I did the numbers a dozen times on the residential power wall.
As I have solar and am on EVTOU2 rate, it made no sense.
For a 11-12K investment, I might save $300-$400 best case per year.
Believe me, I really wanted the numbers to work but ended up cancelling my SGiP application. Just decided to add more solar instead.
There may be an additional investment tax credit of $3-4K on top of the SGIP incentive but even then the payback was about 17-18 years vs a 10 year battery life/guarantee.
For commercial users, the math is very different if you can get away from demand charges. I’m looking into a system for the factory I run and the payback may be 5-6 years but need to do more homework.
