The world famous Sears Tower, now Willis Tower, in Chicago is set to turn partially solar. A pilot project set to take place on the 56th floor of the Tower will feature photovoltaic glass from Pythagoras Solar. The insulating windows have a unique solar design. The PV cells lay 90 degrees from the glass's surface. Prisms in the glass reflect sunlight down into the horizontal PV cells, while diffused light still enters inside the building. This system makes the windows produce as much solar power as rooftop mounted panels.
If the project goes well, which I am sure it will, the solar windows will be expanded throughout the entire building. The equivalent solar surface of these windows, if applied to every window of the building, is approximately 10 acres, or about 8000 kW on sunny days.
Eavesdropper