Van Oord has installed the final monopile for CrossWind’s Hollandse Kust Noord (HKN) offshore wind farm at the construction site some 18.5 kilometres off the coast of Egmond aan Zee in the Netherlands.
Van Oord , as a Balance of Plant contractor for CrossWind, installed all 70 monopiles at the construction site with the first unit being placed on the seabed in October last year.
Van Oord engaged DEME to deploy the jack-up vessel Innovation to install the monopiles.
Sif Group was responsible for the fabrication and supply of monopiles for the 759 MW offshore wind farm.
With a combined weight of 64,356 tonnes, the monopiles are designed in such a manner that they do not require transition pieces. The design is said to allow faster installation and cost reductions.
“The installation of the monopiles was an immense operation, with the monopiles weighing between 788 tons and 960 tons each. During the installation works CrossWind and Van Oord promoted and maintained an open culture, in which we acted as one team”, said Wybren de Vries , Balance of Plant Package Manager at CrossWind.
The TP-less monopiles, which were manufactured at Sif’s Maasvlakte facility in Rotterdam, will support Siemens Gamesa’s SG 11.0-200 DD 11 MW wind turbines.
Van Oord is also involved in the design, engineering, procurement, and installation of the inter-array cables, as well as the transport and installation of the wind turbines themselves.
Meanwhile, Van Oord’s offshore installation vessel MPI Resolution is installing secondary steel to complete the foundations.
The secondary steel sets consist of boat landings, main access platforms (with davit cranes), and internal platforms. The platforms will be used for maintenance activities once the wind farm is operational.
Van Oord will deploy the cable-laying vessel Nexus to install the cables starting in March this year.
“ With the supply of secondary steel and inter array cables on target and our offshore installation vessels fully operational, the construction of the Hollandse Kust Noord offshore wind farm is progressing well on schedule “, said Roeland Ris , Project Director Van Oord.
The Hollande Kust Noord offshore wind project will be built and operated by the CrossWind consortium between Shell and Eneco, which won the tender in July 2020, without government subsidies.
The consortium plans to have the offshore wind farm operational in 2023, from when it will be generating at least 3.3 TWh per year.