The MaresConnect Project is a proposed 750 MW, 320 kV High Voltage Direct Current (HVDC) electricity interconnector linking Denbighshire, Wales and North County Dublin, Ireland. Developed by MaresConnect Limited, a joint venture between Foresight Group Holdings Ltd and Etchea Energy Nominees Ltd, the project will transmit electricity via approximately 240 km of subsea and underground cables between new converter stations on each side. It aims to enhance security of supply, market integration, and renewable energy utilisation between the Irish and GB grids. MaresConnect shall utilise Voltage Source Converter (VSC) technology and the configuration shall be a Symmetrical Monopole. The rated DC voltage shall be +/-320 kV. The link shall be bi-directional and shall have a rated power (receiving end) of 750 MW. The project is being procured as separate EPC (Turnkey) contracts, divided into four lots: LOT 1A: EPC for two HVDC Converter Stations; LOT 1B: EPC for one Irish 400kV AC Tail Substation; LOT 2A: EPC for the HVDC subsea and underground cable system, and for the HVAC underground cable system in Wales (Bodelwyddan); LOT 2B: EPC for the supply and installation of HVAC cable system in Ireland (Dublin). The contract model for the lots will be amended FIDIC Conditions of Contract for EPC/Turnkey Projects (Silver Book). MaresConnect has conducted Preliminary Market Engagement prior to publication of this Contract Notice and encourages further collaboration between OEMs and Construction Contractors to establish bidding arrangements in time for the next step of the Procurement Process (notably the Pre-Qualification Questionnaire).

LOT 1A: EPC for HVDC Converter Stations

This lot is for the design, engineering, procurement, manufacturing, construction, installation, commissioning, and testing of two (2) 750 MW, 320 kV VSC-based HVDC converter stations, one at each end of the interconnector, and the grid connection. The LOT 1A scope includes all civil works, AC-side switchyards, and auxiliary systems on a fixed-price, lump-sum turnkey (EPC) basis. This lot also includes the maintenance, repair and spares management of the two converter stations which will be contracted under separate terms and conditions provided to candidates as part of the Procurement Process. (If applicable) separate agreements for the Early Works Contracts for FEED and Enabling Civil Works: FEED - tender design of the two (2) 750 MW, 320 kV VSC-based HVDC converter stations; Civil and structural Enabling Works.

LOT 1B: EPC for Irish 400kV AC Tail Substation

This lot is for the design, engineering, procurement, manufacturing, construction, installation, commissioning, and testing of one 400kV AC Tail Substation in Ireland, in the proximity of the Irish Converter Station. The LOT 1B scope includes a 400kV AC tail substation in the proximity of the converter station compound in Ireland. The scope includes all civil works, AC-side switchyards, and auxiliary systems on a fixed-price, lump-sum turnkey (EPC) basis. This lot also includes the maintenance, repair and spares management of the 400kV AC Tail Substation which will be contracted under separate terms and conditions provided to candidates as part of the Procurement Process. (If applicable) separate agreements for the Early Works Contracts for the FEED and Enabling Civil Works: FEED - tender design of the 400kV AC Tail Substation; Civil and structural Enabling Works.

LOT 2A: EPC for the HVDC Subsea and Underground Cable System, and for the associated HVAC Underground Cable System

This lot is for the design, engineering, procurement, manufacturing, installation, commissioning, and testing of the 320 kV HVDC cable system (symmetrical monopole) and the 400 kV AC cable system for the GB grid connection works. The scope includes route survey, subsea installation, burial, landfall works (e.g., HDD), and underground cable installation to connect to the converter stations (GB and Ireland) and onto the HVAC transmission system connection point in GB. This lot also includes the inspection, maintenance, repair and spares management of the HVDC and HVAC cable systems which will be contracted under separate terms and conditions provided to candidates as part of the Procurement Process. The contract is on a fixed-price, lump-sum, turnkey (EPC) basis. (If applicable) separate agreements for the Early Works Contracts for the FEED and Enabling Civil Works: FEED - tender design of the cable system; Civil and structural Enabling Works for the cable system.

LOT 2B: EPC for the HVAC underground cable system in Ireland (Dublin)

This lot is for the design, engineering, procurement, manufacturing, installation, commissioning, and testing of the 400 kV AC cable systems to connect the converter station in Ireland to the transmission system connection point. This lot also includes the inspection, maintenance, repair and spares management of the HVAC cable systems which will be contracted under separate terms and conditions provided to candidates as part of the Procurement Process. In Ireland the HVAC Onshore Cable System is circa 2km. (If applicable) separate agreements for the Early Works Contracts for the FEED and Enabling Civil Works: FEED - tender design of the cable system; Civil and structural Enabling Works for the cable system.