Dual‐Function Hydrogel Synthesis for Passive Photovoltaic Cooling for Climate‐Resilient Solar Infrastructure

The efficiency of photovoltaic (PV) modules remains limited by unavoidable temperature rise under strong sunlight, particularly in hot, humid regions where solar deployment is expanding most rapidly. While hygroscopic hydrogels have recently been explored for passive PV cooling, most existing systems either lose moisture rapidly or show limited effectiveness under real outdoor conditions. In this work, we introduce a dual‐function polyacrylamide–lithium chloride (PAM–LiCl) hydrogel engineered with a perforated topology that enhances vapor exchange and promotes natural airflow through the material. This structure enables continuous daytime evaporative cooling and nighttime atmospheric moisture regeneration, allowing the hydrogel to operate in a sustained, self‐replenishing cycle. Through a combination of controlled indoor measurements, rooftop field tests, and coupled heat–mass‐transfer simulations, we show that the hydrogel reduces module temperature and improves power output without external energy input. Finally, we extend the analysis to year‐round climate datasets to quantify when such cooling yields the greatest benefit, demonstrating its strong applicability in high‐insolation environments. The study provides a practical, scalable pathway for climate‐adaptive passive PV cooling via a facile coating that can be readily retrofitted to large‐scale solar infrastructure.