Researchers from KAUST, KACST, and the State University of New York at Buffalo have developed a passive cooling method to enhance PV performance in hot, humid climates. The method uses a 10mm sodium polyacrylate–LiCl composite layer applied to the rear of panels, which absorbs moisture overnight and enables evaporative cooling during the day. Lab tests showed a cooling power of 373W/m², while 20-day outdoor trials confirmed stable operation and effectiveness. Under 38°C ambient conditions, the layer reduced PV panel temperature by up to 14.1°C and increased peak output by 12.9%. Over a typical 10-hour cycle, it achieved an average 9.4°C cooling and 10.2% power gain. The system reduced the levelized cost of electricity by 18% and extended panel lifespan by over 200%, with scalable fabrication and minimal maintenance needs.