Friend of mine in AZ has solar on his house. In summer, even with AC, he sells power.........

Our son down in SoCal has a new house with solar. It was required on new construction there. Basically pays the "you're on the grid" fee. It is a no-brainer, which may explain why it's not being done.

My wife's folks, up in Seattle, put in solar hot water in the 70s. Provided a whole lot of hot water. Why places like Hawaii, which require imported fuel, don't require it.