We are at the beginning of stage which we make. As you know there are many world problems such as energy problem, food crisis, reduction of biodiversity and forest, and so on. It depends on your choice; save world or not. In this stage, we focused on energy problem and global worming. World energy demand has been rapidly expanding due to the world economic growth and population increase, especially in developing countries. According to an IEA report, total CO2 emissions and total primary energy supply in 2030 in the world will be twice as much as in 2000. If world energy demands continue to increase, the primary energy may dry up in this century. In addition, too much energy consumption causes a variety of serious environmental problems such as global warming, acid rain and so on. But, renewable energies are expected to resolve both the energy problem and the environmental problems. Photovoltaic power generation system (PV system) is one of promising renewables. Because the PV system need no fuel, no emission and very low maintenance at the operation stage. However, the solar energy has a disadvantage, that is, its low energy density by nature. Therefore, to generate large power such as nuclear power plant, the PV system must be introduced at very large-scale.

We are member of IEA PVPS Task VIII, and Prof. Kurokawa had been O.A this task from 1999 to 2003.