The BIGGEST problem with clean energy

Electric storage is the biggest problem only while we steadfastly refuse to acknowledge the obvious solution we had for 70 years: nuclear. Not the cheapest, granted (although most of cost barriers are artificial), but the most abundant, most reliable, clean (yes, clean) and _the_ safest. Even climbing roofs to install residential solar is more dangerous per joule produced that nuclear.
(Inter)continetal grids _could_ be a solution for making wind and solar more usable, but they are also woefully expansive, plus fragile (both technically and politically).