"This 10¢ Battery Turns Seawater Into Freshwater" https://youtube.com/watch?v=j-C7A8kmJuQ
It looks like stacking this system on this system would be even more efficient; https://news.ycombinator.com/item?id=48425376 :
> "Extreme salt-resisting multistage solar distillation with thermohaline convection" (2023) https://www.cell.com/joule/fulltext/S2542-4351(23)00360-4
Which sustainable production processes take brine as an input?