ABSTRACT
The current state of the art in solar photovoltaic (PV) technology is overviewed, with a brief discussion of the relationship between the industrial revolution and forms of energy resources. Evolutions in energy resources from coal (solid) to oil (liquid), and to LNG (gas) in the past two centuries are examined in view of economy and environmental issues, with electric energy as a final form of the energy in the 21st century. Also discussed is the 3E Trilemma which is the most important issue for the 21st century. Secondly, a new strategy and action plan in Japan is introduced for renewable energy promotion aimed for the year 2010. Thirdly, recent research and development efforts for the improvement of solar cell efficiency are reviewed together with their device physics and recent achievements with innovative technologies introducing new cell structure and materials. Then transitions of the annual worldwide solar cell module productions are reported. Progress of the conversion efficiency in various types of solar cells is also summarized. In the final part of paper, the technological roadmap of PV up to 2030, and its future prospects are demonstrated. Possible new roles to contribute to the global environmental issues with PV system utilizations are proposed and discussed.
