I was looking back at reddit posts (while deleting them), and I realized I’d written a book worth of stuff about this topic. I would write it all again, if it is helpful. But for a brief synopsis of “how it works”, here is what one does:
Assess power needs - look at your living standard and catalog all the devices you power, and estimate the time they operate - power is measured in watts, and time in hours. Multiply to get watt-hours; then divide by 1000 to get kilowatt hours. Compare with your utility bill.
Excellent; this seems to show my system has a high reliability, as I have observed, and at the most severe conditions, about 10% or 15% reserve capacity. I expect to have an EV later this decade, and my existing house system will not provide for that. I may need a stand-alone system for EV charging, or some EVs have their own charging (Aptera looks attractive, there may be others?) I haven’t figured it out yet.