Here in CA I got an 8.25 kWh system with 2 PWs, and based on the math I did its pretty much a break even vs getting just solar, IF you have Net Energy Metering on a Time of Use plan. Arbitraging your energy rates . If you don’t have NEM and TOU, it will never make financial sense. Only thing PW would be good for is peace of mind in a power outage.
With the 26% solar/storage fed tax credit being drastically cut end of 2022, and energy utilies starting to rethink the NEM and TOU programs due to them not being as profitable, I took the plunge. So far I’m very happy with the setup and based on my production & storage, I am paying about $0.13/kWh , my base rate through my utility (SoCal Edison) is $0.17, so I’m ahead, and insulate myself from future rate increases. I actually just ordered another 4.5 kWh solar panel system to add to what I have - these electric cars use way more energy than I had initially accounted for!!! Will end up with a total of 12.75kwh system.
Also, something to note, when I purchased in June I got a 10 year loan @ 0.99%, I believe it is now 1.99% for the same loan through Tesla.