Offshore Foundation Drilling (OFD®) makes it possible to safely install foundations for wind turbines and other coastal infrastructure even in rocky seabed. The technology thus opens up new terrain for offshore wind energy and the expansion of renewables.
For the new offshore wind farm, OFD will be used to drill boreholes for 61 monopiles in the rocky Atlantic seabed between the islands of Noirmoutier and Yeu. Each monopile has a diameter of 7 meters and will serve as the foundation for one of the more than 200-meter-high wind turbines. The new project off Noirmoutier is subject to challenging weather, sea and ground conditions. With water depths of up to 36 meters, the monopiles will be embedded in the rocky seabed.
The monopiles for the Noirmoutier wind farm will be installed by the leader in offshore wind solutions DEME. DEME and Herrenknecht jointly developed the drilling and installation method. Herrenknecht supplies the drilling technology and provides specialized drilling personnel who are constantly on board the installation vessel to control and maintain the OFD drilling machine during the project. DEME is responsible for the installation of the monopiles and the MODIGA (Monopile Offshore Drilling Installation and Grouting Aid). It serves as a drilling template and enables controlled lowering using a liner, which also stabilizes the borehole. In 2021/2002 already the 73 drilled foundations for the Saint-Nazaire wind farm have a been installed using the mechanized drilling method for large-diameter monopiles developed by the two technology leaders as a world first. This reference project was fully completed entirely on schedule. The machine used there was completely overhauled by Herrenknecht for use in the Noirmoutier project.
Installation of the monopiles will began in Juin 2024. Monopiles will be loaded onto the installation vessel in the port of La Rochelle. After the drilling process, the monopile is then inserted into the lowered liner, creating the foundation for a wind turbine. As of February 2025, 41 of 61 monopiles had been installed as planned. After completion, scheduled for the end of 2025, the Noirmoutier wind farm will have a total output of 496 MW and generate around 1,900 gigawatt hours of electricity per year from, covering the needs of 800,000 inhabitants.
The innovative drilling method was already successfully used at the Saint-Nazaire offshore wind farm in 2021/2022.
