A Vietnamese research team has developed a low-cost passive cooling system for PV modules using hydrogel-coated paper that combines water flow and interfacial evaporation to reduce operating temperatures. Outdoor tests showed temperature reductions of up to 14 C and efficiency gains of up to 16.8%, with stable operation achieved using both freshwater and natural seawater. The system was tested under real outdoor conditions and showed strong performance, with the hydrogel-coated paper maintaining effective cooling even with natural seawater. The novel passive cooling technique enables convective heat transfer through flowing water and dissipation of latent heat via interfacial evaporation, leading to significant efficiency gains for PV panels. The study involved researchers from various universities in Vietnam and aims to scale up the system for real-world use, focusing on optimizing materials for different climates, enhancing corrosion protection, and integrating energy generation with water treatment.
https://www.pv-magazine.com/2026/04/28/cooling-pv-modules-with-hydrogel-coated-paper/