Using a unique hydrogel, scientists in Saudi Arabia created a solar-powered system that successfully grows spinach using water drawn from the wind while generating electricity. The proof-of-concept design, described in the journal cell report physicsProvides a sustainable, low-cost strategy to improve food and water security for people living in dry climate regions.
“A portion of the world’s population still does not have access to clean water or green energy, and many of them live in rural areas with arid or semi-arid climates,” says senior author Peng Wang, professor of environmental science and engineering. Huh.” at King Abdullah University of Science and Technology (KAUST). “Our design creates water from the air using clean energy that would have been wasted and is suitable for decentralized, small-scale farms in remote locations such as deserts and oceanic islands.”
The system, called WEC2P, is composed of a solar photovoltaic panel mounted on top of a layer of hydrogel, which is mounted on top of a large metal box to condense and collect the water. Wang and his team developed the hydrogel in their prior research, and the material can effectively absorb water vapor from ambient air and release a watery volume when heated.
The researchers used waste heat from solar panels while generating electricity to draw out the water that was absorbed from the hydrogel. The metal box below collects the vapor and condenses the gas into water. Alternatively, the hydrogel increases the efficiency of solar photovoltaic panels by up to 9% by absorbing heat and reducing the panels’ temperature.
The team tested growing plants using WEC2P in Saudi Arabia for two weeks in June, when the weather was very hot. They used water collected from the wind to irrigate 60 water spinach seeds planted in plastic plant grow boxes. During the experiment, the solar panels, with the same size as the top of a student desk, generated a total of 1,519 watt-hours of electricity, and 57 spinach seeds germinated out of 60 water and normally 18. centimeter. In total, about 2 liters of water were condensed from the hydrogel over a two-week period.
“Our goal is to create an integrated system of clean energy, water and food production, especially the water-generating part in our design, that sets us apart from current agrophotovoltaics,” says Wang. To turn the proof-of-concept design into a real product, the team plans to create an improved hydrogel that can absorb more water than air.
“Ensuring that everyone on Earth has access to clean water and affordable clean energy is part of the Sustainable Development Goals set by the United Nations,” Wang says. “I hope that our design can be a decentralized electricity and water system to light homes and water crops.”
