HomeRenewablesMarineSiemens and TenneT celebrate offshore wind milestone

Siemens and TenneT celebrate offshore wind milestone

A major milestone has been recorded for German offshore wind, with the news that Siemens has installed its third HVDC offshore grid platform for TenneT.

“We have achieved one more major interim milestone, and are step by step accomplishing the German government’s offshore expansion goals”, said Lex Hartman, a member of TenneT’s executive board.

The newly installed HelWin2 platform lies 35 km north of Heligoland, the island for which it was named, directly adjacent to the HelWin1 platform Siemens successfully erected earlier in August 2013. Earlier this year Siemens erected the BorWin2 platform off the coast of Borkum.
Siemens offshore
All told, Siemens is building five North Sea grid connections for TenneT. The first four are to begin commercial operation successively over the second half of 2014 and the first half of 2015, providing a total transmission capacity of over 2.9 GW. The fifth connection ordered this year, BorWin3, is to be ready for operation in 2019.

Using the Siemens technology installed on the platforms, the alternating current generated by the wind turbines is transformed into direct current for efficient transmission to the mainland. At the associated land-based stations, the electricity generated by the connected wind farms is converted back into the alternating current power required for feeding into the transmission grid.

Thanks to Siemens’ low-loss, high-voltage direct current (HVDC) technology, transmission losses are less than 4 per cent. The platforms are designed to operate for decades in rough North Sea conditions, and are fully automated.

The HelWin2 platform was constructed and installed by Heerema. The marine and land-based cabling were supplied and laid by cable specialists the Prysmian Group.