The house I bought had solar thermal panels (from 1975!) to heat pool water. I took them off last year and put photovoltaic panels up instead. That ~zeroed my e

The house I bought had solar thermal panels (from 1975!) to heat pool water. I took them off last year and put photovoltaic panels up instead. That ~zeroed my electric bill and I'm starting to electrify to make use of the low-cost energy. First up is my gas pool heater.