I have a small 5kWp PV at home, with a small lithium storage (8kWh) just to cover my arse in case of outage, since here (French Alps) there is a very big day-ni

I have a small 5kWp PV at home, with a small lithium storage (8kWh) just to cover my arse in case of outage, since here (French Alps) there is a very big day-night thermal delta it's very good in summer, where at night I just need the VMC in passive mode and A/C only during the day, for the rest it's enough for heating sanitary water almost ONLY from the Sun, winter included, and to run some appliances (dishwasher, washing machine etc) in self-consumption. Doing more is needed for trying to charge an EV from PV during the day, likely the double at minimum, but to heat the house in winter OR: - I need a very expensive battery (60kWh/~30k€ at least just to avoid big daily deep discharge cycles) who might or might not last 10 years with an expensive geothermal heat-pump 15k€ at least; - I need a giant insulated, probably underground for mere easiness of design, pool and PV plant (I do not know how to estimate but surely few swimming pools of water and enough PV to heat it) to store enough heat for the night. Both options are ridiculously expensive especially since they still NOT give autonomy since they can support day-to-day winter IF the Sun shine enough, witch might but also might not happen. Perhaps in a future H₂ from hydrolysis will be on sale to offer a fuel-cell third option, but I imagine it will be even more expensive. So far it's still FAR, FAR, FAR, cheaper using the grid + an emergency wood based heating. Long story short I might accept investing (I'm actually in the planning stage) a 15kWp or so PV for an EV charging (WFH so without daily car usage) but trying more is just money gifted to some company pocket. Oh BTW that's JUST for private homes. We also have public buildings AND industry...