The foundation for the offshore substation of the 332MW Nordsee One offshore wind farm was installed in the German part of the North Sea on 9 May.
After loading the piling hammer, the foundation was transported to the construction site approximately 40 kilometres north of the island of Juist, where a floating crane placed the jacket foundation weighing over 1,400 tonnes onto the sea bed.
The 50-metre tall foundation was anchored with four piles on the four pedestals at the bottom of the sea. Each pile has a weight of over 240 tonnes and a length of over 67 metres.
Installation of inter-array cables is expected to begin in June, and the substation topside is scheduled to be fitted onto the jacket foundation during this summer.
The offshore substation will transform the electricity generated by the 54 wind turbines at 33 kV to a transmission voltage of 155 kV. Submarine high-voltage cables will then transmit the electricity to Dolwin Beta converter station of the grid operator where the AC voltage is transformed to 250 kV DC voltage and transmitted to the nearest grid access point at Hagermarsch.
Bladt Industries was awarded the contract for the design, fabrication, installation and commissioning of the offshore substation. Bladt also produced and delivered the jacket foundation.
Once commissioned in 2017, Nordsee One is expected to produce an annual output of more than 1,300 gigawatt-hours of electrical energy.