Atmospheric humidity provides water to off-grid communities

A partnership between MIT and Berkeley researchers, a new solar-powered device is able to harvest water from air by changing vapor into drinkable liquid.

Using compounds invented 20 years ago by a team at the University of California Berkeley, a team in the Massachusetts Institute of Technology (MIT) Device Research Laboratory created a solar-powered method for gathering potable water from air-borne water vapor. Based around the capabilities of a metal organic framework (MOF), drinking water is collected by taking advantage of the change in phase of water from vapor to liquid. MOFs can be many different sizes and composed of different materials. The one used to gather water has been engineered to work best with air of 20 percent humidity. That amount is far lower than what other devices are currently capable of working with, which is what makes it ideal for use in arid regions.

Running on ambient sunlight only, the device is simple to run. Users open it at night, and then close it when the sun comes up in order to capture the water that results from the heated vapor. Currently very small, the device provides enough water for one person. The team is now looking into commercial production of the device, at a scale large enough to provide water for at least a family of four. Additionally, MOFs are being tested to find options that work in changing levels of humidity.

With up to two-thirds of the world experiencing some water shortage, smart, sustainable solutions are essential. Moroccan mountain communities are gathering potable water from fog, and a solar-powered water purifier is making contaminated water usable. How could sufficient water be gathered in these alternative ways to provide enough to share?