Saudi Researchers harvest water near solar panels to improve efficiency

Researchers at the King Abdullah University of Science and Technology in Saudi Arabia have come up with a novel technology where a solar panel is fitted with an additional system which can harvest water without consuming power from the panels. In the three months long trials, the system used day and night temperature differences and cooled off the solar panels.

The researchers engaged in the project found that the add-on system in the solar panels actually increased the electricity generating capacity of the panels as they were kept comparatively cooler.

In the new system, the researchers employed a layer of hydrogel just below each solar panel closed in a metal box. The box is opened at night when temperature falls and the air passes through the box. The hydrogel absorbs the water vapour present in the air. It was found during the trial – from May to June 2021 – the system collected about 600 ML of water per square meter of solar panel each day.

The box is closed during the day and sun rays warms both the solar panels and the hydrogel which is just below the panel. The high humidity in the closed box allows the water to condense on the metal which can be taken out from the box. The University team claims that they are the first to create an ‘integrated system’ where water and electricity both can be generated.

The electricity generation was found to have increased by about two percent because the heat of the panels is transferred to the hydrogel and water harvesting metal box further cools the solar panels. In very high temperatures the power generating efficiency of panels is reduced.

The trial also reveals that if the water is not harvested and the metal box containing hydrogel is left open during the day, this increases the cooling effect on the solar panels. The natural result found was that the electricity generation capacity rose by upto 10%. Hence, the system is a flexible one that allows the owners to choose between water extraction and higher power generation.

The research team says that the developed technology requires no extra land and the team had used the water harvested from the panels to irrigate patches of plants.

Researchers also say that the system can be manufactured economically and they are looking forward to working with potential industrial partners to speed up this process. They say that a large-scale system can enable a virtuous cycle where food, water and electricity can be produced all at once.