Ready for Japan

Japan's New Energy and Industrial Technology Development selected Principle Power and its partners Renova and Mitsui Engineering and Shipbuilding for a single unit demonstration project 29 km offshore Akita Prefecture featuring a 5 MW Hitachi WTG.

Principle Power completed a FEED design that was granted an Approval in Principle by ClassNK (Nippon Kaiji Kyokai), proving that WindFloat® is ready for Japan's extreme conditions, including exposure to both typhoons and seismic events. 

First power


Project capacity

5 MW

Wind turbine

Hitachi 5.0-126

Wind turbine capacity

5 MW

Operational design life

20 years

Distance to shore

29 km

Water depth

70 m

Project sponsors

Renova, Mitsui Engineering and Shipbuilding





Huge potential of 140 GW of floating offshore wind in Japan

The tsunami generated by the Great East Japan Earthquake struck the Fukushima Daiichi Nuclear Power Plant on March 11, 2011, leading to the eventual shutdown of all Japan’s nuclear reactors. This led the nation to revitalize its decarbonization efforts, with renewables becoming a significant part of Japan’s energy mix. Since the disaster Japan has installed over 50 GW of solar capacity, enough to supply roughly 5% of the nation’s electricity demand, but shortage of available land hinders further development.

The way forward for Japan’s denuclearization and decarbonization goals lies at sea: according to the Japanese Wind Power Association (JWPA), there is over 140 GW of wind power potential to be harvested. Given that 90% of the country’s waters are deeper than 50 meters, and with shallow waters in high demand for port infrastructure and fishing, floating offshore wind technology, and WindFloat®, in particular, is key.

The WindFloat® is uniquely suited to address the challenges of the Japanese market

The NEDO research project was aimed at demonstrating the WindFloat at a site in Akita prefecture with typhoon and earthquake exposure. Principle Power completed a FEED design for the 5 MW Hitachi wind turbine and worked with partner Mitsui Engineering and Shipbuilding to achieve an Approval in Principle from ClassNK, indicating that the technology is ready for deployment in Japan. 

The WindFloat® presents several advantages over traditional fixed-bottom offshore wind that are especially relevant in Japan:

  • The WindFloat® is decoupled from the seabed, meaning that the system is virtually unaffected by seismic activity or tsunamis.
  • Both the wind turbines and the WindFloat® are designed to withstand typhoon conditions.
  • Finally, floating offshore wind allows for responsible siting of wind arrays, further off the coast and away from competing ocean uses, such as recreation, fishing, and shipping lanes, and in areas with stronger, more consistent winds ideal for environmentally sustainable power generation.

Strong government support for accelerating the expansion of the Japanese offshore wind industry

In April 2019, the Japanese government approved new legislation that enables Prefectures to lease the ocean surface for up to 30 years, providing a pathway for the development of floating offshore wind projects, and established a consultation body to facilitate coordination with local stakeholders. 

Prime Minister Yoshihide Suga has committed Japan to achieve carbon neutrality by 2050 and aims to build a “Green Society” by increasing the share of renewable energy power generation from 18% in 2018 to up to 60% in 2050. Offshore wind energy is at forefront of these efforts with official government targets of 10 GW by 2030 (average of over 1 GW per year spread over 3-4 sites) and up to 45 GW by 2040. The commercialization and expansion of floating wind technology, investment in the power grid and port infrastructure, and a competitive domestic supply chain are regarded as critical to realizing these goals.