TenneT begins laying the NordLink subsea cable in the German North Sea

Transmission system operator TenneT has begun laying its “NordLink” subsea cable section in the German North Sea. During the next weeks TenneT will wind out 99 kilometres into the seabed between the cable landfall at the Büsum dike (Schleswig-Holstein) and southwest of the Island of Sylt through the tidal flat area (Wadden Sea).

Next year, another 55 kilometres of subsea cable will be laid in the German offshore area up to the border of the Danish territorial waters. Here, the cable end will be connected to the 228-kilometre-long cable section to be laid in 2018 and 2019 in the Danish North Sea area by means of a subsea cable joint. The 134-kilometre-long subsea cable section in Norwegian territorial waters is already complete. Construction of the 53-kilometre-long overhead line on Norwegian mainland is scheduled for completion in 2019. On German mainland, NordLink will be laid as an underground cable on a 54-kilometre route between Büsum dike and the Wilster converter station (Steinburg district) starting in 2019. Overall, the NordLink interconnector is 623 kilometres long. The “green link” will directly connect the energy markets of Germany and Norway for the first time and serve as an exchange between German wind energy and Norwegian hydropower.

The subsea cable work in the German sector will be carried out in close collaboration with the nature conservation agencies. TenneT complies with strict nature conservation requirements set out by the German Federal Maritime and Hydrographic Agency, National Park administration and the Ministry of Energy, Agriculture, the Environment, Nature and Digitisation of the Federal State of Schleswig-Holstein. Nature conservation construction site monitoring ensures careful and considerate operations within the Wadden Sea National Park. TenneT urges tourists and hikers in the Wadden Sea not to enter areas that are cordoned off for safety reasons and to keep sufficient distance to anchor cables.

Two horizontal drills of 550 metres in length were used across the land protection dike in Neuenkoog (by Büsum) and the empty conduits were drawn into the boreholes last year. The subsea cables to be delivered on a cable laying ship in case of high water springs are set to be drawn into these boreholes in autumn 2018, and will later be connected to the underground cable on the landward side of dike. The underground cable will then run to the Wilster converter station from there.