70 million kWh later, a floating wind icon heads for shore

While decommissioning marks the end of an era for this specific turbine, it represents a massive leap forward for the industry. At METCentre, we believe there is just as much to learn from taking a structure out of the water as there is from putting it in.

As the floating wind sector moves towards large-scale deployment, access to long-term operational data and physical verification of structures is increasingly important. The decommissioning of the demonstrator will enable full inspection and analysis of the submerged structure after nearly five years of uninterrupted normal operation.

Exceptional performance by the numbers

The TetraSpar unit, equipped with a 3.6 MW 130-meter Siemens turbine, has proved that industrialized floating wind is not just a concept, but a reliable reality. The data speaks for itself:

• Total energy produced: Almost 70 million kWh.
• Aggregate capacity factor: An impressive 51.4%.
• Availability: A remarkable 98%.

These figures confirm that the TetraSpar design can withstand real-world offshore conditions while maintaining high efficiency, providing a rock-solid foundation for the commercial scaling of floating wind.

Learning from the finish line

The decommissioning process, recently awarded to Global Maritime following a competitive tender, is a significant milestone for the Norwegian supply chain. We are particularly proud to see a member of the Norwegian Offshore Wind (NOW) cluster secure such a major contract. In total, at least 20 local or Norwegian companies, ranging from small businesses to large enterprises, have provided deliveries or services to the TetraSpar project.

By bringing the structure back to shore, engineers will gain a "look under the hood" that is impossible to achieve while the unit is at sea. Full subsea inspections and data analysis of the submerged structure will provide unique insights into material wear and structural integrity after five years of uninterrupted operation.

“We would like to thank the TetraSpar team for their time at METCentre and for the good cooperation throughout the project," says Cecilia Girard-Vika, Director at the METCentre. "We have experienced a highly competent team with a clear doer spirit, and we look forward to continuing the collaboration and ensuring a safe and efficient decommissioning process."

"The TetraSpar project has been very important for METCentre and the Norwegian industry, and marks a significant step towards industrializing floating wind. We are pleased to see the strong test results and will continue to closely follow the development of Stiesdal’s floater design.”

Bridging the gap to large-scale wind

As Henrik Stiesdal, Chairman of the Board of TetraSpar Demonstrator ApS, noted, this project has been essential in bridging the gap between innovation and large-scale deployment. The lessons learned here, from installation to the final bolt removed during decommissioning, will help reduce risks and optimize designs for the next generation of floating wind farms.

"As the floating wind market continues to mature, we are progressing towards commercial execution. We are developing our next-generation TetraSub foundation for 15+ MW turbines and have been selected as foundation provider for the Pentland Floating Offshore Wind Farm in the UK", Stiesdal states in a press release. And the results from the decommissioning will be used directly in the verification and certification of the commercial TetraSub design.

At METCentre, we are excited to facilitate this final phase alongside Global Maritime, ensuring that the knowledge gained from TetraSpar continues to power the global energy transition.