(CN) — With a quarter inch of rain in the spring and summer temperatures in the triple digits, Saudi Arabia might be the last place on Earth one would imagine lush crops of of the leafy green vegetable kangkong flourishing. Research published in Cell on Tuesday, however, demonstrates that solar panels can pull enough water vapor from the air to water seeds to harvest in a matter of weeks.
The World Health Organization estimates at least two billion people worldwide lack safe drinking water, while 800 million lack access to electricity and 700 million battle consistent famine.
“A fraction of the world’s population still doesn’t have access to clean water or green power, and many of them live in rural areas with arid or semi-arid climate,” said Peng Wang, a professor of environmental science and engineering at the King Abdullah University of Science and Technology in a statement. “Our design makes water out of air using clean energy that would’ve been wasted and is suitable for decentralized, small-scale farms in remote places like deserts and oceanic islands.”
The atmosphere holds an estimated 12.9 billion tons of fresh water, which California researchers projected could easily provide 5 liters of water per day each to the more than two billion people in need.
Most solar panels only absorb 20% of the sunlight they are exposed to, while the other 80% heats the structures. Wang’s team developed a unique hydrogel that absorbs vapor from the air and releases water when heated. Used on solar panels, the hydrogel can capture and use water to cool the solar panels and increase their energy output.
Collected water vapor can also be funneled into bottles for drinking or hydrating a crop of plants.
Researchers tested the idea with three sets of photovoltaic panels that were each roughly the size of a broadsheet of paper. The experiment ran from May to June last year. With the application of the hydrogel, researchers recorded nearly 10% increased electricity generation, producing 1,519 watt-hours of electricity, which is just about enough energy to power an incandescent lightbulb for 24 hours.
Using a condensation chamber to collect water vapor, researchers also grew a small crop of kangkong, also known as water spinach, from seed to 7-inch stalks. Researchers only ran the test for 16 days, at which point the plants began outgrowing their space.
Ninety-five percent of the seeds flourished on this solar panel water, while zero seedlings sprouted in the control garden.
Researchers call the contraption a “a self-sustained and solar-driven, integrated water-electricity-crop coproduction system,” or WEC2P for short.
The effectiveness of water collection depends on the amount of sunlight the solar panels are exposed to, as well as ambient temperature and wind speed.
The team plans to improve the hydrogel to pull even more water from the air.
“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,” Wang added. “I hope our design can be a decentralized power and water system to light homes and water crops.”
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