Towards practical applications of radiative cooling

Radiative cooling (RC) technologies channel excess heat into outer space or cooler environments, potentially mitigating high temperatures in the built environment. However, despite progress in research, the transition from laboratory breakthroughs to widespread practical deployment remains challenging. In this Review, we aim to bridge the gap between theoretical studies and practical implementations of RC technology. Developments in material science and system architectures have begun to facilitate the transformation of RC technology from laboratory innovations towards real-world applications. We analyse three representative applications with different operation temperatures: thermal management of buildings (sub-ambient temperature), personal thermal comfort (near-ambient temperature) and solar-cell cooling (above-ambient temperature). We also discuss the current challenges and opportunities encountered in advancing RC technology for commercial use, such as ensuring that the technologies are economically viable, can be produced on large enough scales to meet the demands of the desired application and can perform effectively in a range of environments and weather conditions. For the widespread uptake of RC technologies to occur, collaboration among researchers, engineers and industry stakeholders is needed to design sustainable and scalable manufacturing processes and to develop standardized protocols for evaluating the performance of RC materials. Radiative cooling is a passive cooling approach that could reduce reliance on air conditioning. This Review outlines the challenges, progress and opportunities for the application of radiative cooling technologies for the thermal control of buildings, people and solar cells.