German energy company RWE has confirmed that all monopile foundations for wind turbines and their accompanying secondary steel structures have been installed at the Nordseecluster A offshore wind project site in the German North Sea 50 kilometres north of the island of Juist.
Each of the 44 monopile foundations measures around 85 metres in length and weighs an average of 1,500 tonnes. Before installation, the foundations were in interim storage in Eemshaven in the Netherlands, from where they were then shipped on Van Oord’s offshore wind installation vessels Boreas and Aeolus to the construction site at sea and installed there.
Rather than using foundations topped with an overlapping separate transition piece, extended single monopiles were installed and secondary steel structures, which include the boat landing, the main access platform and the internal cassette, were fitted to them offshore. RWE said this design approach reduced the total amount of steel needed.
In addition to the wind turbine foundations, the foundation (monopile) for one of the two offshore substations located at the wind farm has already been laid. The second foundation (the jacket) is to be installed before the end of this year, while the two substation topsides will follow in 2026.
In addition, preparatory soil investigations are underway for the laying of internal cabling for the wind farm. The approximately 70 kilometres of cable are to be laid at the beginning of next year.
Installation of the 44 wind turbines is scheduled to begin in summer 2026.
After full commissioning in early 2027, Nordseecluster A will have a total capacity of 660 MW. The second expansion stage, Nordseecluster B, will contribute an additional 900 MW through its 60 wind turbines, which will commence commercial operation in 2029.
