Prysmian Group has announced the successful commissioning of the High Voltage Direct Current (HVDC) offshore grid connection projects BorWin2 and HelWin1 which have both been realised off the North Sea coast of Germany.

Prysmian secured these two projects in mid-2010 as part of overall contracts awarded to consortia between the Group and Siemens Energy by the Dutch-German transmission system operator TenneT for the grid connection of offshore wind farms to the mainland.

BorWin2 now links the Global Tech 1 offshore wind farm in the North Sea to mainland Germany and has the same grid connection capacity available for further offshore wind farm connections.

This important project marks a series of significant milestones, being the first large-category offshore grid connection worldwide to take up commercial operation with HVDC technology, employing an extruded cable connection along a 200 km route (125 km offshore and 75 km onshore) with the highest power transmission capacity (800 MW) and the highest DC voltage level (+/- 300 kV DC) worldwide, a record previously also held by Prysmian with the +/-200 kV DC Transbay Project in San Francisco (California).

HelWin1 is the second HVDC grid connection to be handed over to TenneT in the first weeks of this year and links the offshore wind farms Nord See Ost and MeerWind to mainland Germany with a +/- 250 kV DC, 576 MW cable connection along a total route of 130 km (85 km submarine and 45 km land).

Both BorWin2 and HelWin1 use extruded HVDC cable technology from Prysmian together with Siemens HVDC Plus converter technology at the offshore platform and onshore stations. Prysmian Group has also installed the multiple 155 kV HVAC submarine cables which connect the converter platforms to the respective individual offshore wind farm transformer platforms.

The completion and hand-over of these important projects re-affirms the Group's continued successful relationship with TenneT who have awarded Prysmian the submarine and land cable systems for a total of six HVDC grid connection projects in recent years.

BorWin2 and HelWin1 are the first and second grid connections to be handed over; a further two DC offshore grid connection projects, SylWin1 and HelWin2, near completion and are scheduled to take up commercial operation within the first half of 2015. Prysmian is currently implementing also the HVDC cable systems for the DolWin3 and BorWin3 projects.

Over the last years the Group has continued to develop a wide range of state-of-the-art products and technologies for the renewable energies sector. These latest achievements underline the Group's pre-eminent role in the development of HVDC cable transmission systems and its leading position in the commercial application of HVDC cable technology.