Iberdrola and 50Hertz ink Baltic Eagle substation agreement

4C Offshore | Tom Russell
By: 18/05/2021 Iberdrola
Spanish energy giant Iberdrola and German transmission system operator 50Hertz have signed an agreement for the Baltic Eagle wind farm being developed in German waters of the Baltic Sea. The two entities will cooperate with regard to the construction, installation and commissioning of the project's Offshore Substation (OSS).

The substation is one of the key elements of the wind farm, tasked with collecting and exporting the entire electricity produced by 50 wind turbines -estimated to provide around 1.9 TWh per year. It will connect to the onshore transmission grid in Lubmin.

Iberdrola has awarded contracts to the joint venture Iemants-Fabricom, responsible for the manufacturing of all structural elements of the substation, and to marine contractor Heerema, who will transport and install the substation on the Baltic Eagle site. Siemens Gas and Power is responsible for the delivery of all main electrical equipment for Iberdrola`s low-voltage part of the OSS.

The substation is made up of a foundation and a topside housing the transformers as well as electrical equipment. The four-legged steel jacket foundation weighs approximately 2,900 tonnes and will be fastened with two hammered piles at each leg. The topside consists of a closed multi-storey module of 5 decks with a total estimated net weight of around 4,250 tonnes.

Fabrication is already progressing at different locations in Europe and platform manufacturing has already started at Belgian yards. Sail out to the site is planned for 2022, while completion of the offshore installation and commissioning is expected to take place in 2023.


When the Baltic Eagle wind farm is connected to the grid, the wind turbines will deliver electricity via the 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.


Iberdrola was awarded the rights to construct the 476MW  
Baltic Eagle offshore wind farm in the Baltic Sea in 2018. It is located northeast of the German island of Rügen, off the Pomeranian coast in the Baltic Sea, in a water depth of 40-45 metres. The wind farm will comprise 50 wind turbines of 9.525 MW capacity, to be installed on monopile foundations. It will cover an area of 40 km2. Commissioning is expected in 2024.

For more information on offshore wind farms worldwide, click here.