Nordsee Ost Foundation Installation Complete

All foundations of the Nordsee Ost offshore wind farm have been successfully installed some 35 kilometres north of the island of Heligoland. A total of 48 jacket foundations were installed for the wind turbines and one for the substation in water up to 25 metres deep.

Each of the foundations for the wind turbines is approx. 50 metres high with a weight of some 550 tons. The heavy-duty crane of RWE’s own installation vessel “Victoria Mathias“ placed the foundations on the sea bed and then anchored them firmly with foundation piles with a length of some 50 metres and a weight of more than 100 tons. The jacket foundations were manufactured by the company Kvaerner in Verdal, Norway, and transported by pontoons to the Nordsee Ost base port at Bremerhaven. Once there, two foundation structures at a time were loaded with the associated eight foundation piles onto the installation vessel and taken to the construction site at sea.

“With the successful completion of all foundations we have reached an important milestone and demonstrated that our logistics chain has been working exceptionally well”, emphasised Marcel Sunier, project director for the Nordsee Ost wind farm at RWE Innogy. “Starting in May, we intend to begin with the installation of the wind turbines, followed by the substation at sea in the summer. All the facilities are due to be connected to the grid by spring 2015.”

A total of 48 wind turbines of the 6-megawatt class are being erected across some 24 square kilometres for the Nordsee Ost wind farm. The total weight carried by each individual foundation amounts to some 700 tons. The key components of the wind power systems are already stored in the base port at Bremerhaven. This includes, for instance, the rotor blades with a length of over 60 metres, the steel towers of the turbines weighing over 240 tons and the nacelles with the size of a single-family home. The “Victoria Mathias“ installation vessel is currently being converted in the Mützelfeld shipyard at Cuxhaven so that it can accommodate these huge components: To this end, the transportation frames for the foundations are being removed from the ship’s deck and replaced by appropriate transport restraint systems for the wind tubrines. The “Victoria Mathias“ is due to leave the port for the first time with tower segments and nacelles on board in May. Moreover, its sister vessel “Friedrich Ernestine“, which is currently still erecting Gwynt y Môr offshore wind farm off the Welsh coast, will help installing the turbines starting in the summer.

Once complete, the Nordsee Ost offshore wind farm will have an installed capacity of some 295 MW and supply the equivalent of some 300,000 residential households per year with electricity. Equipped with the currently most powerful offshore turbines, Nordsee Ost ranks among the largest commercial wind power projects off the German coast.

Press release, March 14, 2014; Image: rwe