A team from the Institute of Micro and Nanotechnology at Spain’s Spanish National Research Council (CSIC) has developed a material that can cool surfaces without consuming electricity. The work, led by the FINDER group and published in the journal Nanophotonics, is part of the COOLed project, coordinated by researcher Cristina Vicente.
The material uses passive radiative cooling: it reflects on average 82.4% of solar radiation and emits 96.7% of its heat in an infrared band that allows it to escape into space. It is made of a polymer known as PVDF, set into nanoporous aluminium oxide moulds, and it resists ultraviolet rays and repels water, giving it a self-cleaning effect.
In tests on a rooftop in Tres Cantos, Madrid, the treated surface stayed up to 12.9 °C cooler than an uncoated sample on the hottest, sunniest days. It could be used on façades, roofs, electronic devices, vehicles and personal cooling systems.
At a time when cooling accounts for almost 20% of the world’s electricity consumption, the researchers stress that the technology is still in development, but that it is relatively cheap to make and compatible with existing industrial processes.
