Engineers Develop Device That Turns Saltwater Into Freshwater Using Sunlight

MIT News -  What do you get when you combine the vastness of the ocean and the power of the sun? Drinkable freshwater that may be cheaper to produce than tap water. And it’s all thanks to engineers from the Massachusetts Institute of Technology and Shanghai Jiao Tong University in China, who developed a revolutionary solar-powered desalination system inspired by oceanic processes.

In a recent study, the researchers describe a passive device that takes in saltwater and uses natural sunlight to heat it. The unique design enables water to circulate in a way reminiscent of the ocean’s circulation, thus facilitating the evaporation of water and leaving salt behind. The resulting vapor is then “condensed and collected as pure, drinkable water,” while the remaining salt continues to flow to prevent clogging issues, per a press release from MIT.

“That means that, for the first time, it is possible for drinking water produced by sunlight to be cheaper than tap water,” explained co-author Yang Zhong. “This opens up the possibility for solar desalination to address real-world problems.”

If scaled to the size of a small suitcase, the solar desalination system could produce 4 to 6 liters of drinking water per hour and remain operational for several years before requiring replacement parts. The system’s affordability and adaptability also make it suitable for off-grid, coastal communities, presenting a promising solution to water scarcity.