Atmospheric water harvesting
With drought threatening many parts of the world, Nina Notman explores technologies for sucking water out of thin air
One reason it can be hard to persuade consumers to reduce consumption is the perception that water is all around us. Over 70% of the Earth’s surface is indeed covered with water. However, only around 2.5% of that is fresh water, the rest is saline. And most of the fresh water is locked up in ice caps, glaciers and permanent snow. Less than 1% of Earth’s water is available for drinking.
Technical solutions are increasingly being sought to supply our ever thirstier world. Desalination plants, that strip salt from sea water, are undergoing a huge boon. But another lesser known family of technologies is also starting to grow in popularity: atmospheric water harvesters.
As their name suggests, these devices capture water from the atmosphere. These include technologies able to capture both gaseous water (vapour) and liquid water (droplets) from the air around us.