SuedLink – The wind power line from north to south

SuedLink will connect wind farms in the north, hydroelectric power stations in Scandinavia and solar parks in southern Germany. The underground cable connection enables fluctuating renewable energy sources to be flexibly integrated into the grid, thereby ensuring a stable and secure electricity supply

The basis for the construction is the Federal Requirements Plan Act, which defines the expansion of electricity grids as a prerequisite for a secure and sustainable energy supply. Approval is granted in accordance with the Grid Expansion Acceleration Act in a two-stage procedure.

The approximately 700-kilometre-long route runs from Schleswig-Holstein to Baden-Württemberg and Bavaria respectively and will be implemented entirely as an HVDC underground cable system. The line consists of two parallel direct current systems with a voltage level of 525 kV and a total transmission capacity of 4 gigawatts (2 × 2 GW).

The cables are predominantly laid using open-cut construction methods in trenches with a depth of approximately 1.5 to 1.8 metres. For crossing under sensitive areas such as roads, railway lines, waterways, existing infrastructure or protected areas, closed construction methods such as horizontal directional drilling (HDD) or microtunnelling are used. The two cable systems are mostly laid in bundles within a route corridor approximately 40 to 45 metres wide.

The client is TenneT TSO GmbH. The services include planning coordination and project management, including technical and digital planning, permit management, environmental and emission control, and alignment management.

The project is divided into 15 planning approval sections and affects around 20,000 land parcels. Planning will take place from 2019 to 2026, with the construction phase running from 2023 to 2028.