Radiative cooling for high-efficiency solar energy utilization technologies: mechanisms, methods, and applications

Solar energy utilization technology, which converts solar radiation into electrical or thermal energy via the photovoltaic effect and the photothermal effect, opens up an innovative path to meet the growing global energy demand. However, as the heat flux density on the device continues to increase, its operating temperature rises sharply, which imposes significant harm on both energy conversion efficiency and durability. As a cooling technology that does not require additional energy input, radiative cooling dissipates heat into outer space (~ 3 K) through the atmospheric window, providing a key solution to the above challenges. In this work, we systematically review the combination of radiative cooling and solar energy utilization technologies (photoelectric, photovoltaic/thermal, and photothermal systems) and demonstrate that radiative cooling technology can effectively reduce device temperature and improve system efficiency. We also explain the enormous application value of radiative cooling in building energy conservation, plant heat stress mitigation, personal thermal management, and spacecraft thermal protection. Finally, we summarize the key challenges facing radiative cooling in solar energy utilization and propose corresponding prospects for future development. We believe that the combination of radiative cooling with solar energy technologies extends beyond enhancing device performance to play a vital role in promoting sustainable energy development.