In order to further promote the expansion of offshore wind energy, the Federal Maritime and Hydrographic Agency (BSH) has issued two planning approval decisions for the connection of offshore wind farms to the transmission grids in time for the end of 2023.
They cover the construction and operation of grid connection systems and platforms in the German Exclusive Economic Zones (EEZ) of the North Sea and Baltic Sea. The so-called 66 kV direct connection concept will be implemented, which makes the construction of additional transformer platforms within the offshore wind farms unnecessary. According to the BSH, it is the new standard for the connection of offshore wind farms [ds_preview].
BSH grants approval for the Baltic Sea
With the “Ostwind 3” project of 50Hertz Transmission GmbH, the BSH has for the first time issued a planning approval decision that allows a transmission system operator in the Baltic Sea to build and operate both the grid connection system and the transformer platform.
The “Jasmund” transformer platform is located around 42 km north-east of Rügen in the “Westlich Adlergrund” area. The total length of the submarine cable system from the platform to the coast is around 100 km. Around 23.5 km run through the EEZ. Submarine cables within the park conduct the electricity from the wind turbines directly to the transformer platform. To reduce power losses, the voltage there is increased from 66 kV to 220 kV. The grid connection system can transmit up to 300 MW of electricity. The project is scheduled to go into operation by the fall of 2026.
Compensation required in the North Sea
With the “DolWin4/ delta” planning approval decision, Amprion Offshore GmbH has received approval for a project in the North Sea EEZ for the first time. The “DolWin delta” converter platform is located around 45 km north of Norderney. With a capacity of 900 MW, it converts alternating current from the wind turbines into direct current and transmits it via the “DolWin4” submarine cable system.
The total length of the submarine cable system is around 60 km. Of this, 26 km run through the EEZ. Due to the impact on the marine environment associated with the construction and operation, the real compensation measures “Reintroduction of the European oyster” and compensation money were ordered. The grid connection system is scheduled to go into operation by fall 2028.
In order to ensure faster and easier accessibility in addition to access by ship, both platforms have helicopter landing decks.
