Significantly ahead of schedule, Jan De Nul’s Offshore Jack-Up Installation Vessel Vole au vent has successfully completed her mission on the Saint-Nazaire Wind Farm project in France, according to the company's release. The Vole au vent transported and installed 80 sets of 6 MW Wind Turbine Generators (WTG) for the very first commercial wind farm in French waters. This wind farm will have, by the end of 2022, a total capacity of 480 MW, which is equivalent to 20% of the Loire-Atlantique’s annual electricity consumption.
The Vole au vent loaded the 6 MW wind turbines, in sets of four, at the ‘Forme Joubert’ lock in the port of Saint-Nazaire and then transported the components approximately 12 kilometres offshore for installation on top of the foundations located on the Banc de Guérande seabed, in the northern part of the Bay of Biscay.
On 1 April, the first turbine was loaded in the port. On 5 September, the 80th and very last turbine was successfully installed.
The Saint-Nazaire Offshore Wind Farm will contribute to achieving the target of 40% renewable energy by 2030 and carbon neutrality by 2050 in France.
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.
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 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.
In the summer of 2021, Jan De Nul’s ocean-going Cutter Suction Dredger Fernão de Magalhães performed these preparatory works.
The dredger fragmented the seabed using her rotating cutter head to smooth the seabed that then allows the Vole au vent to perform jacking activities.