Shimizu Begins Construction of Ishikari Bay New Port Offshore Windfarm

Nippon Steel Engineering Co., Ltd. (President: Yukito Ishiwa) and Shimizu Corporation (President: Kazuyuki Inoue) formed Joint Venture, began construction of offshore windfarm at Ishikari Bay New Port in the waters between Ishikari City and Otaru City in Hokkaido. The windfarm upon completion will be the largest in Japan. This project was ordered based on the client’s evaluation of the specification of the SEP vessel that Shimizu is building, which will be one of the largest in the world. The project execution with the SEP vessel will start in June 2023.

The Ishikari Bay New Port offshore windfarm will be constructed in an area of approximately 500 hectares located 1,600 meters offshore from the port. Consisting of 14 units of 8 MW wind turbines and a 15.5 km 66 kV submarine cable, and power-generating capacity will be 112 MW (with a connection capacity of 99 MW). The client is Green Power Ishikari LLC, a special-purpose company established by Green Power Investment Corporation and the contractor is a joint venture of Nippon Steel Engineering and Shimizu. The commercial operation is scheduled to begin in December 2023.

When completed, 8 MW wind turbines will be the largest offshore wind turbines in Japan, with the highest point of the blade being 190 meters high. The wind turbines consist of a 90-meter-tall tower (post), a nacelle (motor unit) installed at the top of the tower, and three 80-meter-long blades connected to the nacelle. All are huge components, but our SEP vessel can transport them with their full tower for efficient installation. With other SEP vessels, based on the capacity of the main crane and the loading capacity of the vessel, the tower might be divided into two parts and assembled at offshore. It is estimated that construction would take around four months due to the many trips reguired between the base port and the construction site. However, with our SEP vessel, the construction can be completed in two months.

Shortening the SEP vessel operation period reduces the construction period and costs, directly contributing to profitability of the power generation business. Moreover, as wind turbines and wind farms become bigger, the performance of the SEP vessel used for construction will have a significant impact on the construction period and costs. For this reason, offshore wind farm developers in Japan and overseas have high expectations for our SEP vessel. Outfitting work is in progress at Aioi Shipyard of Japan Marine United Corporation (Aioi City, Hyogo). This is the final process of shipbuilding, and we expect it to be completed in October according to schedule. She will go to Etajima City in Hiroshima where our engineers and crew will have training for SEP vessel operation. In March, it will be used for installation of three units of 3 MW wind turbines and foundations offshore of Nyuzen-machi, Toyama where Venti Japan Inc. is planning an offshore windfarm. Then she will head to Ishikari Bay where rigging work for the project will take place.

With Japanese government’s pledge to cut greenhouse gas emissions to net zero by 2050 and a looming energy crisis in Japan arising from the Russian invasion of Ukraine, demand for renewable energy is increasing steadily. Offshore wind power is the most promising source of renewable energy, and many construction plans are taking shape in Japan and overseas. By proposing construction plans using the SEP vessel we are building, Shimizu aim to expand contracts and become a major player in the construction of offshore windfarm.