Wedding on the high seas: Substation for Nordsee One offshore wind farm successfully installed

  • 2,100 ton substation platform successfully placed on foundation
  • The system will now be connected with the export cables and the inter-array cables
  • Turbine installation is expected for early 2017
  • Commissioning of the 332 megawatt wind farm anticipated in 2017

Nordsee One offshore wind farm celebrates a wedding: This is the construction term used for the process of marrying a substation platform to its foundation. With the offshore transformer substation, transformer and all associated electrical components now completed, the project, located approximately 40 km north of the island of Juist, is celebrating another milestone.

The three-day journey of the substation began in Aalborg, Denmark. Upon arrival a floating crane placed yesterday the heavyweight substation onto the 50-meter tall foundation. The 2,100 ton substation is the heaviest component of the offshore wind farm.

Tim Kittelhake, Managing Director (COO) of Nordsee One GmbH noted: “The heart of the wind farm has now been installed. Comprising four levels, the substation is a steel building that houses the project’s grid transformers and switchgears, as well as the auxiliary power supply for the safety systems, lights, and data and control system. Our thanks to Bladt Industries, who developed and built the substation over the past 18 months.”

The structure extends approximately 40 meters above sea level. A helicopter landing platform on the top deck of the substation allows all-weather access to the platform for operation and maintenance work.

Matthias Esken, Package Manager for the substation added: “I’m glad to report that the design and fabrication phase was successfully completed on schedule. With installation complete, we are now in the process of offshore commissioning with our suppliers Bladt Industries and Semco Maritime, out of our base harbor in Norderney. Looking ahead, in the upcoming weeks the grid operator, TenneT’s export cables and the inter-array will be installed. We will then commission all of the systems, so that we under current planning are ready in autumn for the connection of the wind turbines, which we plan to install early 2017.”

The 54 turbines will be connected to the offshore substation by ten strings of cables, with an overall length of approximately 70 kilometres – a longer distance than the length of the Eurotunnel, which connects the UK with Continental Europe. 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 the grid operator’s converter station, where the AC voltage is transformed to 320 kV DC voltage and transmitted to the nearest grid access point at Hagermarsch.

Once completed, Nordsee One wind farm is planned to consist of 54 wind turbines with an overall installed capacity of 332 megawatts. Under current planning full commissioning of the wind farm is anticipated in 2017. Nordsee One is owned by Northland Power Inc. (85%) and RWE International SE (15%).