The transmission system operator TenneT has commissioned the cable production companies NKT, Nexans, and a consortium of Jan De Nul, LS Cable, and Denys to produce and lay ten 525 kV direct current cable systems for corresponding grid expansion projects. The total volume of the orders amounts to around 5.5 billion euros. TenneT completes the major tenders for grid connection systems that started last year with this second framework agreement. These include fourteen offshore connections, five of which had already been commissioned by the Dutch at the beginning of 2023, and one direct current project on land.

Advertised projects

NKT will realise the connections for Nederwiek 3 with connections in Geertruidenberg or Moerdijk and the connections for Doordewind 1 and Doordewind 2 with connections in Eemshaven.

Nexans has received the order for the cable connections of the offshore projects BalWin3 and LanWin4, which are to be connected in Wilhelmshaven, as well as that of LanWin2, which leads to the Heide area in Schleswig-Holstein.

The consortium of Jan De Nul, LS Cable and Denys will implement the other cable systems for the projects in Lower Saxony. These include BalWin4 and LanWin1, both of which are to be connected in the Unterweser area. The portfolio also includes LanWin5, which has its onshore network connection point in the Rastede area. The consortium has also been awarded the contract for the TenneT-side part of the 525 kV onshore DC project NordOstLink in Schleswig-Holstein. NordOstLink is a TenneT partner project with the transmission system operator 50Hertz.

The scope of the contracts includes cable design and engineering, production, delivery, project management and subsequent onshore and offshore laying of the 525 kV DC cables. The contractors plan to start work during 2023. Onshore cable laying work is expected to start after 2025. At sea, cable-laying work is expected to begin in 2026. The offshore projects, each with a transmission capacity of 2 gigawatts, are expected to be operational by 2031 and NordOstLink by 2032.

7,000 kilometres of cable

Tim Meyerjürgens, COO of TenneT, said: “We are very proud to be able to name the partners for the manufacture and installation of the cable systems for these important and innovative grid connection systems today. These are essential steps for the success of the energy transition. Together, with this award alone, we will implement around 7,000 kilometres of DC cable for onshore and offshore grid connection systems in Germany and the Netherlands by 2032.”

NKT President and CEO Alexander Kara said: “We are very pleased to have been selected again as a lead partner for the ambitious 2GW program, confirming our strong position in the EHV cable market. We recently announced TenneT’s IJmuiden Ver and Nederwiek 2 contracts. Both projects are also part of the 2GW program and are among the first offshore wind farms in the world to use 525 kV high-voltage direct current (HVDC) transmission technology for offshore power cables. With this framework agreement, we are continuing our close cooperation with TenneT and applying this innovative cable technology to other projects in the North Sea.”

Vincent Dessale, Chief Operating Officer and Senior Executive Vice President of Nexans, said: “The need to invest heavily in offshore grids in Europe can only be met by building strong and long-term partnerships between suppliers and transmission system operators – based on trust, Transparency and joint technology developments. The framework agreement developed by TenneT is the perfect answer to these challenges, and Nexans is proud to be part of these groundbreaking developments. We are delighted that TenneT has placed its trust in us. Our partnership can only reinforce our respective and ongoing commitments to the offshore wind energy transition around the world.”

Philippe Hutse, Director Offshore Division at Jan De Nul Group: “Right from the start, we welcomed TenneT’s new approach to tenders, which emphasises cooperation and transparency, and the result of a potential multi-year framework agreement gives us the long-awaited planning security that we and the offshore energy industry has been in dire need of for some time. Together with our consortium partners LS Cable & System and Denys we are therefore pleased to sign this contract with TenneT and to contribute to Europe’s vision of energy security and decarbonisation. This award is a recognition of our expertise in realising complex cable laying projects and building the energy transition.”

investment push

Marco Kuijpers, Director Large Projects Offshore at TenneT, said: “We are delighted that we have awarded these framework agreements in such a short period of time. The new tendering procedure speeds up the process so that agreements could be reached with all suppliers within six months. Such a process would normally take up to 18 months. These contracts involve significant investments and give our suppliers the planning security they need to invest in additional resources in the form of production facilities, cable laying vessels and excavation tools, etc.”

Innovative collaboration between TenneT and market participants

Each of the 2GW cable systems will consist of four cables: a positive and a negative conductor, a metallic return conductor and a fibre optic cable. In the firm belief that the energy transition can only succeed in a spirit of cooperation, TenneT, together with market participants, started developing a research and development (R&D) initiative for the 525 kV HVDC grid connection system with a transmission capacity of 2 GW started. The certification of cable suppliers in 2022 is a result of the constructive and intensive dialogue between TenneT and the relevant market participants.


With the Esbjerg Declaration, Belgium, Denmark, Germany, and the Netherlands agreed in May 2022 at the North Sea Energy Summit to jointly install at least 65 gigawatts (GW) of offshore wind energy by 2030. Europe’s leading offshore transmission system operator TenneT will provide around two-thirds of this volume with 40 GW of grid connections. To this end, TenneT is building offshore grid connection systems with a total capacity of 20 GW each in Germany and the Netherlands.

As part of its 2GW program, TenneT has developed the new global offshore standard for grid connection systems – together with the world’s leading suppliers in the industry. This new standard combines TenneT’s extensive expertise in offshore grid expansion with a transnational approach. With a focus on the harmonisation and standardisation of offshore grid connection systems, the program provides the necessary blueprint for the future and necessary acceleration of the energy transition. Due to the increased transmission capacity of two gigawatts per system, the number of new systems can be significantly reduced compared to previous offshore grid connections. The 2GW program is thus setting new standards for the European energy transition. It will bring more green energy to Europe and its citizens in a safe and cost-effective way, with as little environmental impact as possible.

More information on TenneT’s 2GW program: The 2GW Program – TenneT

Image source: Courtesy of TenneT

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