Seems pretty obvious. Fire was the first means of harnessing solar panel, why have you forgotten it? Mills using water and wind have been around for 2000+ years. We still have hydro and wind, just generating electrical power, rather than being used directly for mechanical advantage.
We have lots of "usable" energy all around. I don't understand how someone can care about a subject so much to comment on it, but so obviously oblivious of it.