50Hertz can finally begin work on the Ostwind 3 grid connection for the offshore wind farm Windanker in the Baltic Sea. The Ministry for Economics, Infrastructure, Tourism and Labour of Mecklenburg-Western Pomerania has issued the permits for the onshore route of four kilometers as well as a substation with a surface of approx. ten hectares in the municipality of Brünzow, near Lubmin. Earlier, the authority already approved the offshore route in the coastal waters, which will have a length of around 100 km. The Federal Maritime and Hydrographic Agency (BSH) already greenlit the route and the construction of an offshore platform in the Exclusive Economic Zone (EEZ). The grid connections for the projects Ostwind 4 and Bornholm Energy Island are currently the subject of preliminary planning.

Reinhard Meyer, Minister for Economics, Infrastructure, Tourism and Labour in Mecklenburg-Vorpommern: “Our ambitious goal is to cover the state’s entire energy consumption for electricity, heat and mobility from renewable sources by 2035. To achieve this, it is necessary to accelerate the expansion of wind energy, among other things. The potential of the wind power industry in Mecklenburg-Vorpommern can be significantly expanded with the development of offshore wind power. The Ostwind 3 grid connection will help with this.”

Stefan Kapferer, CEO of 50Hertz: “The region around Lubmin will become an important hub for electricity from renewable sources in the following years. Such renewable energy sources are linked to regional value creation and opportunities for the sustainable economic development of this energy region by attracting companies. Several hydrogen projects are already in the works, as a connection to the gas system infrastructure is available.”

The wind farm that is planned north of Rügen island by Iberdrola will be connected by our Ostwind 3grid connection system. The transmission capacity of the alternating voltage system amounts to 300 megawatts (MW). 50Hertz already commissioned the Dutch-Belgian joint venture HSI to deliver the Jasmund offshore platform, which is currently under construction in a shipyard in Stormpolder, near Rotterdam. The completion of the Ostwind 3 grid connection is planned for the third quarter of 2026.

New substation in the municipality of Brünzow

The new substation, with a surface comparable to 14 football fields, will be built on the municipal territory of Brünzow, between the districts of Stilow and Klein Ernsthof. Here, the wind power from the Baltic Sea will be fed into the transmission grid. The construction measures commenced in April with archaeological surveys of the construction site; the actual construction of the substation will begin in the summer of 2024 and continue into the second quarter of 2026.
The submarine cable will be brought onshore next to the port of Vierow using horizontal directional drilling. From there, the land cable will be entrenched and continue underground to the Stilow substation. For the first time, 50Hertz will fully plan, construct and operate the offshore substation in addition to the cable systems that will connect the wind farm to the transmission grid.

Other grid connections in the region

In the scope of the onshore route for Ostwind 3, cable conduits were already laid for the two future grid connections Ostwind 4 and Bornholm Energy Island. By laying three cable systems at the same time, the inconvenience caused by regional construction sites is limited.

Ostwind 4 will be the first system in the German Baltic Sea to use the new 2-GW technology. From the landing point in the Vierow port area, the electricity that is generated offshore will be transported to the Stilow substation. For the grid connection on land, 50Hertz is planning a new converter next to the substation. This converter will convert the direct current generated at sea into alternating current for the transmission grid. The project is the subject of an approval procedure as well as preliminary planning.

Another new project is the joint project by 50Hertz and Danish transmission system operator Energinet, named Bornholm Energy Island. Thanks to the project, two gigawatts of electricity from offshore wind farms off the coast of Bornholm island can be integrated into the German transmission grid. Coming from the Danish island of Bornholm in the Baltic Sea, the onshore grid connection on the German side is planned near Greifswald, in the survey area of the municipalities of Kemnitz/Brünzow. There, a new substation and converter system are to be erected. The project is currently the subject of preliminary planning.

In the final development phase, the three systems Ostwind 3, Ostwind 4 and Bornholm Energy Island will be able to supply a total output of up to 4.3 gigawatts of green electricity when the wind conditions are optimal.

Source: 50Hertz