Water is in the air

With global demand for water expected to increase by nearly one third by 2050, and around two billion people already lacking access to safe drinking water, it is easy to see why there is such a buzz around innovative technologies to produce water from the air.

It is estimated that the atmosphere contains around six times as much water as all the world’s rivers. However, until recently, atmospheric water generation was often deemed too costly, too energy-intensive and too inefficient.

Now innovators are combining renewable energy technologies with cutting-edge water capturing methods to respond to needs in some of the world’s driest places without adding to the carbon emissions fuelling global warming and contributing to water scarcity.

Take WeDew, the winner of this year’s Water Abundance XPRIZE, which challenged inventors to extract a minimum of 2,000 litres of water per day from the atmosphere using 100 percent renewable energy at a cost of no more than two cents per litre.

A biomass gasifier generator is used to run the system. WeDew says it operates at less than one-tenth the cost of solar power while occupying the area of a single panel. The gasifier is fuelled by organic by-products such as wood chips, coconut shells or whatever biomass is locally available. Biomass gasification superheats the material and converts it into electricity, hot humid air and biochar, which can be added to soil to store carbon.

Other innovators have developed similar systems. US company Zero Mass Water’s SOURCE technology involves roof-mounted solar panels that can pull on average 4 – 10 litres a day from the air. A fan draws in the water vapor and it is absorbed using a unique hygroscopic concept that also cleans the water.

Zero Mass Water is active in Kenya, South Africa and Australia, where it has partnered with the Australian Renewable Energy Agency to set up a demonstration project involving 150 hydro panels in schools, farms, homes and water-stressed communities.

These successful innovators demonstrate the kind of out-of-the-box thinking that UN Environment hopes will abound at the fourth UN Environment Assembly. The motto for the meeting is: think beyond prevailing patterns and live within sustainable limits.

Original source: UN Environment 
Published on 6 December 2018