Research and application of an efficient hygroscopic hydrogel for cooling of photovoltaic panels

The global energy transition is urgent, and photovoltaic (PV) power generation, as an important method of utilizing solar energy, is playing an increasingly crucial role in the global energy transformation. However, the excessively high operating temperature of PV panels remains a pressing issue. High temperatures lead to an increase in the internal resistance of PV cells, thereby reducing their energy conversion efficiency and power generation performance. In this study, a highly efficient cooling PV module with moisture-absorbing properties was fabricated using a crosslinking-vacuum freeze-drying method, with agarose modification. The moisture-absorbing hydrogel absorbs and stores moisture from the atmosphere at night, and during the day, the excess heat from the PV panel is used to evaporate the moisture, providing cooling. Laboratory and outdoor experiments were conducted to validate this approach. At a solar irradiance of 1 kW/m 2 , the cooling effect of the PV panel can achieve a temperature reduction of approximately 9 ℃, with a 2.7 % increase in maximum power output compared to a standalone PV panel. Its low cost, significant cooling effect, and good outdoor applicability indicate that this hydrogel film-based cooling solution holds potential for practical applications.