DEME to Use Special Drilling Tech Again as It Wins Second Major Offshore Wind Deal in France

Offshore installation firm DEME Offshore will need to deploy its special drilling technology again to install offshore wind monopiles at an offshore wind farm in France, due to rough ocean conditions and a rocky seabed.

The company recently secured two deals for the transportation and installation contracts for the foundations and the offshore substation for the Yeu and Noirmoutier islands’ offshore wind farm. 

For DEME this is the second major offshore wind farm project in France following groundbreaking solutions and industry-first technology deployed at Saint-Nazaire.

DEME Offshore will execute the pre-piling works for the offshore substation jacket, and the transport and installation of the 2,700-ton topside. The company is also responsible for the transport and installation of monopile foundations and transition pieces. The combined contracts represent a ‘large’ contract, which DEME defines as having a total value of more than EUR 300 million.

The wind farm is being developed by Éoliennes en Mer des Îles d’Yeu et de Noirmoutier (EMYN), a consortium including Ocean Winds (an ENGIE and EDPR joint venture), Sumitomo Corporation, La Banque des Territoires and Vendée Energie.

Giant Drill & MODIGA System

According to DEME, just like the Saint-Nazaire project, the wind farm is located in a very rocky area, with challenging ocean conditions. The installation of the monopile foundations will thus again call for DEME’s special drilling technology and some of the equipment, method and tools deployed at Saint-Nazaire will be reused. 

This includes the giant 350-tonne Offshore Foundation Drill developed with Herrenknecht and the so-called MODIGA. 

At 60 m high, the MODIGA encapsulates the drilling and installation operations, protecting them from the harsh marine conditions, which in turn, improves operational working time substantially.

Allseas to install the Substation

DEME’s offshore installation vessel ‘Innovation’ will carry out the foundation installation. Similar techniques and vessels successfully deployed at the Saint-Nazaire wind farm will be used for the substation pre-piling works, which will be executed in the second half of 2023, DEME said.

Allseas’ vessel ‘Pioneering Spirit’ will be used to install the substation jacket and topside. The installation of the monopile foundations, substation jacket and topside are scheduled to start in the first half of 2024.

Once operational in 2025, the Yeu and Noirmoutier offshore wind farm will produce enoug electricitz for nearly 800,000 people.