Sony Corp prototyped lanterns using dye-sensitized solar cells and exhibited them at Eco-Products 2008, which is taking place at Tokyo Big Sight, Japan.
The company crafted dye-sensitized solar cells into the pattern on the lamp's lateral shade panels so that the lamp can generate power by itself. The generated power charges the secondary battery module located at the bottom of the lamp. When the miniature bulb is turned on, the flower pattern depicted by the colors of dye-sensitized solar cells is projected on the panels.
The prototyped lanterns can light the miniature bulb for one minute after charging for 15 minutes indoors. The dye-sensitized solar cells used in those lamps have a module conversion efficiency of about 4%. Of the lanterns exhibited in four different colors, the tortoise-shell colored prototype has the highest conversion efficiency, Sony said.
Sony prototyped the lamps as concept models with no plans for commercialization. The company is currently exploring the possibilities of dye-sensitized solar cells. To achieve commercial application, it is continuing the research, taking into consideration the market scale and applications that can make the most of dye-sensitized solar cells' properties. Sony said it is considering the use in the room, mobile devices and roofs on the north side as potential applications.
Sony has already achieved a cell conversion efficiency of slightly more than 10% and a module conversion efficiency of 8.2% using its dye-sensitized solar cells though they were not exhibited this time. The module conversion efficiency was set by a module with an aperture area of 18.5cm2 at the National Institute of Advanced Industrial Science and Technology (AIST) in June 2008. Its maximum output was 151.4mW.
Sony is further improving the module, targeting a module conversion efficiency of 10%.