The US already has tons of reservoirs in the mountains. I think California does do some pumped hydro energy storage at the moment. https://en.wikipedia.org/wik

The US already has tons of reservoirs in the mountains. I think California does do some pumped hydro energy storage at the moment. https://en.wikipedia.org/wiki/Helms_Pumped_Storage_Plant https://en.wikipedia.org/wiki/Helms_Pumped_Storage_Plant https://www.sdcwa.org/projects/san-vicente-pumping-facilities/ https://www.sdcwa.org/projects/san-vicente-pumping-facilitie...