The Jasmund offshore substation (OSS), developed by HSI—a collaboration between HSM Offshore Energy, Smulders, and Iv—has been installed to connect the Windanker offshore wind farm to the German electricity grid in the Baltic Sea.
The Jasmund platform is part of the Ostwind 3 grid connection project, which will collect 300 MW from Windanker wind farm starting in October, transmitting it to the German grid. 50Hertz, the responsible transmission system operator (TSO), notes this is the first offshore platform in the Baltic Sea under its management.
The Jasmund OSS jacket foundation was produced by Smulders in Vlissingen, Netherlands, and sent to the Baltic Sea in December 2025. The topside, manufactured at HSM Offshore Energy’s Stormpolder yard near Rotterdam, followed shortly after.
Heerema Marine Contractors conducted the installation at the site northeast of Rügen island, lifting the platform onto the foundation on December 17, 2025, according to 50Hertz.
Upcoming offshore testing and commissioning activities will prepare the Jasmund OSS for operation, as per HSI Joint Venture, which holds the contract for the full EPCIC scope (engineering, procurement, construction, installation, and commissioning).
The Ostwind 3 grid connection system and Windanker offshore wind farm, built and operated by Iberdrola, are expected to be completed by September 30, 2026, according to 50Hertz.
Jasmund OSS is the first of three offshore substations HSI Joint Venture is delivering for 50Hertz. OSS Zingst and OSS Darß will follow, connecting the Gennaker East and West offshore wind farms, respectively, to the onshore network as part of the OST-6-1 grid connection.
“After Ostwind 1 and 2, Ostwind 3 is the next project in the sea area northeast of Rügen, which we will complete on time and within budget,” said Stefan Kapferer, Chairman of the Management Board of 50Hertz.
“We are also progressing well with the OST-6-1 project, which has a transmission capacity of 927 MW to connect the Gennaker wind farm. Two offshore platforms are under construction, protective pipe laying has started, and a new substation near Gnewitz is developing.”
Original Story at www.offshorewind.biz