Wed Sep 25 07:53:34 UTC 2024: ## Hong Kong Researchers Develop Eco-Friendly Coating to Cool Buildings and Save Energy
**Hong Kong, China** – Researchers at Hong Kong Polytechnic University (PolyU) have developed a revolutionary solar-driven adaptive radiative cooling (SARC) coating that can significantly reduce building temperatures, cut energy consumption, and mitigate the urban heat island effect. This innovative coating is a potential game-changer in the fight against climate change.
Buildings in Hong Kong account for a staggering 90% of electricity consumption and over 60% of carbon emissions. The new SARC coating, which can be applied to roofs and walls, offers a sustainable and energy-efficient solution to reduce this burden.
“Our novel SARC coating demonstrates exceptional cooling performance and is suitable for a wide range of climates,” stated Prof. Lu Lin Vivien, who led the research team. The coating works by converting solar energy into light energy, increasing solar reflectance and preventing buildings from absorbing excessive heat.
The SARC coating outperforms traditional radiative cooling materials by automatically adjusting cooling capacity based on solar irradiance. Unlike previous solutions that relied on rare earth metals and perovskite materials, the PolyU team has developed a non-toxic, metal-free, and environmentally friendly coating using polymer-based carbon dots.
“This water-soluble coating can be produced in various colors, allowing it to be easily applied to building roofs, walls, roadways, and urban surfaces, using paint rollers,” said Prof. Lu. “It achieves both cooling and aesthetic enhancements and offers a promising solution for sustainable urban development and mitigating the urban heat island effect.”
The SARC coating has already been successfully tested in a demonstration project with the Hong Kong government, where it was applied to the roofs of container houses. After two and a half years of continuous outdoor exposure, the coated roofs remained 24°C cooler than uncoated concrete roofs. The coating also demonstrated exceptional durability, with solar reflectance decreasing by less than 2% over the two-year period.
The team is currently developing a paraffin-based self-adaptive radiative cooling coating, which will provide both heating and cooling benefits depending on the weather conditions. They are also integrating the photoluminescent coating with bifacial solar photovoltaics (PV) to create a dual-functional system that enhances power generation while simultaneously cooling buildings.
The research team believes that this innovative SARC coating has the potential to significantly reduce energy consumption and carbon emissions in buildings, making a substantial contribution towards a more sustainable and climate-resilient future.
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