Radiative Cooling for Energy Sustainability: From Fundamentals to Fabrication Methods Toward Commercialization

Abstract

Radiative cooling, a technology that lowers the temperature of terrestrial objects by dissipating heat into outer space, presents a promising ecologically‐benign solution for sustainable cooling. Recent years witness substantial progress in radiative cooling technologies, bringing them closer to commercialization. This comprehensive review provides a structured overview of radiative cooling technologies, encompassing essential principles, fabrication techniques, and practical applications, with the goal of guiding researchers toward successful commercialization. The review begins by introducing the fundamentals of radiative cooling and the associated design strategies to achieve it. Then, various fabrication methods utilized for the realization of radiative cooling devices are thoroughly discussed. This discussion includes detailed assessments of scalability, fabrication costs, and performance considerations, encompassing both structural designs and fabrication techniques. Building upon these insights, potential fabrication approaches suitable for practical applications and commercialization are proposed. Further, the recent efforts made toward the practical applications of radiative cooling technology, including its visual appearance, switching capability, and compatibility are examined. By encompassing a broad range of topics, from fundamental principles to fabrication and applications, this review aims to bridge the gap between theoretical research and real‐world implementation, fostering the advancement and widespread adoption of radiative cooling technology.

Durable and Scalable Superhydrophobic Colored Composite Coating for Subambient Daytime Radiative Cooling

“…The energy consumption required for cooling increased continually with the growing global warming, which has further exacerbated the greenhouse effect and environmental issues. − An environmentally friendly cooling technique known as passive daytime radiative cooling − could cool objects by reflecting sunlight in the solar spectrum (0.3–2.5 μm) and by simultaneously radiating excessive heat by the atmospheric transparency window (8–13 μm) to the cold outer space spontaneously. , Numerous radiative cooling materials with exceptional solar reflectance and infrared emissivity − have been demonstrated, which show potential cooling applications in architecture, − personal thermal management, − photovoltaic modules, , water harvesting, , etc. However, the requirement for high reflectance of radiative cooling results in materials that are primarily white in color, which restricts the possibilities for practical applications.…”

Self-sustained and Insulated Radiative/Evaporative Cooler for Daytime Subambient Passive Cooling

“…As the global population continues to expand and living standards improve, the demand for cooling is on the rise. Active cooling technologies currently consume approximately 15% of the world’s electricity annually and contribute to around 10% of greenhouse gas emissions. − This places a significant burden on both global energy supplies and environmental preservation efforts. In contrast, passive cooling technologies, exemplified by radiative cooling (RC), and water-based evaporative cooling (EC), are recognized for their environmentally friendly nature, as they require minimal consumption of fossil fuels or electricity during operation.…”

Highly Optically Selective and Thermally Insulating Porous Calcium Silicate Composite SiO2 Aerogel Coating for Daytime Radiative Cooling

“…8 Therefore, investigating novel facade coatings possessing exceptional thermal insulation properties alongside sky radiative cooling capabilities holds immense practical significance in curbing daytime summer energy consumption within buildings. 9,10 In the past decade, passive daytime radiative cooling (PDRC) materials have developed rapidly because of their high atmospheric window emissivity and high solar reflectivity. 11−16 Early selective materials, using photonic structures with multilayer stacks or well-defined micromodes, could achieve near-perfect selective emission coolers.…”

“…Especially, during summer months when external walls receive intense solar radiation while ambient temperatures surpass indoor levels, heat typically infiltrates indoors necessitating air-conditioning for cooling purposes . Therefore, investigating novel facade coatings possessing exceptional thermal insulation properties alongside sky radiative cooling capabilities holds immense practical significance in curbing daytime summer energy consumption within buildings. , …”