Atmospheric Water Harvesting – How Leveraging Gravity Can Advance this Technology

Water is perhaps the most valuable resource our planet has to deal with. Despite covering 70% of our planet, freshwater, the water we use to drink, take a bath, or irrigate our farmlands, is scarce. Only 3% of the world’s water is freshwater. Moreover, two-thirds of that 3% dwells in frozen glaciers or is unavailable for use.

The outcome of water scarcity is something that is reflected worldwide. Globally, close to 1.1 billion people lack access to water. A total of 2.7 billion people in the world suffer from the scarcity of water for at least one month of the year.

Shortage of water also leads to many other problems, such as inadequate sanitation, a problem for 2.4 billion people who get vulnerable and exposed to diseases like cholera and typhoid, and many other fatal diarrheal diseases.

The growing population and the ever-expanding demand for water have always been at loggerheads. The more populated our planet has become, the more stressed its water systems have become.

Rising pollution levels have taken a toll on the planet’s rivers, lakes, and aquifers. What appears even more distressing is that over half of the world’s wetlands have disappeared.

If the scientific community fails to evolve with time and offer solutions to combat the menace of disappearing water, our agriculture systems won’t have enough water soon, leading to food insecurity and much more.

However, fortunately, the scientific community is up to the challenge worldwide. Today, we will discuss one such breakthrough solution in the coming segment and then do a deeper dive.

Device Extracts Water from the Air Using Nothing More than Gravity

A team of international researchers, led by KAUST Professor Qiaoqiang Gan, has designed a device that can potentially run with no electricity and extract water from the air with the help of nothing but gravity. The device, already free from the need for a costly energy supply, can be made with cheap and readily available materials.

The experiment paper, titled ‘Lubricated Surface in a Vertical Double-Sided Architecture for Radiative Cooling and Atmospheric Water Harvesting’, seeks to make atmospheric water harvesting more efficient.

The water harvesting process improves significantly in radiative cooling. Radiative cooling works by significantly lowering condenser temperatures below ambient levels and making atmospheric water harvesting possible without additional energy.

One issue that radiative cooling systems face is the challenge of traditional sky-facing condensers having low cooling power density, and water droplets remaining pinned on the surface, requiring active condensate collection.