Sharp Corp exhibited a stand-alone photovoltaic power system composed of a solar-cell module and a storage battery at African Fair 2008, which is now taking place in Yokohama.

Targeting the off-grid areas such as in Africa, the company aims to commercialize the system in 2010. In order to spread the use of the system, it is necessary to establish new business models such as leasing, unlike the current marketing style, which relies on sales of the product, the company said.

The product exhibited at the Show is a stand-alone photovoltaic power system composed of Sharp's thin-film Si solar cells connected to a Li-ion battery manufactured by Eliiy Power Co Ltd. The solar cell has a tandem structure, and the conversion efficiency after stabilization is 8.5%.

While the output of a crystalline Si solar cell is lowered by 0.5% when the temperature rises by 1°C, the reduction of output in a thin-film Si solar cell is only 0.25%/°C at the most. Thus, this photovoltaic power system using thin-film Si solar cells is suitable for installation in regions with high ambient temperatures.

The system comes in two types, one composed of a 90W solar-cell module combined with a 1,024Wh Li-ion battery and the other with a 360W module and a 4,096Wh battery. The two systems are utilized depending on home appliances used.

A fully-charged 1,024Wh Li-ion battery can power the lighting equipment (five hours a day), a radio (five hours a day) and a fan (two hours a day) for three days, according to the company. With a fully-charged 4,096Wh battery, it is possible to power the lighting equipment (four hours a day), a fan (two hours a day), a TV (two hours a day) and a refrigerator (24 hours a day) for three days.