ABSTRACT
Research and development (R&D) on photovoltaics (PV) and governmental support for deploying PV systems are active on a global scale. So far, PV systems are only complementary power sources for existing large scale centralized power plants due to the unstable output and expensive generation cost of PV systems. PV should become a main energy source over the long range, considering the future cost reduction in PV modules from further R&D and market growth, as well as global energy and environmental issues. At the same time, future increase in consumption due to economic growth is expected in emerging countries, especially in Asia.
