Germany: Alstom and TenneT to reach another important milestone in the offshore DolWin3 project

Alstom and the German-Dutch transmission system operator TenneT have reached another key milestone in the North Sea offshore grid connection project - ‘Dolwin3’. Two 700 MVA power transformers were successfully delivered and installed on the platform based in the Warnemüde shipyard in Germany, operated by Nordic Yards. The offshore grid connection project DolWin3 will provide clean energy by connecting the North Sea wind farms to the mainland. TenneT awarded DolWin3 to Alstom in February 2013. The project is on track to be completed in 2017.

The transformers were designed and built by Alstom specifically for the DolWin3 converter project at its Mönchengladbach plant in Germany. During routine inspections, one transformer can continue to operate allowing the converter platform to transmit the energy generated uninterrupted. Weighing in at about 500 tonnes – they were transferred on a 1,200-km-long journey by road, river and sea before being installed on the platform in Warnemünde, where they are  located in rooms specially designed with special corrosion protection against the harsh and aggressive offshore climate.

“The energy transition is this century´s big national task. For this reason we need the offshore wind power. Today is an important day for the entire DolWin3 project. This day shows the progress in the important industrial part of the energy transition – the development of the offshore wind power!”, said Erwin Sellering, Prime Minister of the Federal State of Mecklenburg-Vorpommern.

“With the grid connection DolWin3, we will provide a total of about 7,000 MW connectivity in the North Sea, transporting offshore wind power to the shore. This is equivalent to the supply of about nine million households with green energy. The German government´s offshore-expansion target for the North Sea and the Baltic Sea of 6,500 MW until 2020 will be fulfilled early”, said Wilfried Breuer, Member of the Management at TenneT Offshore GmbH.

“The 900 MW  wind energy DolWin 3 is the most powerful and largest HVDC-converter platform built at Nordic Yards. In cooperation with Alstom and TenneT we are moving the German energy transition another step further”, said Herbert Aly, CEO of Nordic Yards.

“The two power transformers are core components of the DolWin 3 offshore converter platform. Today’s milestone further confirmsour leadership in HVDC technology. This installation is the prerequisite for completion of the platform’s steel structure by Nordic Yards and the onward completion of the project” said Gerhard Seyrling, Vice President Alstom Grid, Region Central & Eastern Europe and Russia.

As the general contractor for TenneT, Alstom supplies and constructs both the onshore and offshore converter stations as well as the connecting cable systems for DolWin3. The project will use direct current technology with Voltage Source Converters (VSC) (±320 kV, 900 MW) to deliver the energy generated at sea to the mainland.