Offshore marine contractor Jan De Nul finished its 2025 transport and installation campaign for three HVAC grid connection cables at TenneT’s DolWin kappa platform, 33 km offshore in the German North Sea.
Jan De Nul and partner Hellenic Cables are responsible for design, production, transport, installation and protection of three 155 kV HVAC cables with a total length of 37 km, which are buried 1.5 m beneath the seabed. These cables connect the Nordseecluster 1 and 2 offshore wind farms to the DolWin kappa offshore converter station, ultimately facilitating the transport of approximately 660 MW of electricity.
Cable-laying vessel Isaac Newton, which is part of Jan De Nul’s fleet, transported the three 155 kV cables from Hellenic Cables’ plant in Corinth, Greece, installing them between DolWin kappa and Nordseecluster 1 and 2. Concrete mattresses, burial cables and installation of rock beams put the finishing touches onto Jan De Nul’s on the project for this year.
The final connection and testing works are slated for spring 2026. In the future, numerous export cable projects are planned to connect 2 GW converter stations to the onshore German grid.
Earlier this year, Jan De Nul started the monopile foundation installation campaign for RWE’s Thor offshore wind farm.
