Transmission system operators (TSOs) 50Hertz and Tennet have formed a new partnership that aims to deliver more renewable energy capacity generated offshore onto the grid for reliability and sustainability.

The TSOs will develop a multi-terminal hub in Schleswig-Holstein at the North Sea coast and a 200km high-voltage DC underground cable to Mecklenburg-Vorpommern to enable the transportation of offshore wind power capacity to the Germany grid.

The projects will be implemented as part of the 2035 grid development plan which the German regulator BNetzA approved in 2021.

The transmission network will add 4GW of renewables capacity on the German grid, thereby helping the country to achieve its renewable energy and greenhouse gas emissions reduction targets.

The projects will include the installation of switch gears and converters to convert DC into AC in Heide. This will enable the use of offshore wind capacity to power planned electrolysers for green hydrogen production which can be used to help decarbonise local industry.

The 200km underground cable, to be installed in Klein Rogahn near Schwerin, will transport electricity at 525kV voltage level resulting in more renewables capacity being transported.

Stefan Kapferer, the CEO of 50Hertz, said: “If Germany is to become climate-neutral by 2045, there must be even more focus on cooperation in the future. 50Hertz and TenneT are therefore working together and joining forces to tackle this challenging project in order to transport as much electricity generated at sea as quickly as possible to where it will be urgently needed in the future.”

Tim Meyerjürgens, the COO of TenneT, added: “With the joint implementation of the onshore hub in Schleswig-Holstein, TenneT and 50Hertz are laying the foundation for even higher utilisation of onshore DC lines while at the same time increasing the level of security of supply.

“In addition, the concept enables to accelerate the expansion of offshore wind energy, as envisaged by the new German government. With the implementation of the onshore hub and the three grid expansion projects linked to it, it will be possible to connect four gigawatts of offshore wind energy from the North Sea in the area of Heide as early as 2032. This means that one part of the project will be completed three years and another even five years earlier than originally planned in the grid development plan.”