A team of scientists has created a solar-powered self-contained system that not only uses solar panels to generate energy but also uses the excess heat to make water from air. “Improving [the] efficiency of solar power plants is the need of the hour,” Sunil Mysore, founder, and CEO at alternate energy and water conservation startup, Hinren Engineering, told Lifewire via LinkedIn. “This will be a landmark invention in the photovoltaic industry and will go a long way in ensuring sustainability in the water-energy-nutrition cycle.”
Water Sports
Led by Peng Wang, a professor of environmental science and engineering at the King Abdullah University of Science and Technology (KAUST), Saudi Arabia, the scientists placed regular solar panels atop a special hydrogel that can collect airborne water vapor. When the excess heat from the panels gets to the gel, it releases steam into a box, where it’s then condensed into drops of water. To test the concept, the researchers built a prototype version of their system and put it through its paces in three tests during different times of the year. In the two weeks during the hottest time of the year, the system generated 1,519 watt-hours of electricity and about two liters of water from air. Those two liters were used to irrigate 60 water spinach seeds planted in a plastic box, and the researchers noted that 57 of them sprouted and grew normally. In a statement, Wang noted that the scientists want to use the system to provide energy and water for cheap to help the millions of people living off-grid, particularly in remote and especially dry-climate areas. That’s a worthy objective considering the World Health Organization (WHO) estimates that over two billion people lack access to safely managed drinking water services. In fact, a 2019 report from Our World In Data discovered that unhygienic water results in over a million deaths every year. “Our goal is to create an integrated system of clean energy, water, and food production, especially the water-creation part in our design, which sets us apart from current agro-photovoltaics,” noted Wang.
Less Waste
In addition to using the heat to trap atmospheric water, the scientists note that the hydrogel also helps increase the efficiency of solar panels. According to Mysore, less than 20 percent of the energy that hits a solar panel gets turned into electricity. The rest is turned into heat, which results in the panels becoming even less efficient. Wang’s system helps solve this problem by operating in two modes. In the cooling mode, the hydrogel is exposed to atmospheric air at all times. During the night, it collects water molecules which, when heated during the subsequent day, evaporate, and take the excess heat from the panel, bringing down their temperature. “It’s how the human body reduces temperature by sweating,” Wang says. The cooling mode doesn’t collect any water, but according to the researchers, it can help increase the electrical output of a solar panel by about 10 percent. Jordan Macknick, the lead Energy-Water-Land analyst at the National Renewable Energy Laboratory (NREL), told Lifewire over email that Wang’s research could provide a meaningful solution to simultaneously addressing energy, water, and food access challenges in areas lacking infrastructure around the world. “However, there are still challenges associated with the land use requirements of these technologies in the context of how much water they can produce in a given area, which could limit their potential in scaling up for larger applications,” observed Macknick. To turn the proof-of-concept design into an actual product, the team plans to create a better hydrogel that can absorb more water from the air before pushing the system into real-world use. “Making sure everyone on Earth has access to clean water, and affordable clean energy is part of the Sustainable Development Goals set by the United Nations,” noted Wang. “I hope our design can be a decentralized power and water system to light homes and water crops.”
