I have 5.6 kW solar and a single PowerWall2 in Arizona SRP territory, and so far it's working well, considering SRP's anti-solar tactics. For my 1st SRP bill in March with the PowerWall, my peak demand for the month was 0.2 kW and the March demand charge was only 70 cents. Based on the results so far, I am hopeful that I will be able to maintain negligible demand and negiligible on-peak usage even during the summer.
There is definitely room for improvement from the Powerwall software to better work for demand management and with multiple daily peak periods, but the net results so far look pretty good to me. I'm currently using a single 5am to 9pm shoulder period in cost-savings mode to cover SRP's two 5am-9am and 5pm-9pm winter peak periods.
I had my PowerWall mounted in the garage to avoid the extreme afternoon sun and heat, and had it mounted higher on the garage wall just to make sure it wasn't accidentally hit with a vehicle bumper. Sun Valley Solar Solutions did the install for both my solar and PowerWall and did an excellent job.
Now that
SRP is committing to up to a $3,600 incentive for battery systems, incuding a PowerWall with a solar install in SRP territory is almost a slam dunk.
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