University Of California Researcher Solves Drought Problems With Solar-Powered ‘Water Harvester’ [Video]By Khaleb Skye A. Cruz
Omar Yaghi, a chemist at the University of California, Berkely, invents a new sponge-like device that uses sunlight to "suck" water vapor from air. Interestingly, it works even in places with the lowest humidity. For one, the device produces about three liters of water per day.
Indeed, homes in the driest parts of the world could soon avail of the solar-powered water harvester. The University of California study will definitely offer relief to billions of people. Per Science Mag, there are roughly 13 trillion liters of water "floating" in the atmosphere from Earth's lakes and rivers.
As a matter of fact, different researchers from all over the world have tried to develop various ways to grab even just a few drops from fog banks using fine nets. Others utilized power-hungry dehumidifiers to condense water out of the air. However, both procedures require "very humid" air.
According to Science Daily, the prototype was able to pull three quarts of water from the air under conditions of 20 to 30 percent humidity over a 12-hour period. The test was done at a rooftop, using one kilogram of Metal-Organic Framework (MOF), confirming that the device works in real-world conditions. Basically, the water harvester soaks up water vapor during nighttime and uses heat from the sun to release it as liquid during the day.
Yaghi, in 2014, reached out to Evelyn Wang, a mechanical engineer at the Massachusetts Institute of Technology in Cambridge, to work on a project using MOFs in vehicle air conditioning. After synthesizing the new zirconium-based MOF called MOF-801, both researchers agreed to come up with a water harvesting device. The latest discovery presses MOF crystals into a thin sheet of porous copper metal. The sheet is placed between a solar absorber and a condenser plate placed inside a chamber.
At night, the chamber is opened permitting ambient air to diffuse through the porous MOF. On the other hand, water molecules stick to its interior surfaces, gathering in groups of eight to form tiny cubic droplets. During daytime, the chamber is closed and sunlight enters through a small window on top of the device to heat up the MOF. This "liberates" the water droplets and drives them toward the cooler condenser.
In particular, the change in temperature causes the creation of liquid water. It allows the vapor to condense into its liquid form. The end product then drips into a collector.