Offshore wind energy

Following the rapid development of onshore wind energy technology, large wind farms might increasingly be installed at sea (offshore) in the future. The German Federal Government established ambitious expansion targets installing about 25,000 megawatts offshore generation capacity by 2030, nearly as much as the onshore wind turbines installed by 2009. Due to the constantly strong winds far out at sea, offshore wind energy has a huge potential to contribute to a successful energy transition. However, the elaborate construction of wind mills at sea and the connection to the onshore power grid are causing high costs as well as a variety of technical and environmental challenges.

Impacts on marine environment

Construction, operation and maintenance of offshore wind turbines pose significant risks to the marine environment such as harmful effects on birds, marine mammals, fish and animals living on the seabed (benthos). One of the most serious problems during construction is the high noise level that occurs when hammering the basements of the wind turbines into the sea ground. The noise may seriously injure and disturb the strictly protected harbor porpoises as well as other marine mammals and drive them away from important habitats. Sea and migratory birds are threatened to collide with the rotors of wind turbines. Especially wind farms built at unfavourable locations are becoming obstacles.

Solutions

A deliberate spatial and temporal coordination of the construction process of approved wind farms in the North and Baltic Sea can help to mitigate cumulative effects on the marine environment. Independently conducted monitoring of the construction processes by nature conservation specialists make sure that permit conditions and critical values are met and ecological impacts are reduced. In order to minimize the negative effects of the grid connection work in the Wadden Sea and the coastal habitats, it is necessary to develop a power transmission concept with as few cable lines as possible.