The Interconnector was out for a total of seven days—three days for a full system outage and four days for single pole outage.

The Moyle Interconnector links the electricity transmission grids of Northern Ireland and Scotland through submarine cables running between converter stations at Ballycronan More in Islandmagee, County Antrim and Auchencrosh in Ayrshire.

Planned maintenance is carried out on the Interconnector annually, and this year there was an extended scheduled outage to allow for several important upgrades.

In addition to regular maintenance, the fire detection and control system was replaced, while a new radiator bank was installed on one of the converter transformers. The team also updated the software for the HVDC (High-voltage direct current) control and protection system and carried out preparation work for future equipment replacements. This ensures no single failure of the equipment shall cause total failure of the HVDC system.

The HVDC Centre team pictured on a recent visit to the Moyle Interconnector

With the Moyle Interconnector reaching the midpoint of its operational life, these upgrades are part of larger plans to ensure reliable performance for the future. In line with Mutual Energy’s Asset Management System, this long-term planning and delivery provides assurance that Mutual Energy are managing strategically important energy infrastructure in the long-term interests of NI consumers.

Sam Gibson, the Moyle Operations Manager, said, “A great variety of work was completed safely and on schedule last week. The entire team did an excellent job planning and managing the outages, leaving us in a strong position moving forward.”

The project involved several companies: Siemens Energy, Winder Power, Chubb, ESS, and DB Attenuation, with additional support from Siemens Energy’s HVDC specialists in Erlangen, Germany. Our thanks to all partners and the project team for their work in ensuring this vital energy asset is managed and maintained effectively for Northern Ireland energy consumers.