Major Maintenance

Viking Link's first annual maintenance outage following entry into commercial service was carried out in August 2024 and lasted 14 days, the longest single planned outage of the link's first operational year. ENTSO-E's HVDC Utilisation and Availability Statistics 2024 records the August window as the dominant planned-maintenance event for the year, accounting for 226.7 GWh of unavailable capacity per pole (~44% of monthly capacity) and roughly half of all planned-maintenance hours across 2024. The August campaign was complemented by four shorter planned outages distributed across April, June and November: three covered contractual warranty work on the converter and cable systems, and one was used for zero-current testing. The split-pole bipole HVDC design means warranty work that requires bringing one pole offline for fault-finding or component replacement typically involves taking the full link out of service. Annual maintenance is expected to settle into a recurring late-summer pattern aligned with low-import demand on the GB system; future cycles are published in advance under the project's annual Outage Programme.