Our key tasks

We are primarily tasked with providing power transmission services, system services and facilitating the energy market. Our core tasks follow from our appointment as grid operator under the Dutch 'Elektriciteitswet' (E-wet) and the German 'Energiewirtschaftsgesetz' (EnWG).

Explore our key tasks

Innovation

TenneT presents Hub and Spoke concept for large scale wind energy on the North Sea.

Read more
Our grid

TenneT manages the high-voltage grid in the Netherlands and large parts of Germany. TenneT transmits electricity at 110,000 volts (110 kV) and higher. With around 24,500 kilometres of high-voltage lines, we cross borders and connect countries.

Explore our grid

Offshore Outlook 2050

Already by 2030, the originally planned capacity of 15 gigawatts of offshore wind energy will increase to 20 GW.

To Offshore Outlook 2050
Electricity market

The energy sector is developing rapidly. The process of European market integration began some years ago. Its purpose is to create a single European market that enables market parties to trade gas and electricity across national borders easily and efficiently.

Explore the electricity market

Transparency data

We provide transparency data on our operations on our Dutch and German transparency page and on ENTSO-E. 

To transparency pages
E-Insights

Our vision is to be one of the most transparent Transmission System Operators (TSO) in Europe and thereby creating value for society. In this Energy Insights section we present selected energy related topics and show data, information and valuable insights. 

E-Insights

E-Insights

Facts & figures related to TenneT facilitating the market can be found here.

Read more
Company

TenneT is a leading European electricity transmission system operator (TSO), with activities in the Netherlands and in Germany. We strive to ensure a reliable and uninterrupted supply of electricity in our high-voltage grid for some 42 million people.

Explore our company

We are TenneT

Meet us
News News German

Offshore grid connection BorWin6: TenneT awards contracts for cable

Downloads & Contact
  • The contract for production and installation of the DC cables at sea and on land is awarded to Nexans Norway AS
  • 235-kilometre-long direct current connection
  • Commissioning of the 980 megawatt connection is scheduled for 2027

    In the tendering process for the award of the contract to build the 235-kilometre-long offshore grid connection system BorWin6, TenneT has now also awarded the contract for cable pro-duction and laying. Nexans will be the contractor for the sea, tidal flat and land cables. This means that the important contracts for the construction of the BorWin6 grid connection have been awarded. TenneT had already commissioned the converter stations at sea and on land in February.

    "We have a long and trusting partnership with Nexans, which guarantees us reliability and quality at the same time," said Tim Meyerjürgens, COO of TenneT. BorWin6 is the last grid connection project in the German North Sea to be realised by TenneT before the technologi-cal leap to two gigawatts and 525-kilovolt cables.

    Various direct current cables with 320 kilovolts will be used in the project. Among other things, about 400 kilometres of cables with copper conductors, which have a diameter of up to about 14 centimetres, will be produced for laying at sea, including reserve cables. They weigh about 47 kilogrammes per metre. On land, cables with an aluminium conductor are also used, which weigh 16 kilograms per metre with a diameter of 12.5 centimetres. In sections of about 1,400 metres, these will then be connected to each other with sleeves. The laying work is scheduled to start in 2025.

    Two cable strings will be laid for the grid connection, one positive and one negative pole, as well as an additional fibre optic cable, which will later be important for controlling the system.

    The wind turbines are connected directly to the BorWin kappa offshore platform via innovative 66-kilovolt three-phase cables. This eliminates the need for the transformer stations that were previously required in each wind farm and the 155 kV three-phase cables that were previously used to connect to TenneT's offshore platform.

    Using the extra-high voltage direct current cable, which is 235 kilometres long in total, TenneT transmits the electricity to the converter station in Büttel (Schleswig-Holstein) on land after conversion using low-loss direct current technology. Here, the direct current is converted back into three-phase current and fed into the extra-high voltage grid.

     

    With the innovative 66 kV connection, the wind farms are directly connected to TenneT's offshore platform. Transformer stations in the offshore wind farms are thus no longer necessary.

     

    Facts and figures on BorWin6

    BorWin6 will be realised with a capacity of 980 megawatts off the coast of Borkum. With 190 kilometres of submarine cable, it will be the longest submarine cable route to date. On land, the cable will be laid parallel to the existing routes of the HelWin1+2 and SylWin1 connec-tions, whose onshore converters are also located in Büttel.

    • 235 kilometres long connection using high-voltage direct current transmission technol-ogy (HVDC) with a maximum transmission capacity of 980 megawatts
    • 45 kilometres of land cable, 190 kilometres of submarine cable
    • Grid connection point: Büttel (Schleswig-Holstein)
    • Planned commissioning 2027

    Share this:

    Do you want to know more?

    Cornelia Junge

    Spokesperson - Project Communication Offshore

    0049 05132 89-2357

    cornelia.junge@tennet.eu

    Do you want to stay informed?

    Like the

    facebook page

    Go to Facebook page