Hollandse Kust (north) jacket successfully installed

The jacket for TenneT’s Hollandse Kust (North) platform has been successfully installed off the coast of North Holland. The next step for this offshore power station is that the ready-made superstructure containing the transformers will be placed on the jacket next May. The construction will be ready in 2023 and TenneT will ensure that sustainable wind energy is transported to the onshore high-voltage grid. Anchored in the seabed After leaving the port of Vlissingen, the jacket arrived at its destination over 18 kilometres off the coast of Egmond in 20 hours. After exact positioning at the site, the 2,100-ton steel structure was set on the seabed by the cranes on hoisting vessel “Gulliver”. The jacket was secured at the four corner points using piles driven into the seabed to approximately 38 metres. The piles are large 10-metre tubes that are welded to the feet of the jacket. By filling the space between the piles and the tubes with grout, the platform will soon be able to withstand even the heaviest storm in the North Sea. Solid foundation Prior to placement, the soil conditions on the site were carefully examined. It was also investigated whether there are any unexploded explosives from the Second World War. The contractor then poured a large bed of stones to create a firm and flat foundation. The stones also ensure that the soil under the jacket is not washed away by the flow of seawater. With regular maintenance, the structure has a minimum lifespan of up to 40 years. Installation of power cables Early next year, in anticipation of the placement of the topside, the power cables will be installed that will come ashore on the Heemskerk/Wijk aan Zee beach. These cables will be laid at a safe depth and connected behind the dunes to the land cables to the new transformer station at Wijk aan Zee to the national high voltage grid.  Offshore wind energy until 2023 TenneT is building 3.5 gigawatts (3,500 MW) of offshore grid connections for wind farms at sea until 2023. With the completion of Borssele Alpha and Beta in 2020, the first 1,400 MW will have been realised. Currently, TenneT is realising the connections for Hollandse Kust (south) Alpha and Beta and Hollandse Kust (north) . For these wind farms, TenneT uses five times the same type of 700 MW transformer platform, which is located close to a wind farm and five times the same type of 220kV cable connection to the coast. This standardisation allows TenneT to build these projects more efficiently, faster and cheaper. Programme Offshore Grid 2024-2030 From 2024 to 2030 at least another 8.1 GW (8,100 MW) of offshore wind farms will be developed, according to the follow-up Wind at Sea Roadmap. This concerns the wind farms in the wind energy areas Hollandse Kust (west), TenneT is again using three standardised 700 MW platforms (2.1 GW) for the first two areas. For the efficient connection of the wind energy areas further away in the North Sea, such as IJmuiden Ver (6 GW), other techniques are needed based on direct current instead of alternating current. At least three offshore connections of 2 GW each are being developed for IJmuiden Ver. The Ministry of Economic Affairs and Climate (EZK) is currently investigating further expansion possibilities. Source: https://www.tennet.eu/Image source: Courtesy of TenneT Read more Power news here

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