@Syonyk has some good stuff here: https://www.sevarg.net/tag/solar/ - I'm sure he'll comment on this eventually, but he has built his own solar in Idaho.
I skimmed most of his off grid article and he states this:
"If you want to get a rooftop solar system that powers your home with the grid down, you can do it! The hardware is out there. But such a system will be significantly more expensive than a normal grid tied system, and it will likely never “pay off” in terms of money saved."
That may be true if he was paying $0.10 kw/hr in Idaho, but that's definitely false for a few reasons.
-In California, it's $0.43 kw/hr so the ROI for solar+battery is getting much faster with the price of panels, inverter, battery coming down. Price of electricity will continue to go up in the short term.
-A lithium iron phosphate EG4 5kw/hr battery for $1600, or even an EcoFlow Delta Pro for $2500 is a good deal considering around 8000 discharge cycles
-Most critically, net metering (grid tie) means that all that excess solar power you are producing in the middle of the day is being bought back by the power company at CHEAPER rates than what you are paying, so that needs to be accounted for in grid-tie vs off-grid pricing. If you are off-grid producing x amount of your power needs and you are using 100% of that power via lithium battery (at night), you are getting full retail price for producing your own power at $0.43 kw/hr or $0.49 kw/hr peak rate from 5-9pm in California. Off-grid doesn't mean truly off grid if you already have electric hookup, it just means an off-grid panel for some or most of your house. Think of it like this... if you have 15 solar panels grid-tied, you are being "taxed" ~4 panels by your power company.
PGE is ridiculous. But apparently whatever serves San Diego is even worse.
There's Silicon Valley Power, with rates that are a fraction of PG&E's, smack in the middle of the Bay Area. Can get as low as $.10 Kw/h during off peak hours.
