FaBTest is a 2.8km2 non grid connected, pre-consented nursery test site consisting of three test berths situated within Falmouth Harbour. It is located between three and five kilometres offshore in Falmouth Bay, approximately 4.5km from the entrance of Falmouth Harbour. Due to the site’s pre-consented status, any device conforming to the design envelope may be deployed subject to scheduling and berth availability. The device envelope allows for the following:
- Substantially buoy-shaped device with a maximum diameter of 30m;
- Substantially box-shaped device with a maximum dimensions of 30m x 30m or equivalent area
- Substantially tubular-shaped device with a maximum length of 180m;
- Floating platform type device with maximum dimensions of 35m x 35m or equivalent area; and subsystem connectors and umbilicals
Mooring systems are restricted to gravity and drag embedment anchors. Guarded underwater turbines are also permitted and work towards achieving consent for a defined range of floating wind devices is underway.
Due to the pre-consented status, the application process for deployment on FaBTest is relatively straightforward. Upon application the developer must provide evidence of engineering due diligence, environmental and other risk assessments, as well as deployment and decommissioning plans and evidence of required insurance and financial bonds.
The site itself offers water depths from 15m on the northern boundary to 50m on the eastern side of the southern boundary and seabed types of rock, gravel and sand. The site is sheltered from prevailing south westerly wind and swell directions but is exposed to significant sea states from the east and south east. This combination enables the high levels of accessibility to the site, but also provides significant testing conditions. As a result FaBTest provides a step in the device development process, between tank testing and demonstration deployment. It allows the testing of marine energy technologies (concepts or full scale devices), components, moorings and deployment procedures in a moderate wave climate.
The peak tide height range is around 6.0m while the peak tidal surface current is around 0.8m/s. Wave and tidal climate modelling results can be found within FaBTest’s publication Appendix 9: Description of Site Characteristics and Eligible Test Installations.
Falmouth Bay, Cornwall, United Kingdom.
Between the four corners of:
Falmouth Harbour Commissioners (FHC) hold a Marine Licence issued by the Marine Management Organisation (MMO) which licenses certain MEC development test works according to set procedures and conditions. Similarly, FHC has a seabed lease agreement with The Crown Estate (TCE) allowing the use of the seabed, again according to certain procedures and conditions.
The FaBTest site is administered by Falmouth Harbour Commissioners supported by a steering group with representatives from industry, academia, agencies and other stake holders. The steering group is divided into two sub-groups, a core group further named as the ‘Regulatory Body’ and the industrial group. The Regulatory Body has two permanent members, Falmouth Harbour Commissioners (FHC) and the University of Exeter (UoE). The specific task of the Regulatory Body is to implement a diligence process to establish that each specific FaBTest installation proposal meets with the requirements according to the Marine Licence, FHC regulations, The Crown Estate (TCE) lease and good practice in accordance with stakeholder expectations. In so doing the Regulatory Body advises and informs the decision of FHC to approve or decline an application for a berth at FaBTest.
This process includes reviews of the following documents.
- Application form
- General overview of the project
- Engineering assessment & general arrangement drawing
- Independent validation of the mooring design
- Quality, Health, Safety and Environment (QHSE) management plan
- Project execution plan
- Decommissioning plan
- Emergency response plan
- Navigational risk assessment
- Seabed habitat risk assessment
- Environmental risk assessment
- Proposal for noise monitoring
- Description of any deviation from the Specification for Navigational Safety
- Security bonds
Based on the outcome of the assessment meeting, FHC will authorise or refuse a berthing application. In the case of a refusal, details of any deficiencies will be reported back to the applicant in order to assist with a re-submission.
It should be noted that conditions on monitoring noise, which were included in earlier versions of the licence, have since been removed following confirmation from statutory consultees that they did not feel them necessary.
Test site is in operation and has been used by developers:
- Bolt ‘Lifesaver’, Fred Olsen – installed 2012, sea trials completed and device transported in 2015 to US Navy’s Wave Energy Test Centre, Hawaii, for further testing
- Volta, Polygen Ltd –installed August 2015
- Wavesub, Marine Power Systems – installed 2018, sea trials completed in September 2019
- Wave energy converter device, AMOG Consulting, installed August 2019
FaBTest is a key testing facility incorporated within “Marine Hub Cornwall”, a centre established in 2017 which supports marine technology businesses by offering resources drawn from Cornwall’s marine infrastructure including testing facilities and marine engineering expertise. Further information is available from: https://marinehubcornwall.co.uk/about
Key Environmental Issues
The main environmental issues in the test site concern the seabed habitat and disturbance from anchor installation and presence. FaBTest encompasses five different seabed habitats. Of these five, maerl beds and subtidal sand gravels are classified as ‘Habitats of Conservation Interest’. However, the maerl within FaBTest site is dead gravel rather than living maerl. A sensitivity analysis of the impact was undertaken.
Although maerl gravel on the site is a feature of conservation importance, Cefas and Natural England are satisfied that additional information provided by FaBTest gives reassurance over assessment of activities on the site and protection to sensitive habitats.
As the site is not grid connected, no export cable is present. All produced electricity is consumed on site by a dump load.
Used to install dump load
Exact vessel used unknown
Papers, Reports, Research Studies
- Guide to Deployments & Application Process Requirements
- Data collection, analysis and provision for the FaBTest site
- Acoustic Life Cycle Assessment of Offshore Renewables - Implications from a Wave-Energy Converter Deployment in Falmouth Bay, UK
- Underwater Sound Levels at a Wave Energy Device Testing Facility in Falmouth Bay, UK
- Statistic assessment of the effect of a Wave Energy Converter in Falmouth Bay, UK
- Presentation: On Peak Mooring Loads and the Influence of Environmental Conditions for Marine Energy Converters
- Monitoring the Condition of Marine Renewable Energy Devices through Underwater Acoustic Emissions: Case study of a Wave Energy Converter in Falmouth Bay, UK
- Work by the University of Exeter on sound at FaBTest was presented at the work package 3 workshops in Brest at SeaTech week in October 2012 and Le Conquet in October 2013 with the aim of sharing methodologies in environmental monitoring at renewable energy sites. Presentations can be downloaded from here: http://www.merific.eu/documents/work-package-3-technology-support
Baseline Assessment: Falmouth Bay Test Site (FaBTest)
|Receptor||Study Description||Design and Methods||Results||Status|
|Physical Environment||Current and wave characterization.||An acoustic Doppler current profiler (ADCP) was tethered to the buoy. The ADCP was set to continuously record current and wave activity. The ADCP was deployed to inform developers of the wave climate and to provide current and wave references for the noise data.||Not available.||Completed (2011)|
|Physical Environment, Sediment Transport||Sediment characterization.||Collection of sediment grab samples over 12 pre-defined locations supplied by University of Exeter using mechanical grab techniques.||Samples were subsequently delivered to the client for Particle Size Analysis using their own facilities.||Completed|
|Physical Environment||Measurement of underwater noise.||Underwater noise was monitored using an Autonomous Multichannel Acoustic Recorder (AMAR) mounted on the seabed in 25m (above chart datum) water depth. The AMAR was shielded from trawling / scallop dredging activities by placement adjacent to a large special mark buoy.||Installation activity was found to considerably increase the local sound levels, with a median difference of 8.5 dB re 1 μPa2 Hz−1 (10–5,000 Hz).||Completed (2011)|
|Physical Environment||Seabed imagery.||The seabed conditions were monitored using video imagery at sample points along two transect lines with sample points at 200m intervals. The positions of the sample points were recorded and replicated (within the bounds of GPS accuracy) during each sampling study.||The R2Sonic 2024 broadband multibeam echo sounder was operated at a nominal frequency of 400kHz, this gives a |
high resolution image and is capable of resolving high levels of seabed detail.
|Physical Environment|| Multibeam Bathymetric Survey (MBS), shallow seabed penetration using a Sub-Bottom Profiling (SBP), and Side Scan Sonar (SSS). ||MBS High resolution bathymetry to ensonify entire area with particular emphasis on detection of natural upstands and debris. |
Shallow seabed penetration using a SBP technique to ascertain sediment thickness over bedrock within the survey extents.
High resolution SSS acquisition across the entire survey extents presented as geo referenced mosaic seabed imagery.
|The MBS data shows in high resolution the change in bottom type throughout the site, from predominantly sand in the south east to rocky outcrops in the northern area. |
SBP show areas of sand build up in the south of the survey area but very little accumulation around the rocky outcrops in the north.
SSS produced high & medium resolution geo-referenced SSS mosaic images (GeoTIFF), individual high resolution geo-referenced SSS records (GeoTIFF), raw SSS data files.
Post-Installation Monitoring: Falmouth Bay Test Site (FaBTest)
|Stressor||Receptor||Study Description||Design and Methods||Results||Status|
|Noise||Marine Mammals||Noise characterization.||Passive acoustic monitoring (PAM) devices have been used at the site, including: a broadband sound recorder that records from 10 Hz to 32 (or 48) kHz and a C-POD that detects echolocation clicks of dolphins and porpoises. These PAM devices are deployed for around two months at a time and have been recording the local soundscape since March 2012.||The median sound level during the baseline period ranged from 60-80 dB re 1 µPa in the frequency range 0.01-10 kHz, then decreasing to ~45 dB re 1 µPa at 48 kHz. It is likely that the considerable shipping present at the site affects the sound levels. |
Sound levels were, on average, higher during installation activity compared to periods of no installation activity in the frequency range 10-5000 Hz with a median increase of 8.2 dB re 1 µPa (interquartile range = 6.7 dB re 1 µPa).
Average sound levels were found to be louder at times when the WEC was producing power compared to times when the device was in situ and not producing power in the frequency range 10- 1000 Hz with a prominent peak in the frequency range 57-63 Hz.
From the long term monitoring of the site it has been identified that the sound levels are highly variable, and it is difficult to determine the effect of the wave energy converter in such a variable ambient noise environment.
|Habitat Change||Invertebrates||Video monitoring of seabed habitat.||Environmental monitoring at FaBTest will focus on site-specific (not device-specific) seabed habitat monitoring. This regulatory system ensures that risk of damage to sensitive seabed habitats by installation, operation and decommissioning of deployments at FaBTest is minimised. |
Underwater camera work is undertaken at 24 locations within the FaBTest site annually in late spring/early summer.
Where appropriate, work will comply to best practice as set out in Ware, S.J. and Kenny, A.J., (2001) ‘Guidelines for the conduct of benthic studies at marine aggregate extraction sites’ and Coggan et al. (2008) ‘Recommended operating guidelines (ROG) for underwater video and photographic imaging techniques.