Researchers at Eindhoven University of Technology have designed smart reflective windows that act as blinds in the summer and let all the sunlight through during the winter. Jim Drury reports.
These glass windows are bright for a good reason. They're smart reflective windows that act as blinds in the summer and let through sunlight during the winter.... Potentially cutting cooling and heating costs by up to 12 percent. SOUNDBITE (English) PROF. MICHAEL DEBIJE, EINDHOVEN UNIVERSITY OF TECHNOLOGY, SAYING: "This is a luminescent solar concentrator. It's a sheet of plastic that contains a very bright fluorescent dye molecule. The idea is to be able to use these devices to replace normal silicon solar panels in areas of the built environment. So it would simplify integration into buildings or as a sound barrier or as a bus stop." Thw windows contain liquid crystals similar to those found in our smartphones. The crystals selectively reflect infrared light of different wavelengths. When an electrical charge is applied, they re-align to reflect the sunlight. SOUNDBITE (English) JEROEN SOL, MASTERS STUDENT AT EINDHOVEN UNIVERSITY OF TECHNOLOGY, SAYING: "And if they all lie flat the fluorescent dye molecules will absorb sunlight and redirect it to the edges of your glass. And if you have solar panels on the edge of the glass you can use it to generate electricity. And if you turn on the power the fluorescent dye molecules will stand upright, like liquid crystals, and that will leave the sunlight to go through unharmed." The Eindhoven University of Technology team created a reflective coating that can be retrofitted to existing windows. It could be used on buildings, bus stops, cars, and greenhouses. Greenhouses fitted with the glass saw strawberry yields rise by 11 percent in trials. The team is working with commercial partners to bring the technology to market.