Jan De Nul has completed the installation of 80 sets of 6 MW wind turbine generators (WTG) at Saint-Nazaire, France's first commercial offshore wind farm.
The company said Tuesday it had completed the project "significantly ahead of schedule." The first turbine was installed back in April using Jan De Nul's Vole au Vent jack-up vessel. On September 5, the 80th and the final turbine was successfully installed.
Once operational, the offshore wind farm will have a total capacity of 480 MW, equivalent to 20% of Loire-Atlantique’s annual electricity consumption. The wind farm is owned by EDF Renouvelables and EIH S.à r.l, an indirect subsidiary of Enbridge Inc., and CPP Investments.
During the project, the Vole au vent would load the 6 MW wind turbines, in sets of four, at the ‘Forme Joubert’ lock in the port of Saint-Nazaire and then transport the components approximately 12 kilometers offshore for installation on top of the foundations located on the Banc de Guérande seabed, in the northern part of the Bay of Biscay.
Pieter Vandezande, Project Manager at Jan De Nul Group: “The Saint-Nazaire wind farm is a milestone project for Jan De Nul, as this is France’s first offshore wind farm. We are proud to support the country in its energy transition by making possible the delivery of the first electricity produced by the very first French offshore wind farm. The exceptional installation progress has been the result of an extensive engineering process, optimized vessel preparation, and planning, and an excellent collaboration with Parc éolien en mer de Saint-Nazaire and the turbine supplier GE.”
According to Jan De Nul, the majority of the Saint-Nazaire turbines needed to be installed on an uneven rocky seabed. Since the self-elevating jack-up vessel Vole au vent needs a stable seabed to safely jack on, some additional rock fragmenting operations were required to prepare the seabed for jacking.
"Jan De Nul brought its dredging and offshore wind installation expertise together to develop a unique method of construction consisting of preparatory rock fragmenting operations," the company said.
In the summer of 2021, Jan De Nul’s ocean-going Cutter Suction Dredger Fernão de Magalhães performed the preparatory works. The dredger fragmented the seabed using her rotating cutter head to smooth the seabed which then allowed the Vole au vent to perform jacking activities.