The real low hanging fruit is energy use you were going to do earlier/later anyway but where timing isn't important. Heating water, cooling water, pumping wate

The real low hanging fruit is energy use you were going to do earlier/later anyway but where timing isn't important. Heating water, cooling water, pumping water, charging batteries, running power hungry machines. It's half century old tech and usually the only thing missing is a financial incentive to do so.