TenneT, the prominent offshore transmission system operator in Europe, has inked multi-year framework agreements with Allseas and Heerema Marine Contractors for the transport and installation of fourteen 2 gigawatt (2GW) offshore platforms.
These converter stations will be positioned in the Dutch and German sectors of the North Sea, with the agreements covering a span of twenty-eight slots until 2031.
Under the framework, Heerema will utilize the Semi-Submersible Crane Vessel (SSCV) Sleipnir and a floatover barge, while Allseas will employ its single-lift installation vessel Pioneering Spirit. Both vessels have been employed by TenneT in the past for similar installations. Heerema secured around 60% of the available slots, while Allseas obtained approximately 40%. Additional contracts can be added to the awarded slots, which are not tied to specific 2GW projects. The HVDC suppliers responsible for constructing the jackets and topsides for TenneT can choose from the appointed installation contractors.
Boskalis, acting as a subcontractor to Allseas, will construct one or two new transport vessels tailored to meet future sustainability and emissions standards.
Earlier, TenneT awarded framework agreements for the civil works of land stations, offshore and onshore converter stations, and cable connections for the fourteen 2GW projects in the Netherlands and Germany. The streamlined tendering approach facilitated swift agreements with all suppliers involved.
In April 2023, during the North Sea Energy Summit, nine countries including Belgium, Denmark, Germany, the Netherlands, France, Ireland, Luxembourg, Norway, and the United Kingdom signed the Ostend Declaration. The declaration stipulates a collective commitment to installing a minimum of 120 gigawatts (GW) of offshore wind power capacity by 2030. TenneT, being responsible for about one-third of this capacity, equivalent to 40 GW of grid connections, is actively constructing offshore grid connection systems in Germany and the Netherlands, each with a capacity of 20 GW.
Image source: TenneT