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Omar Yaghi in Berkeley, and his metal-organic models
Omar Yaghi and his metal-organic models

Scientists have created a device that can literally extract water from the air using solar power.  Solar Water could revolutionise off-grid living which currently requires a natural water source to be viable – even if its just  rain. This device could one day provide personalized water to those in areas affected by chronic drought.

Researchers at Massachusetts Institute of Technology (MIT) and the University of California Berkeley published their findings in the journal Science on Thursday.

The invention can harvest water from the atmosphere in conditions where relative humidity is as low as 20 percent, which makes it potentially usable in many of the planet`s driest regions.

This is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity,said Omar Yaghi from Berkeley, who along with colleague Evelyn Wang from MIT created the revolutionary tech.

In order to harvest water, the system uses a specially designed material, a metal organic framework (MOF) designed by Yaghi over 20 years ago. By combining metals like magnesium or aluminium with organic molecules the MOF creates rigid, porous structures ideal for storing liquids and gases.

Essentially the system absorbs and traps air in nanometer sized pores. When sunlight is added, water molecules inside the trapped air get released and condensed into drinkable H2O. Using just 2.2 pounds (997g) of MOF the device can harvest 2.8 litres of water over a 12 hour period.

One vision for the future is to have a solar water device at home running on ambient solar for delivering water that satisfies the needs of a household, Yaghi told Berkeley news.

The ingenious device is not yet ready for commercial production but the scientists have big plans for their technology.

There is a lot of potential for scaling up the amount of water that is being harvested. It is just a matter of further engineering now, expressed Yaghi.

To have solar water running all the time, you could design a system that absorbs the humidity during the night and evolves it during the day, he said. Or design the solar collector to allow for this at a much faster rate, where more air is pushed in. We wanted to demonstrate that if you are cut off somewhere in the desert, you could survive because of this device. A person needs about a Coke can of water per day. That is something one could collect in less than an hour with this system.

There is no other way to do that right now, except by using extra energy. Your electric dehumidifier at home produces very expensive water, he added.

Wang echoed these statements; This solar water device 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, the mechanical engineer said.

With an estimated 1 in 10 people lacking access to clean drinking water and 4 billion people worldwide facing severe water shortages the potential for this technology is huge.

Buy our book - OFF THE GRID - a tour of American off-grid places and people written by Nick Rosen, editor of the off-grid.net web site

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