[gregwebs]

I think you are describing pump-back hydro dams which are only a subset of pumped storage. Strictly speaking pumped storage only requires an elevation change and a water supply

[mjevans]

If not near a water supply or lack of intent to use some of the pumped water for irrigation anyway, as the parent post said, (nearly) everywhere it was worthwhile to do is already doing it.

The alternative is another form of gravity battery, often involving railway on a hillside and cars loaded with stone.