Multifunctional solar facades-a new challenge for photovoltaic

Glass has become a very attractive material for sophisticated design on large buildings such as office or public buildings, hotels, shopping malls or manufacturing buildings. To protect employees in those buildings from light, heat or noise the glass industry has developed a number of multifunctional glass systems for windows, facades and roofs. As a logical step, the glass industry had the idea of including photovoltaics into facade elements to generate electricity in addition to the above mentioned functions. FLACHGLAS SOLARTECHNIK GmbH, Germany, developed this new type of photovoltaic facade elements into a building owned by a city utility. In May 1991 the facade was inaugurated and this system received the tradename OPTISOL. In the specially designed production line for OPTISOL facade elements the solar cells are embedded with a special clear cast, UV-resistant resin between two glass panes. OPTISOL elements can be produced in sizes up to 2.1 m x 3.2 m. The light permeability can also be adjusted to the respective requests by arranging the solar cells in different ways. Depending on the application, the photovoltaic facade elements can be built as insulation glass design with high heat insulation, with noise protection or with security (break-up) protection