Germany has approved the planning of a new offshore electricity connection in the North Sea that will transport power from the Waterekke offshore wind farm and, in the future, from the N-10.2 offshore area to the mainland.

The Federal Maritime and Hydrographic Agency (BSH) granted planning approval for the BalWin4 and BalWin delta offshore grid connection system, with TenneT Offshore GmbH as the project developer. The approval was handed over to TenneT Offshore on July 21, 2026.

The project is designed to transmit up to 2,000 MW of electricity through an offshore converter platform and a high-voltage direct current (HVDC) cable. The connection is scheduled to enter operation in the fourth quarter of 2029.

Importantly, the approval concerns offshore grid infrastructure, not a new offshore wind auction. The project provides the transmission infrastructure needed to bring electricity generated at sea to the German grid.

BalWin delta platform will convert offshore power

The BalWin delta converter platform will be built on the northeastern edge of the Waterekke offshore wind farm, around 117 kilometres from the nearest islands, Borkum and Juist. A helicopter landing deck will provide access to the platform.

Electricity generated by the wind turbines will initially reach the platform as alternating current through subsea cables. At BalWin delta, the electricity will be converted from alternating current to direct current before being fed into the BalWin4 HVDC cable.

The use of direct current allows large amounts of electricity to be transported efficiently over long distances with relatively low losses.

The BalWin4 HVDC cable will be around 272 kilometres long in total between the offshore and onshore converter stations. Approximately 130 kilometres of the cable will run through Germany's Exclusive Economic Zone (EEZ) in the North Sea, which falls under the BSH's jurisdiction.

Construction work to begin in 2026

According to the BSH, the first preparatory offshore work is expected to begin in late summer 2026. Installation of the HVDC export cable is scheduled to start at the beginning of 2027, while installation of the BalWin delta converter platform is expected to begin in September 2027.

The offshore connection is planned to be operational in the fourth quarter of 2029.

BSH President Helge Heegewaldt said the planning approval establishes the basis for reliably bringing offshore wind power to shore. He also highlighted the importance of grid connection systems for allowing offshore wind development to contribute to climate protection and security of supply while providing greater planning certainty for investors.

TenneT to compensate for environmental impacts

The project will involve interventions in the marine environment. TenneT Offshore will compensate for these impacts through a replacement measure focused on the restoration of geogenic reefs in Germany's North Sea EEZ.

The measure involves placing natural stone blocks to restore geogenic reefs.

Once completed, BalWin4 and BalWin delta will provide 2 GW of transmission capacity for electricity produced by the Waterekke offshore wind farm and, subsequently, the N-10.2 area, strengthening Germany's offshore grid infrastructure as the country continues to expand its offshore wind capacity.