How big a battery bank do you have for off-the-grid/near off-the-grid living?
BilljustBill
| Posted in Energy, Heating & Insulation on
I’ve collected enough PV solar electric panels to equal 800 watts at 48 volts. Small DC wind has some advantages where I am, but would be limited to under 1,000 watts due to cost and site and could amount to 1,500 watts total generating power. What size battery bank do you use to either reduce your grid costs or to live comfortably on? Brand, costs, best vendor/price? Thanks, Bill
Replies
It depends on how much power you need.
That depends on how you live.
You might look at the solar living institute website as a starting point, and at home power magazine online, too.
Cliff
Bill,
Most off-grid homeowners spend between $1,000 and $2,000 for their battery bank. Batteries last about 6 years before needing replacement. You will find that you will be able to use far less electricity living this way than your on-grid friends.
You will also need a gasoline-powered generator to make it through the winter.
Here are two recent article on wrote on small wind turbines:
http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/backyard-wind-turbines
http://www.greenbuildingadvisor.com/blogs/dept/musings/resisting-allure-small-wind-turbines
Martin Holladay, senior editor
http://www.greenbuildingadvisor.com
Not to make things more complicated than they need to be, but the size of the battery bank is something that depends on how much energy is needed (especially peak load),, how much you want to depend on a generator, and how much you want to spend on batteries.
It's like asking, I'm looking at buying a car, how big an engine does it need? Well, that depends on what you need the car to do, your performance expectations, and how much dough you want to spend (both initially and for fuel).
The range you gave for battery cost is useful, but most off-grid homes have been configured to be exceptionally energy-efficient, and the residents usually live with moderate to severe limitations on how much power they use. Not that that's a problem, most off-grid people approach it as a game/challenge/opportunity to use as little energy as possible.
The nature of Bill's question suggested to me that he is at the beginning of the journey. There's a whole lot to off-grid than just the size of the system (including the battery bank).
Cliff
Of course, you don't need a
Of course, you don't need a battery pack at all to reduce your costs -- just install the appropriate controller to split the load with the power line. And few semi-modern homes will have a steady state daytime load much below 800W, so probably no need to work out a backfeed arrangement if you have just the PV.
Get it up to 1500W and you probably need either the batteries or the backfeed setup, though.
As others have said, there are certainly websites that can give you extensive details.
One interesting thing about batteries is that it may be possible to use a used prius battery.
I belieive they get changed out under warrenty when there performance falls to a certain level but that that level is fine for home back up.
You'd need the correct battery charger-controller to charge the NimH batteries.
I believe these used Prius batts are much cheaper /watt-hr and have a much longer useful life.
OK, les see.
Central or West TX, if you are ON the grid, like already stated by Dan and others, dont bother with any battery, waste of $$.
Off grid? 800 W array - if a commercial tracking array, you may get up to 5-6 kW-hrs per day total power.
A prius battery is all of a whoppin' 1.3 kW-hrs, whoopee - that is why they do NOT try to sell it as a 'plug-in' vehicle, all you could do is go to the store and back.
Avg. house uses about 20 kW-hrs per day, well over 1/2 of that when the sun does not shine in the winter.
I think you can see the math? If really off grid (like my cabin)you can get by on < 1 kW-hr storage ( 12 V marine batteries) to run the LCD TV and DVR and the fluorescent night lite for the kiddies. Use vapor absorption fridge and propane cooking and water heat naturally, etc, area fluorescent lights or candles or propane mantles. BTW, that 800 W is only about 650 Watts after you go thru a battery charger and inverter ....... gotta fold that into the equations.
Actually, I don’t have any idea about this but I am sure that it wouldn’t cost several [url=http://personalmoneystore.com/Payday-Loans/]payday loans[/url] if you needed to buy a new one.