On Sun, 07 Oct 2012 01:07:26 -0700, Gunner
wrote:
On Sat, 6 Oct 2012 23:51:42 -0400, "Existential Angst"
wrote:
Awl --
In discussing using inverters+car alternator as a backup power supply, and
observing some hefty cobra 5,000 W inverters ($310, google shopping), I was
wondering if these can be made even heftier with stock parts? I wonder if
these large ratings in cobra units aren't like Sears hp....
It seems like the bottleneck in this strategy as a house backup power supply
is the car alternator. 5,000 W would require about a 500 Amp alternator!
Or a couple/three smaller ones.
But mebbe a regular car alternator + a bank of batteries could handle all
the peak loads/draws, as long as they didn't last forever. Anyone here ever
do this?
Gensets, even nat gas ones, seem to be a real pita, and the noise is
considerable, unless you get real pricey.
Of you look around..you should be able to find a nice quiet natural
gas powered genset someplace for very little money.
Then you'll find out why they're going for cheap. I've heard the cost
to run them is simply -outrageous-. From the Generac website:
--snip--
7) How much does it cost a month to run the generator when it runs for
15 minutes a week?
Depending on the price of natural gas, it shouldn’t cost more than
$4 or $5 per month to run the unit in test mode. During a power
outage, under 50% load expect to pay less than $30/day for gas usage.
A lot cheaper than a hotel room or spoiled food!
--snip--
That's up to $900/mo ($10,800/yr) for gas at half power! IF The
pipeline remains pressurized. (yes, worst case scenario)
You will absolutely need a running power source for an inverter. Ive
got a 6000 watt Hart inverter that came out of a brand new but wrecked
greyhound bus sized RV...and I dont have anything big enough to feed
it the 12 volts required to output 6000 watts of 120 volts AC
That's a whole lotta inverter!
Ive got a Xantrex 3000 watt inverter in my big van. It has dual
batteries and a second set of paired deep cycle batts mounted inside
the cargo compartment. Works very very well for about an hour or so
when Im running close to 3000 watts of power tools and lights. So I
had to install an oversized alternator to keep the batteries charged
when the inverter is running.
How often do you use it for more than an hour? And what tools are
hooked up to it? Will it handle a good sized welder?
Now if you can stack up forklift batteries in a big enough pile..with
a big enough charger ..you might be able to run the important stuff in
your house for day or so..at most.
http://www.ebay.com/itm/Natural-Gas-...-/400323091362
etc etc
Building a small noise canceling cover for it...like a small shed is
not a big deal
....but it's a necessary thing. Engine noise really grates on nerves.
Especially non-tool-user nerves. vbg
--
You never hear anyone say, 'Yeah, but it's a dry cold.'
-- Charles A. Budreau