heating uses the vast majority of domestic (and dare I say often industrial) energy consumption. so it matters, even if it's not for electric generation. A lot

heating uses the vast majority of domestic (and dare I say often industrial) energy consumption. so it matters, even if it's not for electric generation. A lot of rooftop solar systems go direct to water heating, being more efficient than rouoting that through electrics. (ideally, you want both)