Tesla Power Wall and a generator?

[armourereric]

I posted this here because IIRC, the Tesla Power Wall runs off of a Lithium Iron system. Please move it if that is incorrect. Anyhow, is there a point that the Power Wall will be made available for installation with the setup being a recharge via generator only. How long would it take to recharge the 10Kwh, frequent cycle Tesla unit using a 7500e generator? I would intuitive guess about 2.5 Hours. Where I live electricity is now 29.9c a Kw, the second highest in the US and annual 15% increases are on the horizon, and SDG&E wants $6000 just to "send a consultant" to see if I can be hooked up.

[inetdog]

I posted this here because IIRC, the Tesla Power Wall runs off of a Lithium Iron system. Please move it if that is incorrect. Anyhow, is there a point that the Power Wall will be made available for installation with the setup being a recharge via generator only. How long would it take to recharge the 10Kwh, frequent cycle Tesla unit using a 7500e generator? I would intuitive guess about 2.5 Hours. Where I live electricity is now 29.9c a Kw, the second highest in the US and annual 15% increases are on the horizon, and SDG&E wants $6000 just to "send a consultant" to see if I can be hooked up.

It is a Lithium Ion not Iron system. And I do not think that it is Lithium Iron Phosphate (LiFePO4).
Your charging estimate is probably not too far off, although C/2 is a pretty high charging rate for regular use even for Li.
As far as cost is concerned, the generator is going to cost you even more than SDG&E, so the main use for something like what you describe would be for pure off grid when you want to minimize generator use and maintain quiet hours.

[armourereric]

This would be an off grid situation. Why would the Generator be more than $6000? I frequently see 10000w units with key ignition start and LP/gasoline bi fuel for under $1K It would be just me and I don't use that much electricity. The house is a good 500 feet from any property line, I could likely run the gen at will.

[sensij]

No, the generator will cost more per kWh than what you pay (and will pay) for energy from the grid. Whoever convinced you to expect 15% increases in perpetuity is trying to sell you something. The Powerwall might make sense to charge from the grid when energy is cheap (at night), and then discharge during peak times (late afternoon/evening). As an off-grid solution, the case isn't obvious yet.

[Willaby]

This would be an off grid situation. Why would the Generator be more than $6000? I frequently see 10000w units with key ignition start and LP/gasoline bi fuel for under $1K It would be just me and I don't use that much electricity. The house is a good 500 feet from any property line, I could likely run the gen at will.

You'll need an inverter to go with the Powerwall, add at least $1k. After that expense, might as well add some solar if it suits your exposure. Also, the Powerwall is limited to 2kw continuous, 3kw peak, so just a couple of appliances will load it up pretty quickly. You could still time those to work with the gen-set on though.

[Mike90250]

This would be an off grid situation. Why would the Generator be more than $6000? I frequently see 10000w units with key ignition start and LP/gasoline bi fuel for under $1K It would be just me and I don't use that much electricity. The house is a good 500 feet from any property line, I could likely run the gen at will.

Wow ! i'd like to see a source for that

[emartin00]

If you have a generator, a powerwall is just going to add cost and complexity with little to no benefit. Converting electricity from AC to DC, then charging the battery, then discharging, converting back to AC is just going to be a big hit to efficiency. Generators already modulate fuel usage based on electricity demand.

[inetdog]

Generators already modulate fuel usage based on electricity demand.

Inverter type generators do a far better job of handling partial loads than conventional generators, even without factoring in any eco-throttle (standby) options.
Running a large generator at a high constant RPM even for low loads is inefficient.