Water from the air? It is now possible. Researchers at ETH Zurich (Eidgenössische Technische Hochschule Zürich) have developed a new revolutionary technology. It allows for 24-hour water harvesting, even under the sun, without any energy input.
The device is essentially a specially coated glass pane. It reflects solar radiation and cools itself down by radiating its own heat into outer space. Underneath the pane, water vapour from the air condenses into water. It produces at least twice as much water per area as the best passive technologies based on foils.
The pane is coated with a specially designed polymer and silver layers. They emit infrared radiation at a specific wavelength window to the outer space without absorption by the atmosphere or reflection back onto the pane. The device also features a cone-shaped radiation shield. It deflects heat radiation from the atmosphere and shields the pane from incoming solar radiation. The shield also allows for the device to radiate heat outward and self-cool passively.
The production of the coated panes is relatively simple and is aimed at countries with water scarcity and emerging nations. Several water condensers can be positioned side by side to create a large-scale system.