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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. 
I've also seen a version of this that uses an electric locomotive that moves a big weight up and down a slope.
Personally I think we should put big weights on pulleys in every high rise, like a grandfather clock.
That's a good idea. They already have shafts that have the capacity for big weights as well