Foundations Completed for World’s Largest Floating Offshore Windfarm

construction of foundations for world's largest floating offshore windfarm
One of the foundations being towed to the second stage of construction (Woldcam/Equinor)

Published Apr 22, 2021 4:08 PM by The Maritime Executive

The first part of the construction of what is expected to be the world’s largest floating offshore windfarm has been completed. Aker Solutions built the concrete foundations that will be used for the Hywind Tampen project under development by Equinor. 

"Hywind Tampen is an important project for the transformation of the energy industry," said Kenneth Simonsen, interim executive vice president and head of the renewables business for Aker Solutions. “We are happy to maintain progress in the midst of a pandemic and are now ready for the next phase of the project.”

In the first part of the project, the initial approximately 65 feet of 11 concrete foundations were built in the dry dock at Aker Solutions’ yard in Stord, Norway. The 11 substructures are currently being towed to Vindafjord where the concrete slip-forming will continue to a height of 351 feet along with the mechanical outfitting of the foundations. Finally, all the assemblies will be staged at Gulen, Norway for installation of the wind turbines. The last phase of the project is tow-out and installation offshore, which will be carried out in a 50/50 partnership between Aker Solutions and DOF Subsea.


Built in Aker Solutions' dry dock the base of the foundations will now be extended to a full height of 351 feet (Aker Solutions)


According to the companies, these foundations were also notable as they were the first concrete slipforming for an offshore project on the Norwegian continental shelf since 1995. The concrete technology developed for the petroleum industry is also now utilized to support the development of this renewable energy project. 

Equinor’s Hywind Tampen is also considered to be an important project as it will assist in the development of new competencies which the companies believe will lead to the industrialization of offshore wind in Norway.

Aker Solutions’ contract with Equinor on Hywind Tampen includes the construction of 11 floating concrete foundations for windmill turbines. The project includes the engineering, procurement, and construction of the foundations, as well as marine operations. 


Concept drawing of a completed wind turbine assembly for Hywind Tampen (Aker Solutions)


Other elements for the project are also currently being constructed, including the steel anchors which are being welded together at Aker Solutions yard in Verdal. The nacelles, blades, and turbine towers are also being produced in Europe and will be shipped to Gulen for the final assembly which should be completed by the end of 2022.

In addition to becoming the world’s largest floating offshore wind farm, Hywind Tampen will be the world’s first to power offshore oil and gas platforms. It is also the first time Equinor is using concrete technology for wind projects. Hywind Tampen will provide 88 MW of floating wind power for the electricity used at Equinor’s Snorre and Gullfaks offshore field operations in the North Sea.