4C Offshore Empowering Intelligence

TenneT signs multi-year framework agreements with Heerema and Allseas

4C Offshore | Kaitlin Walsh
By: Kaitlin Walsh 17/05/2023 TenneT

TenneT has signed multi-year framework agreements with Heerema Marine Contractors (Heerema) and Allseas for the transport and installation of at least fourteen 2 GW offshore platforms.

The framework agreements covers at least twenty-eight slots until 2031; half are for the transport and installation of a jacket and the other half are for the transport and installation of a topside. The fourteen 2 GW converter stations will be installed in the Dutch and German parts of the North Sea.

Heerema will deploy its Semi-Submersible Crane Vessel (SSCV) Sleipnir, as well an owned floatover barge. Meanwhile Allseas will use its single-lift installation vessel Pioneering Spirit for the installation of the jackets and topsides. Both vessels have been utilised several times in recent years for jackets and topside installations for TenneT in the Dutch and German North Sea.

Heerema has been awarded roughly 60% of available slots, whereas Allseas has been awarded approximately 40% of the slots. There is an option for additional work to be added to the awarded contracts. The awarded slots are not linked to specific 2 GW projects.

The HVDC suppliers that are building the jackets and topsides for TenneT (Hitachi Energy/Petrofac, GE/Sembcorp, GE McDermott and Siemens/Dragados) are able to choose from the suppliers whereby Heerema and Allseas can install both jackets and topsides.

Additionally, Boskalis will act as a subcontractor to Allseas. Boskalis have plans to build one or two new transport vessels specifically to assist in the 2 GW Program, in order to meet the most stringent future legislation standards on emissions and sustainability.

Tim Meyerj├╝rgens, COO at Tennet, stated: "With this agreement we secure global marine transport and the heaviest offshore installation capacity in the market for our HVDC partners while expanding transport capacity in the market. We are proud to have signed this framework agreement with these Dutch and Swiss-Dutch suppliers.

"These European partners once again prove that they are global market leaders in offshore transport and installation. They have the equipment to carry out projects of such magnitude safely and successfully

Norway, Luxembourg, the United Kingdom, Ireland, France, the Netherlands, Germany, Denmark and Belgium signed the Ostend Declaration at the North Sea Energy Summit in April 2023. As part of this declaration, the countries agreed to jointly install at least 120 GW of offshore wind capacity by 2030.

Europe's leading offshore transmission system operator, TenneT, will account for approximately 30% of this volume, the equivalent to 40 GW of grid connections. Correspondingly, TenneT is building offshore grid connection systems in Germany and the Netherlands with a total capacity of 20 GW each.


ForeSEE Premium, our most popular subscription, gives you full access to use the ForeSEE WebApp which includes exclusive offshore wind, transmission and vessel reports, news and downloads.

Request a 30 minute Demo

Trending News!