Onshore cabling work begins on Thor offshore wind farm, largest in Denmark

Onshore cabling work has officially begun on the Thor offshore wind farm, the largest in Denmark. Located in the Denmark’s side of the Northern Sea, the wind farm is planned to have an output of 1-GW. Works started this week with RWE laying down onshore cables that will be carried out at and around the onshore substation south of Lemvig. Last year in May, groundbreaking was held for the onshore substation of the Thor offshore wind farm. According to officials, progress on all onshore activities is going as scheduled.

Project timeline

The onshore cabling work, at least the first phase of it, is expected to take place from this week until the end of June. Work on the onshore cabling will take place in 3 phases. Horizontal directional drilling works will be carried out under the dune and a field immediately south of Tuskær. In an effort to protect and preserve the dunes, drilling works will take place at depths of more than 20 metres. RWE is also making efforts to avoid road closures and impact on protected waterways. They will carry out smaller horizontal directional drilling works along the approximately 4 kilometres cable route between the onshore substation at Volder Mark.

RWE intends to have two ducts running under the dunes and the nearby field. Tod do so, they are carrying out landfall works that will prepare for cable pull-in in 2025. The drill holes are not too large, at 425 metres length and 71 centimetres diameter. The duct sections will be welded together on the beach. From here, they will be pulled through the drill holes.

The Thor offshore wind farm Project Team

RWE signed a contract in March with Jan De Nul–Hellenic Cables consortium for the supply and installation of the entire cable system for the Thor offshore wind farm. The terms of the contract outline that 60 kilometres of export cables on the 30-kilometre-long cable route from the offshore wind farm to shore will be manufactured and installed by both Hellenic Cables and Jan De Nul. Additionally, they will also supply and install approximately 200 kilometres of inter-array cables. Further, Siemens Energy and MT Højgaard Danmark were both signed to work on the civil engineering and construction work for the onshore substation.

The offshore phase of the project

The offshore windfarm will have a total of 72 wind turbines and will be located 22 kilometres from Thorsminde on the west coast of Jutland. Specifically, Siemens Gamesa SG 14-236 DD wind turbines installed on monopile foundations. 40 of these turbines will be equipped with recyclable rotor blades. Work on the production of the monopile foundation started early this year. Furthermore, the wind turbines are expected to be installed within the first quarter of 2026. Full operation of the 1-GW Thor offshore wind fam is expected to begin in 2027.