Seismic surface surveys from the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) are enabling the 385 MW Arkona wind farm to stay on schedule, despite changes to the facility design.
The EUR 1.2 billion wind farm, located 35 kilometers northeast of the island of Rügen, in the German Baltic Sea, will utilize 60 turbines instead of 80 because of a switch to the larger 6 MW class.
The prospect of fewer turbines generating the same total capacity is an attractive one, according to the institute, because it cuts the costs of construction, grid connection and operation.
According to Fraunhofer, the drilling of new boreholes and pressure sounding in the 39-kilometer-squared area “would have resulted in longer lead times and would really have squeezed the budget.”
Fraunhofer says its multi-channel seismic system makes it possible to look at deeper layers – which is significant in that the support structure of a wind turbine penetrates 50 meters into the seabed – rather than having to conduct new surveys for the larger turbines.
Fraunhofer IWES says its experts conducted a “close-profile, multi-channel seismic survey of the wind farm area” and worked up a 3D model of the seabed based on these seismic data, allowing the wind farm to move forward amidst post-approval design changes.