TenneT, a leading European electricity transmission system operator, has announced the commencement of cable production at LS Cable in Donghae, South Korea, for new cables capable of transmitting up to 2GW of offshore wind capacity.
The introduction of the new 525kV cables enables the transmission of 2GW of direct current over long distances with minimal losses, according to TenneT.
Previously, offshore grid connections relied on 320kV cables, such as those used in TenneT's 900MW projects.
This milestone in cable production is part of a framework agreement TenneT signed with a consortium consisting of the Jan De Nul Group, LS Cable & Systems, and Denys in May 2023.
Under the agreement, four 525kV DC cable systems will be produced and installed for TenneT's grid connection projects in the North Sea.
The initial cables from LS Cable are designated for the BalWin4 and LanWin1 grid connection projects.
Each grid connection will feature an additional metallic return conductor alongside positive and negative poles to ensure uninterrupted electricity flow during maintenance or repairs.
The combined cable length for the BalWin4 and LanWin1 projects will span 1,650 kilometers, with submarine cables comprising 165 kilometers and land cables 110 kilometers per project.
Constructed from copper, the inner conductor of the cables contributes to their substantial weight, with submarine cables weighing approximately 76 kilograms per meter.
Production of the cables is slated for completion by 2028, with sea cable laying set to commence in the second half of 2026 utilizing the specially-designed vessel ‘Fleeming Jenkin' by the Jan De Nul Group.
Furthermore, Denys will begin land cable construction in the latter half of 2026 using methods such as open trenching and horizontal drilling to navigate water bodies and existing infrastructure.
TenneT expects BalWin4 to become operational by 2029, followed by LanWin1 in 2030.
