Floating offshore wind: platforms for growth

Above: WindFloat semi submersible platform with wind turbine being towed to site (WindFloat Atlantic demonstration project) (photo: Dock90)

The addition of Tokyo Gas further enhances Principle Power’s existing shareholder base, which includes EDP Group, Repsol, Aker Solutions and ASM Industries, and brings to bear the Japanese company’s expertise in development, engineering and operation of large energy and infrastructure projects around the world.

In addition, the accompanying co-operation agreement signed by Principle Power and Tokyo Gas establishes a strong foundation for creating commercial-scale deployment opportunities for Principle Power’s WindFloat® technology in Japan and “brings the necessary leadership to unlock the large floating offshore wind potential in Japan and to build an industrialised WindFloat supply chain.”

“With Tokyo Gas on-board we gain a trusted local partner, which is a key success factor in Japan. The investment by Tokyo Gas sets a strong foundation for our expansion in Asia, which is expected to lead global floating offshore wind development in the coming years,” said Principle Power CEO Joa~o Metelo. Closing the deal in the current business environment overshadowed by Covid-19 pandemic was also a significant achievement.

“Tokyo Gas has been diversifying into power generation over the last few years and building a portfolio of renewable energy projects around the world. We have a strategic interest in offshore wind in order to expand our domestic and international power business and to lead to achieve net-zero CO2 emissions. And we strongly believe that floating wind holds great promise for Japan,” said Tokyo Gas President Takashi Uchida.

According to Japan’s 5th Strategic Energy Policy, renewable energy is expected to comprise 22-24% of Japan’s total energy mix by 2030. The government anticipates that offshore wind will make a significant and important contribution to this target as conditions in Japan favour its development, including excellent offshore wind speeds, limited space for onshore development, and long coastlines. Furthermore, the Ministry of the Environment (MOE) estimates that over 80% of Japan’s total potential offshore wind resource of 1900 GW is in water depths greater than 50 m, necessitating the use of floating offshore wind solutions such as WindFloat.

Demonstrating SATH

Meanwhile, in Europe, RWE Renewables and Saitec Offshore Technologies of Spain are collaborating on a pilot project in the Bay of Biscay off the Spanish coast called DemoSATH to test a new design of floating platform for offshore wind employing Saitec’s SATH (Swinging Around Twin Hull) concept, which aims to reduce the cost of floating wind.

SATH’s twin hulls are made of modularly prefabricated and subsequently braced concrete elements, with a single mooring point, allowing the platform to align according to wind and wave direction. Design and deployment of the pilot facility will take about 18 months, followed by two years of operation.

Above: SATH concept (source: Saitec)

RWE says it sees great potential for floating wind farms worldwide, especially in countries with deeper coastal waters, such as Japan.

DemoSATH is expected to be Saitec’s second project in open waters, with a 1:6 scale model scheduled for deployment off the coast of Santander.

For the large prototype, the floating structure with 2 MW wind turbine will be assembled in the port of Bilbao. The base of the structure will be about 30 m wide and some 64 m long. The platform including the turbine will be towed to its anchorage point in a test field (BIMEP) two miles off the coast. The sea is about 85 metres deep at this point. Hybrid mooring lines, composed of chains and fibre, anchored to the seabed, will hold the structure in position.