Name and Location
DolWin2 project, North Sea, Germany.

Client
TenneT.

Project Description
DolWin2 is part of Germany’s energy transition roadmap, called ‘Energiewende’, which foresees the generation of more than 6.5 GW from offshore wind by 2020 and 15 GW by 2030.

The DolWin beta grid connection, which involves the installation of the world’s most powerful offshore converter station in the North Sea, forms part of DolWin2. The station will connect offshore wind farms in the North Sea’s DolWin cluster, currently the largest offshore wind farm cluster worldwide, with the German grid.

The 320 kV converter station, housed on an offshore platform, has a 916 MW power transmission capacity – enough to power more than one-million households with clean energy.

The main function of the station will be to convert the electricity generated by the offshore wind farms from alternating current into high-voltage direct current for efficient and reliable transmission to the mainland.

Value
Not stated.

Duration
Not stated.

Latest Developments
Power and automation technology group ABB handed over the DolWin beta project to TenneT in July this year.
ABB was awarded the turnkey responsibility for the design, engineering, supply and installation of the offshore wind connection by TenneT.

The project scope included the offshore converter station, the sea and land cable systems, and the onshore converter station.

The complete platform, including substructure, weighs about 23 000 t and is about 100 m long, 70 m wide and 100 m tall. It was transported in 2014 from Dubai, where it was built, to Aibel’s shipyard, in Norway.

DolWin beta uses a self-installing gravity-based structure concept, whereby the platform is slowly ballasted down to the seabed by filling the six columns with water, which will then be completely replaced by gravel to permanently secure the platform.

Key Contracts and Suppliers
ABB (design, engineering, supply and installation of the offshore wind connection).

On Budget and on Time?
Not stated.

Contact Details for Project Information
TenneT, Cornelia Junge, tel +49 5132 89-2357 or email cornelia.junge@tennet.eu.
ABB group media relations, Michael Schiendorfer, tel +41 43 317 7111.