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. 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. 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 adjacent ‘blank’ test area. The pre-laid foundations comprise 5m x 5m x 2m gravity-base frames loaded with densecrete blocks for equipment moorings. An area of seabed is also available for rehearsal or deployment of other tools and techniques.
As the site is not grid connected, no export cable is present.
Used to install anchors and test support buoy
Exact vessel used unknown
The EMEC Scapa Flow nursery wave test site is situated in the natural harbour of Scapa Flow south of Kirkwall in the Orkney Islands, Scotland. The two test berths on 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).
A developer wishing to deploy a device at the test site must provide an outline of the proposed project. This document must also identify any potential device-specific environmental or navigational risks, as well as any proposed mitigation measures. This information will be submitted alongside EMECs application to update their generic Marine Licence, a process which must be carried out for every new development at the site. MS-LOT typically requires 6-8 weeks from receipt of application to issue a licence amendment. EMEC is also 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 nursery wave test site was completed in 2011 and EMEC welcomed their first client on site in 2012. EMEC hold a valid consent for the installation of an additional set of foundations which gives the potential for two serviced berths to become available in future. The EMEC nursery 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:
- Energy Bag Device, University of Nottingham
- Installed 2012
- CorPower WEC, CorPower Ocean
- Installed January 2018
Although some seals have been recorded in the area of the site, SNH have commented that this area is not a site of concern. There have been sporadic sightings of cetaceans within the observation area, in particular Harbour Porpoise and Risso’s Dolphin. Scapa Flow is an important wintering area for many species of marine bird. In relation to these species at the sensitive periods, the key issues to be addressed within the developer’s environmental monitoring plan are:
- Displacement due to noise (during installation, maintenance, operation and decommissioning of device)
- 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
Environmental Website: http://www.emec.org.uk/facilities/scale-test-sites/
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.