Researchers in the US are a step closer to commercialising smart windows that can selectively let in
light and heat. The researchers belong to the US National Renewable Energy Laboratory (NREL).
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and
Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
The concept includes a simple coating that creates a new “warm mode”, in which visible light can be blocked while nearinfrared light can enter. This new setting would be most useful on a sunny winter day, when an occupant would want infrared radiation to pass into a building for warmth, but the glare from sunlight to be reduced, the researchers said.
The same researchers in 2013 developed a smart glass that could switch between blocking light, heat or both using a small jolt of electricity. Now they have further refined the development with a new “cool mode” and “warm mode”.
According to the researchers the cool mode material was a major step towards commercialisation because it enabled the blocking of 90 per cent of nearinfrared light and 80 per cent of the visible light from the sun, and took only minutes to switch between modes, whereas in 2013 it required hours.The development of the “nanostructured architecture for electrochromic materials” could reduce energy costs associated with cooling buildings and homes in summer, the researchers said.
“This material could be ideal for application as a smart electrochromic window for buildings,” Cockrell School of Engineering chemical engineering professor Delia Milliron said.The researchers are now working on a lowcost manufacturing method.
In a separate paper published in the Journal of the American Chemical Society, Milliron and her team reported a proofofconcept demonstrating how they could achieve optical control properties in windows from a wellcrafted, singlecomponent film.
“These two advancements show that sophisticated dynamic control of sunlight is possible,” Professor Milliron said. “We believe our deliberately crafted nanocrystalbased materials could meet the performance and cost targets needed to progress toward commercialisation of smart windows.”
