RWE and Sumitomo target offshore wind off Akita

Interest is growing in offshore wind off the coast of Akita prefecture in the north-west of Japan’s main island, with groups led by RWE and Sumitomo recently announcing they are working to secure development rights for two fixed-bottom foundation sites.

The 7MW Fukushima floating offshore wind demonstration - one of Japan's operational offshore wind farms (pic credit: Hitachi)

Tokyo-based investment group Sumitomo Corporation is leading a consortium of construction firms, renewable energy developers and oil and gas companies to build offshore wind farms off Japan, including a 480MW project off Noshiro.

Meanwhile, German developer RWE’s Japanese arm has teamed up with Kyushu-based utility and renewables developer Kyuden Mirai Energy Company to carry out a feasibility study into a site off Yurihonjo.

Japanese government ministries have identified the two sites off Akita as among those closest to being ready for offshore wind tenders to be launched.

The RWE-Kyuden Mirai partnership is aiming to develop a site off Yurihonjo, while the Sumitomo-led group is targeting a different site off Noshiro.

Obayashi Corporation also plans to develop a 455MW project off Akita.

Noshiro project

The Sumitomo consortium is completed by Akita oil and gas companies Inpex Corporation and the Japan Petroleum Exploration Company, Tepco Renewable Power — the clean energy arm of the Tokyo utility — construction firms Kato and Narita, engineers Venti Japan, and renewables developer JR-East Energy Development Company.

It aims to build a 480MW offshore wind farm near the cities of Noshiro, Mitane and Oga in Akita.

Sumitomo has been carrying out environmental impact assessments, seabed surveys, wind condition studies and other research since 2018, according to the company. 

It claimed the site experiences yearly average wind speeds of 7m/s or more and has waters no deeper than 30 metres — making fixed-bottom foundation turbines possible.

“The sea area offers a very suitable natural environment, with its favourable wind conditions and relatively shallow waters, so it appears likely to be designated a promotion area,” Sumitomo stated.

Yurihonjo site

Meanwhile, RWE Renewables Japan and Kyuden Mirai are also studying opportunities for fixed-bottom offshore wind off the coast of Japan.

They plan to jointly carry out a full-scale feasibility study for a project off the city of Yurihonjo and enter the wind farm in a potential tender.

The partners are preparing an environmental impact assessment ahead of entering a tender organised by the government

Kyuden Mirai had signed a cooperation agreement with E.on in April 2019, pledging to target Japanese offshore wind, including a site off the country's southernmost island, Kyushu. RWE acquired E.on’s renewables business last year.

Japan has just 65MW of offshore wind capacity currently installed, according to Windpower Intelligence, the research and data division of Windpower Monthly.

Last year, the government and the Port Authority of Japan identified 11 sites with the potential for offshore wind development, with four being more advanced than the others.

The economy ministry is currently preparing the regulatory details for auctions, according to the Japanese Wind Power Association.