Vattenfall announced it has adopted a suction-bucket technology that is virtually noiseless. Instead of monopiles, these buckets paired with jacket substructures will anchor the wind turbines to the seabed.
The buckets will be 10.5 metres in diameter and along with their foundations will be constructed in Newcastle, UK.
During installation, water will be pumped out of the buckets, thus creating a pressure difference that forces the buckets into the seabed. In principle, piledrivers are replaced by water pumps.
After the water is pumped out of the suction buckets, they sink in to the sea bed sediment. For decommissioning, water is pumped back in to retrieve the entire structure.
The offshore construction for this project will star at the end of this year, at Vattenfall’s European Offshore Wind Deployment Centre (EOWDC) in Aberdeen Bay.
In addition to the suction bucket foundations and the turbines, the project is will incorporate a voltage of 66 kilovolt inter-array and export cabling, rather than the traditional 33 kilovolt. This will reduce power losses and installation costs and also result in copper savings.
The overall capacity of the European Offshore Wind Deployment Centre (EOWDC) will be at 92.4 MW, after its completion in September 2018
“The seabed conditions in Aberdeen Bay are ideal for this foundation concept and as Scotland is known for its whales and dolphins, we will minimize the sound impact on these animals. Also, reducing the noise from pile driving is expensive, an investment that is not needed with this technology. We also reduce disturbance for people living in nearby villages at the coast. Last but not least, when the wind farm’s life has come to an end, the decommissioning process is just a reversal of the installation process – you simply pump the water back in and retrieve the entire structure,” says Adam Ezzamel, project leader for the European Offshore Wind Deployment Centre.