CPS failures on Ørsted’s offshore wind farms

Ørsted has identified Cable Protection System (CPS) issues on array cables at three more offshore wind farms. The developer has already applied for licenses from the Marine Management Organisation (MMO) to replace or repair CPS on the following wind farms.

Burbo Bank Extension:
Large-scale degradation of CPS has been found in a recent survey, on inter-array cables where they exit foundations, at the 254 MW Burbo Bank extension offshore wind farm. Tekmar’s sixth-generation CPS was installed. The CPS condition suggests that degradation may continue and cause transmission loss, unless remedial action through stabilisation of the existing CPS is carried out urgently. The stabilisation work will comprise the placement of permanent rock or rock bag berms on the existing scour protection. The offshore wind farm contains 32 wind turbines , which are connected through 65 km of 34 kV array cables. The marine license application is currently open for consultations. The remedial work is expected to start immediately after the MMO’s approval, and is expected to be completed in around 60 days, within the next 24 months.

Westermost Rough Offshore Windfarm:
The 210 MW Westermost Rough offshore wind farm has been experiencing similar issues with the CPS on array cables. Fully operational in 2015, the wind farm includes 35 wind turbines, connected through 53 km 33 kV array cables. Presently, 15 foundations are installed with single Scour Protection Pads (SPPs), while 20 foundations are installed without any SPPs. All 35 foundation locations will be protected by rock or rock bag berms, after approval of remedial work is received from MMO. Tekmar provided its fifth-generation CPS for the offshore wind farm.

Walney Extension Array Cable Stabilisation:
CPS issues have been detected on 190 km 33 kV array cables, where they exit the foundations, at the 659 MW Walney Extension wind farm. Rock or rock bag berms will be placed on the existing SPPs at the location of all 87 foundations. Tekmar’s seventh-generation CPS needs to be stabilised as soon as possible, or it may cause transmission loss. A marine license application has been submitted to MMO and is currently open for consultations. The remedial work may take up to 120 days within a two-year period.

Ørsted highlighted CPS issues with up to 10 offshore wind farms across the UK and Continental Europe in its Q1-2021 interim report. According to the report, earnings were negatively impacted by a Kr0.8 bn (~€78.9m) warranty provision in Q1 2021 related to array CPS issues. Ørsted identified a two-phased remediation approach whereby the CPS will be stabilised this year and replacements/repairs will take place 2022-23.

This story was first reported exclusively for 4C Offshore subscribers. For more information, click here. For more information on offshore wind farms worldwide, click here.