Arup Supports Certification for Oga, Katagami, and Akita Offshore Wind Power Generation Project

Arup (Headquarters: London, UK / Tokyo Office: Chiyoda-ku, Tokyo), a global engineering and consulting firm, was selected as the Owner's Engineer by Oga, Katagami, Akita Offshore Green Energy LLC and supported the acquisition of certification for the offshore wind power generation project off the coast of Oga City, Katagami City, and Akita City in Akita Prefecture.

On June 30, 2026, Oga, Katagami, Akita Offshore Green Energy LLC, the project developer for the offshore wind power generation business off the coast of Oga City, Katagami City, and Akita City, obtained a Certificate of Conformity from Bureau Veritas Japan Ltd., a registered conformity assessment body in Japan. This certification confirms that the design of the offshore wind power generation equipment complies with Japanese technical standards and legal requirements, serving as a crucial milestone for the construction plan under the Electricity Business Act.

Project Structure and Technical Approach

Key stakeholders participating in the project include Kajima Corporation (Collaborating Companies: Kobori Research Complex Inc., COWI AS) responsible for the monopile foundation design, and Vestas Wind Systems A/S and MHI Vestas Offshore Wind A/S responsible for the wind turbine and tower design. This achievement was realized through the strong collaboration among stakeholders, systematically and meticulously executing a series of processes from understanding site conditions and reviewing design standards to analyzing overall loads and evaluating the design of supporting structures and wind turbines.

Arup, as the Owner's Engineer, contributed to the certification acquisition by undertaking technical verification and coordination among stakeholders.

Advanced Significance in Japan and Globally

This project holds advanced significance in Japan's offshore wind sector. Firstly, it is the first fixed-bottom offshore wind power generation project to obtain conformity confirmation among public tender projects in Japan's general sea areas. Furthermore, it is the first case in Japan to obtain conformity confirmation for large-scale offshore wind power generation equipment exceeding 10MW. Additionally, the design incorporates considerations for Japan's unique natural conditions, including earthquakes, making it the world's first design case for offshore wind power generation equipment in the 15MW class that accounts for seismic effects.

These achievements demonstrate the response to technical challenges in large-scale offshore wind power generation, particularly in earthquake-prone regions, and will significantly contribute to the development of Japan's offshore wind market.

Arup will continue to provide support in close collaboration with developers as the Japanese offshore wind market evolves.

▼ The English version of the article can be found below.

Arup supports certification for Oga, Katagami and Akita Offshore Wind Project

<Contact Information>

Arup Tokyo Office (Ove Arup & Partners Japan Ltd.)

Marketing & Communications: Komatsu

Email: Japan.MCBD@arup.com

Official Website:https://www.arup.com/

Tokyo Office X:https://x.com/ArupTokyo

Arup

About Arup Arup is an engineering and consulting firm that has been operating globally with a focus on architecture, urban planning, and infrastructure since its establishment in 1946. It has approximately 18,000 staff across 98 offices in 34 countries worldwide. With a diverse range of specialists including planners, designers, engineers, and consultants, Arup offers a wide array of services at each stage of a project, from planning to completion and even operation and maintenance, in addition to various technical design and related consulting services.

About Ove Arup & Partners Japan Ltd. Arup established its Japanese office in Tokyo in 1989. Since then, it has developed its business as one of the few foreign-affiliated engineering and consulting firms (registered Class 1 Architect Office) in Japan. Ove Arup & Partners Japan Ltd. is a wholly-owned subsidiary of its parent company, Arup Group Limited.