Nature‐Inspired Sustainable Cooling for Photovoltaics with Enhanced Temperature‐Salinity Dynamics

Abstract High operating temperatures reduce the efficiency and lifespan of photovoltaic (PV) systems. Developing efficient cooling strategies, such as sorption‐based cooling using atmospheric moisture for evaporation, is essential, although it faces challenges like limited capacity and quick performance decline. Here, a sustainable and passive cooling scheme for PV systems is developed, inspired by the natural meridional overturning circulation (MOC) observed in ocean currents. This approach features a membrane‐encapsulated hygroscopic solution layer that passively triggers an MOC‐like process. Utilizing solar heating, radiative cooling, and the thermochemical effects of moisture absorption and desorption, it establishes a temperature‐salinity gradient that enhances the desorption and absorption kinetics. Through comprehensive multiphysics simulations and empirical testing under standard 1‐sun illumination, the prototype achieves a record‐high temperature reduction of 18.2 °C with a magnitude low degradation rate of 0.5 °C h ⁻¹ , significantly outperforming existing methods. Additionally, the enhanced absorption enables the hygroscopic solution layer to regenerate ultra‐fastly at 102.5 g/(m ² ·h). In a long‐term field test, PV‐MOC can provide sustained cooling that helps PV‐MOC generate much higher electrical output than PV alone, especially in sunny weather. The work will set a new benchmark in PV cooling, pioneering the use of nature‐inspired technologies in enhancing photovoltaic performance.