Enhancing photovoltaic power generation through hydrogel-based passive cooling: Theoretical model and global application potential

Hydrogel-based passive cooling emerges as a promising technology due to its high efficiency and low carbon footprint. It demonstrates the significant potential in decreasing the temperature of photovoltaic (PV) panels and boosting the power generation. However, the lack of a comprehensive theoretical model to clarify the cooling mechanisms has significantly blocked the applications of hydrogel-based PV cooling. In this work, a theoretical model integrating hydrogel structural characteristics with environmental impacts is presented, guiding the hydrogel design and assessing their global potential in PV applications. The results indicate that hydrogel PV cooling presents the encouraging prospects in low and mid-latitudes with a payback period of <5 years, but it exhibits the limited benefits in high-latitudes. Specifically, in low-latitudes such as Singapore, the application of hydrogel cooling leads to an annual average temperature drop of 10.2 °C, enhancing power generation by 6.28%. However, due to the low temperatures and limited solar radiation intensity in high-latitude regions, the power generation improvements are usually <3%, and the payback period extends to >45 years. The deployment of hydrogel PV cooling in high-latitudes should be evaluated carefully due to suboptimal cooling effects and the risk of freezing. Overall, this research establishes a theoretical foundation for the applications of hydrogel PV cooling and paves the way for its global deployment.