When the European Marine Energy Centre (EMEC) was established by Highlands and Islands Enterprise (HIE) and its funding partners in 2003, it was with the intention of stimulating and accelerating the development of tidal prototype energy generating devices. As part of the Prime Contracting Framework Agreement, Highlands and Islands Enterprise (HIE) engaged Tulloch Prime Contracting Limited (Tulloch) to undertake the design and construction of the tidal test facility.
The establishment of a test centre for assessing the performance of new and developing tidal energy technology is a strategically important facility for Scotland and the UK. AURORA Environmental Ltd (AURORA) was contracted by Tulloch to undertake the environmental works for the construction and installation phase of the tidal test facility, including a number of baseline studies and the production of an Environmental Statement (ES) to support consent applications. The scope of the Environmental Impact Assessment (EIA) originally produced for the test site covers the construction, installation and generic presence of the test site. In order to be able to assess the impacts of the long-term presence and operation of the site, it was necessary to consider a range of likely potential devices at a generic level. The detailed consideration of individual devices is the responsibility of each developer making use of the site. To this end, EMEC has developed impact assessment guidance for potential developers in consultation with a wide range of regulatory organisations and local stakeholders.
In order to streamline the developer consenting process at the test site, in 2014, EMEC published an Environmental Appraisal which effectively pre-appraises an envelope of tidal energy device types to undertake testing activities with regard to the potential environmental effect. EMEC has acquired a site-wide Section 36 consent for an envelope of device types and activities with an an installed capacity of 10MW. All developers accessing EMEC’s facilities must develop a robust environmental monitoring programme to support developer licence applications.
The EMEC Fall of Warness grid-connected tidal test site is situated off the island of Eday where the Atlantic Ocean meets the North Sea, approximately 20km north of Kirkwall in the Orkney Islands, Scotland. EMEC’s grid-connected tidal test site is situated in a narrow channel between the Westray Firth and Stronsay Firth. The site has a very strong tidal current, with a typical spring flow of 4m/s (8 knots). The eight test berths on site range in depth from 12m to 50m.
EMEC has been examined and accredited as a test laboratory for full-scale wave and tidal test facilities by the United Kingdom Accreditation Service (UKAS), since 2005. EMEC is accredited to test the performance of wave and tidal energy devices against IEC Technical Specifications. EMEC can provide developers with independent verification in accordance with ISO 17020 to confirm that your technology satisfies conceptual reliability, survivability and performance targets.
EMEC has been granted the consents required to install an agreed ‘envelope’ of device types and activities at the site, holding licences and consents relating to the following legislation:
- Town and Country Planning (Scotland) Act 1997
- Marine (Scotland) Act 2010
- Crown Estate Act 1971
- Food & Environment Protection Act 1985 Part II Deposits in the sea (FEPA)
- Coast Protection Act 1949 (section 34) (CPA)
- Electricity Act 1989 (section 36)
- The Conservation (Natural Habitats, &c.) Regulations 1994
- The Wildlife and Countryside Act 1981
All projects at EMEC require a Marine Licence under the Marine (Scotland) Act 2010. For clients wishing to install at EMEC’s test sites the consenting process requires the client to produce the following documentation to accompany their Marine Licence applications, alongside the relevant site-wide environmental report and navigational risk assessment: Project Information Summary (PIS), Project-specific Environmental Monitoring Programme (PEMP), Project-specific Navigational Risk Assessment (NRA), Third-party Verification/Certificate (TPV/TPC), and Decommissioning Programme (DP). The project-specific assessments should make reference to the findings from the site-wide assessments and be direct in their findings and recommendations. EMEC is continually working with regulators to make sure that the most efficient and effective licensing processes are put in place at the sites.
Construction of the EMEC Fall of Warness tidal test site was completed in 2005 and the facility was commissioned shortly afterwards. EMEC welcomed their first tidal developer client in 2006. Two new subsea cables were installed at the test site in 2010 bringing the total number of EMEC-owned test berths to seven. All seven berths are now contracted and options for accommodating further test devices are being considered. The following is a list of all EMEC tidal clients who have deployed devices at the Fall of Warness test site:
- OpenHydro Turbine, OpenHydro
- Installed December 2006
- Deepgen, Alstrom
- Installed September 2010, Decommissioned 2016
- SR250, Orbital Marine Power
- Installed March 2011, Decommissioned 2013
- AR1000, Atlantis Resources Corporation
- Installed August 2011, Decommissioned 2012
- HS1000, ANDRITZ HYDRO Hammerfest
- Installed December 2011, Decommissioned 2015
- HyTide 1000, Voith Hydro
- Installed September 2013, Decommissioned April 2015
- PLAT-O, Sustainable Marine Energy
- SR2000, Orbital Marine Power
- Installed October 2016, Decommissioned September 2018
- CoRMaT, Nautricity
- Installed April 2017, Decommissioned 2019
- T2 Array, Torcardo
- Installed May 2017
- ATIR Tidal Platform, Magallanes Renovables
- Installed February 2019, Ongoing
- O2, Orbital Marine Power
- Installed May 2021, Ongoing
EMEC acquired and implemented a site-wide Section 36 consent for the Fall of Warness tidal test site in 2016. In February 2019, Crown Estate Scotland granted an extension to EMEC’s lease for the Fall of Warness tidal energy test site in Orkney until 2040.
Key Environmental Issues
The following potential environmental issues were identified for the construction of the Fall of Warness site:
- Modification to coastal processes (e.g. water movement and sedimentation patterns)
- Disturbance/modification to benthic habitats and communities due to cable laying in inshore waters.
- Disturbance (noise and physical presence) to wildlife including birds, cetaceans, turtles, pinnipeds and otters
- Pollution of water column from antifoulants, lubricants and hydraulic fluids.
- Ongoing minor disturbance to seabed communities in the immediate vicinity of the routes where the cable is laid on the seabed.
- Seabed disturbance/modification during foundation installation and during device installation/removal e.g. anchors etc.
- Disturbance (noise and physical presence) to local fish, seabird, seal, otter and cetaceans populations as a result of device installation.
- Loss of water current energy from the marine environment due to presence/operation of test devices may result in sedimentation and habitat and community modification and increased stratification in the water column.
- Foundations could affect seabed current flow and consequent sedimentary processes.
- Seabed scour around device foundations
- The effect of tidal turbines on seals and cetaceans is at present unknown as is the extent to which these populations pass through the waters of the Fall of Warness
- Wildlife entanglement/entrapment and collision with device blades e.g. diving bird populations, cetaceans (in particular the harbour porpoise), seals (in particular pups) and otters present in the area.
- Devices that break the sea surface may attract roosting birds and provide a seal haulout
- Electrical and electromagnetic effects – wildlife interactions
Of these environmental issues, those relating to seabed and coastal processes, water column contamination, and disturbance to wildlife were screened out due to the residual impact being classed as negligible. The only remaining environmental issue was:
- Disturbance/modification to benthic habitats and communities as a result of cable-laying in inshore waters.
Developers are not required to undertake a baseline seabed survey as this was carried out as part of the ES. They are however required to undertake a seabed survey post-decommissioning to assess the effect of the device upon the seabed. Other commitments are defined in the Guidance for Developers Document. .
Potential residual impacts and their pathways associated with device testing are listed in EMEC’s Environmental Appraisal for the Fall of Warness site.
The following section describes environmental mitigation measures undertaken during construction of the Fall of Warness site:
- Construction activities were planned to occur for 7 consecutive days in August, towards the end of the bird breeding season (cormorants) and before the start of the grey seal pupping season thus minimising any disturbance;
- Any evidence of wrecks encountered during cable laying were to be reported immediately to the County Archaeologist;
- Recognised marine standard materials held on vessel(s) and recognised marine working standards and regulations were applied;
- A Navigation Risk Assessment was undertaken and the site was marked on the appropriate charts providing the mariner with adequate information;
- The cable laying vessel complied with the International Regulations for Preventing Collisions at Sea (COLREGS) and displayed the appropriate lights and marks for a vessel restricted in her ability to manoeuvre;
- The works were promulgated by appropriate Notices to Mariners and Navigational Warnings;
- Consideration was given to test berths being clear of the adverse weather ferry routes were possible (in the case of the surface piercing device), and away from the main transit route (in the case of the buoyant surface device);
- Appropriate marking, lighting and aids to navigation to be specified for all surface piercing devices;
- EMEC have implemented a wildlife monitoring programme to in an attempt to investigate the effect of device presence on marine wildlife; and
- EMEC has been involved with a number of other research institutions to identify the knowledge gaps and initiate research aimed at addressing these.
Within EMEC’s Environmental Appraisal the following potential monitoring measures (where relevant) were listed for deployments at the Fall of Warness site:
- *Site-wide monitoring of wildlife abundance and density is currently delivered by EMEC for the developers. In the event that EMEC become unable to fund or conduct this monitoring, each developer must contribute accordingly to the continuation of this monitoring and data analysis;
- Focal studies on animal behaviour in the vicinity of devices and marine works;
- Monitor colonisation of selected devices and infrastructure. This may also form part of a marine non-native species (MNNS) management protocol or bio-fouling management;
- *Use of appropriate method(s) to detect collision or near miss, and monitor any other interaction between mega-fauna and the operating device;
- *Any use of underwater lighting at night to be gradual and alongside monitoring to determine any fish/bird attraction and collision risk for predators;
- In situ measurements of strength and range of Ei and B fields under different energy generation scenarios;
- Pursue passive and active monitoring on and around selected devices and infrastructure to inform knowledge base. This may also form part of a MNNS management protocol;
- Monitoring changes to hydrodynamic forces around particular devices would provide data that could inform impact modelling for later commercial-scale proposals. Lambkin et al (2008) may provide some useful information;
- *Acoustic monitoring of drilling and anchor/mooring installation noise at various distances and frequencies, particularly if novel methods are in use;
- *Establishing the acoustic signature of operating devices;
- *Reporting of observations from MMO records;
- *Depending on timing and duration of activities specific short term monitoring of, for example, seal haul outs may be required;
- *Device monitoring should be capable of alerting the developer to an entanglement event (e.g. use of load cells, underwater video); and
- Reporting of behavioural reactions through wildlife surveys (e.g. underwater video) and opportunistic observations.
(*) Monitoring measures which are a likely condition of a licence or consent (Note: although some of the above measures are described as not being required by the Regulator as a licence/consent condition, developers may choose to undertake research in these areas for their own purposes).
The Fall of Warness test site consists of eight berths, each with an 11kv seabed cable to export electricity to the onshore substation at Caldale, Eday. The cables are wet-type composite cables consisting of three EPR-insulated stranded copper power cores designed for alternating current, three 2.5mm2 copper signal/pilot trip cables and a 12-core single-mode fibre-optic bundle. The cable is then armoured with two layers of galvanised steel wire. Cables were provided by AEI (wave test site cables) & Pirelli (tidal test site cables).
The cables were laid as standard sub-sea cables on the seabed. As the cables approached the shore, in 15m of water, ductile iron cable protectors were attached. At the low water spring tide mark, each passes into a trench dug 12m into the seabed and beach. Onshore, the cables are fed into a manhole and then into the substation.
At the seaward end, each cable, when not occupied by a developer, is terminated using a specially designed connector provided by J+S Ltd, which allows EMEC to carry out planned condition monitoring of any cables not in use by developers. These terminators can, if required, be converted into splices to enable developers to use umbilical cables to attach their devices to the cables.
The onshore substation is a single storey building covering an area of 30 x 5.5m. Inside the substation, each cable terminates at an 11kV circuit breaker, along with the tripping cable. The fibres are terminated in the communications area of the substation. The electrical output performance of each of the devices is measured by equipment within the substation and transmitted to the data centre. EMEC then analyse the quality of the electricity to demonstrate that the devices can provide a smooth and reliable supply of electricity to the grid. The metered data is also provided to the developer through the Supervisory Control and Data Acquisition (SCADA) system and the power data is logged in the data historian to be made available for historical trending. We ensure the confidentiality of the data collected.
EMEC’s hydrogen production plant is located onshore next to EMEC’s Caldale site substation. Producing hydrogen and using it as an energy storage medium is a solution to overcome local grid constraints, enabling large scale renewable integration. In 2016, EMEC installed a 0.5MW rapid response PEM (Proton Exchange Membrane) electrolyser in the laydown area adjacent to the substation to produce ‘green’ hydrogen from excess renewable energy produced by tidal energy converters testing at the Fall of Warness and from the 900kW community wind turbine. In 2017 EMEC achieved the world’s first tidal generated hydrogen using power from tidal energy clients, Orbital and Tocardo, which were testing tidal energy devices on site. Control switchgear inside EMEC’s substation determines whether the power fed to the electrolyser is to be routed from tidal generators testing at the Fall of Warness site or the community wind turbine. The electrolyser is housed in a standard 20′ by 10′ ISO container and can generate up to 220kg of high purity, fuel cell grade hydrogen per day. Hydrogen gas is produced via electrolysis at 20 bar which is then passed into a compressor to further pressurise the gas to 200 bar at which point it is stored. Up to 500kg of hydrogen can be stored in storage cylinders on site. The hydrogen can then be transferred to specially designed mobile storage units (MSUs) and transported to the Orkney mainland by road and ferry. Each MSU can transport 250 kg of hydrogen. The MSUs consist of 59 lightweight composite cylinders made of aluminium with a Kevlar wrap, specially designed to comply with road restrictions. The hydrogen can then be used locally in a variety of fuel, power and heat applications in hydrogen technology projects.
Vessels used in the installation of the EMEC tidal test site were:
Swathe bathymetry – site characterisation surveys
Exact vessel used unknown
ROV seabed surveys
Exact vessel used unknown
Cable lay vessel
Installation of sub-sea export cables
Papers, Reports, Research Studies
Papers and Reports:
- Fall of Warness Navigational Risk Assessment 2019
- Fall of Warness Environmental Appraisal 2014
- Navigation Risk Assessment Update: Fall of Warness 2010
- Fall of Warness Environmental Description 2006
- Fall of Warness Environmental Statement 2005
During the development of the facilities, Environmental Impact Assessments (EIAs) were performed for the grid-connected wave and tidal test sites, detailing considerations of the potential issues relating to the build of the test facility and use of the site in principal. Environmental characteristics of each site (including the two scale test sites) have been detailed in the Environmental Descriptions. Environmental Appraisals were produced to support developers’ applications for Marine Licences and a site-wide Section 36 consent for deployment of an ‘envelope’ of device types and operations at the grid-connected sites.
EMEC has carried out or has been involved with a number of research projects. These include national, international and site-specific projects. More information about these can be found at the following locations: http://www.emec.org.uk/research/ and http://www.emec.org.uk/projects/ocean-energy-projects/. Selected projects relevant to environmental impacts, assessment and monitoring are listed below:
Site specific projects:
- Acoustic Monitoring Programme (2008-2009, 2011-2012): aimed to develop a methodology and procure equipment for characterising the acoustic output of devices, and establish an acoustic baseline. Outputs:
- Wildlife Observations Programme and Wildlife Analysis Project (2005 – 2015): aimed to collect data which can inform on whether or not displacement, or other alteration to behaviour and distribution, occurs in the resident wildlife due to the presence and/or operation of marine energy devices. Outputs:
- EMEC Fall of Warness Wildlife Observation Data 2005 - 2015 (available from Marine Scotland)
- Long, C. (2018). No evidence of long-term displacement of key wildlife species from wave and tidal energy testing. Paper presented at 4th Asian Wave and Tidal Energy Conference (AWTEC), Taipei, Taiwan
- Analysis of the Possible Displacement of Bird and Marine Mammal Species Related to the Installation and Operation of Marine Energy Conversion Systems 2017
- EMEC Fall of Warness Tidal Test Site: Wildlife Observations Project Annual Report 2014
- Fall of Warness Wildlife Observations Methodology 2013
- Analysis of Bird and Marine Mammal Data or Fall of Warness Tidal Test Site 2012
ReDAPT (Reliable Data Acquisition Platform for Tidal): In 2012 EMEC designed, built and tested a bespoke Integrated Monitoring Pod capable of operating in high velocity tidal flow. Conference paper output: Baird, S. (2016). Integrated Monitoring for Marine Energy. Paper presented at 4th Annual Marine Energy Technology Symposium (METS), Washington D.C., USA.
- Hydrodynamic modelling
- Marine safety course
- Underwater Acoustic Monitoring at Wave and Tidal Energy Sites: Guidance Notes for Regulators (2014)
- A review of the potential impacts of wave and tidal energy development on Scotland’s marine environment (2014)
- FLOWBEC (Flow, Water Column and Benthic Ecology 4D) 2012 – 2016: aimed to improve the understanding of how the physical behaviour of the water such as currents, waves and turbulence at tide and wave energy sites influences the behaviour of marine wildlife, and how tide and wave energy devices might alter the behaviour of such wildlife. Development of an autonomous seabed platform with integrated monitoring technologies.
- Understanding how marine renewable device operations influence fine-scale habitat use and behavior of marine vertebrates (RESPONSE) 2011 – 2015
- Offshore Renewable Joint Industry Programme (ORJIP): as part of EMEC’s remit, a short summary of the opportunities, issues and challenges associated with sharing environmental monitoring data was published in 2020, which is available here.
- FORWARD2030 (Fast-tracking Offshore Renewable energy With Advanced Research to Deploy 2030MW of tidal energy before 2030) 2021 - 2025: part of the project will see the development of environmental monitoring to support the consenting of future large-scale floating tidal arrays.
- SEA Wave (Strategic Environmental Assessment of Wave energy technologies): involved environmental research at Billia Croo, undertaking a gap analysis to address the lack of knowledge regarding the potential environmental impacts associated with deploying wave and tidal energy converters in the marine environment and provide strategic recommendations for consenting. Project deliverables are available here.
- CEFOW (Clean Energy From Ocean Waves): device-specific research was conducted to investigate responses of species receptor groups to the deployment of single and multiple wave energy converters at EMEC.
- MaRINET and MaRINET2 (Marine Renewables Infrastructure Network): provided marine energy development companies, entrepreneurs, start-ups and researchers with funded access to marine energy experts and the world’s leading wave, tidal and offshore-wind test facilities. A short course on “Methods and environmental data collection in Marine Renewable Energy sites” was delivered in 2021 and is available here.
- FloTEC (Floating Tidal Energy Commercialisation) 2016 – 2021: EMEC carried out resource and environmental assessments around Orbital Marine Power’s floating tidal technology, with a final webinar on lessons learnt presented in September 2021.
- EquiMar: Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact
- RESOURCECODE (Resource Characterisation to Reduce the Cost of Energy through Coordinated Data Enterprise): aimed to support investment and growth in the wave and tidal energy sector through the creation of an integrated marine data toolbox. The open source toolbox (available here) was launched in March 2022, using 27 years of model data to create the highest resolution wave model in North West Europe.
Baseline Assessment: EMEC Fall of Warness Grid-Connected Tidal Test Site
|Receptor||Study Description||Design and Methods||Results||Status|
|Marine Mammals, Cetaceans||Survey of cetacean and otter populations.||Survey the use of the area by otters and cetaceans.||It is likely that otters occur all-round the coastline of Eday and Faray, however no occupied holts were found in the survey. Evidence of otter presence was found at a number of sites along the six kilometres of coast surveyed. |
Harbour porpoise use the area for passage between Westray and Stronsay Firths and for feeding. Occasional sightings of Minke and pilot whales were made. Unidentified dolphins were also reported on several occasions, between the months of May and August.
|Marine Mammals, Pinnipeds||Seal tagging study by SMRU.||Telemetry data to characterize the use of the area by seals making use of nearby haul out sites.||From the available data, there were no major movements of common seals through the Fall of Warness. Seals did use the haul-out sites on The Graand and the Green Holms. These tracks were from seals tagged at haul-out sites some distance from the test site. |
The pattern of use of the Fall of Warness by grey seals is unclear. Muckle Green Holm and Little Green Holm appear to be important haul-out and breeding sites and there has been some use of the waters to the south and west of Eday. However, as with common seals, none of the grey seals were tagged in the vicinity of test site as part of the survey and this might be reflected in the pattern of use.
|Birds||Survey and desk based study of birds, onshore and offshore.||Characterize the species present in the area of the test facility including the south west coast of Eday and the Green Holms.||The coastline between the east end of the Bay of Greentoft and the west end of Sealskerry Bay provides shelter, nesting sites and feeding sites for a large variety of bird species.||Completed (2005)|
|Physical Environment, Invertebrates||Intertidal survey (Aurora Environmental Ltd).||Flora and fauna survey near landfall site.||The fauna present represent those commonly found on rocky shores with patches between the algal turf colonised by barnacles and limpets. More exposed area supported dog whelks, periwinkles, shore crab and starfish.||Completed (2005)|
|Physical Environment||Bathymetrical survey (HR Wallingford).||Bathymetrical survey (HR Wallingford) Swathe bathymetry of the tidal test site.||The bedrock is exposed throughout the majority of the test bay area, with occasional boulders. |
The swathe bathymetry shows that the bedrock forms a series of ridges.
|Physical Environment, Sediment Transport||Preliminary seabed survey (Aquatera Ltd) and Additional seabed survey (SULA Diving). Video and still photography data collected by divers and ROV.||Survey area was selected to cover the areas where the cables would be laid, the location of the tidal devices, and to obtain a general picture of the seabed habitats in the area. Due to unfavorable weather conditions surveying in the exact locations preferred became difficult and divers were moved off course by the strong tidal stream in the area. The majority of areas that had been proposed as seabed survey stations were videoed/photographed and are considered to be representative of the wider habitats of the project area.||It appeared from the survey that there are no species of importance in the area, with no unusual species being recorded.||Completed (2005)|
Post-Installation Monitoring: EMEC Fall of Warness Grid-Connected Tidal Test Site
|Stressor||Receptor||Study Description||Design and Methods||Results||Status|
|Noise||Marine Mammals||Chickerell BioAcoustics was contracted by the European Marine Energy Centre (EMEC) to characterise the ambient noise field in both ebb and flood conditions at the Fall of Warness tidal energy test site in Orkney, UK. ||The current project called for three surveys to be carried out using drifting acoustic recorders. Initial surveys were carried out using the existing EMEC drifting hydrophone equipment but later surveys used an upgraded system, the Drifting Acoustic Recorder and Tracker (DART) system developed by Chickerell BioAcoustics and EMEC.||The noise level of frequencies above 1 kHz can vary by at least 26 dB across the site; this is believed to be primarily due to flow-induced noise generation. It was not possible to locate the individual noise sources accurately as this was outwith the scope of this project, but future studies could investigate this further. Based on the data gathered during this study, it seems unlikely that the noise generated by tidal energy converters operating within the site would have a significant impact on marine mammals. However, further detailed studies will be required in order to gain more understanding of this. ||Completed (2013)|
|Attraction, Avoidance||Birds, Marine Mammals||Land-based visual observations.||Watches were carried out by an experienced observer from Ward Hill on Eday overlooking the test site during daylight hours, ranging between 04:00hrs and 20:00hrs during summertime. The study area is scanned and the time and location of any marine mammal or seabird sightings are recorded. Where possible, the geographic location of each marine mammal or seabird group will be recorded using a pre-defined grid.||Completed between July 2005 and December 2015. |
During the period 1 April 2013 to 31st March 2014 a total of 909 hours of observations were completed.
Seasonal peaks in grey and harbour seal abundances corresponding with pupping seasons were observed.
The majority of cetacean sightings during this reporting period have been white-beaked dolphins, whereas typically the most sighted cetacean is harbour porpoise.
A typically diverse range of marine birds has also been observed, although for several species numbers in April and May 2013 fell below the mean.
|Attraction, Avoidance||Birds, Marine Mammals||Assessment of the extent of any displacement of key wildlife species arising from the installation and operation of marine energy converter systems (MECS). ||Nearly 18,000 hours of land based observations data, collected since 2005, were utilised for the project, drawn from EMEC’s Wildlife Observations Programme. These data were collected, primarily, to aid in site characterisation of EMEC’s two MECS test sites, at Fall of Warness (tidal energy) and Billia Croo (wave energy), rather than to inform an impact assessment study. Comprehensive analyses were conducted on data for ten species/groups of species selected from each of the two test sites. ||Many of the outputs produced from the fitted models, particularly at the Fall of Warness test site, suggest that the greatest change in density occurs when device-associated infrastructure (including anchoring systems, foundations and mooring systems) is installed onsite. This change in density is not limited to test berths but tends to stretch beyond, to the rest of the survey grid. For most species in the Fall of Warness survey area, the extent of this change is reduced with the installation of devices and when they are operating. This would suggest that it may not be the physical presence of the device or its infrastructure that is causing this change in density, but rather the increased vessel movements that are associated with installation activities. Further research regarding this particular potential impact pathway, possibly using the Automatic Identification System (AIS) data collected at both sites, may prove valuable. ||Completed|