Skyborn Renewables and the German transmission system operator (TSO) 50Hertz, which is leading the development of the grid connection (OST-6-1) for the 976.5 MW Gennaker offshore wind farm, have signed an agreement that clears the way for the commissioning of the entire system by mid‑2028.
The contract governs the legally compliant cooperation for the construction and operation of the two offshore substations required for the Gennaker offshore wind farm, OSS Darß and OSS Zingst.
“The agreement resolves legal and regulatory uncertainties and sets a pioneering precedent for grid connection of an offshore wind farm located in territorial waters”, 50Hertz said on 27 January.
The Gennaker offshore wind farm will be built in German territorial waters, within the 12-nautical-mile zone, off the coast of the Fischland-Darß-Zingst peninsula, and is the first offshore wind farm to be connected under the “territorial waters regulation”, with operators being entitled to a grid connection once approval has been granted under the Federal Immission Control Act (BImSchG).
The agreement between 50Hertz and Skyborn for the two offshore platforms with a combined grid connection capacity of up to 927 MW, jointly used as part of both the wind farm and the grid connection system, defines key aspects such as collaboration, responsibilities, liability, payment terms, design, construction, installation, commissioning, and decommissioning, as well as fundamental principles for operation and maintenance (O&M).
Gennaker’s offshore substations are being delivered by a consortium comprising HSM Offshore Energy, Smulders, and Iv, with Allseas responsible for the transportation and installation of the two substations. The OSS Darß and OSS Zingst platforms are currently under construction in the Netherlands.
Once operational, the platforms will collect the electricity generated by Gennaker and transform it to 220 kV high voltage, before transmitting it to the new Gnewitz substation, some 70 to 90 kilometres away.
Construction at the substation site is already well advanced following approval under the Federal Immission Control Act, 50Hertz says.
For the territorial waters section, the state of Mecklenburg-Western Pomerania issued a planning approval decision in 2025, enabling offshore cable route work and onshore landing activities near Dierhagen to begin last year. Although approval procedures for the two offshore platforms and the onshore cable route are still ongoing, all documents required for planning approval have already been submitted, according to the TSO.
Located approximately 15 kilometres north of the Fischland-Darß-Zingst peninsula, the Gennaker offshore wind farm will feature 63 Siemens Gamesa 13-236 turbines, with the installation of the wind turbines scheduled to begin in late summer 2027.
The project received full approval from the state of Mecklenburg-Western Pomerania in December last year. The cooperation agreement that 50Hertz and Skyborn now concluded represents a prerequisite for the planned commissioning of the grid connection system in July 2028.