Boskalis was contracted by OWP Butendiek GmbH & Co. KG to supply, install and protect (by post-lay burial) the high-voltage inter-array cable at the offshore wind farm of Butendiek. This German wind farm is situated in the German Bight (Nordsea), approx. 35 km west of the island of Sylt. The 33 km2 wind farm consists of 80 wind turbines with a capacity of 3.6 MW each and a total capacity of 288 MW. The inauguration of the wind farm took place on September 8, 2015. It provides renew-able energy to approx. 370,000 households.
The infield cables were loaded in one load-out at Drammen in Norway and then cut down to the correct size on site. The WTGs were connected in a grid of infield cables. 86 individual cables were installed between the turbines, including 6 redundancy cables, amounting to a total length of approximately 90 km for the infield cabling. Cable production commenced in December 2013. The cables were installed in the summer of 2014 using the Stemat Spirit. This vessel was converted to enable the handling of the long cable protection system lengths. Trenching of the cables was performed using a separate trenching spread. Termination, testing and commissioning of the 12 cable strings were carried out using in-house resources.