THE NETHERLANDS - The offshore substation of the Hollandse Kust - zuid (Dutch Coast - South) Alpha platform was installed on the jacket in the North Sea, about 20 km (12.7 miles) off the coast of The Hague.

The installation was completed on December 26, 2021. The substation, also called topside, is one of the two topsides of the Dutch Coast (South) offshore grid, which will connect the offshore wind farm area with the same name to the Dutch onshore high-voltage grid.

"With the installation of the Alpha topside, the offshore grid that TenneT is building in the North Sea is starting to take shape," said Marco Kuijpers, Director of Large Projects Offshore. "Hollandse Kust (zuid) Alpha is the first connection of an offshore wind farm to the Maasvlakte, with a capacity of 700 MW."

Over the past year, contractor Petrofac has been working on the fabrication of two HVAC substations - Alpha and Beta - at the Drydocks World fabrication yard in Dubai. Mid-November, Mammoet, a specialist in heavy transport and lifting, took care of the weighing and loading of the 3,830-tonne Alpha topside onto the transport vessel Tai An Kou. From Dubai, the Tai An Kou sailed in one month to the Alexiahaven on the Maasvlakte, where it arrived on December 21.

In the Alexiahaven, the Alpha topside was loaded from the transport vessel onto the multipurpose platform installation and removal vessel Pioneering Spirit of offshore company Allseas, which then sailed to the installation location in the North Sea. After completion of preparatory work, Pioneering Spirit accurately positioned the Alpha topside on the substructure, also known as a jacket.

The Beta topside - also with a capacity of 700 MW - is expected to follow in the first quarter of next year. When the wind farm area Dutch Coast (South), developed by wind farm developer Vattenfall, is fully operational in 2023, it will generate an amount of renewable energy that is equivalent to the annual consumption of more than two million households, TenneT said in a press release.

Source: TenneT