A research team led by Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) has developed a hydrogel passive cooling composite that it claims boosts solar cell power output by 12.9% and extends their lifespan by more than 200%. 

Led by KAUST Professor Qiaoqiang Gan and including researchers from the King Abdulaziz City for Science and Technology (KACST), the research team developed a sodium polyacrylate (PAAS)-LiCl composite material that can absorb air moisture at night and release it during the day. Its solid structure adheres directly to the rear side of the solar panel without the need for ‘external glues’, reads the research.  

Solar cells made with this material demonstrated higher power output and longer operational lifetimes when deployed in the Saudi desert compared to those without it. As per the research findings, 20-day outdoor experiments confirmed the durability of the cooling layer under real-world conditions. 

In ambient temperatures of 38°C, the layer achieved a peak temperature reduction of 14.1°C, boosting the PV panel’s maximum power output by 12.9%. During a typical 10-hour daily cooling cycle, the layer delivered an average evaporative cooling power of 175 W/m², lowering the panel temperature by an average of 9.4°C and increasing its average power output by 10.2%.

Moreover, the team also carried out similar experiments in some of the coolest parts of the mainland US under rainfall to prove that the passive cooling technology works in any environment. 

“We tested the new cooling technology on top performing solar cells in multiple environments and saw excellent results in every case," said KAUST Professor Stefaan De Wolf.

The materials are thin and offer a low-cost solution to cooling challenges in solar energy projects, stressed the team. The complete research work, titled Streamlined fabrication of an inexpensive hygroscopic composite for low maintenance evaporative cooling of solar panels, was published in the Materials Science and Engineering: R.