Orsted is planning a two-phase campaign to remedy problems with array cable protection at up to 10 of its offshore wind farms as part of a DKr3bn (£350m) O&M campaign that will run into 2023.
Sea-floor currents are dragging cable protection systems across rock-scour protection which is installed on the seabed around turbine foundations to prevent erosion.
This movement is abrading installed projection and leading to cable failures in some cases, according to the developer.
“The issue was recently identified following the recent replacement of a cable at the (Orsted-operated, 573MW) Race Bank wind farm in the UK” company chief financial officer Marianne Wiinholt told reporters during a Q1 results call.
“It’s something we see at European projects and is not present on first-generation assets, but those that were installed more recently,” she explained.
Orsted did not disclose the names of other projects where interventions may be needed, but Wiinholt said changes to cable protection designs and scour installation practices mean the problem is confined to more recent projects in its portfolio such as Race Bank, which was commissioned in 2018.
The developer will this year add rock protection to affected projects to pin the wires down and stop them from moving.
Wiinholt said the developer still does not “have significant overview” of how many cables may need to be replaced or repaired because of the problem.
Survey campaigns will take place next year to inform eventual replacements and repairs which will take place in 2022 and 2023.
Orsted has made a DKr 0.8bn (£68.5m) warranty provision to cover some of the remediation costs in its Q2 2021 results.