Sectoral marine plan for offshore wind energy: strategic habitat regulations appraisal pre-screening report

Results of the pre-screening stages of the habitat regulations appraisal.

1 Introduction

1.1 Purpose

1.1.1 The purpose of this report is to set out the results of the initial pre-screening stages of the Habitat Regulations Appraisal ( HRA) for the draft Sectoral Marine Plan for Offshore Wind Energy which encompasses deep water plan options (hereafter referred to as the “draft Plan”). This includes setting out the evidence base and proposed methodology for undertaking the subsequent screening and assessment stages of the HRA. This work has been undertaken by ABPmer on behalf of Marine Scotland.

1.1.2 The HRA pre-screening study has been overseen by a Project Advisory Group ( PAG) which includes representatives from within Scottish Government, Crown Estate Scotland, and Scottish Natural Heritage.

1.2 Background

1.2.1 The UK is the current market leader in offshore wind power, with around 5.8 GW of installed capacity by the end of 2017, all of which consists of conventional fixed-bottom foundation technology located in relatively shallow water depths (<40 m) and near to shore (<30 km). As installed capacity increases and the opportunities in shallow near-shore sites is exhausted, projects will need to be developed further from shore and in deeper water, which will pose greater technical challenges and constrain efforts to reduce costs.

1.2.2 In response to this challenge, momentum is building around the potential for floating offshore wind foundation technology to unlock near-shore deep water sites at a lower cost of energy than far-shore fixed-bottom locations. Scotland has natural advantages in terms of a combination of high wind speeds and abundant near-shore deep water sites.

1.2.3 The Draft Sectoral Plan for Offshore Wind published in 2013 focused on conventional offshore wind technologies. The Scottish Government is therefore seeking to develop an updated Sectoral Marine Plan for Offshore Wind Energy which encompasses deep water plan options (the Draft Plan) to provide the strategic framework for the deployment of future offshore wind in Scottish waters.

1.2.4 A range of different technologies have been proposed for floating offshore wind [1] (Figure 1):

  • Spar-buoy: a cylindrical ballast-stabilised structure which gains its stability from having the centre of gravity lower in the water than the centre of buoyancy
  • Semi-submersible platform: Buoyancy stabilised platform which floats semi-submerged on the surface of the ocean whilst anchored to the seabed with catenary mooring lines
  • Tension leg platform: a semi-submerged buoyant structure, anchored to the seabed with tensioned mooring lines, which provide stability.

1.2.5 These technologies all have different strengths and weaknesses and may be appropriate in different conditions. Over time further technologies may become available for deployment in deep water. The draft Plan would be technology neutral with technology preferences determined by the market.

Figure 1. Floating wind foundation typologies [2]

Figure 1. Floating wind foundation typologies

1.3 Plan Development Process

1.3.1 The draft Plan will be developed based on Marine Scotland’s established process for developing sectoral offshore energy plans (Figure 2). A scoping exercise has been undertaken by Marine Scotland Science to identify areas of constraint and opportunity for offshore wind development (Marine Scotland, 2018). The scoping exercise has identified a number of strategic Areas of Search (AoS) for offshore wind including deep water wind development (Figure 3). These areas will be refined to develop Draft Plan Option ( DPO) areas based on informal consultation and draft Regional Locational Guidance documents which provide further information on the planning process and detailed environmental, socio-economic and planning related information for each AoS.

Figure 2: Sectoral marine planning process

Figure 2: Sectoral marine planning process

Figure 3: Areas of Search for future offshore wind development

Figure 3: Areas of Search for future offshore wind development

1.3.2 These DPO areas will be appraised through:

  • Strategic Environmental Assessment ( SEA);
  • Habitats Regulations Appraisal ( HRA); and
  • Socio-economic Impact Assessment.

1.3.3 Based on the findings of the Sustainability Appraisal, Marine Scotland will refine the DPO areas and take forward a draft plan for public consultation.

1.3.4 Together, these assessments will take account of strategic social, economic and environmental effects of possible development within the DPO areas as well as assessing the potential effects on species and habitats protected by European legislation (Natura 2000). These assessments will inform an overall Sustainability Appraisal of the DPO areas for offshore wind development.

1.4 Report Structure

1.4.1 The report has been structured as follows:

Section 1: Introduction Provides background to the plan, together with details of the plan development process, the scope of the document and report structure;

Section 2: Approach to HRA Presents background information on the legislative context and overall approach to the HRA;

Section 3: Outcomes of Pre-screening Stages of HRA Provides the results of the initial pre-screening stages of the HRA;

Section 4 Method and Scope of Appraisal Outlines the proposed methods for the next screening and assessment steps in the HRA process;

Section 5: Summary and Next Stages of the HRA Provides a summary of this report and overview of the next stages of the HRA.

1.4.2 The following supporting information is provided in the appendices:

Appendix A: Pre-screening Tables Presents the key pressures or impact pathways [3] associated with the plan together with a table of all the European/Ramsar sites and interest features. These will be the starting point for the next screening and assessment stages of the HRA.


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