Among my broken-record themes is that the energy-storage solution of pumped hydropower is trivial compared to the potential value of dispatchable hydropower - that is, to stop treating hydro as a baseload energy to be released on a constant basis, and instead shape your releases around solar and other variable, renewable power sources. Looks like I babbled this here at Rabett first in 2019, and complained again in 2020 about there being no 24-hour variation in hydro use. So take a look at this chart from Mark Jacobson showing typical spring power deployment for California (light blue is hydro):