Jul. 16, 2019
Sumitomo Corporation
Electric Power Development Co., Ltd

Commencement of Offshore Ground Investigation off the Coast of Saikai City, Nagasaki PrefectureExploring the Possibility of Developing an Offshore Wind Power Plant

Sumitomo Corporation (Head Office: Chiyoda-ku, Tokyo; Representative Director, President and Chief Executive Officer: Masayuki Hyodo) and Electric Power Development Co., Ltd. (J-POWER) (Head Office: Chuo-ku, Tokyo; President: Toshifumi Watanabe) have begun an offshore ground investigation around Hirashima and Enoshima islands off the coast of Saikai City, Nagasaki Prefecture, to explore the possibility of developing an offshore wind power plant. 


The Japanese government is currently in the process of determining areas to be designated as offshore wind power development promotion areas under a new law enacted this fiscal year*1, for which the government will invite applications and select a wind power plant operator. The waters off the coast of Sakai City are considered as one of the most promising candidate areas in Japan due to their favorable wind conditions and relatively shallow depth. With the understanding of local residents and other concerned parties, Sumitomo Corporation and J-POWER will conduct boring surveys, sonic prospecting, and other investigations to determine the soil structure in the area and acquire other data required for designing the wind power plant’s foundation structures.


Sumitomo Corporation is actively engaged in developing and running renewable energy projects worldwide, and now possesses 1.4 GW in generation capacity. Sumitomo Corporation embarked on the offshore wind power generation business in 2013 and ever since has built up its expertise in the development and operation of the plants by taking part in various projects in Belgium, the United Kingdom, and France. In Japan, because large-scale offshore wind power plants are expected to emerge under the new law, Sumitomo Corporation will pursue the possibility of getting involved in such projects by leveraging its expertise accumulated overseas. Sumitomo Corporation will continue to promote the development of offshore wind power and other renewable energy sources with the aim of contributing to the sustainable growth of communities in harmony with the global environment.


J-POWER possesses wind power generation facilities with a total output of approximately 450,000 kW, making the company the second largest wind power producer in Japan. The company established a Renewable Energy Headquarters in June 2018 to further expand its renewable energy business, including hydroelectric and geothermal power sources. J-POWER has been gaining expertise in offshore wind power generation through various major projects, such as its involvement in the construction and operation of an offshore wind power demonstration facility off the coast of Kitakyushu City, its execution of commercialization surveys in the port area of Kitakyushu, and its participation in a Triton Knoll offshore wind power project in the United Kingdom. Apart from the investigation currently being conducted with Sumitomo Corporation, J-POWER also has several other similar investigation plans to be implemented in general sea areas*2 where there is a high possibility of building offshore wind power farms. J-POWER will continue to promote the development of wind power farms that are friendly to the global environment by making use of its expertise and experience accumulated in and outside Japan.


*1 Law to promote offshore renewable power generation in Japan’s waters

*2 Japan’s territorial waters and inland waters, excluding fishing ports, port areas, etc.




Outline of the Investigation


Within common fishery right areas around Hirashima and Enoshima islands in Sakito-cho, Saikai City, Nagasaki Prefecture (excluding national and quasi-national parks)



○ Investigation items
・Seabed boring survey: A boring survey will be conducted using a self-elevating platform on the sea to investigate soil structure and geological characteristics.
・Sonic prospecting: Sonic waves emitted from a boat and reflected off the seabed will be obtained and measured to investigate the ground conditions within the investigation area.

○ Period
July and August 2019 (subject to change)



■Sumitomo Corporation’s  Material Issues

Sumitomo Corporation Group positions “Six Material Issues to Achieve Sustainable Growth with Society” as an important factor in developing business strategies and in the decision-making process for individual businesses. Going forward, we will pursue sustainable growth by resolving these issues through our business activities. This project especially contributes to “Achieving Harmony with the Global Environment” “the Development of Local Communities and Industries” and “Establishing a Foundation for Comfortable and Enriching Lifestyles”.



Corporate Communications Department, Sumitomo Corporation
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