OFF GRID POWER; various thoughts on...

[Windpower]

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

[MountainDon]

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.

[Windpower]

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

[glenn kangiser]

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.

[Windpower]

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

[glenn kangiser]

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.

[MountainDon]

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 , if that would help in any planning.

DC breakers are supposed to be mounted vertically, although not everyone does that.    ... something to do with arc flame travel.

[glenn kangiser]

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.

Around 24 volts at 100 to 250 amps is a very common DC welding volt and amperage.

[Windpower]

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 ....

[soomb]

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.

[tesa]

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

[tesa]

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

[harry51]

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!

[MountainDon]

G/L on the dispute with eBay / PayPal.

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

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?

[MountainDon]

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.

[Windpower]

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

[tesa]

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

[glenn kangiser]

I would say so - it is a required part of the system.

[MountainDon]

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.

[MountainDon]

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.

[glenn kangiser]

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.

[MountainDon]

The following question was asked on another topic. I thought it would be relevant to post my reply here.

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.

[MountainDon]

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?

[soomb]

What does dropping one panel do?

[MountainDon]

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.