Dutch offshore installation services firm Van Oord said Friday it had completed installing and burying inter-array cables at CrossWind’s Hollandse Kust Noord offshore wind farm, bringing it a step closer to being fully operational by the end of this year.
The cables are used for connecting the offshore wind turbines and transmitting electricity.
Van Oord’s cable-laying vessel Nexus and trencher Dig-It (a remotely-operated vehicle operated from the vessel Subsea Viking) have installed a web of 69 inter-array cables measuring 140 km in total.
The offshore wind farm is located 18.5 kilometers off the coast of the Netherlands, near the seaside resort of Egmond aan Zee.
Van Oord designed a 66kV inter-array grid for the Hollandse Kust Noord offshore wind park and Dutch manufacturer TKF (Twentsche Kabelfabriek) supplied the cables.
The Nexus cable laying vessel, equipped with a large 5,000-ton cable carousel, installed the inter-array cables.
Trencher Dig-It subsequently buried the cables to the required depth of between 1.0 and 1.5m.
"The Dig-It, a Tracked Remotely Operated Vehicle (TROV), can be used for burying cables both in “jetting mode” for sandy soils and in “chain cutter mode”’ for harder soils. At the Hollandse Kust Noord project both modes were used successfully," Van Oor dsiad.
The offshore wind farm is being developed by Crosswind, a joint venture between Shell and Eneco, which contracted Van Oord for the complete Balance of Plant scope for the construction of the offshore wind farm.
Van Oord’s activities cover the design, engineering, procurement and transport and installation of the wind turbine foundations, inter-array cables, as well as the transport and installation of the wind turbines themselves. Earlier this year, Van Oord completed the installation of all 70 monopile foundations for the offshore wind farm.
Currently, Van Oord is deploying two offshore installation vessels to install the wind turbine generators and is also performing the electrical termination works of the cables in the wind turbine generators.While construction is still in full swing, the Hollandse Kust Noord offshore wind farm has already produced its first megawatt hours (MWh) of electricity and delivered it to the Dutch mainland. In coming months, production capacity will be constantly increased. Once finished, the wind farm will have a total installed capacity of 759 MW, generating at least 3.3 TWh per year. This is enough renewable electricity to meet 2.8% of the Netherlands’ electricity demand.