like the ability to store up power from home solar
or the ability to keep your furnace running in a power outage.
In any case, a "total" solution for a 10kw gas backup power can be had for less than $7,000, including installation costs. While the 10kw battery solution is closer to $15,000+.
A Gas Generator can be wired up to either a propane tank, offering perpetual energy. (Gas lines rarely rupture). If you don't want to be hooked up to gas lines, then propane tanks are also an option.
They kill people on a regular basis (due to misuse, but misuse happens). I don't need 10KW, either, I just need enough to power the furnace so I don't freeze to death.
> Why would you want to do this when net-metering exists? Let the grid store your excess power, and buy it back from them. Run the math, you'll see which one is cheaper.
The math will change if everyone does it, I'd imagine.
> I don't need 10KW, either, I just need enough to power the furnace so I don't freeze to death.
Erm... what kind of furnace is in your house?
http://www.shop.thefurnaceoutlet.com/Electric-Furnaces_c15.h...
Ignoring the fact that furnaces are typically 10kw or more... then lets say you "only" need 3kw of power (so you can run off of a single Tesla battery). (Maybe you're running a smaller room-heater or something)
Then why not get a smaller $500 generator?
http://www.amazon.com/DuroStar-DS4000S-4-Cycle-Portable-Gene...
Or I dunno... a fireplace at that point. Since we're talking about small scale if you're using something smaller than a 10kw furnace...
That's great in places where the grid is required to take your excess power at rates similar to what you will end up paying at the times you may want to buy it back.
How many places does that apply to? (EDIT: I'm genuinely curious; it's not a rhetorical question, just to be clear)
On the contrary. Any form of net-metering makes batteries a hopeless situation.
Lets say you use net-metering, and it returns power at less than HALF of "off peak" levels. Lets say you're paying absurd California prices, of 40-cents kw-h at peek, and 10-cents at non-peek. And then you only manage to sell power back at 4-cents.
IIRC, these numbers are somewhat close to California numbers. Mind you, Virginia has 9-cents peek and 1-cent off peek. So... California prices are about as good as it gets for batteries.
Well, lets see here... first off all, you don't pay peek anymore. Because your solar panels are active between 11am and 4pm. Lets say you're selling it back at 4-cents. So you're paying in essence... 6-cents for nighttime power through the net-metering system (for every kw-h stored in excess by your solar panels)
You need to use 58333 kw-h before you break even with Tesla's $3500 battery (not counting inverter costs or installation costs). Considering that the battery has a capacity of 7kw-h, that is 8333 cycles or 22-years.
Unfortunately, the Tesla Battery Pack only has a 10-year lifespan. So you've lost money in the long run.
Not counting inefficiencies in the battery, inefficiencies in the inverter or installation costs.