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Cable repair team arrive at Gwynt y Môr

By: Bridget Randall-Smith 05/02/2021 4COffshore

Cables General Grid Windfarms

Cable repair operations are underway at the Gwynt y Môr Offshore Wind Farm, located approximately 16km off the Welsh coast in the Irish Sea.

Briggs Marine Contractors has been contracted by the Gwynt y Môr Offshore Transmission Owner (OFTO) to undertake repair works to the SSEC3 export cable due to a power core fault.

The vessel Zwerver I arrived on site on the 27th January 2021 and has commenced deburial operations before cutting and recovering the existing cable. The DP2 jack up installation vessel, MPI Resolution is also now on site with support fromcrew transfer vessel Iceni Spirit. Work is expected to be completed by 23rd February 2021.

The 576 MW Gwynt y Môr offshore wind farm was built in 2015 and operated by RWE (Innogy) with partners Stadtwerke München and Macquarie Infrastructure and Green Investment Group. Gwynt-y-Môr OFTO plc, a consortium of Balfour Beatty and Equitix, acquired the transmission assets in 2015, through the Offshore transmission owner (OFTO) regime.

Over the past few years the wind farm has experienced multiple failures and outages caused by the export cables. Gwynt-y-Môr OFTO plc has repeatedly appealed to Ofgem for compensation during transmission downtime.

Most recently Gwynt-y-Môr OFTO plc has been granted an Exceptional Event claim by Ofgem due to export cable downtime.

In July 2020 Gwynt y Môr OFTO plc undertook a pre-emptive repair of the cable sealing ends (CSE). Independent technical analysis determined that the root cause was the result of low oil pressure and leakage caused by a failure of the tape within the terminations of the CSEs and a flat on the O ring within the CSE.

Gwynt y Môr OFTO plc submitted an Exceptional Event claim to Ofgem on 23rd September 2020 explaining that there was "no routine maintenance intervention that the OFTO could have undertaken to avoid this event occurring".

On 28th January 2021 Ofgem approved the Exceptional Event claim. Given the technical analysis and explanation provided, Ofgem agree that routine maintenance could not have prevented such faults and is satisfied that the root cause of this event did in fact occur before asset transfer and was beyond the reasonable control of Gwynt y Môr OFTO plc.

4C Offshore monitors subsea cable failures in its Quarterly Subsea Cables and Grid Report. Get in touch to find out more!

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.

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Cable repair team arrive at Gwynt y Môr

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