Two transmission system operators—TenneT TSO GmbH and 50Hertz Transmission GmbH—have awarded contracts to the Prysmian Group and NKT GmbH to supply a total of 1,000 km of 525kV underground power cable for the 2-GW SuedOstLink transmission line in Germany.

When completed, the SuedOstLink will be the world’s first large commercial 525 kV XLPE high-voltage DC 2GW transmission line. The initiative is part of German corridor projects to significantly increase renewable energy supply in the country. The overall project, being funded within the EU’s Connecting Europe framework, will see TenneT and 50Hertz investing some €5 billion.

“The underground cables are the heart of SuedOstLink,” said TenneT Managing Director Tim Meyerjürgens. “We will use the innovative, plastic-insulated 525 kV underground cables for the first time worldwide, and will thus set new standards in technology and the reduction of environmental impact.” He noted that with the higher voltage level, the cables can transmit more power than a conventional 320 kV cable systems. “The route can be narrower and the necessary civil engineering work during the construction phase will decrease.”

Prysmian and NKT will each supply about 500 km of 525 kV cable, both using their own insulation designs, Prysmian will supply power cable with its P-laser technology while NKT will provide its XLPE technology. There is a total of five cable lots, three being provided by NKT.

Per a Prysmian press release, its contract from TenneT TSO GmbH, a Dutch-German grid operator, calls for the company to design, manufacture, supply, lay, joint, test and commission the 2GW underground cable system through the TenneT region of this first German Corridor. It will include Prysmian’s innovative P-Laser insulation technology that will help enable a transmittable power of more than 2GW on a single system for the first time. The contract is valued at approximately €500 million, depending on options.

“This prestigious award confirms our ambition to play a strategic role in the shift towards a low-carbon economy and to drive the energy transition forwards with smarter, more reliable and more sustainable solutions,” said Prysmian Group CEO Valerio Battista. “It gives us great satisfaction to be involved in the development of this vital infrastructure project and to set this milestone in the upgrading of the E.U. power transmission grid.”

Per an NKT press release, the company will deliver to 50Hertz Transmission GmbH its XLPE cable for the NKT expects to start production of the high-voltage DC power cables and accessories by the end of 2021, with installation in mid-2022 and final completion in 2025. NKT has a strong footprint in Germany, with facilities in Cologne, Nordenham and Berlin, and it has worked with 50Hertz on other projects, all of which made it an ideal choice.

“I am very pleased that we have booked our largest high-voltage DC order ever by getting a significant part of the SuedOstLink project,” said NKT President and CEO Alexander Kara. “This underlines our role as a key partner in the green transformation of Germany.”