Funtional Windows and Energy

     Windows play more of a part in energy use than initially perceived. They are ways in which heat is lost and gained. We may be familiar with energy efficient windows, but now there are even more possibilities with windows. There are windows that function as windows and more.

     We are used to windows that only open one way, but new innovations in building materials have created windows that can be opened multiple ways. The windows can open like a book, slide like a glass door, or only open one part. This helps with air circulation for different times of year.

     New developments have also made windows that can help power homes. They act as solar collectors. It has more of an aesthetic appeal than a roof that is covered in solar panels. Researchers at MIT found ways to make solar panels transparent and flat so that they can be put in a window frame. Solar concentrators in use today "track the sun to generate high optical intensities, often by using large mobile mirrors that are expensive to deploy and maintain," Baldo and colleagues wrote in Science magazine. Further, "solar cells at the focal point of the mirrors must be cooled, and the entire assembly wastes space around the perimeter to avoid shadowing neighboring concentrators."

     The window’s solar concentrator involves a mixture of two or more dyes that is basicially painted onto a pane of glass or plastic. The dyes work together to absorb light across a range of wavelengths, which is then re-emitted at a different wavelength and transported across the pane to waiting solar cells at the edges so that the enegy can be used for powering home devices.

     The engineers, who are experts in optical techniques developed for lasers and organic LED lights, had the idea that perhaps those same innovations could be applied to solar concentrators. It resulted in a mixture of dyes in specific ratios, which were applied only to the surface of the glass. This allows some control over light absorption and emission. The team is starting a company, Covalent Solar, to develop and commercialize the new technology. They have already won several entrepreneurship contests. We can look forward to benefitting from more of their eco-friendly discoveries.