Enhancing year-round photovoltaic performance using the dual cooling and warming functions of hydrogels

Summary The efficiency and longevity of photovoltaics (PV) are sensitive to high operation temperatures, while their operational reliability can be compromised under winter conditions. Evaporative passive cooling can help control the temperature of PV by using hydrogels as water-rich materials. However, the lack of clear design principles and the uncertainty in ensuring the winter performance of PV in mid-to-high-latitude regions remain critical gaps. In this work, we establish the design principles for hydrogels with efficient and sustained evaporative cooling capabilities and demonstrate their application in enhancing PV performance across all seasons. The developed polyacrylamide (PAM) hydrogels can deliver a maximum temperature drop of ∼27°C and a peak cooling power of 612 W/m 2 for PV heat dissipation. The developed hydrogels can alleviate snow accumulation and accelerate snow melting of PV panels in winter via vapor adsorption.