Denmark transmission line – strengthening the Danish–German energy network

Denmark, known for its ambitious renewable energy goals, is constructing one of the largest transmission lines in the region – the 400 kV double-circuit Endrup–Idomlund–Endrup–German border transmission line. This project links the Danish and German power grids, enabling stable transmission of green megawatts from wind farms.

Denmark is one of Europe’s leaders in the adoption of renewable energy. This transmission line plays a key role in connecting wind farms with national and international networks. It has been designed as part of a broader energy transition strategy aimed at increasing transmission capacity and reducing dependency on fossil fuels. Works begin in April 2023, along the windy North Sea coast, where heavy rain and harsh weather conditions add significant challenges for field crews.

• Total length: 150 km
  
• Number of towers: 438
  
• Tower type: Primarily Thor towers, designed for environmentally sensitive areas
  
• Span between towers: 350 m
  
• Tower height: Up to 40 m
  
• Tower weight: 24–55 tons
  
• Foundations: Low-carbon concrete
  
• Weather resistance: Designed for strong wind and high humidity
  

The towers used in this project are not standard structures – they are designed to reduce visual impact and blend into the Danish landscape. Thor towers, named after the Nordic god of thunder, were selected not only for their strength and durability but also for their reduced ecological footprint.

These new tower types resemble Thor’s hammer – strong enough to withstand extreme weather, yet low enough to blend into the flat terrain of Western and Southern Jutland. Their height ranges from 27 to 32 meters to allow agricultural machinery to pass freely beneath the conductors. Each tower is made of 71 components and weighs up to 55 tons. With a thick galvanised coating, their expected lifespan is up to 80 years without additional treatment.

Unpredictable Danish weather is one of the project’s biggest challenges – strong winds frequently interrupt works and force teams to adjust plans continuously. Weather conditions can change rapidly, with sunny hours turning into storm-level winds and heavy rain in a matter of hours, requiring exceptional flexibility from all field teams.

The installation of towers demands precise planning and logistics – each tower must be assembled on the ground from 71 individual components before lifting. With heights up to 40 meters and weights up to 55 tons, specialised lifting equipment is essential.

• Assembly and erection of 438 towers, including Thor towers
  
• Engagement of 50–60 fitters during the most critical phases
  
• Cooperation with Danish partners and local communities
  
• Ensuring grid stability during works through coordination with existing transmission infrastructure
  

Our teams work in extremely demanding conditions, facing constant weather changes and challenges of outdoor operations. However, thanks to their professionalism and extensive experience in high-voltage transmission line construction, all key tasks are executed successfully and on schedule.

• Part of Denmark’s plan to quadruple renewable electricity production by 2030
  
• Ensuring stable transmission of green energy between Denmark and Germany
  
• Foundation for future expansion of wind farms and solar energy
  
• Reduction of CO₂ emissions and contribution to regional environmental sustainability
  
• Strengthening transmission stability and enabling greater integration of renewable energy into the broader European grid