Stiesdal TetraSub Floating Foundation Gets DNV Statement of Feasibility

DNV has presented Stiesdal with a Statement of Feasibility for its semi-submersible floating wind foundation TetraSub, demonstrating the technical feasibility and commercial readiness of the technology.


TetraSub is part of Stiesdal’s modular, industrially manufactured Tetra foundation concept. It is suited for floating wind installations at water depths ranging from 50 metres and up.

Stiesdal’s TetraSub floating wind foundation. Source: Stiesdal

Issuing a Statement of Feasibility for TetraSub concludes the first stage of the certification process, DNV said.

”Floating offshore wind is a new industry and certification helps to demonstrate the performance, reliability and commercial viability of technological advances which push the boundaries of current technical and engineering knowledge,” said Kim Sandgaard-Mørk, Executive Vice President for Renewables Certification at DNV.

”Mitigating risks via certification is particularly valuable for floating offshore wind projects in securing project finance and demonstrating operational application.”

In its latest Energy Transition Outlook report, DNV forecasts that floating wind will grow to contribute around 260 GW by 2050.

This corresponds to a development of more than 3,000 times the size of Hywind Tampen, the world’s largest floating offshore wind farm, currently under construction in Norway, or 15,000 turbine units.

”We are very happy to have reached this first and very important milestone in the certification process for our concept,” said Peder Nickelsen, Chief Executive Officer for Stiesdal Offshore Technologies.

”During the certification process, DNV has provided technical insight and feedback at the highest competence level, and we have been and continue to be highly satisfied with the constructive dialogue with the staff at DNV. The Statement of Feasibility is an important first step, and we are on track for the full certification next year.”