Norderney: BorWin5 Grid Connection

The transmission system operator, TenneT, has decided to build a 900 MW grid connection from the EnBW He Dreiht wind farm to the converter station at  Garrel/East. The 320 kV direct current connection is meant to support the German supply network. TenneT has opted in favour of building this direct current grid connection using egeplast protective pipes for high & extra high voltage cables of up to 525 kV.

Horizontal drilling protects natural habitats

Connecting the offshore wind farms to the supply network is very important if the expansion objectives for renewable energies in Germany are to be met. One of these offshore connections is BorWin5 – a 230-km grid connection connecting the EnBW He Dreiht wind farm north of Borkum to the extra high voltage onshore grid. The grid connection point is the converter station at Garrel in the Cloppenburg region. The submarine cable measures 110 kms in length. The total
share of the underground cable is 120 kms. For the construction work, TenneT commissioned a working community comprised of three companies, Matthäi, Beermann and Matthäi Wasserbau. The pipeline construction works are carried out by Strabag by order of the working community. The offshore link runs across the island of Norderney. To protect the sensitive natural environment of the tidelands and to ensure the security of the dyke on the island, TenneT opted in favour of horizontal drilling. In this context, the high-temperature resistant
Macroduct High-T in 450 x 61.5 mm was the product of choice. It is a protective pipe for high and extra high voltage cables of up to 525 kV which provides enhanced thermal stability, enabling it to withstand the high thermal stress involved. The combination of high flexibility and the solidity of the PE pipe
provide the optimum properties required for performing these horizontal drilling operations.