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 24,500 kilometres of high-voltage lines, we cross borders and connect countries.

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Offshore Outlook 2050

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

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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 42 million people.

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Offshore wind from Lower Saxony



  • 32 km long und 111 MW capacity
  • 4 km onshore cable
  • 28 km offshore cable

Grid connection point

  • substation Inhausen (220 kV)

Status of project

  • in operation since November 2017

About the project

Nordergründe is the third project within the twelve nautical mile zone of Lower Saxony for which TenneT has implemented a three-phase grid connection. This is both technically and economically the most efficient solution, as the Nordergründe wind farm is only around 30 kilometres from the coast. The 155 kilovolt connection has a total length of 32 kilometers and can transport up to 111 megawatts (MW) of clean wind power. The grid connection point for the Nordergründe offshore project is the Inhausen transformer station north of Wilhelmshaven, which was extended for this purpose in 2012. Here the electricity is transformed to 220 kV and fed into the 220 kV transmission grid.

TenneT had already completed the installation of the cable in summer 2016. Since then, the end of the offshore cable in the wind farm area 15 kilometres east of the island of Wangerooge has been ready to move into the wind farm's transformer station. Due to the insolvency of the platform builder, the platform was not erected until September 2017 and TenneT was now able to pull the submarine cable from the monopile, the foundation foundation, into the platform. This was followed by numerous tests and further installation work in preparation for the commissioning of the offshore grid connection. The three-phase connection has been in operation since November 2017.

Tim Dampmann

Spokesperson - Projekt Offshore Communication