TenneT selects NKT and Prysmian for world’s largest offshore cable systems to connect increasing Dutch offshore wind volumes

NKT and Prysmian will install five 525 kV XLPE HVDC cable connections for Dutch 2 GW projects to be completed between 2028 and 2030
Innovative cooperation between TenneT and cable suppliers leads to new global market standard for 525 kV XLPE HVDC offshore cables, reconfirming TenneT’s position as the front runner in offshore grid development and its commitment to deliver on the joint ambition to develop the North Sea into the green power plant of Europe
Suppliers minimise environmental impact with high standards on CO2 and NOx emission reductions and use of recycled copper.
In the Esbjerg Declaration in May 2022 at the North Sea Energy Summit, Germany, the Netherlands, Denmark, and Belgium agreed to jointly install at least 65 gigawatts (GW) of offshore wind energy by 2030. Transmission system operator (TSO) TenneT will account for almost two-thirds of this with 40 gigawatts – 20 gigawatts each in the German and Dutch North Seas. Recent geopolitical developments have underlined the need to invest in electricity transmission, to ensure energy security by accelerating the energy transition. TenneT’s innovative 2GW Program plays a crucial role in managing the energy transition from offshore and will help Europe become the world’s first climate-neutral continent. This new standard combines TenneT’s extensive expertise in offshore grid connections with a unique transnational approach. With its strong focus on harmonisation and standardisation, it provides a blueprint for future offshore grid connection systems and enables faster deployment. The awarding of the world’s first 525 kV XLPE HVDC cable connections systems for five Dutch 2 GW projects is the next step in realising the new 2 GW standard. In the next months, TenneT expects to announce the partners for the Framework agreements of the 2 GW HVDC suppliers for Dutch and German 2GW projects and partners for the Framework agreement for cable connections of other 2 GW projects.

Front runner in offshore grid development
Tim Meyerjürgens, COO TenneT says: “Recent geopolitical developments have again underlined the need to invest in electricity transmission, to ensure energy security by accelerating the energy transition. We are proud that we developed this new offshore grid solution together with the market. Our qualification programme has shown that cable suppliers are on track for this new offshore connection standard. By realising the world’s first 525 kV XLPE HVDC offshore cable systems to connect 2 GW projects, TenneT reconfirms its front runner position in offshore grid development and its commitment to deliver on the joint ambition to develop the North Sea into the green power plant of Europe.”

NKT President and CEO Alexander Kara says: “I am very satisfied with the award which confirms our strong position in the high-voltage power cable market and our long-standing relationship with TenneT. I am excited that our leading turnkey expertise within 525 kV XLPE HVDC technology results in NKT being the first power cable manufacturer to apply this technology to sea cables. We welcome that TenneT increases the focus on sustainability factors by introducing Environmental Cost Indicators in the projects with the aim to reduce the carbon footprint of power cable systems.”

Hakan Ozmen, EVP Projects BU, Prysmian Group said: “We are proud to be part of this strategic project that confirms Prysmian as a reliable partner in support of the Dutch ‘Routekaart 2030’ plans to reduce net Green House Gas emissions and achieve the Netherlands’ carbon neutrality targets. The implementation of our innovative 525 kV HVDC technology for submarine cable systems underlines our ongoing commitment to the energy transition and enables our customers to further reduce the costs of offshore wind power and minimise their environmental impact.”

Cable suppliers challenged with high sustainability and safety standards
NKT will realise the cable connections for IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2, landing onshore at Maasvlakte (Port of Rotterdam). Prysmian has been awarded a contract for the cable connections of IJmuiden Ver Alpha and Nederwiek 1, landing onshore at Sloegebied (Zeeland). The scope of work in the contracts includes design, engineering, production, delivery, project management, offshore-, nearshore- and inshore installation of 525 kV HVDC cables and all jointing works in submarine and land sections. The selected parties expect to start activities this year. Onshore cable laying activities starts in 2025, offshore cable laying activities are expected to start in 2026. All projects are expected to be in operation between 2028 and 2030. TenneT challenged market parties in this tender with high sustainability and safety standards. Suppliers are encouraged to minimize environmental impact with strong CO2 and NOx emission reductions. To reduce the carbon footprint, suppliers will use recycled copper. Challenging suppliers in safety by design and safety culture, helps in TenneT’s ambition to eliminate safety incidents. To meet these standards, cable suppliers will invest in new production capacity, vessels and trenching tools when needed.

Innovative cooperation TenneT and market parties
A 2 GW direct current (HVDC) solution, based on 525 kV, requires only one cable system, limiting the impact on the environment and the surroundings. One cable system will consist of four cables, a ‘plus’ and ‘minus’ pole cable, a metallic return cable and a fibre optic cable. Since cooperation is crucial in the energy transition, TenneT together with market parties started developing a research and development (R&D) initiative for a 2 GW, 525 kV XLPE HVDC grid connection system in 2020. To transport the required 2GW power, an offshore cable system operating at a voltage level 525 kV HVDC using extruded insulation types is needed. With a design and layout study for the offshore platform a generic platform was designed, to enable interoperability of the proprietary solutions offered by all HVDC suppliers participating in the R&D phase. The intensive interaction between TenneT and the market parties involved has resulted in providing insights on the required functionality and performance of the innovative HVDC system and led to certification of cable suppliers in 2022.