Milestone: SuedLink power line fully approved
Year of issue 2025
Date of issue 2025.10.10
The Bundesnetzagentur has today completed the planning approval procedure for the last section of the SuedLink power line. The exact route of the new underground direct-current cables in the section, which is around 76 kilometres long, has now been decided. The transmission system operator TransnetBW can now begin work on this section of the line as well.
Route
Projects 3 and 4 in the Federal Requirements Plan Act (BBPlG) run parallel to each other from the boundary between Hesse and Thuringia to a point level with Henneberg, south of the boundary between Thuringia and Bavaria. The section begins in the Werra valley near Herleshausen, immediately south of the boundary between Hesse and Thuringia. The route runs south to southeast past Marksuhl and reaches the Werra valley again at a point level with Bad Salzungen. It runs south along the east side of the valley and crosses the Werra river between Schwallungen and Wasungen. The route then runs south down to the boundary between Thuringia and Bavaria near Henneberg. The route ends at a point immediately south of the federal state boundary, where it joins section D2, which has already passed the planning approval stage.
The Bundesnetzagentur is due to publish its planning approval decision on 8 November 2025 at www.netzausbau.de/vorhaben3-d1 and www.netzausbau.de/vorhaben4-d1.
Background to SuedLink
The SuedLink power line consists of two direct-current lines and is the largest direct-current project that is currently being implemented. Project 3 connects Brunsbüttel in Schleswig-Holstein with Großgartach/Leingarten in Baden-Württemberg. Project 4 runs from Wilster to Bergrheinfeld in Bavaria. The two lines will be laid as underground cables and run mostly parallel to each other. TenneT and TransnetBW are the transmission system operators responsible for planning, constructing and operating the lines. The projects each have a transmission capacity of two gigawatts and a voltage of 525 kilovolts.
The lines are due to be connected to the grid by 2028. Starting in December 2022, the Bundesnetzagentur approved 30 applications for an early start to work, allowing the initial construction work – in particular compensatory measures under nature conservation legislation, boring and clearing – to get underway.
A 5.5-kilometre-long, walk-through cable tunnel is being constructed for the SuedLink power line under the Elbe river near Glücksstadt. Between Bad Friedrichshall and Leingarten the line runs for 16 kilometres within the Südwestdeutsche Salzwerke AG mine. New shafts and routes were dug in the mine to lay the cables running towards Großgartach grid connection point.
The Bundesnetzagentur regularly updates the forecast on progress in electricity grid expansion and publishes the updates (in German) at www.netzausbau.de/prognose.