The BIGGEST problem with clean energy

I know there's a million other people begrudging tech that wasn't mentioned here (probably because Diana only mentioned tech she secured interviews for and could research in depth herself, which is awesome) but I am a touch disheartened that molten metal batteries weren't mentioned. They're in development for usage in Arizona where standard LION battery storage facilities literally lit on fire because they got too hot. The molten metal storage facilities are a perfect application for that.

I really did like that cryogenic air storage was mentioned, that tech is super cool!