Prysmian Netherlands Launches Lakebed Cable Laying for Two 4 GW Offshore Wind Transmission Projects

en.Wedoany.com Reported - On October 28, cable laying for two offshore wind transmission projects of Dutch transmission system operator TenneT commenced in the Veerse Lake in Zeeland, involving 525 kV high-voltage direct current (HVDC) cables. The projects cover two offshore transmission links, IJmuiden Ver Alpha and Nederwiek 1, each with a designed transmission capacity of 2 GW. Prysmian serves as the general cable contractor, while Belgium's DEME is responsible for laying operations in the lake area. The construction uses a dedicated modular floating platform, with the lake section scheduled for completion in spring 2027.

The two transmission links each use approximately 12 km of lakebed cable routes, extending from near the Veerse Lake dam to the De Piet port area. Each route in the lake area is equipped with two HVDC transmission cables, one metallic return cable and one fiber-optic communication cable. The transmission cables are manufactured at Prysmian's plant in Finland, with each cable approximately 16 cm in diameter and weighing about 67 kg per meter.

DEME developed a modular floating cable-laying platform for the lake construction. Once assembled, it is approximately 75 meters wide and 40 meters long, with the tallest component reaching 31 meters. Due to the size restrictions of the lock gates entering the Veerse Lake, the platform is deployed by transporting it in sections and assembling it within the lake. The platform is equipped with cable carousels, anchor winches, vertical injection equipment, water pumps and spud legs, and can handle transmission cables, spare cables and fiber-optic lines simultaneously.

The laying uses a vertical injection process, in which high-pressure water jets temporarily fluidize the sand layer beneath the cable, burying the cable at least 3 meters below the lakebed. As the floating platform moves forward, the sand resettles and covers the cable. DEME adopts this process to reduce lakebed excavation and water turbidity during construction.

The two links ultimately connect to onshore converter stations in the Sloegebied area of Borssele, where 525 kV direct current is converted to 380 kV alternating current and fed into the Dutch national transmission grid. TenneT plans to complete the Veerse Lake construction by May 2027, with the IJmuiden Ver Alpha link scheduled to enter operation in 2029 and the Nederwiek 1 link in 2030.