Last week our Powerwalls really paid off with multiple outages during triple digits and evening while still in the high 90s. I even went to the nearby Supercharger for the Tesla to save all my stored electrons for outages. Worked well. A key issue is too much residential solar generation blowing out transformers. Solar subsidies have created another class of royalty in CA, just like prop 13 did for all those pre-78 owners.