The UK energy sector is preparing for a major infrastructure project as procurement kicks off for contracts worth £848M. These contracts will facilitate the construction of converter stations and the installation of high-voltage electricity cables for the LirIC interconnector between Scotland and Northern Ireland.
Major Energy Project Takes Shape
The LirIC interconnector, spearheaded by Transmission Investment, aims to establish a 142km High Voltage Direct Current (HVDC) sub-sea electricity link between Kilroot in Northern Ireland and Hunterston in Scotland. Once operational in 2032, it will enhance energy exchange between the two regions, offering a rated capacity of 700MW at each receiving end.
Two notices have been issued to inform the market about upcoming tenders. The first covers converter station construction and commissioning, while the second pertains to HVDC and HVAC cable supply and installation.
Breakdown of Key Contracts
The contracts are divided into different lots, covering various aspects of the project. Each lot has distinct responsibilities and funding allocations.
Converter Stations and Civil Works
A total of £544M has been allocated for converter stations and associated civil engineering works, split into two lots:
- Lot A1 (£424M): Covers the design, supply, installation, testing, and commissioning of two HVDC converter stations, one at each end of the link.
- Lot A2 (£120M): Focuses on civil engineering, enabling works, and building infrastructure required for the converter stations.
These contracts will span from December 2025 to June 2032.
HVDC and HVAC Cable Installation
Lot B, worth £304M, is dedicated to supplying and installing the subsea and onshore cables that will transmit electricity across the Irish Sea.
- Lot B1 (£294M): Includes offshore and onshore HVDC cables, covering subsea cable laying, transition bays, and underground cables.
- Lot B2 (£10M): Involves HVAC cables and civil works, ensuring grid connection from the Scottish converter station.
The work under these contracts will also run from December 2025 to June 2032.
Technical Aspects and Infrastructure Challenges
The LirIC interconnector will employ Voltage Source Converter (VSC) technology, enabling bidirectional energy transfer. The route includes multiple complex elements:
- Subsea cables: Approximately 140km long, these will be buried or laid on the seabed.
- Transition bays: Onshore cable landing points will require horizontal directional drilling (HDD) for smooth transition.
- Onshore connections: HVDC cables will run up to 2km from landfall points to the converter stations, while HVAC cables will extend from Hunterston to the Scottish grid.
Procurement and Timeline
Interested contractors have until 1am on April 24 to register their interest. The official tendering process will determine the successful bidders, with winners expected to be announced on November 30, 2025. Given the scale and complexity of the project, companies may opt to bid for combined solutions across multiple lots.
The project aligns with the UK and Ireland’s broader energy strategies, strengthening grid reliability and promoting renewable energy integration. As the procurement phase progresses, industry players will closely watch how this significant investment unfolds.
