Author Topic: OFF GRID POWER; various thoughts on...  (Read 561295 times)

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Offline MountainDon

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Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #201 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.



Closer view...



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.



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...



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



and, the positive end...



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.

« Last Edit: August 25, 2009, 05:52:14 AM by MountainDon »
Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #202 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

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #203 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.



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.



I used this triangle calculator to compute the distances between adjustment holes.


Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #204 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.



Just because something has been done and has not failed, doesn’t mean it is good design.

Offline rick91351

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Re: OFF GRID POWER; various thoughts on...
« Reply #205 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

 



 

   
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #206 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.

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #207 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
Just because something has been done and has not failed, doesn’t mean it is good design.

Offline Dandlite

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Re: OFF GRID POWER; various thoughts on...
« Reply #208 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...
Without wind power the vikings don't find America...!

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #209 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

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #210 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.

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline Dandlite

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Re: OFF GRID POWER; various thoughts on...
« Reply #211 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...
Without wind power the vikings don't find America...!

Offline Windpower

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Re: OFF GRID POWER; various thoughts on...
« Reply #212 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/


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Offline Dandlite

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Re: OFF GRID POWER; various thoughts on...
« Reply #213 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
Without wind power the vikings don't find America...!

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #214 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.

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #215 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. 

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #216 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.

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.




Just because something has been done and has not failed, doesn’t mean it is good design.

Offline glenn kangiser

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Re: OFF GRID POWER; various thoughts on...
« Reply #217 on: September 19, 2009, 05:22:39 AM »
All that agrees in what I see with mine, Don.
"Always work from the general to the specific." J. Raabe

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Offline glenn kangiser

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Re: OFF GRID POWER; various thoughts on...
« Reply #218 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.
"Always work from the general to the specific." J. Raabe

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Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #219 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.

Just because something has been done and has not failed, doesn’t mean it is good design.

Offline MountainDon

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Re: OFF GRID POWER; various thoughts on...
« Reply #220 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

Just because something has been done and has not failed, doesn’t mean it is good design.

emcvay

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Re: OFF GRID POWER; various thoughts on...
« Reply #221 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!

Offline glenn kangiser

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Re: OFF GRID POWER; various thoughts on...
« Reply #222 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. :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

emcvay

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Re: OFF GRID POWER; various thoughts on...
« Reply #223 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!

Offline Dave Sparks

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Re: OFF GRID POWER; various thoughts on...
« Reply #224 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......
"we go where the power lines don't"

 

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