Can radiative cooling coating truly achieve efficient cooling and long-term self-maintenance without electricity?
Publish Time: 2025-12-19
Against the backdrop of the global energy transition and the accelerated pursuit of "dual-carbon" goals, how to reduce the temperature of outdoor equipment with zero energy consumption has become a critical technological bottleneck that industries such as photovoltaics, energy storage, and chemicals urgently need to overcome. Traditional active cooling solutions relying on fans, air conditioners, or water cooling are not only energy-intensive and complex to maintain, but also difficult to implement in remote or grid-free areas. At this juncture, a new type of electricity-free energy-saving technology called radiative cooling coating has emerged—it requires no electricity and relies solely on the material's own optical properties to dissipate heat into outer space in the form of infrared radiation, achieving "passive cooling."The core principle of radiative cooling lies in cleverly utilizing the "transparent window" of the Earth's atmosphere for specific infrared wavelengths (8–13 μm). The JHF series coatings are designed based on this physical mechanism: its functional topcoat, JHF-201, possesses the dual characteristics of high solar reflectivity and high thermal infrared emissivity. During the day, it reflects most sunlight (especially visible and near-infrared light), preventing surface heat absorption. Simultaneously, regardless of day or night, the object's own heat continuously radiates outwards in the mid-infrared band, penetrating the atmosphere and dissipating into the near-absolute-zero depths of space. This synergistic effect of "reflection + radiation" allows the coated surface temperature to be significantly lower than the ambient temperature, especially under clear night skies.However, the real test lies in its reliability during long-term outdoor service. Dust, oil, bird droppings, or industrial contaminants, once covering the coating surface, significantly weaken its reflection and radiation capabilities, leading to performance degradation. To address this, the JHF-201 topcoat incorporates biomimetic self-cleaning technology—by controlling the surface microstructure and low surface energy chemical composition, the coating possesses hydrophobic and oleophobic properties similar to lotus leaves. Rainwater easily carries away adhering particles, creating an "automatic washing" effect; even in areas with little rain, wind can assist in removing floating dust. This design, which "maintains its function with the power of nature," greatly extends the effective cooling cycle and reduces manual cleaning costs.Furthermore, a systematic approach is crucial to ensuring performance. The JHF-100 primer not only provides excellent adhesion and a corrosion barrier, but also effectively isolates the substrate's heat conduction, preventing internal heat from backheating the coating surface. This dual-layer structure works synergistically to ensure stable cooling performance on various substrates, from metal storage tanks to battery cabinet shells. Simultaneously, the coating itself uses a UV-resistant resin system, resisting chalking, cracking, or yellowing under long-term exposure, guaranteeing consistent performance for years.Expanded application scenarios further demonstrate its practical value. In photovoltaic power plants, the coating can reduce module backsheet temperature and improve power generation efficiency; on energy storage containers, it reduces air conditioning load and extends battery life; in the field of chemical storage tanks, it helps inhibit the volatilization or decomposition of contents due to high temperatures. These scenarios all point to a core advantage: improving system safety, efficiency, and lifespan without increasing energy consumption.Of course, its effectiveness is affected by weather, installation angle, and local climate, and it cannot completely replace active cooling. However, in the comprehensive thermal management strategy of "energy saving first, peak shaving and valley filling," it has become an indispensable part.In conclusion, radiative cooling coating is not just a conceptual gimmick, but a mature technology integrating optical physics, materials chemistry, and engineering applications. It accomplishes its most demanding task in the quietest way possible—without electricity, operation, or emissions. While the sun scorches the earth, that thin white coating silently transmits heat to the stars and the sea. Therefore, it not only achieves efficient cooling without electricity and self-maintenance, but also represents a sustainable wisdom of returning to nature and coexisting with the cooling principles of the universe.
