A group of researchers has developed a sustainable, low-cost, solar-powered prototype that combines electricity generation, atmospheric water extraction, and water spinach cultivation, which could improve food and water security for people living in dry climate regions.
According to Cell Reports Physical Science, the system, called WEC²P, is composed of a photovoltaic solar panel placed on a layer of hydrogel, which is mounted on a large metal box that condenses and collects atmospheric water.
The atmosphere constantly conserves more than 12.9 billion tons of pre-distilled freshwater, and atmospheric water is continuously replenished through the global circulation of water, the study states.
The hydrogel developed by the team of researchers in a previous investigation can effectively absorb water vapor from the air and release the water content when heated.
Researchers used the waste heat from the solar panels when generating electricity to expel the water absorbed from the hydrogel. The hydrogel increases the efficiency of photovoltaic solar panels by up to 9% by absorbing heat and reducing the temperature of the panels.
The team conducted a plant culture test using the WEC²P system in Saudi Arabia for two weeks in June when the weather was very hot. They only used the water collected from the air to water 60 seeds of water spinach planted in a plastic culture box.
In the course of the experiment, the solar panel generated a total of 1,519 watt-hours of electricity, and 57 of the 60 water spinach seeds sprouted and grew normally to reach 18 centimeters. In total, about 2 liters of hydrogel water were condensed over the two-week period.