McDermott Cuts First Steel for LanWin1 HVDC Platform
McDermott International has held a steel-cutting ceremony marking the official start of fabrication for the offshore converter platform for TenneT's LanWin1 HVDC grid connection system in the German North Sea. The milestone, reached in February 2026, signals the beginning of production of structural steel panels that will subsequently be shipped to McDermott's fabrication yard in Batam, Indonesia, for assembly of the topside.
LanWin1 is McDermott's second project within TenneT's 2 GW Programme, following BalWin4, on which topside fabrication began in June 2025 and jacket foundation work commenced in September 2025. Both projects were awarded to a consortium of GE Vernova and McDermott under contracts signed with TenneT in April 2023, valued at a combined approximately €4 billion. Under the arrangement, McDermott is responsible for the engineering, procurement, fabrication, installation, and commissioning of the offshore converter substation platforms for both systems.
Each platform is designed to convert up to 2 GW of offshore wind-generated electricity from 66 kV alternating current to 525 kV direct current, enabling efficient transmission to onshore infrastructure. For LanWin1, the offshore converter station will be located approximately 160 km off the coast of Germany in the North Sea, with the onshore converter station situated in the Wesermarsch region of Lower Saxony, where the system will connect into the Unterweser area of the German high-voltage grid.
The commissioning target for BalWin4 is 2029, with LanWin1 scheduled for completion a year later in 2030. Cable installation for LanWin1 is planned for 2028, with nearshore installation work allocated to Asso.subsea under a contract with main contractor Jan De Nul. The cable connections for both BalWin4 and LanWin1 in Lower Saxony are being realised by a consortium of Jan De Nul, LS Cable, and Denys.
In addition to BalWin4 and LanWin1, McDermott is also fabricating TenneT's BorWin kappa offshore converter platform, part of the 980 MW BorWin6 grid connection in the German North Sea.
TenneT's 2 GW Programme forms part of a broader effort to connect 40 GW of offshore wind generation in the North Sea to the high-voltage grids of Germany and the Netherlands. The programme originated from the Esbjerg Declaration of May 2022, in which Germany, the Netherlands, Denmark, and Belgium committed to jointly installing at least 65 GW of offshore wind capacity by 2030.
