Japanese Firm Seeks to Build Floating Offshore Wind Farm

Japanese solar power company Shizen Energy has signed an agreement with French offshore wind developer Ideol to collaborate on a full-size floating wind farm off the coast of Japan. 

At a signing ceremony in Tokyo Thursday, the two firms agreed to explore a floating wind farm in Kyushu, and could expand their efforts to other areas in the future. Bruno Le Maire, the French Minister of Economy, attended the event.

Shizen has historically focused on solar energy, and it has helped develop about 800 megawatts of renewable power across Japan. It is now expanding its portfolio into other areas, including wind and hydro. “Working on floating wind projects in Japan means to expand the country’s potential of renewable energy significantly, as the country is surrounded by sea areas with deep water and complex geographies," said Shizen founder Masaya Hasegawa. "This is [an] especially valuable challenge for Shizen Energy, [as we] aim to co-create 100% renewable-powered world."

Floating offshore wind is a new frontier, and it builds upon technologies developed for deepwater oil and gas development. To date, all large commercial offshore wind farms have been built using fixed jackets or pylons, which limits installation to relatively shallow water. Many areas with high potential for wind power - like regions off the U.S. West Coast - have water too deep for conventional offshore wind.

Marseilles-based Ideol has built two full-scale demonstrator projects for its offshore wind technology, one off the coast of France and another off Japan, and it has a pre-commercial scale wind farm in development in the Mediterranean. Its design places the turbine tower atop a donut-shaped floating barge with an open "damping pool" at the center, which is designed to reduce the impact of storm conditions. All construction is done alongside the quay before the unit is towed out for anchoring and hookup - just like a floating oil and gas production platform. This saves the substantial costs associated with assembling turbine towers at sea. (Ideol is also working on a floating offshore substation design, in partnership with ABB and Chantiers de l'Atlantique.)

The first significant pre-commercial demonstrator for floating offshore wind, Equinor's Hywind project off Scotland, has had five turbines running since last year. On June 19, Danish trading house Danske Commodities said that it would buy Hywind's power production for the next two decades, validating the concept's commercial potential. Hywind survived 27-foot swells and severe North Sea wind conditions last winter, which may have contributed to its attractiveness.