I don't think it's there yet at capacity. The change over would be disruptive and that's a political third rail.

I really wish I could find it, but there was this old video of a guy giving a roadmap plan for cities to use less electricity with no loss of quality of life. He got down to things like how the motors in elevators are so inefficient because of how they get produced. And that's because of how ALL motors get produced to be the standards that we use. (bad paraphrase by me of course)