After living with nuclear naysayers for decades (and rolling my eyes at them), I hate to be a nuclear naysayer myself; but there's been some use of "pumped hydro" for storing electricity generated by solar power.

The principle is simple: build a hydroelectric dam and run it in reverse. Of course, this can't be done everywhere; you need a lot of peak solar production, a lot of water, and an easily-dammed valley, and you don't often see all three together... But it does get used to store power, and solar plus pumped hydro represent a kinda-sorta alternative to nuclear.