Under the multi-year framework agreements, Allseas and Heerema Marine Contractors have been awarded at least 28 slots, which include fourteen slots each for the transportation and installation of jackets and HVDC converter topsides until 2031

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Allseas and Heerema secure 2GW offshore platform contracts from TenneT. (Credit: TenneT)

Transmission system operator (TSO) TenneT has awarded contracts to Allseas and Heerema Marine Contractors for the transportation and installation of at least fourteen 2GW offshore platforms in the German and Dutch parts of the North Sea.

Under the multi-year framework agreements, the companies have been awarded at least 28 slots. These include fourteen slots each for the transportation and installation of jackets and high voltage direct current (HVDC) converter topsides until 2031.

Heerema Marine Contractors has bagged nearly 60% of the available slots while Allseas will be responsible for the remaining 40% slots.

Heerema Marine Contractors chief financial officer Robbert Sloos said: “We are very pleased to support the ambition of TenneT to develop the North Sea Europe’s green energy powerhouse.

“Heerema looks forward to bringing decades of experience to some of the world’s largest offshore wind developments, which will significantly contribute to the renewable targets of the Netherlands and Germany.”

The agreements secure the early transportation as well as the installation of jackets and topsides for at least eight Dutch and six German projects and future projects of 2GW each.

With the new agreements, TenneT has awarded all major contracts for its 2GW programme that aims to develop at least 14 HVDC offshore grid connection systems of 2GW each in the Dutch and German North Sea by 2031.

Allseas is expected to leverage its Pioneering Spirit single-lift installation vessel and Heerema will utilise the Sleipnir semi-submersible crane vessel (SSCV) and an owned floatover barge for the operations.

Boskalis will serve as a subcontractor to Allseas for developing one or two new transport vessels for the 2GW offshore grid connection programme.

TenneT COO Tim Meyerjürgens said: “With this agreement we secure global marine transportation and the heaviest offshore installation capacity in the market for our HVDC partners while expanding transportation capacity in the market. We are proud to have signed this framework agreement with Dutch and Swiss/Dutch suppliers.”

In March 2023, TenneT awarded contracts worth nearly €23bn for 11 2GW grid connections to three consortia to connect certain offshore wind farms in the German and Dutch parts of the North Sea to shore.