Imagine, boondocking without ever worrying about restocking water even in dry or desert climates, using only the power of the sun.
That future may be around the corner, with the demonstration recently of a water harvester that uses only ambient sunlight to pull liters of water out of the air each day in conditions as low as 20 percent humidity, a level common in arid areas.
The solar-powered harvester, reported in the journal Science, was constructed at the Massachusetts Institute of Technology using a special material — a metal-organic framework, or MOF — produced at the University of California, Berkeley.
It offers a new way to harvest water from air that does not require high relative humidity conditions and is much more energy efficient than other existing technologies.
“This is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity,” said Omar Yaghi, one of two senior authors of the paper, who holds the James and Neeltje Tretter chair in chemistry at UC Berkeley and is a faculty scientist at Lawrence Berkeley National Laboratory. “There is no other way to do that right now, except by using extra energy. Your electric dehumidifier at home ‘produces’ very expensive water.”
The prototype, under conditions of 20-30 percent humidity, was able to pull three quarts of water from the air over 12-hours, using 2.2 pounds of MOF. Rooftop tests at MIT confirmed that the device works in real-world conditions.
“One vision for the future is to have water off-grid, where you have a device at home running on ambient solar for delivering water that satisfies the needs of a household,” said Yaghi, who is the founding director of the Berkeley Global Science Institute, a co-director of the Kavli Energy NanoSciences Institute and the California Research Alliance by BASF. “To me, that will be made possible because of this experiment. I call it personalized water.”
For RVers who camp far from a water supply, this is an exciting development.