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.

EMEC Fall of Warness Grid-Connected Tidal Test Site

Project Site OES-Environmental

Title: EMEC Fall of Warness Grid-Connected Tidal Test Site
Start Date:
July 01, 2005
Technology Type:
Info Updated:
July 02, 2019
EMEC Fall of Warness Grid-Connected Tidal Test Site
Project Status: 
Test site operational
Project Scale: 
Test Site with eight berths
Installed Capacity: 
Site-wide grid capacity 4.5MW and installed consent capacity 10MW

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.



Export Cables:

The Fall of Warness test site consists of eight berths, each with an 11kv seabed cable to export electricity to the onshore substation. 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.


Onshore Infrastructure:

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 the site’s 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. The hydrogen is then used locally in a variety of fuel, power and heat applications in hydrogen technology projects.


Vessel Spread:

Vessels used in the installation of the EMEC tidal test site were:


Vessel type



Survey vessel

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

CS Sovereign



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.

Project Timeline: 

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 8 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:

Licensing Information: 

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 you 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.


EMEC holds 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


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.


Each developer is required to submit device-specific information in order to acquire a marine licence to allow the installation of their device. This information includes a project summary and details on how the specific device details align with the EMEC’s environmental appraisal and navigational risk assessment. All developers are expected to submit an environmental monitoring programme.

Key Environmental Issues: 

Site construction


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.[1] 


Device testing


Potential residual impacts and their pathways associated with device testing are listed in EMEC’s Environmental Appraisal for the Fall of Warness site.


Environmental Webpage: http://www.emec.org.uk/services/consents/


Mitigation Measures:  


Site construction:


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.


Device testing


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). 


[1] European Marine Energy Centre (EMEC) (2013) Guidance for Developers at EMEC Grid Connected Sites: Supporting Environmental Documentation. EMEC. Available [Online] http://www.emec.org.uk/services/consents/ Accessed 31/10/2014

EMEC Fall of Warness Grid-Connected Tidal Test Site is located in United Kingdom.

Baseline Assessment: EMEC Fall of Warness Grid-Connected Tidal Test Site

General Description:

The following field surveys were undertaken (or commissioned by) the developer to inform baseline characterisation.

ReceptorStudy Description Design and Methods Results Status
  • Nearfield Habitat

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.

  • Bathymetry

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.

  • Bathymetry

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.

  • Birds

Survey and desk based study. (Mike Cockram)

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.

  • Marine Mammals

Coastal wildlife and cetaceans (Chris Booth) and Further assessment of otter populations (Celtic Environmental Ltd.)

Survey the use of the area by otters.

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

Tagging study (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.

Reports and Papers


Titlesort descending Data Type Date Research End Date Organization
EMEC Fall of Warness Boat-Based Wildlife Surveys (RESPONSE Project) Observation, Boat/Land Based Survey May 01, 2012 October 31, 2013 University of Aberdeen
EMEC Fall of Warness FLOWBEC Platform Acoustic Doppler Velocimeter Data June 02, 2013 July 05, 2013 University of Aberdeen
EMEC Fall of Warness FLOWBEC Platform Fluorometer Monitoring Data June 12, 2012 July 05, 2013 University of Aberdeen
EMEC Fall of Warness FLOWBEC Platform Multi-Beam Sonar and Echosounder Data Active Acoustics, Multi Beam June 12, 2012 July 05, 2013 University of Aberdeen
EMEC Fall of Warness High-Intensity Wildlife Observation Data Observation, Boat/Land Based Survey June 13, 2012 July 03, 2013 University of Aberdeen
EMEC Fall of Warness Wildlife Observation Data Observation, Boat/Land Based Survey July 11, 2005 July 28, 2015 European Marine Energy Centre (EMEC)

Post-Installation Monitoring: EMEC Fall of Warness Grid-Connected Tidal Test Site

General Description:

The table provides a list of the monitoring data carried out by EMEC.ewsaz

ReceptorMonitoring Program Description Design and Methods Results Status
  • Birds
  • Marine Mammals

Land-based visual observations

Watches are 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. For more information on the survey method follow the link below:

Fall of Warness Observation Methodology Guide

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.

Reports and Papers

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 location: http://www.emec.org.uk/research/


Site specific projects:

  • Acoustic monitoring
  • ReDAPT
  • Hydrodynamic modeling
  • Marine safety course
  • Wildlife observations programme
  • Inshore crustacea fisheries project
  • Wave resource assessment
  • Surface Interactions with Wave Devices: Remote Observations

National projects

  • Underwater Acoustic Monitoring at Wave and Tidal Energy Sites: Guidance Notes for Regulators
  • The provision of guidance to inform the simplification of marine renewable energy development application
  • A review of the potential impacts of wave and tidal energy development on Scotland’s marine environment
  • Flow, Water Column and Benthic Ecology 4D (FLOWBEC)
  • Understanding how marine renewable device operations influence fine-scale habitat use and behavior of marine vertebrates (RESPONSE)
  • Optimizing array form for energy extraction and environmental benefit (EBAO)
  • PerAWaT
  • Pentland Firth and Orkney Waters (PFOW) strategic data study
  • The consolidation of wave and tidal EIA/HRA issues and research priorities
  • Offshore Renewable Joint Industry Partnership (ORJIP)

International projects

  • MaRINET and MaRINET2: The EU MaRINET2 project is working towards its vision of unlocking the energy potential of our oceans by ensuring the integration and enhancement of leading European research infrastructures specialising in research, development and testing of Offshore Renewable Energy (ORE) systems. EMEC’s test sites, including Shapinsay Sound scale site, form part of the infrastructure network available to developers with offshore renewable energy projects heading towards commercialisation

  • Equimar

  • FORESEA: Funding Ocean Renewable Energy through Strategic European Action

  • CLEMATIS & ORCHIDS: Cable Lifetime Enhancement via Monitoring using Advanced Thermal and electrical Infrastructure Sensing (CLEMATIS) seeks to prove of a number of concepts devised during a previous desk based feasibility study (ORCHIDS)

  • PERISCOPE: Aims at establishing a permanent innovation ecosystem in the North Sea Region to grow transnational innovation partnerships for sustainable business development in emerging blue markets.

  • MONITOR: Multi-model investigation of tidal energy converter reliability.

  • ProtoAtlantic: Strengthening the transfer of innovation results to facilitate the emergence of new products, services and processes.

  • MET-Certified: Development of International Standards and Certification schemes for Marine Energy Technologies

  • Reliability in a Sea of Risk (RiaSOR & RiaSOR II): RiaSOR established a framework for reliability assessment within the ocean energy sector, which builds upon established practices from the automotive industry. RiaSOR II is aimed at taking the RiaSOR I theoretical reliability assessment framework and applying it to the field test programme for developers to validate the findings and establish a practical monitoring platform.


  • InToTidal: Demonstration of Integrated Solution for offshore Tocardo Tidal power plants

  • FloTEC: Floating Tidal Energy Commercialisation

  • Ocean_2G: The project aims to test, validate and pre-certify a full-size tidal energy harnessing prototype system that will demonstrate the capabilities of an innovative 2MW pre-marketable platform.

  • SEA Wave: Strategic Environmental Assessment of Wave energy technologies

  • ResourceCode: Resource Characterisation to Reduce the Cost of Energy through Coordinated Data Enterprise

  • Marine Energy Alliance (MEA): De-risk early stage marine energy concepts through desk-based technical and commercial services from an industry expert consortium.

  • Ocean Energy Scale-up Alliance (OESA): Delivery of technical and commercial services to TRL4-5 companies to prepare them for ocean site testing and demonstration.

  • Integrating Tidal Energy into the European Grid (ITEG): evelopment of an all-in-one solution that includes clean predictable energy generation (tidal energy); safe export to the grid; and the storage and delivery of the excess capacity in hydrogen

  • BlueGIFT: BlueGIFT brings together partners across the Atlantic Area (southern France, Portugal, Spain and the Canaries) to focus on the development and demonstration of the next generation of Ocean Energy technologies (floating wind, wave and tidal). The project will deliver a coordinated transitional programme which will ensure that the partners and countries involved will see the long term roll out of these low carbon ocean energy technologies in their regions.

  • OceanDEMO: This project will help bring offshore renewable energy technologies to the market by providing free access to North-West Europe’s world leading network of test centres.

  • ReFLEX: Develop and deliver a replicable community based Integrated Energy System demonstration project. Use novel localised power balancing mechanisms alongside digital control to provide robust and responsive energy systems across the electricity, transport and heat networks.​ Develop a Virtual Power Plant to manage energy flows in each of the three sectors.​

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