Initial tests involved short-term deployments of the device on its moorings followed by disconnection and towing back to harbor for inspection. The testing program was undertaken in incremental stages, culminating in a three-month period of continuous grid-connected operation at the end of 2012. In exporting power to the UK grid, the SR250 became the world’s first floating tidal energy device to generate power into a grid.
The device was installed at the European Marine Energy Centre (EMEC) tidal test site in Fall of Warness, Orkney. EMEC’s grid-connected tidal test site is situated in a narrow channel between the Westray Firth and Stronsay Firth, where there is a very strong tidal current with a typical spring flow of up to 4 m/s (8 knots).
Marine Scotland Licensing Operations Team (MS-LOT) was the licensing authority for the project at EMEC. In 2011 Orbital Marine Power was granted a Marine Licence under the Marine (Scotland) Act 2010 to permit the deployment of the SR250 at the Fall of Warness Site.
The SR250, measuring 33 m long, was constructed at Harland & Wolff in Belfast in 2010 where Orbital Marine Power (formerly Scotrenewables Tidal Power Ltd) installed the cable and the gravity anchors for the mooring system during the third quarter of 2010, full scale device was constructed towards the middle of 2010 then undergo towing trials prior to installation, and the four-riser mooring system was installed onsite in early 2011. The device remained at EMEC for testing through 2013. The device then underwent short–term testing within the EMEC site until a safe connection and disconnection procedure was established. A later full-scale version, the SR2000, was developed and deployed at EMEC three years later.
Key Environmental Issues
The interactions of deployed tidal devices with marine wildlife were largely unknown in 2011. Potential impacts that were identified included the risk of disturbance or displacement as a result of noise generated by device operation and associated activities. Direct interactions included the potential for entanglement and also for collision (particularly with rotors) which has clear implications at a population level.
A general review of the risks and existing mitigation measures associated with the lease area is presented in the Scotrenewables Tidal Power Ltd SR250 Deployment Fall of Warness Environmental Statement Volume II – Appendices
Baseline Assessment: Orbital Marine Power SR250 at EMEC
|Design and Methods
|Recorded footage for baseline assessment of seabed communities.
|Nearshore surveys. Offshore cable route and mooring site seabed surveys using skipper, umbilical man for the ROV, ROV pilot, and USBL operator.
|The faunal community recorded in the vicinity is typical of such habitats in Orkney waters and is dominated by sponges, anemones, bryozoans, encrusting invertebrates and associated species such as urchins and starfish. The seabed communities observed further offshore in deeper water (>20 m) are more typical of the offshore deployment sites and dominated by encrusting invertebrates. No particularly sensitive species or communities were recorded in the vicinity of the planned deployment areas or cable route.
Post-Installation Monitoring: Orbital Marine Power SR250 at EMEC
|Design and Methods
|Monitor seal behaviour and potential marine mammal collision and potential biological removal.
|Shore based observations, underwater camera, hydrophones, and strain gauges.
|It is not possible, with any degree of accuracy, to predict the likely risk of collision of common seals with the SR250.
SMRU will be consulted as part of the environmental monitoring strategy development process which will be undertaken in consultation with SNH and EMEC.