Floating wind: Industry leaders collaborate to demonstrate transformative ‘TetraSpar’ concept in Norway

innogy SE, Shell and Stiesdal Offshore Technologies A/S (SOT) have signed an investment and cooperation agreement today committing the partners to build a demonstration project using SOT’s ‘TetraSpar’ floating foundation concept. Its modular layout consists of a tubular steel main structure with a suspended keel. It is expected to offer important competitive advantages over existing floating wind concepts, with the potential for leaner manufacturing, assembly and installation processes with lower material costs. The project has a budget of approximately €18 million.

“These are exciting times. The floating offshore wind market is evolving but until now, floating foundations have been stubbornly expensive. This demonstration project will give us a better understanding of how the cost can be driven down. The industrialised approach of the TetraSpar design, combined with innogy’s experience in delivering offshore wind projects, will enable large-scale, cost-effective deployment of floating wind projects around the world,” says Hans Bünting, Chief Operating Officer Renewables of innogy SE.

Dorine Bosman, VP Shell Wind Development, added: “This initiative could help to lower the cost of offshore wind energy while providing more options for development locations, giving access to higher wind speeds and deeper water depths. Building our offshore wind business is a key part of the Shell New Energies strategy. Investing in innovative projects such as TetraSpar gives us early access to a new technology that could help us become a leading player in this field.”

The demonstration project will use a 3.6MW Siemens Gamesa Renewable Energy (SGRE) direct drive offshore wind turbine and is due to be deployed in 2019. It will be located approximately 10km from shore in water depths of 200m at the test site of the Marine Energy Test Centre (Metcentre) near Stavanger in Norway. The foundation will be manufactured and assembled in Denmark and the turbine will be installed in the port of Grenaa, from where it will be towed to site. At site the floating structure will be moored to the seabed with three anchor lines and connected to the electrical grid.

Henrik Stiesdal, CEO of Stiesdal Offshore Technologies A/S, stated: “We are very excited about the prospects of carrying out the deployment and test of our full-scale demonstration project in collaboration with leading industry players. We have already benefited greatly from the dialogue with innogy, Shell and Siemens Gamesa Renewable Energy during the project planning. Their experience combined with the competences of our manufacturing and installation partners, Welcon A/S and Blue Power Partners A/S, will put us on the fast-track for rapid commercialisation.”

The partners will set up a company with a 33 percent share each for innogy and Shell, with the rest held by SOT and its parent company. SGRE is contributing to the project as a technology partner and will provide the wind turbine and required services. The partners will be part of a project team that will gain detailed, practical insights into the construction, installation and operation of the TetraSpar concept as well as detailed performance data.