One could also argue that a system driven by the background radiation of the universe would provide power far longer than solar energy but like solar the stuff is rather diffuse and difficult to harness.
Folks start looking at the energy content of a kilo of uranium vs. a train full of coal. We have centuries worth of uranium if not hydrocarbons. If we could find a way to store fission energy conveniently such as nuke powered coal gassification or a nuke driven ethanol production process we could break free of the ay-rabs.
Fine, but what's wrong with using solar power too if we can figure out a way to do it cheaply?