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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. 
Cool good to know, but why do they need to keep cleaning the pipes?
Some of molten salt crystallizes on pipe walls, because they are colder, and it makes the pipe narrower.