Expensive emergency-style devices used by armies can be run by generators and pull water from air. They work like air conditioners. And here are 5 ways you can re-use your air conditioner water. Water generation companies from Israel like Watergen have been in the market for a decade and have been made to connect to solar systems. They are bought by agriculture developers for hydroponics in off-grid locations and they can be used at hotels where water might need to be shipped in weekly. Consider that even in countries like Jordan people still get weekly water deliveries!
Related: stackable emergency shelters
New advances in Saudi Arabia, out of its expat-majority majority university KAUST say they have developed improvements on energy-intensive water generation from air systems and that the solar integration they use is seamless. Consider that Maria Telkes, a Hungarian-American inventor working with the US Army has already created a zero-energy passive water from air extractor decades ago that could be improved upon and used for water in disaster zones like in Turkey after one of their regular earthquakes – the latest killed 53,000 in Antakya last year.
Even in arid parts of the world, there is moisture in the air. This moisture could provide much-needed water for drinking and irrigation, but extracting water out of air is difficult because it takes a lot of energy. A new technology developed by KAUST researchers in Saudi Arabia may consistently extract liters of water out of thin air each day without needing regular manual maintenance.
Harvesting water from air is not a new idea, or even a new technology, but existing solar-powered systems are clunky.
Read more: Air Con runoff – cherish it like the rain
According to the researcher postdoc Kaijie Yang, who led the study, “solar-powered harvesters work in a two-stage cycle. An absorbent material first captures water from the air, and once it is saturated, the system is sealed and heated with sunlight to extract the captured water.
“Alternating between the two stages requires either manual labor or a switching system, which adds complexity and cost. The new harvester developed at KAUST requires neither — it passively alternates between the two stages so it can cycle continuously without intervention.
“Our initial inspiration came from observing natural processes: specifically how plants efficiently transport water from their roots to their leaves through specialized structures,” she says.
Looking at plants gave the team the key idea for their new system. “In our system, mass transport bridges play a crucial role as a connection between the ‘open part’ for atmospheric water capture and the ‘closed part’ for freshwater generation,” explains Yang.
The mass transport bridges are a collection of vertical microchannels filled with a salt solution that absorbs water. The water-rich salt solution is pulled up the channel by the same capillary action that pulls water up plant stems, and then the concentrated salt solution diffuses back down to collect more water:
“By optimizing the transport of mass and heat within the system, we enhanced its efficiency and effectiveness,” says Tingting Pan, another postdoc who worked on the project.
https://www.greenprophet.com/2024/01/redsea-hot-climate-and-saltwater-greenhouses/
During testing the system in Saudi Arabia, each square meter produced 2 to 3 liters of water per day during the summer, and about 1 to 3 liters per day in the fall. During the tests, the team ran the system for several weeks without the need for maintenance.
They also showed that it could be used as a direct point source to irrigate Chinese cabbage and desert trees.
“The materials we used were a water-wicking fabric, a low-cost hygroscopic salt and a plastic-based frame. We chose the materials for their affordability and availability, so we anticipate the cost is affordable for large-scale application in low-income areas,” says Qiaoqiang Gan, one of the study’s senior authors.
