Siemens has handed over the second North Sea grid connection, HelWin1, to its client TenneT.
The German-Dutch transmission system operator has now also put this grid connection into commercial operation.
The offshore platform of the HelWin1 grid connection is located around 85 kilometers off the German coast – northwest of the island of Helgoland, after which the project was named. Up to 576 megawatts (MW) of clean electricity can now be transmitted with this grid connection – enough to supply more than 700,000 German households, Siemens wrote in a press release.
The Nordsee Ost and Meerwind Süd/Ost wind farms are linked to HelWin1. At present, wind turbines with a total capacity of around 260 MW are linked to the grid connection, with new turbines being connected almost on a daily basis. The Meerwind Süd/Ost wind farm is made up of 80 Siemens 3.6 megawatt wind turbines.
“This year we have completed the world’s first two large-category offshore grid connections equipped with efficient direct-current technology. We also intend to put the next two projects into commercial operation as planned within a few months,” stated Jan Mrosik, CEO of the Siemens Energy Management Division. “With the completion of HelWin1, TenneT now provides around 2,000 MW of transmission capacity in the German North Sea,” explained Lex Hartman, Member of the Board at TenneT TSO GmbH.
Siemens is implementing five North Sea grid connection projects for TenneT: HelWin1 (576 MW) and HelWin2 (690 MW) off of Helgoland, BorWin2 (800 MW) and BorWin3 (900 MW) off of Borkum and SylWin1 (864 MW) off of Sylt. Two of these, BorWin2 and HelWin1, have already taken up normal operation.
The next two grid connections, Sylwin1 and HelWin2, are scheduled to take up commercial operation in the first half of 2015 as well. The grid connections implemented by Siemens for TenneT will have a total transmission capacity of theoretically more than 3.8 gigawatts (GW), providing electricity from offshore wind power to supply around five million households.
The wind-based electricity is transmitted as alternating current to the converter platform, transformed into direct current and fed to the mainland via a subsea cable. The land-based station converts the direct current back into alternating current and feeds the electricity into the extra-high voltage grid.