Interconnector Kassø - Audorf

Expansion of transmission line across the German-Danish border


German TenneT TSO GmbH and Danish are working to expand one of the two existing interconnectors across the German-Danish border. The purpose of the project is to improve market integration between Denmark and Germany, specifically by increasing the cross-zonal connection between Western Denmark and Northern Germany to a maximum net transfer capacity of minimum 2,500 MW by investing in new infrastructure.




Both Northern Germany and Denmark currently produce large volumes of renewable energy, and the volumes will grow in the years to come. The power grid is therefore being expanded considerably, and expanding the grid between Denmark and Germany will benefit not only the German-Danish border region, but an even greater area. Concurrently with the expansion of the grid in Northern Germany, the new interconnector will improve the possibilities of transmitting power based on renewable sources in Denmark and Schleswig-Holstein to the load centres, especially in the greater Hamburg area and Lower Saxony.


The project in Denmark


In Denmark, the plan is to install a 30 km long 400 kV overhead line from the national border to the substation in Kassø near Aabenraa. The line will replace the existing 220 kV line. In 2014, put in operation a new similar 400 kV line from Kassø to Tjele near Viborg in the centre of Jutland. In Tjele, the line is connected to a new cable to Norway. Read more about the Danish part of the project (in Danish) here.


The project in Germany


In Germany, TenneT will replace the existing 220 kV line between Handewitt and the Danish border by a 10 km long 380 kV (in Denmark defined as 400 kV) overhead line. By doing so, the existing 220 kV substation in Flensburg will be replaced by a new 380 kV substation in Handewitt. Furthermore, TenneT will replace the 70 km long 220 kV line from Handewitt to Audorf with a new 380 kV line. Read more about the German part of the project (in German) here.


In operation


The joint project is planned to be ready for operation in 2020.


Supported by the EU


The transmission line between Audorf and Kassø features on the EU’s PCI – Projects of Common Interest – list and is granted 950,000 euros from the Connecting Europe Facility.

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