Technical and economic aspects of offshore wind energy development in Japan

In Japan, the cumulative capacity of onshore wind turbines has increased rapidly in recent years. Due to Japan's particular conditions such as mountainous island and high population in plains, the necessity for development of offshore wind turbine generation technology has been gradually recognized. Most of European offshore wind turbines are available in near-shore areas, however, most of sea bottoms around Japan get quite deep as apart from coast lines, which causes some technical and economical difficulty. Based on a feasibility study, we have such a prospect that introducing offshore wind technology into Japan is feasible along coastlines or shallow areas at the initial stage, but new technology such as floating stations or sailing plants shall be developed for vast deep sea areas.