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MIT’s New Desalination System Produces Freshwater That Is “Cheaper Than Tap Water”
(scitechdaily.com)
Technology for a Solar-Punk future.
Airships and hydroponic farms...
I mean, if there is a reason I really want to know it. That we aren't doing so suggests there's some reason, although there's a decent chance that answer is, "That would cost anything more than dumping it out the nearest window."