Solar powered windows that generate electricity without spoiling the view? That’s the stuff of science fiction, right? Not anymore. Two groups of researchers — one in the US and another in Italy — have created functioning prototypes for solar powered windows that look clear but harvest electricity from the sunlight passing through them.
First, the Bellingham Herald reports that a team of 8 students at Western Washington University have won a $75.000 grant from the EPA to develop their “Smart Solar Window,” a unit that looks clear but turns ultraviolet light into electricity. That power can reduce a building’s heating and cooling costs up to 30 percent by automatically opening and closing windows to aid cooling and ventilation. The system can be operated remotely from a phone, computer or ventilation system.
The team — composed of graduate and undergraduate students from the departments of chemistry, engineering, design, and business and economics — has been working on the window for the past year. Student project leader James Kintzele says their window required the combined strengths of an interdisciplinary team.
“Western Washington University has such a hands-on approach in their undergraduate programs,” he says. “If I’d been in an electrical engineering program in a different college in junior year, I wouldn’t have had the foresight or capacity to do this.”
“We’re so excited about the solar window and confident about its future,” Kintzele says “It’s not a matter of if this technology is used, but a matter of when. There are certain obstacles for expansion right now, but I feel strongly this could be in buildings a year from now, given the proper funding and a motivated team.”
Second, researchers at the Center for Advanced Solar Photophysics of Los Alamos and the Department of Materials Science of the University of Milan-Bicocca in Italy have developed a non-toxic coating of quantum dots. The coating forms a luminescent solar concentrator that converts any window into a daytime power source. reports Physics.org.
“In these devices, a fraction of light transmitted through the window is absorbed by nanosized particles dispersed in a glass window, re-emitted at the infrared wavelength invisible to the human eye, and wave-guided to a solar cell at the edge of the window,” said Victor Klimov, lead researcher on the project at the Department of Energy’s Los Alamos National Laboratory. “Using this design, a nearly transparent window becomes an electrical generator, one that can power your room’s air conditioner on a hot day or a heater on a cold one.”
“Furthermore,” Klimov noted, “the quantum dots provide a uniform coverage of the solar spectrum, thus adding only a neutral tint to a window without introducing any distortion to perceived colors. In addition, their near-infrared emission is invisible to a human eye, but at the same time is ideally suited for most common solar cells based on silicon.”
Sergio Brovelli, the lead researcher on the Italian team, says “Quantum dot solar window technology now becomes a reality that can be transferred to the industry in the short to medium term, allowing us to convert not only rooftops, but the whole body of urban buildings, including windows, into solar energy generators. This is especially important in densely populated urban area where the rooftop surfaces are too small for collecting all the energy required for the building operations.”
Bovelli’s team calculates that replacing all 775,000 square feet of windows in a skyscraper like One World Trade Center in New York City with quantum dot units would generate enough electricity to power 350 apartments. “Add to these remarkable figures, the energy that would be saved by the reduced need for air conditioning thanks to the filtering effect….. and you have a potentially game-changing technology towards “net-zero” energy cities,” Brovelli said.
Both groups hope to bring their amazing windows to market within the next year. Combined with new high efficiency construction techniques, they could help make the buildings of the future even more environmentally friendly and self-sustaining.