ETH Zurich researchers have created a device that produces water 24/7 without using any type of energy. A coated glass pane reflects solar radiation and emits its own heat into space. Water vapour from the air condenses on the bottom of this glass when it cools itself below ambient temperature. The pilot system with a pane diameter of 10 centimetres supplied 4.6 millilitres of water per day under real-world settings, which is at least twice as much water per area per day as the best passive technologies based on foils.
Image Credit: ETH Zurich/Iwan Hächler