Offshore Construction Start

Offshore construction on the Saint-Nazaire wind farm formally began in May 2021 when the DEME-Eiffage Métal consortium installed the first monopile foundation on the Banc de Guérande, marking the start of sustained at-sea activity following an earlier offshore site preparation campaign in early 2021. The first monopile was installed by Jan De Nul's installation vessel Innovation in early May 2021 and was followed through the summer by a sustained foundation campaign that ultimately delivered all 80 XL monopiles into the rocky calcarenite seabed. The drilling-through-rock approach — most of the 80 positions required full-face mechanised drilling using DEME's Herrenknecht OFD spread — made Saint-Nazaire the first commercial-scale offshore wind project anywhere to deploy that technique at industrial scale. Offshore construction at the wind farm proceeded in parallel with RTE's offshore substation installation in 2021 and the array-cable laying campaign that began later in 2021, with full foundation installation completed by May 2022, first-turbine installation in April 2022 and last-turbine installation by 5 September 2022. The May 2021 onset thus marked an approximately eighteen-month offshore construction window ending in 2022 with commercial operations declared in November 2022, and established the operational footprint for the project's at-sea bases at La Turballe and the wider Loire-Atlantique offshore industry chain.