Hydrogel coating slashes solar panel heat by 29°F, boosts power by 13%

Researchers at The Hong Kong Polytechnic University have developed an innovative, low-cost hydrogel coating designed to cool hot spots on solar panels, significantly enhancing their performance and reliability. Hot spots—localized areas of excessive heat caused by partial shading—are a major issue in photovoltaic (PV) systems, leading to power loss, module failure, and even fire hazards. The new hydrogel coating reduces hot spot temperatures by up to 29°F (16°C), resulting in a power output increase of up to 13% in both laboratory and system-level tests. Importantly, this cooling solution does not require modifications to existing solar panel circuitry, making it cost-effective and user-friendly, particularly suited for urban environments like Hong Kong and Singapore. The hydrogel is composed of natural polymer hydroxyethyl cellulose combined with leafy cotton thread, which addresses common problems in conventional hydrogels such as cracking and shrinkage, limiting volumetric shrinkage to 34% compared to 46% in traditional materials. By mitigating hot spot