However if you can get water between two places it can work quite well. You need to live close to a big change in altitude and do a bit of geoengineering to create the upper and lower reservoirs, which can be destructive to local ecology, but not as much as a dam.
The energy math doesn’t make sense for grid scale applications with solid objects.
https://youtu.be/iGGOjD_OtAM
However if you can get water between two places it can work quite well. You need to live close to a big change in altitude and do a bit of geoengineering to create the upper and lower reservoirs, which can be destructive to local ecology, but not as much as a dam.
https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectricity
You can also use pumped air underwater with higher energy losses than pumped storage hydro because of compatibility of air.
https://electricalindustry.ca/changing-scenes/1785-world-s-first-utility-scale-underwater-compressed-air-energy-storage-system-activated-in-lake-ontario/