Daytime Radiative Cooling: A Perspective toward Urban Heat Island Mitigation

Traditional coolingand heating systems in residentialbuildingsaccount for more than 15% of global electricity consumption and 10%of global emissions of greenhouse gases. Daytime radiative cooling(DRC) is an emerging passive cooling technology that has garneredsignificant interest in recent years due to its high cooling capability.It is expected to play a pivotal role in improving indoor and outdoorurban environments by mitigating surface and air temperatures whiledecreasing relevant energy demand. Yet, DRC is in its infancy, andthus several challenges need to be addressed to establish its efficientwide-scale application into the built environment. In this Perspective,we critically discuss the strategies and progress in materials developmentto achieve DRC and highlight the challenges and future paths to pavethe way for real-life applications. Advances in nanofabrication incombination with the establishment of uniform experimental protocols,both in the laboratory/field and through simulations, are expectedto drive economic increases in DRC.