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What do hexbears think about pumped hydropower storage?
(hexbear.net)
To make solar power viable, we need a solution for overnight energy storage.
Batteries are complicated.
Do you know what isn't? Water go up. 
The pipe and turbine would break so fast it's basically useless. Also, tanks are waaaay more expensive than digging a hole in the ground.
There's good reasons why freshwater open reservoirs are used. If tanks and brine were usable, people already would be using them.