[July 29, 2011] Solar windows that cut heat, generate power [New Straits Time (Malaysia)] Tweet (New Straits Time (Malaysia) Via Acquire Media NewsEdge) PYTHAGORAS Solar of the United States is fitting the south- facing windows at the 56th floor of Willis Tower in Chicago (previously Sears Tower) with its transparent solar powered windows, called photovoltaic glass units (PGUs), as part of a pilot project to save energy by reducing heat gain and to generate power from the sun. According to the social.thinfilmtoday.com website, if the pilot project is successful, PGUs will be fitted beyond Willis Tower's 56th floor to cover enough surface area to provide over two megawatts of solar power. The 1,451ft building has more than sufficient space for solar panels to fit a 10-acre solar power plant. How do PGUs work? Pythagoras Solar, a Californiabased provider of transparent energy-efficient windows which also generate solar power, explained that PGUs are rectangular box-shape units that allow diffused light to pass through them. They use a prism to reflect sunlight down onto a horizontal photovoltaic (PV) cell along the bottom of the unit to generate the same amount of energy as standard rooftop-mounted solar cells. The company said it can address the need for "simultaneous benefits of energy efficiency and high power density while also offering architectural design benefits to increase real estate value and advance Net Zero Energy Buildings". However, integrating solar power into glass modules and window structures is not new per se, but using thin film technology on the entire surface area of a building's windows to generate electricity is. In 2005, XSunX was already developing solar powered windows and in 2008, Rainbow Solar announced it was launching the world's first transparent photovoltaic glass window able to generate 80 to 250 watts of electrical power while saving up to 50 per cent on heating and cooling needs. Also, Rainbow Solar's enclosed super tempered glass window system was said at that time to be capable of producing windows with options such as fire and bullet proofing. Meanwhile, if a new development at the Massachusetts Institute of Technology (MIT) is successful, the entire surface area of a building's windows can be used to generate electricity without interfering with the ability to see through them, a concept many homeowners would welcome. MIT's key technology, a PV cell based on organic molecules, harnesses the energy of infrared light while allowing light to pass through. Coated onto a pane of standard window glass, it can provide power for lights and other devices. In Malaysia, buildings such as G Tower and the soon-to-be- completed Menara Binjai in Jalan Tun Razak, both in Kuala Lumpur, have windows with lowemittance (low-E) coatings which are microscopically thin metal or metallic oxide layers deposited on the glazing surface to suppress radiative heat flow. (c) 2011 ProQuest Information and Learning Company; All Rights Reserved. [ Back To TMCnet.com's Homepage ]