D10 Tidal Turbine at Ushant Island

The D10 Tidal Turbine project was nominated in 2011 as part of the “Marine Renewable Energy Demonstrators” call for interest launched by ADEME (French Agency for Environment and Energy Management) and received funding through the “Investments for the Future” national program.  A complementary subsidy from the European Regional Development Fund was awarded by the Brittany region.

The project is noteworthy in a number of respects:

• widespread social acceptance;
• 100% French construction;
• structural industrial partnerships;
• output dispatched to Ouessant under the control of EDF SEI and ENEDIS; and
• environmental considerations supervised by the Iroise Marine Natural Park.

The project consisted of the construction and 12-month deployment of an industrial tidal stream generator in Fromveur Passage (also known as St Vincent’s Channel). During slack water periods in May 2015, the cable to export the electricity produced was installed between the generator site and the coast of Ouessant (Ushant). In June 2015, the D10 was lowered into the Fromveur Passage in a water depth of 55 m; by November 2015 the D10 was connected to the island network via the previously installed cable. The D10 was the first tidal turbine to supply electricity to the French grid. The generator is 17 m high and has a footprint of 20 x 20 m; its 10-metre rotor can generate 1 MW from the currents in the Fromveur Passage. 

Initial results for the project were promising and in line with expectations, and also opened up future avenues for improvement. In July 2016, at the end of the period for which on-site installation was authorised, the turbine was raised to the surface for technical inspection and expert appraisal. 

The turbine was redeployed in October 2018 as part of the European Intelligent Community Energy (ICE) project. Following continuous electricity production over several months, Sabella’s team focused on testing new control methods at the beginning of 2019 in order to significantly improve the efficiency of the turbine and contribute to the competitiveness of this emerging sector.

The device was redeployed in April 2022 in the Fromveur Passage following improvements to the D10 turbine’s export connections and implementation of a smoothing function. The smoothing function was developed in partnership with the Syndicat d’Energie et d’Equipment du Finistère (SDEF) and ENTECH. The smoothing function had never been tested on an operational device and was supported under the European Interreg ICE project. Since redeployment in 2022, the turbine has been continuously operation and provides energy to Ushant Island. 

In 2024, Inyanga Marine Energy Group purchased the D10 turbine and became the operator for the project, following liquidation of Sabella in January 2024.  Project permissions and permitting for D10 turbine operations under Inyanga Marine Energy Group August 2028 have been completed and confirmed.