RTE, as the French TSO and project owner for the EFGL grid connection, self-performed the engineering, equipment supply and on-site installation works at its existing Saint-Laurent-de-la-Salanque 225/63 kV substation to extend it for the EFGL 63 kV floating wind pilot export connection. Civil works on the substation extension began in May 2022 and were carried out through RTE's internal engineering and regional delivery teams together with its framework contractors. Specific external subcontractors are not publicly disclosed for this pilot-scale extension to an existing transmission substation; attribution to RTE reflects the owner-led delivery pattern typical for in-network reinforcements on the French transmission grid.