Tandem daytime radiative cooling and solar power generation

The daytime radiative cooling technique effectively dissipates heat by emitting thermal radiation while reflecting a majority of sunlight. However, its compatibility with solar cells for efficient energy conversion has posed challenges due to the need to reflect sunlight. Herein, we have successfully developed a transmission-type daytime radiation cooling system and designed a tandem structure that integrates daytime radiative cooling with solar cells. This device achieved up to 40 W/m2 cooling power density and up to 103.33 W/m2 photovoltaic power density in sunny weather conditions (with a solar cell power conversion efficiency of 11.42% and a bare solar cell efficiency of 12.92%). Simulation results demonstrate that increasing the heat transfer efficiency of cooling and reducing the absorptivity in the sunlight band of the emitter can further enhance device performance. This outcome presents a novel approach toward enhancing the practical implementation of tandem daytime radiative cooling and solar power generation.