The MaresConnect 750 MW High-Voltage Direct-Current Interconnector System

Summary

The procurement covers the design, supply, construction, installation, testing and commissioning of the MaresConnect 750 MW, ±320 kV direct-current electricity interconnector between the Dublin area in Ireland and Wales. The connection comprises approximately 240 km of subsea and land cables, and its estimated total value is EUR 1 billion. The project is divided into four turnkey EPC lots: Lot 1A covers two converter stations; Lot 1B covers an Irish 400 kV alternating-current tail substation; Lot 2A covers subsea and underground high-voltage cables; and Lot 2B covers approximately 2 km of underground alternating-current cable in Ireland. Bids for Lots 1A and 1B must be submitted together, as must bids for Lots 2A and 2B; bidders may submit for up to four lots. To participate, submit a completed Pre-Qualification Questionnaire by 31 October 2026 at 12:00 UTC. Bids must be submitted electronically. No tender guarantee is required, and price is not the only award criterion. The contractor for each lot will assume full responsibility for designing and executing its works; the contracts will be based on the 2017 FIDIC Silver Book, as amended by lot-specific conditions.