Xinpeng Zhao

Xinpeng Zhao, 32, invented a glass-based coating that can cool the roof of a building by around 3.5 °C below ambient air temperature, which could reduce air-conditioning energy use by nearly 10% for a mid-rise building.

Today, air conditioning and other cooling systems emit around 7% of global greenhouse gases, a number that is projected to triple by mid-century. Passive cooling materials are an appealing alternative, because they cool themselves without using any energy.

While such cooling materials have been available for years, most are based on polymers and plastics and can’t withstand decades of exposure to the elements. Those materials lose up to 30% of their performance in just a few days on the roof of a building as they turn yellow, says Zhao, and, “after a few months they will totally lose their cooling efficiency.”

Zhao solved the durability problem by working with finely ground glass and aluminum oxide instead of plastics. His new coating can be sprayed or painted on buildings, vehicles, or roads. It’s composed of an aluminum oxide particle of around 500 nanometers, which is perfectly tuned to reflect up to 99% of the sun’s light to prevent heat absorption in the first place.

To take his innovation to market, Zhao founded a startup called Ceracool, and he is working to expand the range of coatings for different applications.