You need a large reservoir at the top, another at the bottom, and as much vertical separation as possible. There aren't all that many places in the world that offer the geography necessary. It can be a good solution in places that do have the correct geography, though.
https://dothemath.ucsd.edu/2011/11/pump-up-the-storage/
You need a large reservoir at the top, another at the bottom, and as much vertical separation as possible. There aren't all that many places in the world that offer the geography necessary. It can be a good solution in places that do have the correct geography, though.