Danish offshore wind installation services firm Cadeler said Tuesday it had completed the installation of the final offshore wind turbine at Vattenfall's Hollandse Kust Zuid wind farm in the Dutch North Sea.
"With a capacity of 1.5 GW, [Hollandse Kust Zuid] will take the record as the world’s largest single offshore wind farm in service and the first ever to be built without subsidies. The wind farm will produce enough renewable energy to power 1.5 million Dutch households a year," Cadeler said.
"When our team of engineers started to plan for this project years ago, it was the first time ever that these giant 11 MW wind turbines were to be installed on a commercial scale. This required skillful engineering work and a good collaboration between engineers from Vattenfall, Siemens Gamesa and Cadeler. The team managed to come up with the best possible solution to successfully carry more components at each load-out, while keeping within the maximum utilization of the vessel and proving the concept for future projects," Cadeler said.
The new generation of Siemens Gamesa 11 MW turbines have a rotor diameter of 200 meters, and a total height of 225 meters measured from the sea level to the top of the blade.
According to Cadeler, when the weather allows it, the team onboard Wind Osprey jack-up installation vessel is able to install such an 11MW offshore wind turbine in less than 24 hours.
Cadeler installed 140 turbines at the Hollandse Kust Zuid wind farm. The first turbine was installed in April 2022. The HKZ site is located 18 kilometers off the coast, in the area between The Hague and Zandvoort, in the Netherlands.
As the turbines get installed, they are connected by cables to offshore grid operator Tennet's two substation platforms recently installed nearby.
The platforms will convert the voltage of the electricity produced at the wind turbines from 66 kV into 220 kV, and will then transport the electricity is shore via subsea cables, to an electrical substation at the Maasvlakte. At this substation, TenneT said, the voltage is converted into 380 kV. Finally, the electricity is transported to the high voltage grid via high voltage station Randstad 380 kV Zuidring, TenneT has explained.