Tokyo-based Nihon Telecommunication System Inc. [JP] is offering windowpanes with built-in photovoltaic cells, mainly aimed at the residential housing market.

According to the company, the electricity produced through the panes will be just enough to power a PC and recharge a cell phone. The electricity will be tapped via USB ports.

On sunny days, the new windowpanes are supposed to generate up to 70 watts of electricity per square meter of glass. The solar cells have a power generation efficiency of 7 to 8%. The glass (thickness: 10.5mm) will prevent up to 90% of sunlight coming into a room and therefore reduce air conditioning costs.

The invention comes at a high price, though. Nihon Telecommunication System charges $1,900 per square meter in average but still expects to sell 10,000 windowpanes annually.

Via Nikkei [registration required, paid subscription]