Siemens Energy is supplying the high-voltage direct-current (HVDC) power transmission technology for a further offshore connection in the German North Sea.

The German-Dutch network operator TenneT and the BorWin5 Offshore Consortium signed a corresponding contract, consisting of Siemens Energy and Dragados Offshore.

In 2025, the platform BorWin epsilon, which is part of the BorWin5 project, will begin the low-loss transmission of electricity produced by the EnBW He Dreiht wind farm off the island of Borkum to the Garrel/Ost converter station around 230 kilometers distant.

The transmission capacity of 900 megawatts is calculated to serve over 1.1 million households with electricity. The project is a further contribution toward decarbonizing Germany’s energy supply. BorWin5 marks the seventh HVDC offshore grid connection project undertaken by Siemens Energy in Germany with TenneT.

“We are especially pleased that we can again join with TenneT to make an important contribution to the decarbonization of Germany’s energy supply. The seventh order in the German North Sea underscores the great confidence in our HVDC technology. When DolWin6 and BorWin5 begin operation, we’ll have installed a total transmission capacity for 5.6 gigawatts of wind power in the German North Sea. This could supply around seven million German households with green electricity.”

Beatrix Natter, Executive Vice President of the Transmission Division at Siemens Energy.

Supply for Siemens Energy and its Spanish partner Dragados Offshore S.A. includes the turnkey construction and installation of the offshore platform in the North Sea and the converter station on land.

The offshore converter station will convert the three-phase alternating current produced by the wind turbines into direct current with a voltage of ±320 kilovolts(kV) for low-loss transmission to land.

The shoreside converter station in Garrel/Ost will then convert the electricity back into a three-phase alternating current for feeding into Germany’s power grid.

Siemens Energy will supply the HVDC technology required for the project and build the shore-side station, while Dragados will be responsible for the design, procurement, construction and installation of the offshore converter platform.