BOURBON is participating in a tidal turbine connection project off the island of Ushant (Brittany, France), a first in France. A pioneer in the towing and installation of the first floating wind turbine off the coast of Portugal, BOURBON is committed in the field of renewable energies and is now supporting SABELLA.
Our mission: to lay the electrical cable for connecting the first tidal turbine to the national grid. The challenges: a narrow corridor, strong currents, 30 tons of cable.
The resources made available by BOURBON for this operation:
- The Argonaute, a vessel measuring 69 meters long by 15 meters wide, equipped with a dynamic positioning system;
- A Falcon series ROV, lightweight and highly mobile, specializing in diving support work and conducting visual inspections in shallow water;
- All necessary equipment for cable laying, landing and burying (winch, floats, fittings, underwater positioning systems, building vehicles, etc.);
- A team of over 30 experienced professionals, including engineers, seafarers, divers and ROV pilots.
After 2 weeks of preparation, in close collaboration with all project stakeholders (client, cable manufacturer, divers, construction company, etc.), the laying of the electrical cable, a complex operation, was successfully conducted from May 23 - 26 2015, in a window of favorable weather. The low tidal coefficient at this time made it possible to avoid strong currents. Rather, the wind and wave conditions were conducive to the work of the divers and the precise positioning of the vessel in order to lay the cable within a narrow corridor.
Teams from BOURBON and Sabella thus landed, placed, and buried 30 tons of 68 mm diameter cable over 2 km at depths from 0 to 60 m in the Fromveur Passage to Ushant. "This cable laying is an essential step of the Sabella D10 project: it makes it possible to connect the tidal turbine to shore. This is a delicate operation, given the very strong currents in the area. We were able to rely with confidence on the expertise and know-how of the BOURBON teams.", says Fanch Le Bris, Sabella CEO.
For this project, BOURBON provided a turnkey service both upstream and downstream:
- Project management and engineering;
- Installation of the submarine cable and connector;
- Landing of cable to the collector;
- Managing the various providers needed to complete the entire operation.
A dedicated team from our research department will also support monitoring the project at the time of final immersion of the tidal turbine expected to occur by late June. Through these experiences in offshore wind and tidal farms, BOURBON positions itself as an integrator, installer of submarine cables for renewable energy.
The first tidal turbine mass developed in France, Sabella D10 is a demonstrator that will supply 15% of the island's energy needs for 1 year. This project follows the installation of an experimental prototype tidal turbine called Sabella D3 in 2008. The data returned will be analyzed and make it possible, ultimately, if it proves successful, to mass produce new, more powerful turbines, to be installed by 2017. An "experimental tidal farm" of 3 Sabella D15 type turbines linked to an energy storage system would then cover 70% of Ushant's electricity needs.