Engineers at MIT and in China have developed a passive solar desalination system that uses the sun’s heat to turn seawater into drinking water. The device, inspired by the ocean’s thermohaline circulation, allows water to evaporate while leaving salt behind. The resulting water vapor is then condensed and collected as drinkable water. The system has a higher water-production rate and salt-rejection rate than other passive solar desalination concepts. If scaled up to the size of a small suitcase, it could produce 4 to 6 liters of drinking water per hour, lasting several years before replacement parts are needed. The system could potentially produce drinking water at a rate and price cheaper than tap water.
https://news.mit.edu/2023/desalination-system-could-produce-freshwater-cheaper-0927