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).


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

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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 23,000 kilometres of high-voltage lines, we cross borders and connect countries.

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Grid maps

Maps of our onshore and offshore high-voltage grid.

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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.

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Transparency data

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

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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.

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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 41 million people.

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Clean wind energy from the eastern North Sea



  • 130 km long and 690 MW capacity
  • 45 km onshore cable
  • 85 km offshore cable

Grid connection point

  • converter station Büttel

Status of project

  • online since Juni 2015

About the project

The HelWin2 project will implement a 690 megawatt grid connection for wind farms near Helgoland. It is the third connection in the eastern North Sea. This will initially connect the Amrumbank West offshore wind farm. The DC submarine cable route runs 85 kilometres at sea from the HelWin beta converter platform to the Büsum landing point. From there, the buried cable runs another 45 kilometers to the onshore converter station in Büttel.

In spring 2011, the first horizontal boreholes for underpassing the Kiel Canal were drilled for the grid connection. Further boreholes for underpassing the state protection dike were drilled in 2012, and in 2013 the underground cable and the submarine cable route were laid in the coastal sea. In addition, the construction work for the onshore converter station in Büttel was completed and the installation of the high-voltage systems began.

The external steel work for the topside of the offshore converter platform HelWin beta was completed in 2013. Installation work on the high-voltage platform systems was completed in 2014. In summer 2014, both the converter platform at sea and the submarine cable were laid in deep water.

Cornelia Junge

Press Referent - Project Communication Offshore

0049 (0)5132 89-2357