Water out of Desert air
From California to sub-saharan Africa, we’re facing a global water scarcity. Receiving less than 1cm of rain annually and with water resources under threat, Peru’s capital city Lima has had to get creative at high altitudes where municipal water departments cannot build reservoirs. The Peruvians without water movement has built vast nets to trap the thick sea fog and mist that regularly covers hilly landscape of Lima to provide up to 400,000 liters of fresh water to the region. In regions where it doesn’t rain much, nor are there many freshwater sources – a situation even more critical as urban populations expand rapidly – environmental innovators are conquering the crisis, resourcefully, one step at a time.
A team of researchers at MIT and the University of California, Berkeley have developed a solar-powered device that can wring water from the desert air. The device works at low power in arid conditions, which means it could help remote desert communities without constant access to drinking water.
The new device works like a dehumidifier, .i.e. it turns excess water vapor in the air into liquid water. Instead of using electricity, the water harvester in the device uses heat from the sun and a new material called an MOF (Metallic-organic Framework). The material, MOF has a large surface area and pores that can be customized to capture h2o molecules. The heat from the sun converts the h2o molecules into vapor, allowing them to rise out of MOF’S pores and into the device, which is a clear acrylic enclosure. The cube houses a condenser at the bottom of the vessel, directing the water molecules
into a chamber below in which drinking water can be stores.
In driest parts of the world like the Sahara, the device can pull 2.8 liters of water from the air over a 12 hour span. The solar-powered device could be used to help over 4 billion people globally who suffer from acute water shortage.