In April E.ON started preparations for constructing the 288 MW, €1 bn Amrumbank West offshore wind farm. An innovative form of scour protection is currently being installed north-west of Helgoland.
In April E.ON started preparations for constructing the 288 MW, €1 bn Amrumbank West offshore wind farm. A novel form of scour protection is currently being installed north-west of Helgoland. This comprises two layers of specially made sand bags on the seabed to prevent the current from washing away the sand around the foundations of the wind turbines, which if not prevented would threaten turbine stability. The sand bags are geotextile sand containers placed on the seabed. This ‘new technology’ draws on experience gained in river engineering and coastal protection where this form of scour protection has already replaced traditional armour stones.
E.ON is a pioneer in the use of this innovative technology for offshore wind farms. Separating the scour protection from the installation of the foundations has significant logistical advantages and helps to further reduce the cost of offshore wind energy. E.ON’s aim is to reduce the construction and operating cost of offshore wind farms by 40 % by 2015, a target that it believes will create a cost effective renewable solution.
Together with Hanover University, E.ON first examined how sand bags react during the installation of the foundations. E.ON has a co-operation agreement with the Peter Madsen A/S shipyard in Denmark, which is now starting to install the one metre cubed bags at the offshore site. The two layers cover an area with a diameter of 25m around the monopile foundations.
Amrumbank West is one of three offshore wind farms being built by E.ON in the North and Baltic Seas in the next two years. A total of 80 wind turbines are being erected, starting this autumn, in an area of about 32km². Commissioning is to be completed in mid-2015.