OES-Environmental distributes metadata forms (questionnaires) to solicit information from developers involved in environmental monitoring around marine renewable energy project sites around the world. This page provides project descriptions, baseline assessment, post-installation monitoring, and links to available data and reports. Content is updated on an annual basis.

SEM-REV Sea Test Site

Description

The test site occupies approximately a 1 km2 test zone area and is fully instrumented and monitored. The test site includes a 8 MVA power cable connected to the national grid through a new 20kV onshore substation to the local electricity distribution grid ENEDIS. The SEM-REV is a fully fitted wave and wind energy test facility intended to test and improve the efficiency of Wave Energy Converters (WEC) and Floating Wind Turbine (FWT) at a prototype stage of development. The facilities for monitoring and controlling the systems are currently available at the site. Optical fibers are included in the export cable for data transmission and for control of MRE. Since 2015, CN has installed a HUB subsea multi-connexion system. This device connects on one hand the electrical export cable and on the other hand could be connected with several connection cables of future prototypes. 
 
The FWT FLOATGEN was installed in April 2018 on SEM-REV and it has been producing on the grid since September 2018. CN has installed in August 2019 another prototype, the WEC WAVEGEM. 
 
Support for this project comes from CAPEX: Investment of 19M€ (VAT included) – 100 % Public funding; CPER Region Pays de la Loire (2007-2013). French Government ANR (2014-2019); and OPEX: Co-funding on collaborative research projects, Services, subsidies.

Location

The site is located 12 nautical miles off the north coast of Le Croisic in Pays de la Loire, at France (West coast). Water depth is 32 to 36m LAT with a maximum tidal variation of 6.2m. 

North: 47°14.70’N – 2°46.58’W 
East: 47°14.34’N – 2°46.08’W 
South: 47°13.94’N – 2°46.88’W 
West: 47°14.34’N – 2°47.38’W

Licensing Information

Concession on the maritime public domain (accepted July 2011 and confirmed January 2014). Permitting process completed for multi-technologies on 2014.

Project Progress

The test site has been operational since the consents were approved in July of 2011 for WEC and in January of 2014 for floating wind. Full electrical connection was finalized in October of 2012. The subsea hub connection system was launched in August 2015. SEM-REV is currently hosting two prototypes, the FWT FLOATGEN and the WEC WAVEGEM.

Key Environmental Issues

The environmental monitoring program of the SEM-REV test site is dual. It comprises both:

  • a mandatory monitoring as part of the legal requirements associated to the permit granted to occupy the Maritime Public Domain;
  • a complementary monitoring developed by CN and organized in research axis on the marine environment and possible environmental impacts.

The mandatory monitoring covers the following environmental stressors and receptors: 

  • Generation of noise,
  • Generation of electromagnetic fields,
  • Benthic habitats and communities alongside the electric cable and on the test site, 
  • Record keeping of every products and materials used, 
  • Tracking in XYZ position (3D displacements) of the electrical cable relatively to the moveable sediments, and of the protective mattresses installed over a small portion of the cable.

The complementary monitoring supplements the mandatory monitoring by targeting other sensors that may sustain significant environmental impacts:

  • Physico-chemical compartment: waves, currents, tides, winds, hydro-sedimentary dynamics, sediments and water quality; 
  • Biological compartment: biofouling, fish and pelagic invertebrates and marine megafauna;
  • Human compartment: sea usages and activities, safety and landscape.

The objective of the post-installation monitoring program is: 

  • To measure the real impacts of the FWT FloatGen and the WEC WAVEGEM prototypes,
  • To compare them to the expected impacts,
  • To evaluate the effectiveness of the mitigation and improvement measures selected.

This environmental management programme is a «live» document likely to evolve as the project progresses.

Environmental Webpage: https://sem-rev.ec-nantes.fr/english-version/access-test-site/environme…

Papers, Reports, Research Studies

Papers and Reports:

Conference Presentations: 

  • Le Crom, Y. Perignon, C. Berhault, J.B. Saulnier, Extreme sea conditions in shallow water: estimations based on in-situ measurements, OMAE2013-10752, Nantes, June 9th to 14th, 2013
  • Le Crom, C. Berhault, G. Le Bihan, SEM-REV feedback from the marine renewable energy test site, Thetis, Cherbourg, April 9th to 10th, 2014
  • Le Crom, C. Berhault, From Lab to reals sea conditions - How to support MRE development, Atlantic Power Cluster - Final Conference, Santander, July 3rd, 2014
  • Le Crom, G. Le Bihan, H. Lugez, Marine Operation Review: Feedback on the implementation of the SEMREV test site for Marine Renewable Energy, ICOE'2016, Edimburg, February 22nd to 26th, 2016
  • M. REYNAUD, Population dynamics of blue mussel Mytilus edulis on buoys and their mooring lines installed on the SEM-REV offshore test site (French Atlantic Coast) to provide a reliable database required for engineering marine renewable energy technologies, 2nd International Symposium on the Advances in Marine Mussel Research, Sète, September 8th, 2017
  • M. REYNAUD, SEM-REV multi-technology sea test site of Central Nantes - Environmental monitoring, GDR CNRS 3763 MRE, Saint-Nazaire, October 20th, 2017
  • M. REYNAUD, Environmental monitoring on the SEM-REV sea test site (Nantes – French Atlantic coast), Environmental Interactions of Marine Renewable Energy Technologies 2018, Kirkwall, April 25th, 2018
  • M. REYNAUD, Environmental monitoring of the SEM-REV sea test site. WeAMEC Meeting « Interaction of MRE with the marine environment », Nantes, February 8th, 2019
  • M. REYNAUD, Environmental monitoring of the SEM-REV sea test site (Nantes – French Atlantic coast), OCEANEXT2019, Nantes, July 4th, 2019
  • C. SPRAUL, H-D. PHAM, V. ARNAL and M. REYNAUD, Effect of Marine Growth on Floating Wind Turbines Mooring Lines Responses, 23rd French Congress of Mechanics, Lille, August 28th to September 1st, 2017
     

Collaborative projects (EU and French Projects): 

  • MOREDATA (wave and current statistics), 
  • FLOATGEN (floating wind turbine protoptype), 
  • OMDYN (health  monitoring of dynamic cables), 
  • ABIOP (biofouling development and impact on MRE components), 
  • FORESEA (tests of MRE components in real conditions). 
  • SOWFIA
  • MARINA PLATFORM
  • MARINET
     

Baseline Assessment: SEM-REV Sea Test Site

Receptor Study Description Design and Methods Results Status
Marine Mammals Resident marine mammal species presence. Bibliographic data. None of species are considered to be resident, 7 species could be observed. Completed
Birds Avifauna community presence. Bibliographic data. 28 species could be observed: some species are present all year with stable effectives while others have attendance peaks. Completed
Invertebrates Impact of cables and mooring systems on marine life, and biofouling development on that infrastructure.
Survey methodology to follow impact of MRE components (mainly high power cables) and used protocol to quantify biofouling (in space and time).
 Specific subsea monitoring system (MOSAIC) for permanent measurements and observations; report on biofouling development on SEM-REV.
Finalizing protocol to issue annual report on environmental impact. ABIOP project (biofouling) starting in 2017.
Invertebrates Benthic community studies. Water Framework Directive (WFD) protocol: 6 sampling stations, 2 on the sea test site and 4 along the electric cable
& bibliographic data.
 In 2009 : 5 sampling stations with good ecological status; 1sampling station with poor ecological status.

No algae at the sea test site. 		Completed
Invertebrates Plankton community presence. Bibliographic data. Phytoplankton: Good ecological status. Completed
Reptiles Resident sea turtle species presence. Bibliographic data. None of species are considered to be resident. 2 species could be observed but observations are very rare. Completed
Physical Environment Waves, current and wind fields analyses. Waves statistics model and weather predictions for marine operation; resource prediction. On site measurements data since 2009 and
Metocean specifications for prototypes design.
Underway
Physical Environment Oceanographic and meteorological conditions. Measurements of waves, currents and wind; on site measurements data since 2009. Waves statistics model, weather down prediction for marine operation, and resource prediction. West Waves with monthly occurrence: Hs = 5.5 ; Tp = 14 s ; Dp = 270°; currents: oriented South-West, between 10 and 50 cm/s; mean wind velocity: 7.5 m/s (1h, 10m); extreme wind (50years): 29 m/s (1h, 10m)
 Completed
Physical Environment, Sediment Transport Studies of sediment quality and sedimentary dynamics. Sampling of sediment (with grab or core) for geophysical and chemical analysis; Bathymetric and side scan sonar survey; Hydrosedimentological models. Medium sand to fine sand (0.2-0.5 mm); Bathymetry: 32 m to 36 m LAT; Sediment transport levels are low with no contaminant pollution detected. Completed
Physical Environment, Water Quality Water quality analyses. Bibliographic data: Ifremer monitoring. In 2016, the Water Framework Directive (WFD) described the FRGC45 (Baie de Vilaine) and the FRGC46 (Loire) water mass as mediocre. Completed
Human Dimensions, Navigation Marine traffic surveillance and safety procedures. Marine traffic statistics, Accident statistics, Risk analysis modelling. Not yet available. Underway
Human Dimensions, Fisheries Fisheries community study. Bibliographic data. No nursery area for species of commercial interest at test site. Completed
Terrestrial Mammals Chiropterans species presence. Bibliographic data. 18 species species could be observed at sea. Completed
Human Dimensions, Visual Impacts Landscape/visual impacts assessment. Photomontage of visual impacts. Low visual impact. Completed
Human Dimensions, Stakeholder Engagement Marine uses and users. Bibliographic data. Low impact on other nautical activities and no cultural heritage near the test site. Completed

Post-Installation Monitoring: SEM-REV Sea Test Site

Stressor Receptor Study Description Design and Methods Results Status
Noise Fish, Marine Mammals Determination of the acoustic footprint of all phases of the prototype life cycle and its impact on marine organisms. Deployment of passive autonomous recorders and acoustic modelling for the SEAc project (2017-2018). Reports are not publicly available. Completed for the installation phase; Planned for operation and dismantling phase
EMF Invertebrates Impacts on benthic communities (endofauna and crustacean) and biocolonisation. Installation of electric and magnetic sensors and temperature probe for the SPECIES project (2017-2020). Not yet publicly available. Underway since 2017
Habitat Change Marine Mammals Monitoring of presence and activities of marine megafauna and assessment of reef and barrier effects.
 Acoustic data, observations during maintenance operation, and bibliographic data. Completed for the EOGP project (2015-2017) and SEAc project (2017-2018).

 Not yet publicly available. Underway since 2015
Habitat Change Fish, Invertebrates Fisheries resources and pelagic invertebrates. Monitoring of reef and barrier effects. Bibliographic data, acoustic data, and observations during maintenance operation.
 Underway
Habitat Change Invertebrates Fauna and flora composition (diversity, abundance and presence or absence of invasive species) Infrastructure design.
 Image analysis (videos & photos taken during maintenance operations) and Systematic sampling (thickness, mass, volume, diversity). Completed for HYDROL44 (2015-2017), OMDYN & OMDYN2 (2015-2021), ABIOP (2017-2018), LEHERO MG (2017-2020), and MHM-EMR(2017-2020) projects.
Not yet publicly available. Underway since 2015
Changes in Flow Physical Environment, Sediment Transport Impact of anchors and electrical cables on the seabed. Study of the modification of the sediment nature by biocolonisation, tracking in XYZ position (3D displacements) of the electrical cable. Geotechnical survey: bathymetry and side scan sonar, particle size, and total organic carbon analysis for the HOOPLA project (2016-2020) and DYNA-REV project (2018).
 Not yet publicly available. Underway since 2016
Changes in Flow Physical Environment Waves statistics model and weather prediction for marine operation and resource prediction. In-situ measurements of waves, currents and wind for the MOREDATAS project (2016-2019).
 Not yet publicly available. Underway since 2009
Changes in Flow Ecosystem Processes Monitoring of temperature, conductivity, turbidity and chlorophyll a and impact of dissolution of sacrificial anodes. Bibliographic data, deployment of a multi parameter probe, measurement of metallic trace elements concentration in Mytilus edulis. Completed for TC2 Focus project (2018-2021).
 Not yet publicly available. Underway since 2018
Human Dimensions, Visual Impacts Monitoring of visual impacts. Confrontation of photomontages in EIA to reality. Planned
Human Dimensions, Navigation Marine uses and user assessment. Monitoring of vessels around test site (frequency, activities). Acquisition on vessels data with AIS around and intrusions into the sea test site. Underway since 2013