NEXANS : E.ON Netz uses aluminium underground cables from Nexans

Paris, December 2, 2013 - E.ON Netz is using an aluminium underground cable from Nexans in the expansion of its grid infrastructure for wind energy. In the administrative district of Dithmarschen, Nexans has installed a double circuit 110-kV underground cable system for E.ON - the first of its kind for a German customer - with a total length of around 5.5 km and an order volume of € 4 million. The section that has now been connected up is part of the concept of the federal state government of Schleswig-Holstein to transport wind power electricity inland along the coast in a 20-km wide corridor via underground cables. As part of the energy turnaround, E.ON Netz has embarked upon an infrastructure project that will enable a future feed-in of 9000 MW of electricity from offshore wind farms into the 380-kV transmission grid along the west coast of Schleswig-Holstein.

Enough transmission capacity for three large cities

The underground cable that has now been taken into operation has a cross-section of 2500 mm², and it is the first time that Nexans has installed a cable of its type in Germany. The underground aluminium cable installed at a depth of around 1.75 m in PE tubes between Dieksanderkoog and Marne has a slightly larger circumference than a comparable copper cable, but it makes up for this by being lighter and more economic overall. The transmission capacity of the cable system is 360 MW - enough power to supply the three cities of Flensburg, Kiel and Lübeck with electricity. As part of the cable installation work, E.ON has also started to modify the grid structure, adding a new transformer substation in Dieksanderkoog and upgrading the substation in Marne. The planning and construction work for the Nexans underground cable between Dieksanderkoog and Marne/West was completed in a record time of two and a half years, with the entire cable system taking just six months to install, including underground work.

Infrastructure project Weststromtrasse

Andreas Fricke from E.ON Netz is confident that the planned west coast wind energy power line project "Weststromtrasse" will help to take the strain off the grids. In Dithmarschen alone, around 1000 MW of wind energy is currently being generated that cannot always be fed into the grid. In an interview conducted with the newspaper "Norddeutsche Rundschau" on the occasion of the first section of the 110-kV line being taken into operation, Dr Robert Habeck - Schleswig-Holstein's Minister for Energy Turnaround, Agriculture, Environment and Rural Affairs - compared the necessity for this gigantic infrastructure project with the tasks involved in the reconstruction of East Germany after reunification.

He explained that, once the 380-kV overhead grid line was complete, Schleswig-Holstein would have completed this important stage in the energy turnaround, but in addition he added that a power line for wind energy produced onshore was also part of the economic promise.

The 110-kV cable system is the first milestone in the grid expansion concept for Schleswig-Holstein and marks another contribution from Nexans to the grid expansion, an issue that is currently the subject of fervent debate. "I am really pleased that this cable, which is the first of its cross-section to be installed in Germany, is making a contribution to the energy turnaround", said Wolfram Flebbe, Project Manager at Nexans Deutschland, at the switching-on ceremony for the cable system.

Route for the double circuit underground aluminium cable system (map: Nexans)

Project managers and construction managers from E.ON and the other companies involved in the building works at the switching-on ceremony for the underground cable (photo: E.ON)