The two biggest problems of desert agriculture relate to water scarcity and a lack of a solid electricity grid. A new hybrid photovoltaic systemcould help improve the situation.
We are talking about an experimental system, at the beginning of his study, which combines photovoltaic panels with an absorbent hydrogel. The project follows the directives of the scientists of the King Abdullah University of Science and Technology (KAUST) of Saudi Arabia: it is called the “integrated water-electricity-harvest co-production system (or WEC2P)”.
Its purpose is to harness the sun's energy to generate electricity and, at the same time, to harness the hydrogel to produce water. In short, the WEC2P aims to solve the problems of agriculture in the desert, through a more than innovative photovoltaic system.
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. (...) I hope our project can be a decentralized electricity and water system to illuminate homes and water cropsProf. Peng Wang, author of the study
How the photovoltaic WEC2P that brings water to the desert works
Let's find out now how this system really works and what its components are. Most of the information comes from an article in the magazine Cell Reports Physical Science, who talked about the study.
The WEC2P relies on a series of connected photovoltaic panels, positioned on top of a layer of hydrogel. Panel and gel form the lid of a metal box, with a small opening at the bottom. At night, the box stays open, allowing the hydrogel to absorb moisture from the air. During the day, however, the box remains closed and the photovoltaic panel produces electricity.
When sunlight hits the panel, the hydrogel underneath heats up. As a result, the absorbed water evaporates from the gel and condenses on the back of the panel. The liquid water thus obtained escapes from the panel and takes away the excess heat (so the photovoltaic panel cools down and works better).
Once out, it slides over the box and comes out of the spout, where it can be collected for irrigation or drinking water.
Currently, a first small-scale test was conducted in June in the Saudi Arabian desert. Setup spawned 1.519 WH of electricity and about 2 liters of water. The water obtained made it possible to irrigate 60 spinach seeds planted in a plastic box, 57 of which sprouted and grew successfully.
If large-scale experimentation proves successful, this system could completely revolutionize the world of desert agriculture. Lack of water and electricity may no longer be a problem, benefiting everyone.