Anyway, if you want to use it as a backup, you'll need to oversize the solar so the battery can get you through power outages on cloudy days.
At that point PG&E will pay you 10-20% market rate for the excess energy you produce on most days. It's much better to dump those electrons into an EV battery than into the grid. My commute costs $4/week in electricity I don't send to PG&E, vs 20x that for the gas for the same commute.
(The EV gets 4.5 miles/kWh, and PG&E pays $0.04 / kWh, or $.008/mile. The old car gets 30mpg. At $5/gallon, that's $0.16/mile)
The punchline: Budget money for an EV for each of your household's commutes when you purchase the solar panels. Regardless if whether you buy panels, consider charging at work, assuming your employer subsidizes it and/or has solar panels.
(Also, check the milage on the EV you want. 3-5 mi/kWh is typical, but they can vary from 1 to 7.)
Part of my reason for thinking about solar is that if I'm going to spend 10k on a backup generator it might be far smarter to spend that on solar. For me the invest and pay cycle doesn't address the problem I'm solving. But I absolutely learned something today.