Giant concrete spar-substructures are on the move for Equinor's 88-megawatt Hywind Tampen project, which will become the world’s largest floating wind farm once operational in late 2022 and help power oil and gas operations off Norway.


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Contractor Aker Solutions is currently transporting the first 20-metre stumps from a shipyard in Stord near Bergen on Norway’s western coast to a deep-water site in nearby Dommersnes, where slipforming work will continue until the 11 structures reach 107.5 metres.

Hywind Tampen marks the first time the technique of slipforming — a method of producing structures through continuous concrete pouring — has been used for an offshore project on the Norwegian continental shelf since the Troll A platform was delivered in 1995.

“The project represents a direct transfer of technology from oil and gas to renewables,” said Olav-Bernt Haga, Equinor’s project director for Hywind Tampen.

“The giant Troll A substructure was 369 metres. Now we are building 11 small Trolls. The project is on schedule despite the challenges around covid-19.”

The Nkr5 billion ($490 million) Hywind Tampen array is slated to provide electricity for the Snorre and Gullfaks offshore oil and gas field operations in the Norwegian part of the North Sea.

It is the first floating wind project by Equinor to use concrete technology.

While the structures are being built at Stord and Dommersnes, the steel anchors are being welded together at an Aker Solutions yard in Verdal.

Nacelles, blades and towers for the project's 8MW Siemens Gamesa turbines will be produced in Europe and shipped to the Wergelands base in Gulen at a later stage.

All the elements will be collected at the site in Gulen in 2022, where assembly work will start using a giant crane.

“We plan to start towing the completed wind turbines to Tampen early summer of 2022 and complete the offshore work by the end of the year. This is a large and complex industrial project where we use our experience from oil and gas projects,” said Haga.

(This article first appeared in Upstream's sister renewable energy publication Recharge on 22 April, 2021.)