Researchers at King Abdullah University of Science and Technology (KAUST) have developed a solar panel coating that helps maintain performance in dusty conditions while capturing moisture from the air, offering a practical approach for solar systems operating in arid environments.

The coating was tested outdoors at KAUST for six months, during which treated panels showed only minimal performance loss, whereas uncoated panels exposed to the same conditions showed significant declines. At the same time, the surface captured moisture from the air at night, which was then successfully used for plant irrigation in a controlled demonstration.

Dust accumulation is a well-known challenge for solar energy systems, particularly in regions with high temperatures and limited rainfall. Cleaning panels often requires water and regular maintenance, both of which can increase operational costs. The KAUST team set out to address this by developing a surface that could clean itself using natural environmental conditions.

The result is a transparent, nanostructured coating made from a food-grade silicone material. It combines three properties in a single layer: it allows sunlight to pass through, repels water and dust, and cools slightly below the surrounding air at night. This cooling effect causes moisture in the air to condense into droplets, which then roll off the surface, removing accumulated dust in the process.

“This work focuses on a practical challenge for solar energy systems — how to maintain performance in environments where dust and heat are unavoidable,” said Qiaoqiang Gan, professor of material science and engineering at KAUST, who led the research. “By using naturally occurring temperature changes between day and night, we can enable passive cleaning without additional water or energy input.”

Alongside self-cleaning, the process also enables the surface to collect moisture from the air. In field tests, coated panels produced more than twice as much condensed water as uncoated surfaces under similar conditions. While modest in volume, this was sufficient to support small-scale irrigation in the study, suggesting potential use in localized agricultural settings.

The research also explored how this approach could be applied in agrivoltaic systems, where solar panels and agriculture are co-located. By maintaining cleaner panel surfaces and providing a supplementary source of water, the coating could support more efficient use of land and resources in environments where both energy and water management are closely linked.

The coating is produced through a simple thermal process and can be applied to standard glass surfaces, supporting its potential for scaling. The team is now working to further assess durability and performance over longer time periods and in different environmental conditions.

The research is published in Energy & Environmental Materials.