The SeaGen tidal turbine is a free stream tidal energy device that converts energy from tidal flow into electricity. The device comprises twin 16m diameter rotors connected to a generator through a gearbox, with a rotor system supported on the end of a cross beam. The cross beam is, in turn, supported by a 3m diameter pile. The cross beam can slide vertically up and down the pile to allow access to the rotors, generator and gearbox for servicing and inspection.
In 2004, Marine Current Turbines Ltd (MCT) identified the Narrows of Strangford Lough, Northern Ireland as their preferred location for the deployment of the SeaGen device. An Environmental Impact Assessment (EIA) was undertaken by Royal Haskoning, and completed in June 2005 with the production of an Environmental Statement (ES).
Based on the consultation responses and requirements of EU Directives and Northern Ireland environmental legislation, a conditional FEPA marine construction license was issued to MCT on 15 December 2005. Subsequent variations of the license have taken into account the increased scientific knowledge built up through the ongoing monitoring program and the adaptive management approach adopted by MCT.
The issue of the license required MCT to establish an Environmental Monitoring Plan (EMP) and a number of mitigation measures. Data collection began, pre-installation, in April 2005 and formed the basis of an Environmental Baseline Report, against which all future monitoring during installation, commissioning and decommissioning could be compared.
The results from each of monitoring strands of the EMP were evaluated regularly to ensure that any impact of SeaGen on the marine environment in Strangford Lough could be detected at an early stage. Using an adaptive management approach, the data collected has provided evidence to support reduction in mitigation requirements.
A small dedicated ‘Science’ Group was set up to advise on the detailed management of the EMP and mitigation measures, while a wider ‘Liaison’ Group was established, to whom progress on the project and decisions of the Science Group would be reported.
Both Science and Liaison groups have operated well since 2006, meeting the requirements of both their memberships, and of the project. The SeaGen EMP was designed to:
- Detect, prevent or minimize environmental impact attributable to the turbine installation and operation; and
- Provide an ongoing monitoring strategy to determine any immediate or emerging adverse impacts on the habitats, species and physical environment of Strangford Lough.