The one who invents a heat-to-electricity converter with suitable efficiency will be the winner of XXIst century. In nuclear installations, we're around 33% efficiency (plus, notably, half this electricity is produced during night). I read about Seebeck generators (heat-to-electricity with no moving parts), but they're even less efficient, and all those generators require a source of cold and warm it up. https://en.m.wikipedia.org/wiki/Thermoelectric_generator