Out of the 7 billion people currently inhabiting Earth, around 800 million face water scarcity on a daily basis. The percentage of people subjected to an acute shortage of water are also on the rise – fueled by an increased water demand and the decline of freshwater due to anthropogenic climate change. Under the current global water stress, we must aim to reduce our reliance on natural freshwater and instead look to develop inexpensive, novel technological processes that churn out usable water from non-usable mediums.
One such process, obviously, is the desalination of ocean water – the technology behind which is still quite expensive. The atmosphere also stores a large amount of water in the form of water vapor. As a matter of fact, the air holds around 12 quadrillion gallons of water as moisture, which is several magnitudes times greater than the household requirement for the entire planet – an estimated 400 billion gallons. A handful of devices already exist, which captures moisture from the atmosphere and transforms it into freshwater. However, such devices are also fairly expensive to use owing to the technology behind them.
However, two water-centric tech organizations based out of California – The Skysource and Skywater Alliance – have teamed up to build a new prototype that’s both scalable and sustainable in its ability to collect water from surrounding air. The device, called Wood-to-Energy Deployed Emergency Water (WEDEW), is located inside a standard shipping container and is built by combining two basic systems. The first system, called the Skywater, takes in the surrounding warm air and through an extremely efficient adiabatic distillation method transforms it into an artificial cloud. As the cloud warms up, it forms droplets of condensation that is stored in a separate tank and can be connected to a bottle refill station or a tap – and can produce enough drinking water to satiate the requirement of 100 people every day.
As the process requires a large amount of electricity, the second system – a biomass gassifier – ensures a sustainable way to generate it. Using a process called pyrolysis, the gassifier vaporizes wood and other organic material like coconut shells and wood chips to produce the power required to carry out the adiabatic distillation. The vaporization also makes the system hot and humid, creating an ideal environment to run the air-to-water machine. The byproduct, carbon-heavy biochar, can be added back to the soil which can aid the growth of plants.
The device is also designed to run on alternative power sources like solar and battery power to work in locations where wood is scarce. Overall, the device is not only cheaper and more efficient than desalination but also doesn’t require the presence of water sources nearby. Moreover, the device uses up dead biomass that would otherwise catch fire and in turn release carbon dioxide into the atmosphere, thus mitigating the release of greenhouse gases. Project leader David Hertz mentions that, “It’s a carbon-negative technology. I think the future of technologies is going to be moving to this restorative, regenerative model that actually helps to repair the damage we’ve done.”
The prototype was built in a competition called “Water Abundance Xprize”, organized by the nonprofit organization Xprize. The goal of the competition was to develop a system that extracted a minimum of 528 gallons of water per day from the atmosphere using 100% renewable energy, at a cost of no more than 2 cents per liter. By fulfilling all the criteria’s, the Skysource/Skywater Alliance device won the competition and was awarded a prize money of $1.5 million. The team is set to use the prize money to rapidly develop and deploy the units worldwide in partnership with other nonprofits.