Words by Smiley Team
While human-driven desertification makes it increasingly difficult to grow crops, scientists in Saudi Arabia have come up with an exciting solution. A new system they have designed runs on solar power, drawing water from the air to help cultivate spinach, all the while producing green electricity.
The system, named WEC2P, uses a solar photovoltaic panel on top of a layer of hydrogel, a highly absorbent but insoluble substance. The hydrogel pulls in water vapour which is released when heated by waste solar power and condenses in a large metal container below.
Peng works as a professor of environmental science and engineering at the King Abdullah University of Science and Technology. He explained: "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 an arid or semi-arid climate."
The system is run on clean energy that would otherwise go to waste and could offer vital support for decentralised, small-scale farmers living in remote areas such as deserts and oceanic islands, according to Peng.
Senior author of the research Peng Wang and a team of scientists designed the hydrogel as part of their previous research. The material offers the additional benefit of increasing the solar panels’ efficiency by up to 9% as it absorbs heat and lowers the panels’ temperature.
[Read more about initiatives to introduce clean and affordable energy to communities]
Already they have seen the potential of the system. In June, one of Saudi Arabia’s hottest periods of the year, the researchers investigated how the system would perform.
Planting 60 water spinach seeds in a plastic container, they watched in excitement as 57 of the seeds sprouted and grew to an average of 18 centimetres over the course of two weeks.
For the experiment they used a solar panel which was the size of a small desk, generating 1,519 watt-hours of electricity - enough energy to power a 50″ LED television for 100 hours. About two litres of water gathered in the container below.
"Our goal is to create an integrated system of clean energy, water, and food production,” said Peng, “especially the water-creation part in our design, which sets us apart from current agrophotovoltaics."
He added that he conducted the research with an awareness of the 6th and 7th Sustainable Development Goals set out by the UN: affordable and clean energy, and clean water and sanitation.
But the research isn’t quite complete as the scientists must increase the hydrogel's capacity to absorb more water in order for it to be rolled out at an industrial scale.
“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,” Peng explained.
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