Droughts could be consigned to history by a water harvester which can pull moisture out of the air using only solar power.
The prototype designed by scientists at MIT and the University of California works even in desert conditions. The device could eventually provide households with all the drinkable water they need, by extracting dampness from the surrounding atmosphere.
The solar-powered harvester can provide 2.8 litres of water from the air over a 12-hour period in conditions as dry as the Mojave Desert, where the average humidity is around 20pc. "This is a major breakthrough in the long-standing challenge of harvesting water from the air at low humidity," said Prof Omar Yaghi, at UC Berkeley.
"One vision for the future is to have water off-grid, where you have a device at home running on ambient solar for delivering water that satisfies the needs of a household."
The device is an open-air chamber containing a lattice-like structure made from zirconium metal and adipic acid sandwiched between a solar absorption panel and a condenser plate.
The zirconium and acid structure traps the water vapour then sunlight drives it towards the cooler condensing plate which returns the vapour to liquid so it can drip into a collector.
Two-thirds of the world's population experience water shortages yet there is an estimated 13,000 trillion litres in the atmosphere.