Iberdrola and 50Hertz, the transmission system operator responsible for connecting the Offshore Windfarm to the grid, have signed an agreement to cooperate with regard to the construction, installation and commissioning of the offshore substation (OSS) for Baltic Eagle wind farm being developed in German waters of the Baltic Sea.
The jointly used offshore substation will house the technical equipment collecting the electricity produced by the wind turbines and will connect to the onshore transmission grid in Lubmin.
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.
The substation is one of the key elements of the windfarm, tasked with collecting and exporting the entire electricity produced by 50 wind turbines -estimated to account for ca. 1.9 TWh per year. With this energy production it will be possible to sustainably meet the demand of 460,000 homes and to avoid the emission of 800,000 tonnes of CO2 into the atmosphere each year.
The Baltic Eagle offshore wind farm is located northeast of the Rügen island off the Pomeranian coast in the Baltic Sea in a water depth of 40-45 meters. Iberdrola was awarded 476 MW of capacity during the transitional auction held in 2018.
The wind farm will comprise 50 wind turbines of 9.525 MW capacity to be installed on monopile foundations and will cover an area of 40 km2. Commissioning is expected in 2024.