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


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 23,500 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

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. 



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

Read more

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


More wind power from the North Sea from 2023



  • 90 km long and 900 MW capacity
  • 45 km onshore cable
  • 45 km offshore cable

Grid connection point

  • converter station Emden/Ost

Status of project

  • initial operation planned for 2023

About the project

In July 2017 TenneT commissioned the construction of the project DolWin6. Completion is scheduled for 2023. Like the preceding projects DolWin3 and BorWin3 DolWin6 is a 900 megawatt DC connection.

On the associated offshore platform DolWin kappa, the three-phase current generated by the offshore wind farms is converted into direct current and transported to Hilgenriedersiel on the mainland by an approximately 45 kilometre long sea cable. From the landfall in Hilgenriedersiel the electricity is transmitted to Emden via another 45 kilometre land cable. Here, TenneT is building a converter station and a transformer station to convert the direct current back into three-phase current and feed it into the power grid onshore.

Like most of the offshore grid connection systems linking wind farms in the Western part of the North Sea to the onshore grid the cable route of DolWin6 leads across the island of Norderney. In order to protect the sensitive nature in the Wadden Sea National Park and to ensure the integrity of the dykes TenneT carried out horizontal directional drillings with a length of up to 1.300 metres on the island. TenneT has pulled protective conduits into the bore holes where the DolWin6 sea cables will be pulled in within the next years.


DolWin6 crosses the island of Norderney – in 2018 on the beach, the minor intervention of the cable laying becomes visible for the first time

Everything under control - process updates of cable laying works to corresponding staff

Ground breaking ceremony for the DolWin6 converter land station in Emden/East in 2020

Project Director Dirk Adam with time capsule (contents: various coins, regional daily newspaper and building plans) for the foundation at ground breaking ceremony

Environmentally friendly 6 km long submarine cable laying in the Wadden Sea near Hilgenriedersiel

DolWin6 converter land station one year after start of the construction in 2021

DolWin kappa topside at the construction site in in Cádiz, Spain

Use of environmentally friendly cable laying technique (Horizontal Directional Drilling, short: HDD) in sensitive ecosystem

Pull-in of two 320 kV DC cables into protection tubes of Horizontal Directional Drilling technique in Hilgenriedersiel 2020.

First stage from Nuremberg to Rotterdam: the DolWin6 transformer transport by ship in 2020

Arrival of the transformers at the converter land station of DolWin6

Start of land cable laying in 2020: a total of 45 kilometres of underground cable is to be laid

In 2021: Further kilometres of land cable laying for DolWin6

Laying of DolWin6 protective plates as a warning for future earthworks directly above laid land cables in 2021

First backfilling of cable trench after successful cable laying works of another section of the DolWin6 land route

Tim Dampmann

Spokesperson - Projekt Offshore Communication