First Steel Cut for Ostwind 4 Platform

Fabrication of the offshore converter station for the Ostwind 4 project has commenced with the first steel cut at Drydocks World's Dubai facility. The milestone marks the transition from design into physical construction for the 2 GW, 525 kV HVDC offshore grid connection in the German Baltic Sea, being delivered by a GE Vernova and Drydocks World consortium for transmission system operator 50Hertz Transmission GmbH.

GE Vernova stated the project will connect offshore wind energy directly to the German transmission grid and, once installed, will deliver renewable electricity equivalent to powering nearly two million households. The company described Ostwind 4 as the largest and most technically advanced 525 kV HVDC offshore grid connection of its kind in the German Baltic Sea.

Project Scope and Technology

The Ostwind 4 connection will transmit 2 GW of offshore wind power from wind farm sites approximately 30 kilometres northeast of Rügen Island in the Arkona Basin to the German onshore grid. The system will use a bipolar HVDC configuration operating at 525 kV over approximately 110 kilometres of subsea cables. It is Germany's first 2 GW HVDC offshore grid connection and the first 525 kV HVDC link for offshore wind farms in the German Baltic Sea.

GE Vernova is supplying voltage-sourced converters, high-voltage transformers and SF₆-free gas-insulated switchgear from its GRiDEA portfolio for the project. The company announced the contract award in December 2024, with responsibility for the design, construction and commissioning of the HVDC transmission system.

Drydocks World was awarded the engineering, procurement, construction and installation contract for the offshore wind energy converter station topsides and jacket structures by 50Hertz. The topside is being fabricated at Drydocks World's Dubai yard, integrating technology manufactured in Europe, and will subsequently be transported to the project site in Germany.

Timeline and Grid Context

Ostwind 4 is provisionally scheduled for completion by the end of 2031, with 50Hertz listing the expected completion date under Section 17d(2) sentence 3 of the German Energy Industry Act as 31 May 2031. The project is the fourth offshore grid connection in 50Hertz's Ostwind programme, which connects wind farm sites northeast of Rügen to the transmission network. 50Hertz is one of Germany's four transmission system operators and is responsible for planning, permitting and constructing the Ostwind 4 connection.