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.

CorPower Ocean – Scapa Flow, EMEC

Project Site OES-Environmental

Title: CorPower Ocean – Scapa Flow, EMEC
Start Date:
January 01, 2018
Technology Type:
Info Updated:
September 13, 2018
Project Status: 
Device in operation
Single surface floating point absorber
Project Scale: 
Single half-scale device
Installed Capacity: 

The HiWave project was initiated to address the reliability and the high Levelised Cost of Energy (LCOE) of current Wave Energy Converters (WECs), which have so far been too large, heavy, and costly compared to their energy output. As part of the HiWave project consortium, CorPower Ocean has developed a WEC with a Power Take-Off (PTO) system, which incorporates a phase control module to make the device oscillate in resonance with incoming waves. This amplifies the motion and power capture, which facilitates the capture of a large amount of energy using a comparatively small device. The phase control module additionally enhances the device’s survivability by detuning the device in stormy conditions.

With funding from the Interreg North-West Europe Funding Ocean Renewable Energy through Strategic European Action (FORSEA) project, CorPower Ocean’s WEC was deployed at the European Marine Energy Centre’s (EMEC) Scapa Flow test site in January 2018. The deployment consists of the following technical elements:

  • C3 WEC single surface floating point absorber, approximately 10m in length and 4.3 in diameter, with a power rating of 25kW;
  • Buoyancy units supporting lazy wave cabling;
  • Tension mooring system and anchor bracket attached to an existing gravity-based anchor; and
  • Umbilical cable attached to a resistive load bank located on the EMEC test support buoy.


A bottom-based foundation module was installed at the test berth which provides force reference from the WEC to the seabed and includes a mooring system with tidal adjustment function and tensioning capacity up to 60 tons. The installation operation included the subsea attachment of the foundation frame to a pre-laid gravity base, and the laying of an umbilical cable which controls the tidal adjustment unit. 


Export Cables:

As the site is not grid-connected, no export cable is present. The WEC is connected to a floating microgrid unit provided by EMEC, which was designed to allow the C3 device to behave as if grid-connected by providing a stable voltage and frequency reference, simulating the impedance of a typical grid connection, absorbing power from the device under test, and providing power to auxiliary systems.


Vessel spread: The following vessels were used during construction:


Name and type of vessel Activity

Large Multicat 

(C-Odyssey/Green Isle)

Installation of bottom-based foundation module and device



EMEC Scapa Flow test site, berth 1, Anchor Point A

Project Timeline: 

CorPower Ocean's product development follows a structured five-stage verification process established as best practices for ocean technology by Wave Energy Scotland (WES) and the European Technology and Innovation Platform for Ocean Energy (ETIP Ocean), which involve step-wise validation of survivability, performance, reliability, and economics.

Stage 1 (2012) and 2 (2013 – 2014) proceeded with the study of primary conversion (wave-body interactions) with numerical models calibrated by tank testing (small prototypes at 1:30 and 1:16 scale), followed by secondary conversion (PTO, mechanical to electricity) with numerical models calibrated by PTO rig testing (1:3 scale)[1]. Fully integrated WEC models will continue to be tested in increasing scales up to array demonstration in Stage 5.

Implementation of the current Stage 3 program (1:2 scale C3 WEC device) is guided by best practice support from EMEC, with experience from offshore power generation company Ibderola Engineering and EDP, the University of Edinburgh, and WavEC Offshore Renewables’ expertise in cost and performance modelling. The stage 3 demonstration is funded by WES, the Swedish Energy Agency, and InnoEnergy, with deployment at EMEC being supported by the Interreg North-West Europe Funding Ocean Renewable Energy through Strategic European Action (FORSEA) project.

At present, the contracted period for testing of the 1:2 scale device in Orkney is six months, including temporary recovery for onshore inspections and testing, with planned decommissioning upon completion of the test period.

In June 2018, EMEC issued a performance statement to CorPower following seven months dry testing of CorPower’s PTO system on the Hardware-In-Loop (HIL) rig.  Onshore PTO testing forms part of the WES funded Hi-Drive project, which has now completed its Stage 3.

CorPower plans to complete C3 testing in summer 2018 and aims to incorporate understanding from wet testing into the development of their next-generation technology, as part of the Horizon 2020 funded project WaveBoost and full-scale HiWave-5 project.

[1] CorPower Ocean HiWave Project – Project Information Summary: http://www.gov.scot/Topics/marine/Licensing/marine/scoping/corpower/summary1216

Licensing Information: 

The European Marine Energy Centre (EMEC) has been accredited with the UK Accreditation Service (ISO 17025) since 2005. EMEC has been granted the consents required to install an agreed ‘envelope’ of device types at these sites.

Licences held by EMEC include:

  • Town and Country Planning (Scotland) Act 1997;
  • Crown Estate Act 1971;
  • Food & Environment Protection Act 1985 Part II Deposits in the sea (FEPA);
  • Coast Protection Act 1949 (section 34) (CPA); and
  • Electricity Act 1989 (section 36).

Each developer is required to submit device-specific information to support amendment of these consents to allow installation of their device. This information includes a project summary and details on how the specific device details align with the EMEC environmental description and navigational risk assessment.

The C3 WEC has an installed capacity of less than 1MW, therefore no Section 36 consent was required. In addition, EMEC test site deployments require no terrestrial planning applications. No Licence to Disturb European Protected Species or Basking Shark was required for this project, therefore only a Marine Licence was necessary.


Licence Competent Authority Reference Date Issued Expiry date
Marine Licence (Marine (Scotland) Act) Consent Marine Scotland 06480/17/2 28 September 2017 30 March 2019


Key Environmental Issues: 

The seabed throughout the Scapa Flow test site is composed of flat muddy sand, with the identified biotope (loose lying mats of Phyllophora crispa on infralittoral muddy sediment) not listed on the UK Biodiversity Action Plan or the Scottish Biodiversity List. The Scapa Flow test site is not located within any designated conservation areas, however, the site is located within a wider expanse of Orkney coastline and inshore habitats which represent, in some areas, Special Areas of Conservation (SACs) and Special Protection Areas (SPAs). The nearest protected sites are:

  • Keelylang Hill and Swartabeck Burn site of special scientific interest (SSSI), 7.6 km north-northwest: moorlands which are important for density and diversity of the bird community including birds of prey and moorland breeding birds.
  • Orkney Mainland Moors SPA, 7.6 km north-northwest: a site that supports populations of European importance of the Annex I species hen harrier, red-throated diver, and short-eared owl.
  • Waulkmill SSSI, 7.6 km northwest: site which encompasses a wide range of nature conservation interests including a sandflat and well-vegetated shingle spit.

Further details can be found in EMEC’s Environmental Description specific to the Scapa Flow test site, which can be downloaded from here

Potential environmental risks anticipated by CorPower in their project information summary[1] include:

  • Loss of the C3 device due to hull breach and water ingress;
  • Breakage of the mooring line; and
  • Fluid leakage – the working fluid for the majority of the device is pressurised air, and the cooling system will use sea water and distilled water that does not contain refrigerant or other additives. The fluid used in device cylinders which will be in contact with the ocean environment is CompWay68, for which here is an MSDS available.

[1] CorPower Ocean HiWave Project – Project Information Summary: http://www.gov.scot/Topics/marine/Licensing/marine/scoping/corpower/summary1216

CorPower Ocean – Scapa Flow, EMEC is located in United Kingdom.

Baseline Assessment: CorPower Ocean – Scapa Flow, EMEC

General Description:

No specific baseline environmental surveys were carried out as part of the deployment. A number of studies were undertaken to inform baseline characteristics for the Scapa Flow test site, which are described in Tethys’ webpage EMEC Scapa Flow Non Grid-Connected Wave Test Site and listed below.

ReceptorStudy Description Design and Methods Results Status
  • Physical Environment

Initial site selection: Bathymetry commissioned by EMEC to Netsurvey Ltd.

Geophysical survey

Water depths ranged from 15 to 30m across the site approximately 1 m deeper than charted depths.

  • Benthos

Initial site selection: determining biota and sediment particle size.

Grab sampling

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.

  • Marine Mammals

Baseline Acoustic Characterisation.

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.

Reports and Papers

Post-Installation Monitoring: CorPower Ocean – Scapa Flow, EMEC

General Description:

CorPower plans to publish an annex to EMEC’s Scapa Flow Environmental Description document, which will consider any project-specific risks and the associated proposed mitigation and monitoring mechanisms. The following measures are described in EMEC’s Environmental Description:

ReceptorMonitoring Program Description Design and Methods Results Status
  • Benthos

Benthic grab analysis

Survey samples sieved and analysed 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 propose.

  • Birds
  • Marine Mammals

Wildlife observations

Observations of birds and mammals by EMEC wildlife observers.

Raw data is publically available from the link below, however no report has been published.

Reports and Papers
Research N/A
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