Siemens has handed over SylWin1, its third North Sea grid connection this year, to the customer TenneT, the German-Dutch transmission grid operator, and it is now in commercial operation. At 864 MW It is the world’s most powerful such grid connection to date.
The offshore platform is located around 70 km west of the island of Sylt, after which the project was named. The electricity generated by wind power is transmitted over a 200 km subsea and underground cable link to the land-based station Büttel.
"This year we have completed the world’s first three offshore grid connections with efficient direct-current technology – SylWin1, BorWin2 and HelWin1. We also intend to put the fourth project HelWin2 into commercial operation as planned in the coming weeks", stated Jan Mrosik, CEO of the Siemens Energy Management division.
"2015 is a special milestone year for TenneT", commented Lex Hartman, a member of the managing board of TenneT TSO GmbH, "as we will be completing further offshore grid connections by the end of the year, meaning that all in all we will have implemented a capacity of more than 5000 MW, or more than two-thirds of the offshore expansion goal set by the Federal German government [for that date]" The government’s offshore expansion goal is to implement 6500 MW by 2020.
The three offshore wind farms DanTysk, Butendiek and Sandbank, each with a capacity of 288 MW, are linked to SylWin1. DanTysk and Butendiek both consist of 80 Siemens WTGs, each rated at 3.6 MW. Sandbank will be realised with 72 WTGs in the 4 MW class. At present, more than 100 wind turbines are already linked to the grid connection, with new turbines being connected almost on a daily basis. Under optimal wind conditions, such as those which the low-pressure storm front Niklas brought with it recently, a capacity of 350 MW is already being transmitted via the SylWin1 grid link.
Transmission system operator TenneT contracted the consortium comprising Siemens and the Italian cable specialist Prysmian for the HelWin1 offshore grid connection early in 2011. The offshore platform was built by Nordic Yards in Germany.
In total, Siemens has been awarded five North Sea grid connection projects by 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. Three of these, BorWin2, HelWin1 and SylWin1, have already taken up normal operation.
The fourth, HelWin2, is scheduled to take up commercial operation in the first half of 2015. All four connections to date emply Siemens’ HVDC Plus technology.