In addition to the grid connected wave test site at Billia Croo, EMEC also have a wave test site that is not connected to the grid aimed at providing less challenging conditions for scale prototypes and marine operations. The site provides a more flexible seaspace acting as a stepping stone between the test tank and real sea conditions. The site is located in Scapa Flow, to the south of Kirkwall, and was chosen for its relatively benign waters which reach almost 0.35m significant wave height. The area is 0.4km across and approximately 0.9km in length situated in water depths of 21-25m with a predominant westerly wave regime.
At the site EMEC offers developers the use of a bespoke test support buoy. If required, the device under test will be connected to the test support buoy via two umbilical cables: one for power transmission and the other for control and communications. A purpose-built Test Support Buoy moored on site acts as a power sink to allow load-dumping of any electricity generated as heat dissipated to air. A simulated grid can be made available to support device performance analysis The buoy can relay data by wireless technology allowing developers to monitor performance remotely, as well as dissipating electricity generated by the device. The buoy is also equipped to supply the marine energy devices on test with power and act as navigational aids.
Each test site comprises one berth with pre-laid foundation and attachment points, and an adjacent test area. The pre-laid foundations comprise 5m x 5m x 2m gravity-base frames loaded with densecrete blocks for equipment moorings. The area of seabed is also available for rehearsal or deployment of other tools and techniques.
The EMEC Scapa Flow scale wave test site is situated in the natural harbour of Scapa Flow south of Kirkwall in the Orkney Islands, Scotland. The testing area within the site range from 21-25m water depth.
EMEC holds an overarching site licence, simplifying the consent process within an agreed envelope of activity. Two consents are required for installation of marine energy converter devices at the scale test sites:
- Marine Licence issued by the regulator Marine Scotland; and
- Harbour Works Licence issued by Orkney Islands Council (OIC).
EMEC has worked closely with Marine Scotland’s Licencing Operations Team (MS-LOT) and its key statutory consultees to establish a consenting process for its scale sites which is inclusive, proportionate, and timeous while still satisfying all relevant legislation. Each new technology to be installed at the scale sites requires a marine licence. EMEC supports clients in developing their marine licence application to MS-LOT and conduct regular engagement with MS-LOT to ensure timeous determination post submission. Applications must be accompanied by supporting documentation from the client, outlining the proposed project and identifying any potential project-specific environmental and navigational risks, together with any proposed mitigation and a decommissioning programme. MS-LOT typically requires 14 weeks from receipt of valid application to determination and issuing a licence.
Similarly, EMEC has worked closely with OIC to establish a process whereby a generic harbour works licence for the purpose of installing technology for testing has been granted to EMEC. This is a requirement as the scale test sites are located within the statutory harbour authority area. Under the terms of this licence, EMEC is required to give OIC at least 21 days’ notice of each new developer wishing to install at its scale sites.
Site selection surveys and environmental studies were carried out in 2009-10. Construction of the EMEC Scapa Flow scale wave test site was completed in 2011 and EMEC welcomed their first client on site in 2012. The EMEC wave test site at Scapa Flow is expected to continue to be operational so long as there is a need for testing in the benign real-sea regime the site enjoys. The following is a list of EMEC clients who have deployed devices at the Scapa Flow site:
Key Environmental Issues
While some seals have been recorded in the area of the site, NatureScot have commented that this area is not a site of concern for seals. There have been sporadic sightings of cetaceans within the observation area, in particular Harbour Porpoise and Risso’s Dolphin. Scapa Flow is selected as a Special Protection Area (SPA) for its important wintering grounds used for feeding, moulting and roosting by non-breeding shag and waterfowl. Qualifying interests of the Scapa Flow SPA include: great northern diver, black-throated diver, Slavonian grebe, common eider, long-tailed duck, red-breasted merganser, and European shag. These rich sheltered waters support large numbers of waterfowl, particularly in the winter months when frequent storms affect the surrounding North Sea and eastern Atlantic. Further information on the Scapa Flow SPA can be accessed here.
In relation to these species during sensitive periods, the key issues to be addressed within developers’ environmental monitoring plans are:
- Displacement due to noise (during installation, maintenance, operation and decommissioning of device)(particularly vessel noise)
- Displacement due to physical presence of device
- Physical harm caused by collision
- Physical harm caused by entanglement in device moorings
- Physical harm caused by noise
Mitigation Measures: Where appropriate, developers are required to implement their own mitigation measures should activities overlap with sensitive times of the year for marine wildlife.
Environmental Webpage: http://www.emec.org.uk/services/consents/
As the site is not grid connected, no export cable is present.
Used to install anchors and test support buoy
Exact vessel used unknown
Papers, Reports, Research Studies
- Scapa Flow Scale Site Environmental Description 2019
- Scapa Flow Scale Wave Site Navigational Risk Assessment 2019
- EMEC Scale Site Consenting Process: Guidance for Developers 2012
- Scapa Flow Scale Site Environmental Description 2011
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:
- Acoustic Monitoring Programme (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 (2011-2013): 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:
- 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 Scapa Flow Scale Wave Test Site
|Design and Methods
|Baseline description of fish in Scapa Flow region.
|As with much of UK waters, fish studies of high spatial resolution are currently poorly represented for this part of Orkney. Despite this, it is possible to make general statements based on the location of the site, known seabed conditions, and from existing resources e.g. the Orkney Biodiversity Records Centre.
|Fish species that are commonly found in Scapa Flow are typical of north Scottish waters and include pollack (Pollachius pollachius), saithe (Pollachius virens), ling (Molva molva), ballan wrasse (Labrus bergylta) and cuckoo wrasse (Labrus mixtus). Less abundant species include poor cod (Trisopterus minutes), goldsinny (Ctenolabrus rupestris), conger eel (Conger conger) and cod (Gadus morhua), which is widely distributed around Orkney in the summer months. Mackerel (Scomber scombrus) present during their migratory passage past Orkney, may also be found in the more energetic waters of Hoxa sound in the south of Scapa Flow. Other species that may be seasonally present include juvenile and non-spawning adult monkfish (Lophius piscatorius) and gurnard (Triglidae spp.).
|Bird characterization survey
|Boat-based bird surveys conducted in Scapa Flow between June
and August 2008. Supplemented with literature review.
|Guillemots, black guillemots and fulmars were the species most often recorded, with greylag geese and European storm petrels in the dominant group of species on some survey occasions. Scapa Flow held the highest populations of redbreasted merganser, red-necked grebe, Slavonian grebe and European shag of all areas of search in Scotland according to Lawson et al. (2015).
|Initial site selection: determining biota and sediment particle size.
|Grab sampling and ROV surveys.
|Moderately low energy site. “Sheltered Muddy Gravels” and “Subtidal Mixed Sediments”.
The infaunal community was composed largely of deposit feeding species (mainly polychaetes and bivalve molluscs), with only a few crustaceans present. Two common species were Lumbrineris gracilis and Thyasira flexuosa which made up approximately 10 - 20% of individuals at all stations.
Aquatera conducted surveys to the west of St Mary’s on the eastern side of Scapa Flow, and reported results that are mostly consistent with the surveys conducted by Moore (2009). The observed habitat resembled the biotope “Loose-lying mats of Phyllophora crispa on infralittoral muddy sediment” (SS.SMp.KSwSS.Pcri), which is not currently list as an Annex I habitat (on the UK Biodiversity Action Plan or on the Scottish Biodiversity List) and no benthic species of conservation importance were identified at the test site during surveying.
|Initial site selection: Bathymetry commissioned by EMEC to Netsurvey Ltd.
|Geophysical bathymetry survey.
|Water depths ranged from 15 to 30m across the site approximately 1 m deeper than charted depths.
|Baseline acoustic characterization
|Seabed-mounted hydrophone deployments.
|Background noise levels were in line with that which could be expected for this type of shallow water site. Contributions over and above these conditions were then identified, with the major contribution being the natural sounds from wind/waves and precipitation. The major anthropogenic source was shipping noise from distant static and mobile sources. Local shipping traffic also contributed to the sound field, although this was only present for around 7% of the time. Other sounds identified included a thunderstorm, aircraft and various biological sources.
Post-Installation Monitoring: EMEC Scapa Flow Scale Wave Test Site
|Design and Methods
|Benthic grab analysis.
|Survey samples sieved and analyzed regarding species and abundance
|Study undertaken to assist in setting up the scale site, no further work deemed necessary unless additional or different types of infrastructure are proposed.
|Invertebrates, Physical Environment, Sediment Transport
|Bottom sediment type and infauna identification.
|ROV surveys conducted to the west of St. Mary’s on the eastern side of Scapa Flow with three sample sites surveyed to within and around the Scapa Flow test site.
|Substrate: Flat muddy sand substrate with some shells and pebbles.
Infauna: a large number of tube-dwelling, filter-feeding annelids (such as sand masons, Lanice conchilega) and bioturbasive mounds were reported. The tube anemone Cerianthus lloydii and terebellid worms were also observed during surveys. Epifauna included occasional harbour crab Liocarcinus depurator, queen scallop Aequipecten opercularis and the common starfish Asterias rubens. Burrow-like holes in the sediment were observed, as evidenced by the presence of the bivalves - razor shells on the seabed. Serpulid worms occupied ocean quahog, Arctica islandica, and scallop shells.
|Characterization of biofouling present of pre-laid foundations using 3D video survey/mapping
|3D model of foundation and associated report.