Methodology for a Decision Support Tool for a Tidal Stream Device

Environmental Impact

It is important to evaluate the role of environmental considerations beyond the initial scoping stage of a project. Post site-selection and initial design, environmental aspirations still play an active role in the project in the form of Environmental Impact Assessments (EIA).

Environmental impact Assessment (EIA) of a tidal project can be a useful tool in the overall detailed design. Theoretically, EIA plays an advisory and passive role in projects only to be considered towards the end of the design [17]. However this role is outdated and not particularly useful in renewable energy projects. Therefore, it is increasingly common for the EIA practitioners to play a more active role and work closely with designers and project planners from the initial stages of a project [18]. This allows for mitigation and enhancement measures, with respect to environmental impacts, to be considered at an early stage, effectively streamlining the process of design and getting more value from an EIA [18].

Within the EIA study the impacts are very site specific however the following is a list of likely impacts which would require investigation [19][20][21]:

         •   Collision risk with local marine species
         •   Habitat disruption during construction and operation
         •   Likelihood of collision with diving birds such as: auks, guillemots, and shags
         •   Impact on sediment transport from a variation of the flow pattern
         •   Visual impact of shore-based infrastructure (substation & transmission)
         •   Underwater noise effect on marine species
         •   Electromagnetic field emissions from sub-sea cables on local marine life that use electroreception to hunt
         •   Shipping & Navigation implications
         •   Socio-economic impact of the project

Evidently, the EIA is an exhaustive study and extremely valuable to the preservation of natural biodiversity, history, and resources. Therefore incorporation as an active role within the planning design process could streamline the operational and construction phases of the project and increase the effectiveness of the study.

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References:
        ➙   [17] Geoffrey T. McDonald et. Going beyond EIA: Environmental Input to Planning and Design. Environ. Impact. Asses.
              Rev., Vol. 15, pp. 483-495. 1995.
        ➙   [18] Morgan, Richard K. Environmental impact assessment: the state of the art. Impact Assessment and Project
              Appraisal, Vol. 30, pp. 5-14. 2012.
        ➙   [19] Chris Frid et. The environmental interactions of tidal and wave energy generation devices. Environmental Impact
              Assessment Review, Vol. 32, pp. 133-139. 2012.
        ➙   [20] ScottishPower Renewables. ound of Islay Demonstration Tidal Array Environmental Statement. 2010.
        ➙   [21] Calum Robertson. Environmental Appraisal (EA) for the Argyll Tidal Demonstrator Project. Nautricity Ltd, 2013.