Energy Products

Off the Grid Possible with PowerWall2?

Hi all,

We're doing a new construction in Oakland, up until this point we were planning on just hooking into the PGE grid. However researching the cost of the power walls and solar and CA incentives it might make sense to skip the PGE if possible. We don't have a complete quote from PGE yet, but we're told that what ever it would cost for a standard hook up to PGE we will have to pay an ADDITIONAL $10k to run the power underground. Due to our site/home location an overhead hook up (like the rest of the neighborhood has) wouldn't really be feasible. So realistically we are probably looking at $15k to $25k for our PGE hook up total. That buys a lot solar and powerwalls. The house has no special demand for electric (no EV charging, no air conditioning, no pool or anything exotic like that) and cooking and heat/water heating will be gas. The site faces due south and has quite a bit of room on 30k sq ft lot so we could do a solar array off of the house.

I know one function of the Powerwall is to store energy from the grid if desired. I guess we'd be looking at adding an additional power wall (over what Tesla thinks we would need) to have enough in times of shade. I would be a bit worried as I can remember a time a few years ago when Oakland got 41 days straight of rain. Maybe off the grid is not a good idea yet? For us it would have to be an all or nothing approach. Either we go PGE or Tesla. Not both.


  • edited October 2017
    You could always go full Tesla and a small generator as an emergency backup, big enough to run the minimum in your house if needed. It will add a couple thousand dollars for piece of mind of going off grid. That or go off grid and put the money to the side expecting you might need a generator, then give it a few years of actual use to see if you ever need it. Based on your low needs it looks to me like you'd be a good candidate to go off grid. In 10 years I think it will become very common to drop the grid entirely, especially in situations like yours with large construction costs to connect to the grid.
  • edited October 2017
    Didn't realize that the incentives were $9k in CA. That is like 4 powerwalls for the price of two.
  • Here in Canada I was given a quote from local solar company and for 9 months I would be off grid. Now I'm not sure about the power wall because this company won't supply one but even with the older technology I can be off grid most of the year with no need for a power wall. As for your concern of enough sun I can say Hope is mainly cloudy due to the mountains over shadowing us. So looking from where you are the sun seems abundant in comaprison. You would probably need to scale the size of your house and how much electricity you use, which you can get a print out of you energy consumption through your electrical utilities provider, who may also have a buy back program. I'm not sure if your aware of it but I am able to sell 4,000 dollars of my solar power to B.C Hydro, at a higher rate then they sell it to us. My information is based on older technology and I'm excited. im sure Tesla would keep you off the grid as a matter of fact you will be fine if not I'll eat a bug a gross one too. If your wanting to be comlleatly off the grid for reassurance you could rry a wind generator or hydroelectric source but wait a bit on purcjasing them I have a feeling tesla will be supplying those as well. Maybe Hope can manufacture the windmills since it's so windy here! Well Hope will just Tesla may not be the name who knows. Go solar, save money, make money your guaranteed to win . My whole town is going solar and like I said the sun is almost taboo here . Good luck I hope this helps !
  • edited October 2017
    Add PGE even if you don't use it. It will be good for your re-sale value when the time comes.
  • edited April 2018
    Hi ZepperOakland, I am in the same situation as you are. Getting Hydro is very expensive to build on Pender Island, BC. Considering Powerwall and solar option.
    Anyone know of an off-grid powerwall, that is, powerwall that can directly hook up with a propane powered generator? According to this site (, it should be coming in 2018.
  • edited April 2018
    Hi jadhikary,
    I'm in a similar situation - a remote property on a BC gulf Island, and BC Hydro wants $20-$40 K to bring service to my property. I will instead be putting that $20-$40K into an off grid system consisting of solar panels, energy storage, and a generator. I'd love to use the Tesla's Powerwall 2 for the energy storage, but am unable to find firm details on if/when this will be an option. If you learn anything along those lines, please share!
  • So, I’ve ordered two Powerwall 2 units and just had the site walk through last Thursday. My goal is to run off grid. I have 5 KW solar and want the Powerwalls to buffer that solar generation to be used during dark/low solar gen times. I also brought up that I am interested in buying a large standby generator (e.g. 22KW) to be used in severe situations. There seems to be some sort of voodoo about allowing a standby generator to be the effective ‘grid’ input to the Tesla backup gateway. I’ve asked specifics but have yet to get an answer. At first response, it was a question of frequency matching that may hurt the Tesla sensitive electronics. I countered that the standby generators are quite sophisticated to frequency match on power up so they don’t cause problems when taking over the grid source. I have yet to get a reply from that fact.

    It doesn’t really click that the standby generator can’t be substituted for the grid input on the Tesla backup gateway. If that could be done, a simple tap off the Tesla communications circuit to get the ‘need help, out of power’ signal which then could be sent to the standby generator to turn it on. Thus, the Powerball 2 and Solar would be 90% sufficient except for extreme situations when the standby generator would start. Seems straight forward to me as an engineer.

    Can someone tweet Elon and see if he can answer all of us.

    I’m an avid Tesla enthusiast and have researched the v2 Powerwall which took on a broader install base that doesn’t have a solaredge inverter.
  • edited May 2018
    I would never consider going off grid without a backup generator of some kind. You said your heat is gas so just buy a 10kW home backup generator, they are relatively cheap, 3-6k or so for stationary natural gas generator.
  • edited May 2018
    Just FYI, from all I have read, the Powerwall rebate (SGIP) comes from your local utility. You may want to verify. I have just had a 5.2 PV system and 2 powerwalls installed last month. I'm waiting to see if I even get the rebate. I was "Off grid" prior to my permission to operate for 14 days. I continue to operate as though I don't have the grid. So far the only time I needed the grid was when I took delivery of my Model 3. I ended up drawing 60 kw from the grid over my solar and 2 powerwalls in 4 hours of charging @ 48 amps, 240 volts. I have since lowered my charging on my M3 to 10 amps (about 2.4 kw), setting the time to charge at 12pm (Time it usually takes from 7 am to noon to recharge my PW's from 70% back up to 100%) I have also set my PW's to save 25% for backup in case grid goes down. I believe I could sustain off grid for a pretty long time, but summer is not here yet, we will see! I also prefer to have grid backup no matter what, but others situations are different.
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