Upside of humidity: New source of water in desert?

German research scientists have found a way to do what might seem unimaginable: obtain drinking water from air humidity, even in the desert. And here’s the cleantech kicker—the system is based entirely on renewable energy.

The inventors, out of the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart, Germany, in collaboration with Logos Innovationen, said they can convert air humidity autonomously and decentrally into drinkable water, according to ScienceDaily.

The process uses thermal solar collectors and photovoltaic cells, so it can function where there’s no electricity, such as in deserts. The way it works is through a salt and water solution that soaks up moisture, which runs down a tower-shaped unit, sopping up water from the air. The saline solution then gets sucked up into an elevated tank by a vacuum. Solar energy heats the solution, which is thinned by the water it has absorbed. The liquid has such a low boiling point because of atmospheric pressure.

The concept is expected to have various potential applications, ranging from individual units to plants that could supply water to hotels. Prototypes have been tested in the laboratory, but researchers said they plan to develop a demonstration facility.

This isn't the German institute’s first cleantech endeavor. Fraunhofer Institute for Solar Energy Systems broke the efficiency record for solar panels in January with a cell boasting 41.4 percent energy conversion (see Solar with 41-percent efficiency?). Last year, Fraunhofer formed a new research center in Massachusetts in collaboration with Massachusetts Institute of Technology focused on solar, green buildings and energy device prototyping (see MIT, Fraunhofer set up energy research center). 

And the concept of obtaining resources from air isn’t all that far fetched. Nevada-based company NewGardens has already successfully commercialized the hitherto fringe science of aeroponics, or growing plants in air. The company grows tomatoes commercially using the technique in the Canary Islands off the west coast of Africa (see Growing food and flowers in air).

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