Jan De Nul Group has completed the export cable installation works in the German North Sea in order to connect the offshore wind farms Trianel Windpark Borkum II, developed by Trianel, and Borkum Riffgrund II, developed by Ørsted, to Tennet’s German transmission grid.
For both cable installation projects, Jan De Nul mobilized cable laying vessel Willem de Vlamingh and trenching support vessel Adhémar de Saint-Venant.
“The successful completion of both projects will add onto our extensive track record for the installation of submarine power and umbilical cables for both the renewable and the oil and gas energy sectors,” said Wouter Vermeersch, manager Offshore Cables at Jan De Nul Group.
In the summer of 2017, Willem de Vlamingh identified and removed potential UXOs from the cable routes. In the spring of 2018, the vessel sailed to the cable load out facilities in Greece to load the three cables with a total length of 26.4 km.
The first two cables connect the Borkum Riffgrund II wind farm substation with the Dolwin Gamma convertor station. The third cable connects the Trianel Windpark Borkum II with the Dolwin Alpha convertor station. These Dolwin platforms convert the electricity generated by the two wind farms into Direct Current (DC) before transporting it to Tennet’s onshore network.
The trenching support vessel Adhémar de Saint-Venant executed the cable protection works by means of post-lay jet trenching using Jan De Nul Group’s UTV1200 trencher.
The Greek cable manufacturer Hellenic Cable is currently terminating and testing the cable connections. Overall commissioning is planned in June/July 2018.