Have a room that has sunlight streaming in, casting shadows across the floor? Well, Tokyo-based Nihon Telecommunication System Inc. thinks you should put that energy to work instead of just letting it lay there.
The company has developed window panes that not only generate power with an efficiency of 7 to 8%, it also cuts down on 90% of sunlight, making it easier to cool the room. On a good day, the built in photo voltaic (PV) cells in the window panes can generate up to 70 watts of electricity per square meter of glass. The company figures that this should be enough to charge a small PC or mobile device, and USB ports for charging are provided.
As with any kind of renewable power source there is a price, and Nihon has set an average price of $1,900 per square meter. But the demand is in place, and they expect expect to sell 10,000 window panes annually. I can definitely imagine the window panes being used in select areas of a building as a "green" PR effort, but at that price I am not sure it would be practical elsewhere.