The first important milestone in the installation of the Borkum Riffgrund 1 Offshore Wind Farm has been achieved: The installation of the offshore substation for the wind farm in the North Sea is completed.
"Though we have more than 20 years' experience in offshore wind, it's a very special moment,” said Christoph Mertens, Senior Director and head of DONG Energy Wind Power in Germany and continued;
"Borkum Riffgrund 1 is our first German wind farm in the North Sea. In addition, we gain a lot of experience from which our future German wind farms can profit. We've a lot of work ahead of us."
The construction of the substation makes it possible to transport the electricity from the 77 wind turbines, which have not yet been installed, and transport it to the converter station of the transmission system operator.
The installation started on 1 August when the substation was shipped from the Aalborg in Denmark. The construction components were loaded on a floating pontoon and sailed to the construction site.
37km north-east of the island Borkum, 54km off the Lower Saxony mainland coast, the foundation was placed on eight monopiles that have been driven into the seabed and anchored. In order to reduce the noise from the construction works, a three-fold bubble curtain was applied.
This technology reduces the noise transmission and makes sure that DONG Energy complies with the noise requirements. At the end, the top site was placed on the platform by means of a jack-up crane vessel. The total weight of the substation is 3,500 tonnes, and it covers an area of 465m2.
The next construction phase of the wind farm is the installation of the foundations, which according to schedule will be initiated at the beginning of 2014. Commissioning of the complete wind farm is scheduled for 2015 at the latest. When Borkum Riffgrund 1 has been commissioned, the wind farm will supply approximately 285,000 German households with green energy.
The wind farm will be operated and maintained from the Lower Saxony harbour Norddeich in Germany. DONG Energy also plans to locate its construction monitoring and operation management for the German offshore wind farms in Norddeich.
In February 2012, DONG Energy sold 50 per cent of the Borkum Riffgrund 1 Wind Farm to KIRBI A/S and William Demant.
From now and until 2020, DONG Energy plans to quadruple its present offshore capacity of 1.7GW to 6.5GW. In achieving this, Germany is one of DONG Energy's core markets.