Metal crystals harvest water from desert air

A solar-powered water harvester can supply fresh water to dry regions.

the closed system, the sunlight heats the crystals, releasing water vapour, which moves into the glass box. Above the glass box, a frame with metal foil reflects the sunlight. The vapour condenses in the glass box, and water is drawn from the bottom of the box.

The scientists have carried out experiments with the water harvester in the desert of Arizona, where the atmospheric humidity is no more than 40 % at night and 8 % in the daytime. Crystals including the expensive zirconium metal were used, and 200 ml of water was collected in 1 kg of crystals. Scientists are now developing new crystals based on aluminium, which is much cheaper, and they expect to be able to double their efficiency rate..

Desert air is too dry to extract water, but American scientists have developed a water harvester that can do the job. On a large scale, the method could be a new source of drinking water in regions that need it very badly.

The secret is special crystals developed by scientists from the University of California, Berkeley, USA. The crystals consist of organic molecules and metal atoms with a highly porous structure, including many cavities that can collect major quantities of water molecules. The crystals are located in a box inside a glass box. At night, the desert air has free access to the crystals that are packed with water molecules, and at dawn, a lid is placed on the glass box. In