Baltic Eagle´s offshore substation topside (OSS) has been successfully installed by Heerema Marine Contractors using the Thialf installation vessel. The jacket foundation had been placed on site in October 2022.
The role of the OSS is to collect the electricity generated by the wind turbines and transform the supply voltage before feeding it into the onshore power grid at the Lubmin grid interconnection point. The move involved the heaviest lifting operation for the Baltic Eagle project with a total estimated net weight of around 4200 t. Iberdrola now starts the offshore phase to make the OSS ready for energisation. This will be followed by the installation of the monopiles to which the wind turbines are attached with transition pieces.
The monopiles have been manufactured by the regional company EEW SPC from Rostock.
Once the wind farm is connected to the grid, the electricity generated by its wind turbines will be delivered via inter-array cables to the offshore substation where it is then transformed from 66 kV to 220 kV and transmitted via two high voltage subsea cables across the 90 km distance to the landing point at Lubmin into the 50Hertz transmission grid. The 220 kV submarine cables were already laid in 2021 and 2022 and deposited on the seabed at a safe distance from the platform position. The next step will be to move the two cable ends into the transformer platform in 2Q23.
In May 2021, Iberdrola and 50Hertz signed an agreement to cooperate on the construction, installation and commissioning of the OSS for Baltic Eagle offshore wind farm, which is currently, being built in German waters of the Baltic Sea. Iemants-Fabricom was responsible for the manufacturing of all structural elements of the substation, the marine contractor Heerema for transportation and installation, and Siemens Gas and Power for the delivery of all main electrical equipment for Iberdrola’s low-voltage part of the OSS.
Iris Stempfle, Managing Director of the Offshore Division and Deputy CEO of Iberdrola Deutschland, said: “The offshore substation is a key piece of technology for supplying sustainable energy to hundreds of thousands of households and for the decarbonisation of German industry. We are very pleased to have achieved this central milestone in close cooperation with 50Hertz as planned.”
Stefan Kapferer, CEO of 50Hertz, added: “The Baltic Sea still has a lot of potential and 50Hertz, together with partners such as Iberdrola, will help to achieve the German and European offshore targets: I congratulate everyone involved on the successful installation of the substation Baltic Eagle. Now we are once again a big step closer to completing the Ostwind 2 grid connection project by next year.”
Ostwind 2 is the project to connect the Baltic Sea wind farms Arcadis Ost 1 and Baltic Eagle to the German high voltage grid. To transfer the power from the two wind farms, 50Hertz is building three submarine cable systems that will transmit a total of 750 MW.
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