Saudi Arabian scientists created a solar-powered device that successfully produces spinach by taking water from the air and producing electricity using a new hydrogel. The proof-of-concept design, which was published in the journal Cell Reports Physical Science on March 1, offers a long-term, low-cost solution for increasing food and water security in dry-climate areas.

"A small percentage of the world's population still lacks access to clean water or renewable energy, and many of them live in rural areas with arid or semi-arid climates," says senior author Peng Wang, an environmental science and engineering professor at King Abdullah University of Science and Technology in Saudi Arabia (KAUST). "Our concept pulls water from the air using renewable energy that would otherwise be squandered, and it's ideal for decentralized, small-scale farms in distant locations such as deserts and marine islands."

How Exactly Does This Work?

A solar photovoltaic panel is installed on top of a layer of hydrogel, which is mounted on top of a huge metal box to condense and collect water in the WEC2P system. Wang and his colleagues previously produced a hydrogel that can absorb water vapor from the environment and then release it when heated.

To force absorbed water out of the hydrogel, the researchers employed waste heat generated by solar panels. In the metal box below, the vapor is collected and condensed into water. The hydrogel, on the other hand, boosts the efficiency of solar photovoltaic panels by up to 9% by absorbing heat and lowering the temperature of the panels.

In June, when the temperature was unusually hot, the team employed WEC2P to undertake a plant-growing experiment in Saudi Arabia for two weeks. They used only water gathered from the air to irrigate 60 water spinach seeds put in a plastic plant-growing box.

57 of 60 water spinach seeds germinated and developed properly to 18 cm throughout the experiment, and the solar panel, which was about the size of the top of a student desk, produced 1,519 watt-hours of electricity. Approximately 2 liters of water were condensed from the hydrogel over the course of two weeks.

One of the United Nations' Sustainable Development Goals is to ensure that everyone on the planet has access to clean water and inexpensive clean energy. Wang's idea can be a decentralized electricity and water system for lighting households and watering crops and that is in line with what he's said as well. The researchers received funding from the King Abdullah University of Science and Technology.