18 November 2025, TOKYO – Tohoku Electric Power Co., Inc. and BW Ideol have obtained Approval in Principle (AiP) from the Nippon Kaiji Kyokai (ClassNK) for the design of a floating offshore wind turbine system. This system features a concrete barge-type floating substructure designed to accommodate a 15MW-class wind turbine.
Tohoku Electric Power and BW Ideol have been jointly conducting feasibility studies since May 2022 with the aim of commercializing a floating offshore wind power project in offshore Kuji City, Iwate Prefecture. This AiP acquisition is part of those efforts. The floating offshore wind turbine system covered by this AiP is specifically designed to meet the environmental conditions off Kuji City and is based on BW Ideol’s patented Damping Pool® technology. The floating substructure is made of concrete, which is expected to suit mass production, and a hybrid mooring system using synthetic fiber rope and steel catenary chains has been selected for the mooring system.
BW Ideol had already obtained Basic Design Certification from DNV in May 2025 for its standardized barge-type floating structure designed to accommodate 15MW-class wind turbines, which demonstrated high technical reliability based on international standards. The acquisition of this new AiP from ClassNK, a leading certification body in Japan, further confirms its suitability and reliability for both global and Japanese markets.
Moving forward, both companies will jointly advance a feasibility study off the coast of Kuji City, Iwate Prefecture, based on BW Ideol’s Damping Pool® technology. Through these efforts to commercialize floating offshore wind power generation, they will actively pursue the expansion of renewable energy adoption in Japan.