Yes, I have done this but not on a house. I used to own a sailboat.
First off if you need to run AC you are going to need to fill your garage
with racks of batteries.
Let's assume you have a smaller AC unit that only uses only 3,000 watts dn
you run it with a 50% duty cycle for 12 hours. That is 18KWH per day. A
good pair of high quality golf cart batteries will give you 1.5KWH but that
assumes you discharge them to full empty. They will not last even one
month if you do that. 50% discharge is the max you should do. so that is
A good rule of thumb is to have on hand two days worth of battery power.
so you need 2 x (18 / 0.75) = 48 pairs of batteries (each is 6 volts) Or
lets just say 100. The Trojan T105 is a great battery for the money. at
$160 each. But the T125 will outlast if the about $200 each. The battery
farm will cost at least $16,000.00 and that is with not chargers and
Ok so maybe you don't need to run A/C. If yu just want to run a fridge
and some light bulbs and maybe a TV or laptop computer you might do with a
smaller battery farm.
The BEST way to estimate the amount f power you need is to look at your
electric bill and then divide it by the number of days. Lets say you
don't have A/C and use only 4KWH per day. Then you need a battery bank
that can give ou t 8KWH and and discharge to 50%. You need a nominal 16KWH
bank. Using the T105 battery (lowest cost good option) you would need 20
of them for about $3,200.00
To charge the batteries just figure how many hours the wind blows and and
de-rate you wind mill by 2X. if you need 4KWH per day as in the last
example above then 16 of your $500 wind mill will be enough. That is about
$8,000. On't forget the electronics. You might be able to build it out
for $20K but yu don't run A/C on a small system like that.
When I had the boats I could live with a LOT less power. No refrigeration
and just a few LED lights when at anchor. I had 6 of the T125 batteries
and one marine engine-start batteries for my 27HP diesel 3 cylinder engine.
The engine has a 20A alternator that could supply up to 200W and it
would take hours to do any charging.
The biggest recurring cost when you go off grid is battery life a 50%
charge discharge charge gives you 125 AH of current but a T105 can do this
maybe 200 times before it is toast and they cost $160 each So you have to
pay $160 for 250,000 AH or 1.250 MWH Or about 12 cents per KWH for power.
You will NOT save much over what the power company charges you. With
today's technology you can about break even
There ARE better batteries but you pay a lot more up front for them. The
T105 is the best deal in cents per KWH over the battery life time.
What I am waiting for is for the market to be flooded with junk electric
cars. A a few years all cars will be electric and then 20 years after that
used batteries will be dirt cheap. No one wants a battery inter car that
can only change to 1/2 of its new capacity for for your house having 10 oe
12 of those is a lot more then you need.
Yes all cars will be electric. Much or Europe, the UK, China, California
and others already have a sales bad on new gas/diesel cars to take effect
in 10 to 20 years.
One more thing. I was talking about Trojan T105 or T125. These ar 6 volt
batteries but you would likey want to wire these up as a 24 or even36 or 48
volt DC system because it saves you ToN of money in copper wire. A
typical 12 volt system will use a lot of size 0 and 00 welding cable but at
48V you are using ## or #4 Why? a 12 volt system for can entire hour
might be 1,000 amps going into the inverter,
On Sun, Apr 15, 2018 at 4:40 PM, Gene Heskett <ghesk...@shentel.net> wrote:
> Greetings all;
> I see Banggood has a 500 watt wind thingy for under $200 that net folks
> are calling professional grade stuff. I am looking to put up an
> anerometer to record the wind speeds, one of those 3 cups designs that
> isn't direction sensitive, and one of these card computers to log what
> it sees so as to get an idea who many of these 500 watt things I'd need
> to keep a bank of truck batteries topped up while running the house,
> including the AC.
> Has anyone else walked this trail, or do I have to start with a machete?
> Cheers, Gene Heskett
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> Emc-users mailing list
Redondo Beach, California
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