controller for offgrid unless you are willing to rewire the array for a cheaper non-MPPT controller while Outback repairs your unit. The 45A Morningstar MPPT is pretty inexpensive and I have a spare one along with the XW gear that I only install these days. Their 600V controller has really made my long distance array runs easy.

An inexpensive Inverter/charger can be bout used or?

I go thru all this with some of my real remote customers who live full time in offgrid homes. It often comes down to how their system and how "they" want to live during a failure in the depth of winter. I have one guy who is a Merchant Marine guy who is gone long periods and just turns off his electric reefer and uses a propane unit. No worries about bad weather with propane.  Everyone offgrid fulltime basically has to have strategy for how they will deal with it.

"It always fails in winter and at night"  OLD Sailor......
How was your summer Don?
Title: Re: OFF GRID POWER; various thoughts on...
Post by: MountainDon on September 16, 2011, 11:48:52 AM
Thanks Dave.  I do have a square wave 900 watt inverter that is there for emergencies. But I haven't got anything to handle the charging chores as yet.

My summer? Well except for...
1.  having the largest forest fire in recorded NM history come as close as 1.5 miles to the cabin,
2.  having my jaw wired shut for a big chunk of the summer,
... it was a fine summer.  :)

Since the fire missed us and my jaw works reasonably well now I guess I should not complain at all.

Heading back up in a few hours to thin some more trees.



Title: Re: OFF GRID POWER; various thoughts on...
Post by: Dave Sparks on September 17, 2011, 05:03:47 AM
Have a good trip and yes we heard about all the fires in the Southwest. I think that they are our version of the weather that the Southeast calls the "mean season". 

If you look at your array, you may be able to figure an easy way to use temporary jumpers to sub a small controller in while the CC is in for repair. Most likely t