TenneT, RWE make progress on Hollandse Kust project
May 23, 2024
The jacket for the Hollandse Kust (west Beta) transformer platform was successfully placed on the seabed offshore the North Holland coast. The topside will be installed next year.
Courtesy TenneT
Offshore staff
EGMOND AAN ZEE/ARNHEM — The jacket for the Hollandse Kust (west Beta) transformer platform was successfully placed on the seabed offshore the North Holland coast.
The topside will be installed next year. Operator RWE/OranjeWind can then connect the wind farm, which will be built at sea in a few years, to what TenneT is calling the "socket at sea."
Last Thursday the jacket sailed on a floating pontoon from the port of Vlissingen to its final destination about 53 km off the coast of Egmond aan Zee. Last weekend the 49-m-high steel structure, weighing more than 2,100 tonnes, was lifted from the floating pontoon by Heerema Marine Contractors' Sleipnir lifting vessel and placed on the seabed.
The jacket is firmly anchored at the four corner points using piles driven more than 50 m into the seabed.
Special equipment has been installed on the jacket to measure the 'skewness' after installation. Certain tolerances have been agreed in advance here, because it is important that the topside containing the transformers is level next year. This way, after piling, the team can see exactly how much metal needs to be cut from the top of the jacket to achieve this. For the safety of shipping, temporary navigation lights are placed on the jacket.
Courtesy TenneT
From the beach at Velsen, contractor NBOS (Boskalis/Orient Cable) is installing the sea cables that will connect the socket to the electricity grid in 2025. These cables (220 kilovolts) are laid at a safe depth and connected to the land cables behind the dunes. Through this connection, the electricity ultimately ends up in the high-voltage grid at the correct voltage (380 kilovolts) via the transformer station in Wijk aan Zee.
TenneT's socket is intended for the wind farm that RWE/OranjeWind will have built at sea in the coming years. The jacket and the topside are built by the contractor combination Equans/Smulders.
The grid operator will soon bring the green energy ashore at Velsen via the 700-MW grid connection, making about 3.3 terawatt hours of sustainable electricity available.
