Danish TSO Finishes Grid Connection for Thor Offshore Wind Farm

June 18, 2025, by Adnan Memija

Danish transmission system operator (TSO) Energinet has completed the construction work related to the connection of the 1 GW Thor offshore wind farm to the national grid.

The construction work began in January 2023 and has been completed on time, said Energinet. The scope of work included moving 95,000 cubic metres of soil and laying 150 cable drums, each weighing 25 tonnes.

Renewable energy will be transported offshore through two 220kV substations located at Volder Mark and Idomlund near Holstebro, via a 30-kilometre twin cable system. Due to environmental restrictions, seven kilometres of the cable were installed using underground drilling.

“In Energinet, we are now ready with our part of the project, so that we can help the green electricity out into the country. This will happen through our station in Idomlund and out onto the high-voltage grid to consumers in both Denmark and our neighboring countries. It is a huge milestone that we have been looking forward to,” said Søren Dupont Kristensen, Chief Operating Officer at Energinet.

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Energinet added that it has finished on time, despite several challenges along the way. The weather has been rainy, the environmental approval came late (not until 2022), and the war in Ukraine led to a shift in the supplier market, which affected time and finances, according to the TSO.

“The environmental approval had many restrictions because there were several areas with vulnerable nature. This meant that we had to drill under some of the cables, and then there was also the stork Keld, who had settled in Bækmarksbro. He was monitored day and night and Energinet was not allowed to work in the area from March to October,” said Martin Hinrichsen, Chief Project Manager at Energinet.

The TSO expects the first of 72 Siemens Gamesa SG 14-236 DD wind turbines to start generating electricity in 2026.

The first monopiles are already installed at the site located approximately 22 kilometres off the west coast of Jutland.

RWE, which is leading the construction and operation of the offshore wind farm on behalf of its partnership with Norges Bank Investment Management, plans to have Thor up and running by the end of 2027.