Winter here isn't just a cloudy day. I have PV. In 3-4 winter months I produce about 15% of the yearly output, but I consume 90+% of the heating energy. Even

Winter here isn't just a cloudy day. I have PV. In 3-4 winter months I produce about 15% of the yearly output, but I consume 90+% of the heating energy. Even 10x my PVs is not going to be enough, and for even that I don't have the roof space. Even if I lay PV for the 95th worst percentile days, I still absolutely must have a grid connection because the kind of batteries to shift summer production to winter consumption simply don't exist.