That seems to make a lot of sense, an we already know pumped hydro is one of the most efficient "batteries" for renewables. But then the tradeoff is how far do

That seems to make a lot of sense, an we already know pumped hydro is one of the most efficient "batteries" for renewables. But then the tradeoff is how far do you have to pump the water from the ocean to get it up to a reservoir above 2000 feet? You might lose all benefits (if there were any) of the technique if you don't have a handy mountain nearby.