Description
Orbital Marine Power (formerly Scotrenewables) first installed their full-scale prototype floating tidal energy technology, the 2 MW SR2000, onto its moorings at the European Marine Energy Centre’s (EMEC) Fall of Warness tidal test site in October 2016. The device provided first power to the grid in November 2016. The project was supported by Scottish Enterprise’s WATERS II (Wave and Tidal Energy R&D Support). The testing programme at EMEC was also supported via the FORESEA Interreg-NEW funded project.
Designed to DNV-GL standards with a 20 year design life, the SR2000 was designed to minimise the whole lifecycle cost of electricity production from tidal energy. The shape and design of Orbital’s technology was developed to enable low-cost fabrication and a simplified installation and maintenance process. The SR2000 device consists of twin turbines with rotor blades 16m in length, each fixed to retractable legs which are mounted to a 64m floating platform, which enables the turbine to be positioned in the most energetic parts of the tidal stream. The flexible mooring system means the devices can be installed in any water depths of over 25m and can be deployed with a range of anchoring systems to suit most seabed types.
Location
The device was installed at European Marine Energy Centre (EMEC) tidal device test area in Fall of Warness, Orkney. Water Depth: 33m. Tidal range: 3m. Tidal speeds up to 3.7 m/s.
Licensing Information
In July 2016 Orbital Marine was granted a Marine Licence under the Marine (Scotland) Act 2010 to permit the deployment of the SR2000 at the Fall of Warness site (Licence no. 05431/16/0), which can be accessed from here.
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)
- Electricity Act 1989 (section 36)
The Marine Licence held by Orbital Marine additionally allowed the company to generate electricity in excess of 1 MW by utilizing the EMEC Fall of Warness Section 36 consent as granted by Scottish Ministers.
Project Progress
The SR2000 was first deployed at the site and produced power to the grid in October 2016, however it was subsequently removed in the same month to avoid winter storms. In March 2017 the SR2000 was successfully redeployed and was operating at full power.
The surface floating SR2000 endured heavy North Atlantic storms throughout autumn and winter into January 2018, enduring wave heights in excess of 7m. The turbine also managed to maintain continuous generation in sea states of over 4m significant wave height and maintained 2MW rated power in seas of 2m significant wave height – demonstrating the turbine is capable of generating through around 99% of conditions experienced at the Orkney site.
The SR2000 was removed from the site in September 2018 to make way for the build an installation of Orbital Marine’s optimized 2 MW floating tidal turbine, the Orbital O2, a 73m long floating superstructure due to be installed at EMEC in 2020.
Up until the project’s completion in September 2018, the SR2000 produced excellent performance results and has delivered several world-firsts, including demonstrating a load factor in excess of 38% in its first 24 hours of continuous generation and generating over 120 MWh in 7 days of generation with load factors in excess of 35%. During this period, the single 2MW device also generated circa 7% of the Orkney Islands electricity demand, with shorter periods exceeding 25% of demand. Over its test programme, the SR2000 produced over 3,000 MWh of electricity.
Key Environmental Issues
The sites seabed ranges from eroding sub-littoral sandbanks in the east to smooth scoured bedrock ridges and platforms with occasional boulders towards the center of the site. Fall of Warness is not a protected area; however, there are protected sites in close proximity. These include:
- Faray and Holm of Faray SAC – protected for its grey seal populations.
- Sanday SAC – Protected for its harbor seal populations, intertidal mudflats and sandflats, inshore sublittoal rock and subtidal sandbanks.
- Muckle and Little Green Holm SSSI – Nationally important grey seal breeding colony (Around 3% of the national breeding population).
EMEC has produced a specific Environmental Appraisal (EA) for the Fall of Warness site which can be downloaded from here.
Papers, Reports, Research Studies
A review of the EMEC Fall of Warness Test Site: Environmental Appraisal identified a number of potential residual impacts that are considered relevant to the SR2000 deployment
No device specific monitoring data is publically available at the moment, however environmental monitoring information at the Fall of Warness tidal test site can be found at: EMEC Fall of Warness Grid-Connected Tidal Test Site
Baseline Assessment: ScotRenewables SR2000 at EMEC
| Receptor | Study Description | Design and Methods | Results | Status |
|---|---|---|---|---|
| Physical Environment | Potential for changes to hydrodynamics and physical processes | Desk based study | No important impacts of relevance to hydrodynamics or physical processes are expected from developments at Fall of Warness. | Complete |
| Marine Mammals | Potential impacts on marine mammals as a result of support vessel activity, e.g. noise and physical presence | Desk based study | Installation of the SR2000 will be completed using a standard multi-cat work vessel assisted by a RIB. Installation activities will be completed in a relatively short timescale. No significant effects on any sensitive species are expected from this low level of vessel activity. | Complete |
| Fish | Electromagnetic field (EMF) effects | Desk based study | No significant effects | Complete |
| Fish | Potential impacts on basking sharks as a result of support vessel activity, e.g. noise and physical presence | Desk based study | Installation of the SR2000 will be completed using a standard multi-cat work vessel assisted by a RIB. Installation activities will be completed in a relatively short timescale. No significant effects on any sensitive species are expected from this low level of vessel activity. | Complete |
Post-Installation Monitoring: ScotRenewables SR2000 at EMEC
| Stressor | Receptor | Study Description | Design and Methods | Results | Status |
|---|---|---|---|---|---|
| Collision | Birds, Fish, Marine Mammals | Underwater video monitoring for environmental interactions between the operational turbine and marine mammals, fish and birds. | Six Vivotek colour cameras were installed to provide underwater footage of the SR2000. Accelerometers were installed in the blade tips with the intention of detecting any abnormalities in blade speed that could be attributed to collision events. Strain gauges were also installed in the blades for collision detection. | Wildlife was observed in 12 sample clips out of 44 reviewed from the dataset. No collision events were observed. Due to image quality, possible receptors could not be definitively identified to a basic ecological level (e.g. bird, fish or mammal). Possible receptors were observed marginally more frequently during blade rotation than during static periods and all were observed to be moving with the current. The accelerometer lacked sensitivity to detect potential collisions. The vast volume of data and the high number of ‘spikes’ produced each day by the strain gauge meant it was difficult to distinguish between spikes caused by swirls and buffets of turbulence and those that may potentially have been caused by an object colliding with the rotor blade. | Completed |