TenneT and RWE have made progress on the Hollandse Kust project

Offshore workers

The upper part will be installed next year. The operator RWE/OranjeWind can then connect the wind farm, which will be built offshore in a few years, to what TenneT calls an “offshore socket”.

Last Thursday, the jacket sailed on a floating pontoon from the port of Vlissingen to its destination, about 53 km off the coast of Egmond aan Zee. Last weekend, the 49 m high steel structure weighing over 2,100 tons was lifted from a floating pontoon by Heerema Marine Contractors Sleipnir ship lifting and placed on the seabed.

The mantle is firmly anchored at four corner points by piles driven into the seabed to a depth of over 50 m.

A special device was installed on the jacket to measure “skewness” after installation. Some tolerances have been agreed in advance here because it is important that next year the upper side containing the transformers is even. This way, once stacked, the team can see exactly how much metal needs to be cut from the top of the jacket to achieve this. For navigational safety, temporary navigation lights are placed on the jacket.

On the beach in Velsen, the contractor NBOS (Boskalis/Orient Cable) is installing marine cables that will connect the socket to the power grid in 2025. These cables (220 kilovolts) are laid at a safe depth and connected to land cables at the back of the dune. Thanks to this connection, the electricity finally enters the high-voltage grid at the correct voltage (380 kilovolts) via a transformer station in Wijk aan Zee.

The grid operator will soon deliver green energy onshore in Velsen via a 700 MW grid connection, making approximately 3.3 terawatt-hours of sustainable electricity available.

May 23, 2024