Re: [Emc-users] Thinking about going off-line eventually.

```On Sunday 15 April 2018 20:47:54 Chris Albertson wrote:

> 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 0.75KHZ.
>
> 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 inverters.
>
> 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,```
```
That puts it in a more practical light, the conclusion being that it
might be practical in 20 years, but rather impractical ATM. But I won't
be around in 20 years, maybe not even 5. So theres the answer, let the
next owner do it.

Thanks Chris.

> 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
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users

--
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