Description
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.
Location
Fromveur Passage, off the coast of Ushant Island, Brittany.
Project Progress
In April 2019 Sabella recovered the D10 turbine from the Fromveur Passage for a servicing period of approximately three months off the port of Brest.
In April 2022, the D10 turbine was redeployed in the Fromveur Passage and has been continuously operational.
Environmental Monitoring: D10 Tidal Turbine at Ushant Island
| Phase | Stressor & Receptor | Design and Methods | Results |
|---|---|---|---|
| Post-Installation Monitoring | Collision Marine Mammals |
Detection of mammals with CPODS (ETIP Ocean 2015) Two CPODS – one on either side of turbine central mast, with 128 days of measurements on station 1 and 150 days of measurements on station 2. |
Complete 2015
Turbine at rest: from June 2015 there were numerous detections of dolphins, less for porpoises (range of detection of 2-3km for dolphins and 200 m for porpoises) Turbine functioning: not enough measurements were collected to conclude effects. |
| Post-Installation Monitoring | Collision Fish, Marine Mammals |
Underwater video monitoring of marine wildlife in 2018 deployment Installation of three underwater cameras orientated to view the turbine blades directly, upwards toward the blades and downwards to the seabed. | Underway Pending review of video footage. |
| Post-Installation Monitoring | Noise Marine Mammals |
Underwater acoustics study. Based acoustic signature off in situ measurements of the tidal turbine installed by Naval Group off the coast of Paimpol. | Underway Noise level measured = 153 dB2 |
| Post-Installation Monitoring | Birds | Monitoring of the Great Crested Cormorant. Video monitoring at the level of tidal turbines, including analysis of videotapes to observe fish behaviour and attendance for a followed by one month in the cold season and one month in the warm season after the installation of the tidal turbines using a camera on concrete stud. | Underway The bird most exposed to tidal turbines, due to its abundance and diving abilities, is the crested cormorant, theoretically capable of reaching the rotors. Given the very low risk of collision between tidal turbines and great crested cormorants, no follow-up action was taken specific to this species was not considered necessary. However, Akuo Energy is committed to ensuring that the mammal visualization is also coupled with monitoring of crested cormorants. |
| Post-Installation Monitoring | Changes in Flow Ecosystem Processes |
Hydro-sedimentary study. Calculating the drag coefficient characterizing the machines that is the final defining parameter the effect of machines on flow. This was calculated by Sabella using a sizing tool internal. | Completed The coefficient is 0.73 and corresponds to the maximum drag obtained for a D14 machine (14 m diameter, but comparable with a D15) with 3 blades and a current velocity of 2.8 m/s, at the torque point maximum. The coefficient used is therefore rather majoring and conservative. |