Abstract
Hammerfest Strøm UK Limited (HSUK) propose to install a tidal turbine known as the HS1000 at a test berth at the European Marine Energy Centre (EMEC) tidal test facility in the Fall of Warness off the island of Eday in the Orkney archipelago. This supporting document provides information on the technical details of the project, with specific relation to environmental impacts and mitigation measures.
Based on a 300 kW prototype which has undergone field trials in Norway, the design of the HS1000 has gone through a detailed conceptual phase with adaption for UK tidal conditions. The device has a rated power output of 1 MW and power will not exceed this output.
The installation is to be carried out in May and June 2011. The device will operate for five years with little or no interference. Visual inspections of the device will take place throughout the five years although more inspections are likely to occur in the first year. It is anticipated that the nacelle will be brought onshore once for routine maintenance.
Previous to this document, a scoping consultation was carried out where relevant stakeholders were consulted and invited to express comments on the project. The main issues of wildlife impacts (such as collision risk and underwater noise) and navigational safety and risk were common themes raised by stakeholders and these have been addressed within this supporting document. HSUK is developing an Environmental Monitoring Plan (EMP) and is keen to work with stakeholders to address any future concerns and monitoring programmes.
HSUK has already been in consultation with EMEC and SNH, to ensure issues are adequately addressed and lie within SNH monitoring recommendations and any requirements raised during the consent application process.
A Navigation Safety Risk Assessment (NSRA) has been commissioned from an established risk consultancy, to assess the risk to navigation posed by the installation, operation and maintenance and eventual decommissioning of the device. This alongside ongoing communication with EMEC and consultation with navigation stakeholders has established the necessary actions for mitigating and monitoring any impacts on navigation likely to arise due to the device. The device will be charted as an underwater object of known size and depth and will lie within the already charted EMEC leased area for testing of tidal energy devices. Notice of all operations at the test berth will be issued in line with the EMEC notification procedure.
In addition to navigation risk the other potential issue raised relates to the impact on wildlife in the area, particularly in relation to potential collision and avoidance associated with seals, cetaceans and diving birds. Tidal technology is a novel industry and little impact investigation has thus far been carried out, so impacts associated with devices are largely unknown. Mitigation and monitoring will be applied with this in mind. HSUK have, where possible, developed technology and methodologies to mitigate potential impacts.
Based on the assessment undertaken and the appropriate mitigation and monitoring proposed by HSUK it is concluded that the deployment of the HS1000 will not lead to any significant negative environmental impacts. Due to the novel nature of the technology associated with tidal technology, there remains uncertainty regarding the potential impacts. This is particularly true with regard to impacts on marine wildlife including collision risk, avoidance/attraction and disturbance from underwater noise. HSUK will put into practice an Environmental Monitoring Programme (EMP) which strives to clarify some of the presently unclear issues.