In the context of the approval process of a wind farm in the German exclusive economic zone the potential issues affecting the sea environment have to be examined. Furthermore it is required by law to execute an environmental impact assessment. To fullfill theses two obligations a so called Environmental Monitoring is installed. Method and range are determined by the permit authority, the Bundesamt für Seeschifffahrt und Hydrographie (BSH).
All phases of a project's lifecycle (planning, construction, operation, decommissioning) are included within the Environmental Monitoring and ranges each within different time frames. In the planning phase data of a minimun of two years needs to be included, in the operating phase a minimum of three years. This periods can be extented by the permit authority BSH up to a maximum of five years.
Subject of protection, to be examined in the monitoring, are benthos, fish, avifauna, bats and maritime mammals. Due to the long time periods and big efforts costs for environmental monotoring are quite high, several million Euros.
For erection of the offshore wind energy generator it is necessary to fasten its foundations in a water depth of up to 40 metres. This is performed by driving the piles between 30 and 40 metres into the seabed. During the pile driving noise emissions of approx. 175 dB occur in approx. 750 metres distance. As this maritime underwater noise can damage maritime creatures, the usage of noise protection actions are obligatory.
In 2011 the so called Offshore Test 1 (OFT 1) was performed within the wind farm BARD Offshore 1 and a novel noice protection system was tested. A Small Bubble Curtain (SBC) was used, which produces small bubbles for noice protection during pile driving next to the piling pipe. It has turned out that noice emissions have been clearly reduced by using the SBC.