Sectoral marine plan for offshore wind energy: social and economic impact assessment scoping report

Sets out the methodology and scenarios for scoping and undertaking a socio-economic impact assessment.

2 Methodology

2.1 Introduction

2.1.1 The methodology to inform the scoping and assessment of socio-economic impacts has built on similar previous studies including ABPmer et al., 2011; ABPmer & RPA, 2012; ABPmer & RPA, 2013 and previous EIAs for offshore developments. It follows wider guidance on impact assessment including Scottish Government guidance on Business and Regulatory Impact Assessment [4] and the Green Book methodology ( HM Treasury, 2013).

2.1.2 The methodology described below covers:

  • The approach to defining development scenarios for future offshore wind development;
  • Defining relevant marine activities for inclusion in the assessment;
  • Defining relevant information sources to provide a baseline description against which impacts can be assessed;
  • The approach to scoping of potentially significant interactions between marine activities and possible development under the Plan;
  • Proposed approach for assessing socio-economic impacts on marine activities; and
  • Approach to cumulative assessment.

2.2 Approach to Defining Development Scenarios

2.2.1 The DPO areas for offshore wind development will identify potential broad areas within which future offshore wind arrays might be located. However, in order to provide a sufficient basis to carry out a quantitative socio-economic impact assessment, it will be necessary to make assumptions about the potential scale (potential installed capacity), nature (the types of technologies) and timing of possible development within these DPO areas. Possible socio-economic impacts associated with array export cables also need to be considered where practicable.

2.2.2 Given the inherent uncertainty in seeking to predict the scale and timing of development, it is proposed to progress the assessment using a number of scenarios, primarily relating to different possible scales of development within the strategic search areas, so that these uncertainties can be explored. The impacts of these scenarios can then be compared against the 'do nothing' option in seeking to estimate the potential socio-economic impacts associated with possible offshore wind development within the strategic search areas.

2.3 Developing Scenarios Relating to the Potential Scale of Future Development

2.3.1 To meet the 2050 carbon reduction target, heating needs to move away from natural gas and use low carbon sources. This change will primarily need to occur through the electrification of heating. The growth in electric vehicles ( EVs) will also have a significant impact on demand.

2.3.2 Based on scenario modelling undertaken by National Grid [5] , peak UK electricity demand is expected to rise from around 62 GW in 2016 to between 65-85 GW by 2050. This includes a forecast requirement for UK offshore wind capacity of between 8-18 GW by 2025 and 16-30 GW by 2050 (equivalent to around 50-100 TWh). Separately, the Energy Technologies Institute estimates that UK offshore wind deployment could reach 20-55 GW by 2050 [6] .

2.3.3 As at May 2018, Scotland had 217 MW of installed offshore wind capacity, but with a further 4.2 GW in construction or consented and awaiting construction [7] (Figure 4). The Robin Rigg Offshore Wind Farm in the Solway Firth accounts for around 174 MW of installed capacity.

Figure 4 Current and planned offshore wind development in Scottish waters
Figure 4 Current and planned offshore wind development in Scottish waters

2.3.4 In 2013, a Draft Sectoral Plan [8] for progressing ten medium-term option areas was published for consultation. The Plan remains to be finalised. This is the result of market uncertainty created by Electricity Market Reform. The DPO areas have been identified in Scotland's first National Marine Plan [9] . In December 2014, Scottish Ministers decided not to progress two of the plan options in South West Scotland and these have been removed from the draft Plan.

2.3.5 In Scotland, there are extensive deep water locations to the east, north, and west of the country, with 123 GW of the estimated 169 GW offshore wind potential located in water depths exceeding 60 m. Scottish Ministers anticipate that an initial plan for offshore wind might comprise 2 to 4 GW installed capacity within a number of DPO Areas.

2.3.6 Based on the above, three scenarios (termed 'Low Case', 'Central Case' and 'High Case') are proposed for the purposes of this study relating to different scales of possible future offshore wind development within the DPO areas in the period 2025 to 2035 as follows:

  • Low Case: 2 GW installed capacity;
  • Central Case: 4 GW installed capacity; and
  • High Case: 8 GW installed capacity.

2.3.7 For the purposes of this study, it is proposed to allocate this capacity pro rata across all of the DPO areas based on their size, assuming a minimum size for a commercially viable array of 100 MW.

2.3.8 It is recognised that the scale of development within individual DPO areas may vary and is unlikely to be proportional to the size of area in every (or even any) case. However, for the purposes of this assessment, it is important that realistic scales of development are considered in each DPO area. It is therefore helpful to consider possible higher levels of potential development (High Case) within each DPO area to help to identify possible capacity constraints and how different scales of development within DPO areas might give rise to differing levels of socio-economic impact. It should be noted that although SG provided direction, the scenarios used are hypothetical and are not a formal commitment or statement of policy.

2.4 Consideration of Possible Future Technologies

2.4.1 There is currently significant uncertainty concerning the nature of possible deep water wind technologies that could be deployed and the methods of their construction. There is also uncertainty concerning the mix of conventional technologies and deep water wind technologies that might come forward under the Plan.

2.4.2 The precise nature of the technologies to be deployed and their construction methods has the potential to affect the nature and scale of impacts, including socio-economic impacts. However, it is not appropriate to make detailed assumptions about project level technologies and construction methods in this plan level assessment. Some reasonable worst case assumptions have therefore been made to inform the socio-economic assessment as follows:

  • Turbine size – up to 15 MW;
  • Blade tip height – up to 280 m;
  • Footprint of arrays – array area (km²) = 0.5 x MW installed capacity [10] ;
  • Construction methods – foundation construction could entail percussive piling or gravity base foundations/anchors

2.4.3 While some socio-economic impacts may arise as a consequence of ecological impacts (which may vary to an extent depending on the technology) it will be a general requirement of the EIA and HRA processes to minimise such impacts to acceptable levels (where necessary underpinned by licence conditions). On this basis, it has been assumed that residual ecological impacts for offshore wind development projects will not be of sufficient magnitude to give rise to significant socio-economic impacts. This has been the experience of offshore wind development to date.

2.5 Developing an Indicative Programme

2.5.1 The timing of possible development at specific locations under the Plan is uncertain. The assumption is that the Plan will look to enable development within the period 2025 to 2035. Assuming Plan adoption in 2019, it is possible that consenting could be completed in some DPO areas within 4 years, with construction in these areas starting as early as 2025, and for those schemes to become operational by 2028. However, given that the draft Plan is seeking to facilitate development within the period 2025 to 2035 and given the uncertainty surrounding the precise timing of development, it will be assumed for the purposes of this assessment that all construction will commence in 2028 and that all developments will become operational in 2031. While this is a simplification, for impact assessment purposes it is likely to provide a broadly similar assessment of costs and benefits to an assumption that evenly distributes development over the period 2025 to 2035.

2.6 Taking Account of Cable Routes

2.6.1 There is currently a high level of uncertainty concerning the possible location and number of export cables associated with potential development within the DPO areas. These requirements will depend on the scale and location of development within the strategic areas and the future development of grid connection points (both onshore and offshore). Some information is available from National Grid (2016) on potential and planned land-side grid connections. However, it is still challenging to predict the likely routes for export cable corridors. Given these uncertainties, the proposed approach for this this study is to identify all areas inshore of the DPO areas as potential export cable route corridors unless there is a clear cable landfall point indicated by current and/or planned grid connection points. The same export cable route corridors have been assumed for each of the three scenarios as these would not be expected to vary significantly as a result of changing the intensity of development within each strategic search area.

2.6.2 As part of the assessment these areas will be screened for possible socio-economic issues and used to inform the RLG. However, given the uncertainties in possible export cable routes, no quantitative assessment of potential socio-economic impacts will be made.

2.7 Defining Relevant Marine Activities

2.7.1 A wide range of human activities occur in the marine environment which could potentially be affected by aspects of deep water wind development. For consistency with previous assessments, the following categories of activity have been considered within the study:

  • Aquaculture (finfish and shellfish);
  • Aviation;
  • Carbon Capture and Storage;
  • Coast Protection and Flood Defence;
  • Commercial Fisheries (including salmon and sea trout);
  • Energy Generation;
  • Military Activity;
  • Oil and Gas (including exploration, production, interconnectors, gas storage);
  • Ports and Harbours;
  • Power Interconnectors (including offshore transmission networks);
  • Recreational Boating;
  • Shipping;
  • Telecom Cables;
  • Tourism (including heritage assets);
  • Waste Disposal (dredge material); and
  • Water Sports (including sea angling, surfing and windsurfing, sea kayaking, small sail boat activities and scuba diving)

2.8 Establishing a Baseline

2.8.1 To assess the potential socio-economic impacts of potential offshore wind development on relevant marine activities, it is necessary to establish a baseline (counterfactual) against which the potential impacts of the Plan (intervention option) can be assessed.

2.8.2 Baseline information is therefore required for each relevant marine activity including:

  • The current location, intensity and economic value of activity; and
  • How the location, intensity and economic value might change over time in the absence of the Plan.

2.8.3 For each relevant marine activity, Appendix A provides an overview of the information sources that can be used to compile a suitable baseline.

2.9 Approach to Scoping

2.9.1 The potential for offshore wind development (including associated export cables) to give rise to socio-economic impacts on other activities depends on the nature and scale of interactions between them. The approach proposed for the scoping assessment is therefore to seek to define the potential interactions and to identify those interactions which have the potential to give rise to significant socio-economic impacts. The scoping assessment will draw on relevant previous studies and taking account of specific factors relevant to each strategic search area. The identification of potentially significant interactions has drawn on previous socio-economic assessments ( e.g. ABPmer et al., 2011 and ABPmer & RPA, 2013) and wider sources on interactions such as MMO (2014).

2.9.2 To identify the potential for significant socio-economic impacts to occur, the scoping process will take account of:

  • Whether the activity spatially overlaps with one or more DPO areas;
  • For tourism, where more than 10% of a DPO is within 15 km of a seascape unit with a low 'Capacity Index', based on Scott et al. 2005 (see Appendix A15 for more detail);
  • The extent to which the spatial overlap is judged likely to give rise to a significant interaction; and
  • The likely scope to avoid a significant interaction through spatial planning of the location of arrays within a DPO area.

2.9.3 Where one or more potentially significant interactions is identified, further consideration will be given to the potential impact pathways by which socio-economic impacts may arise and the extent to which any or all of the relevant pathways require assessment. Where potential for significant socio-economic impacts is identified, these interactions will be subject to more detailed assessment.

2.9.4 Where potential impacts will need to be mitigated up-front by the developer as a condition of consent, it has been assumed that the residual impacts will not give rise to significant socio-economic impacts. The mitigation costs to be met by the developer have not been included in the costs presented in the assessments described within this study. For example, in the case of potential impacts to aviation radar, these will need to be mitigated by the developer and therefore significant impacts to the aviation sector will be avoided and so are not quantified within this assessment.

2.9.5 Similarly, where potential socio-economic impacts are consequential on potential environmental impacts, it has been assumed that mitigation will be required for such impacts as a condition of consent and the residual environmental impacts will not give rise to significant socio-economic impacts.

2.9.6 Appendix A includes a partial scoping assessment for each activity but this will need to be completed once the DPO areas have been defined.

2.10 Approach to Assessing Social Impacts

2.10.1 Social impacts can occur as a result of knock-on effects from economic impacts, due to direct effects associated with changes that result from future development in DPO areas or due to knock-on effects from impacts on affected sectors. Unlike the economic effects, it is unlikely to be possible to monetise the social impacts but it is important that they are assessed so they can inform decision-making.

2.10.2 Our approach to the assessment of social impacts is based on the identification of value clusters. This draws on work undertaken by Collingwood Environmental Planning for Marine Scotland (2016), where value clusters were identified through discussion with local communities around the Scottish coast. Therefore, these value clusters provide the best mechanism for enabling the social impacts to be assessed. The value clusters for use in the study are presented in Table 1.

Table 1 Clusters of social values

Value cluster levels

SIA categories

Value clusters


Way of life

Way of life

Way of life

1. Family/family life/inter-generational issues

2. Jobs/career/employment

3. Money/cost of living












4. Local jobs/local industry/community sustainability

5. Transport connections/technology connections

6. Education

7. Shops/housing

8. Socialising/recreation/parks/leisure

9. Friends/being involved/supporting others

10. Local identity/cultural heritage/Gaelic

11. Healthcare

12. Connection to nature/landscape

13. Local political and decision-making systems

Wider political and environmental context



14. Landscape/seascape/wildlife/environmental change

15. National and EU level political and decision-making systems

Source: Collingwood Environmental Planning Ltd et al. (2016): A two way conversation with the people of Scotland on the social impact of offshore renewables, Final Dialogue Report, March 2016.

2.10.3 The social impact assessment involves considering how development could affect each value cluster. The direct and indirect economic effects will be included to enable the knock-on effects of changes in jobs and GVA to be captured. Wider social impacts that result directly from development or as knock-on effects from impacts on sectors that are not reflected in an economic effect can also be identified and described. A rating system is used to enable comparison across all the social impacts. This is based on the typical level of impact that would be seen. Any variation in impacts across different groups within society is considered as part of the distributional analysis.

2.10.4 The rating system to be applied is provided in Table 2.

Table 2 Rating system

Negative impacts (-)

Positive impacts (+)

Major (- - - -): sufficient negative impacts predicted to have a noticeable effect that is sufficient to cause complaints and/or protests from the community

Major (+ + + +): sufficient positive impacts predicted to have a noticeable effect that is sufficient to enable new services or activities within the community

Moderate (- - -): sufficient negative impacts predicted that result in concerns being raised by the community

Moderate (+ + +): sufficient positive impacts predicted that result in increased levels or expansion of existing activities or services

Minor (- -): negative impacts predicted that may be noticed but which are accepted by the majority of the community

Minor (+ +): positive impacts predicted that may be noticed but which support existing services or activities but not the extent that they can expand

Negligible (-): small negative impacts that are unlikely to be noticed by the majority of the community

Negligible (+): small positive impacts that are unlikely to be noticed by the majority of the community

Neutral/no overall impact: 0

Based on work undertaken by ABPmer and RPA for previous socio-economic impact assessments undertaken for Scottish Government and Marine Scotland

Source: Collingwood Environmental Planning Ltd et al. (2016): A two way conversation with the people of Scotland on the social impact of offshore renewables, Final Dialogue Report, March 2016

2.10.5 The methodology involves identification of one rating for each social impact. The impacts are linked to the sectors or activities that cause the effect and the value cluster to which they are relevant. This draws upon the scoping assessment, in particular the nature and scale of interactions that have been identified between offshore wind development and the activities. The rating assigned includes justification in the form of a description of the reasoning used to assign the rating, again drawing on the evidence from the scoping assessment. Further evidence collection may be required where social impacts could arise independently of socio-economic effects.

2.10.6 The Collingwood Environmental Planning report also identifies those social values that were identified as important to protect or as fragile by participants in different locations. These important social values are shown in Table 3, by location. The social impact assessment involves considering whether any of the important social values in each location are likely to be affected by development. Where this is the case, these impacts will be highlighted. Consideration will be given to the need to increase the rating to reflect the local importance of these social values, with the justification for any increase in the rating also recorded in qualitative terms.

Table 3 Social Values identified as being Locally Important


Social values identified as important to protect/fragile

Kirkwall (Pentland Firth and Orkney Waters)

  • Inter-generational mix
  • Community safety
  • Healthy local economy
  • Jobs to keep young people
  • Remoteness while remaining connected
  • Environmental assets
  • Cultural heritage: sites

Port Ellen, Islay (Argyll and the islands)

  • Inter-generational mix
  • Healthy local economy
  • Jobs to keep young people
  • Connectedness
  • Control over island development
  • Cultural heritage: Gaelic, events
  • Environmental assets

Helmsdale, Caithness

  • Inter-generational mix
  • Strengthening local economy
  • Jobs to keep young people
  • Connectedness
  • Community safety
  • Cultural heritage: fishing
  • Environmental assets
  • Strong community organisations

Stranraer (Dumfries and Galloway-Solway)

  • Restoring local economy
  • Jobs for local people
  • Sociability and community support
  • Connectedness
  • Improving environmental assets

St Andrews, Fife

  • Restoring local economy
  • Environmental assets
  • Cultural heritage: town and events
  • Community diversity


  • Sociability and community support
  • Cultural heritage: town and events
  • Community diversity

2.10.7 The ratings assigned to each impact and each value cluster will also be used as the basis for the distributional analysis (see Appendix B). In summary, the distributional analysis involves reviewing the ratings assigned to each social impact and assessing whether this rating should be increased or decreased for each sub-group. The justifications included with the average rating from the social impact assessment are used as the basis for identifying if an impact is expected to be worse (more negative or less positive) for each sub-group. Where there is expected to be a difference, the rating is revised for that sub-group and further justification (in the form of a narrative description) is provided as to why that change has been made.

2.11 Approach to Quantifying and Monetising Economic Impacts

2.11.1 In advance of completing the scoping exercise, and based on previous assessments for offshore wind development, the main activities for which there might be significant economic impacts associated with offshore wind development are considered to be commercial fisheries, commercial shipping and possibly tourism. Minor impacts could also occur to recreational boating and recreational angling depending on how close to shore arrays might be located.

2.11.2 Draft methods for detailed assessment of potentially significant interactions between offshore wind development and relevant aspects of these activities are provided in Appendix A. The detail of these methods will be further developed as part of the detailed socio-economic assessment as required. Should the scoping exercise identify additional activities requiring detailed assessment, methods for these assessments will be defined as appropriate.

2.11.3 Analysis of interactions between offshore wind development and other marine activities is generally based on spatial analysis using GIS tools to provide a quantitative estimate of the interaction. Estimates of economic impacts are then made in a number of different ways:

  • Where an interaction would result in a material reduction in the level of output from an activity, the economic impact is assessed in terms of a reduction in Gross Value Added ( GVA) and employment;
  • Where an interaction would result in an increase in that activity's operating costs but which would not result in a reduction in economic output from that activity, the impacts are simply expressed in terms of monetary costs; and
  • Where an interaction might create investment uncertainty for an activity, such uncertainties are noted in the analysis but not quantified.

2.11.4 Where an interaction has the potential to affect economic output, resulting in impacts to GVA and employment, in line with Scottish BRIA guidance, a distributional analysis of the economic impact will be carried out. The outputs from this distributional analysis will be used to inform the assessment of social impacts.

2.11.5 Further details on the methods to be used to assess impacts to GVA and employment and for the distributional analysis are provided in Appendix B. Based on previous experience, it is possible that on a worst case basis, development under the Plan could affect economic output from the fisheries sector. Therefore, specific detail is provided on how potential impacts on GVA and employment on the fisheries sector and the distributional impact will be assessed.

2.11.6 It is proposed that the economic assessment is undertaken for a time period of 30 years starting in 2018. This will ensure that the assessment covers the likely period of construction of deep water wind projects (2025 to 2035) and for a period of at least 10 years thereafter. This duration should capture the main period of potential impacts. However, it may be appropriate to increase the time period of the assessment if the scope is widened to include an assessment of potential benefits, particularly as many of the benefits are likely to continue for the life of offshore wind projects (around 25 years from the date of construction, assuming projects are decommissioned after this time).

2.12 Approach to Cumulative Assessment

2.12.1 For the purpose of this study, the cumulative impact of potential offshore wind development will be considered together with possible development under existing and draft offshore wind, wave and tidal plans. The assessment will consider cumulative effect at both regional and national scales, using the Scottish Offshore Renewable Energy Regions ( SORERs) as the basis for the regional assessments. These regions were used previously to inform the cumulative assessment of the draft offshore wind, wave and tidal energy plans ( ABPmer & RPA, 2013).

2.12.2 In general, at low levels of offshore wind development, the socio-economic impacts of additional levels of development are likely to be additive. In contrast, more intense offshore wind development, occupying a significant proportion of local, regional or national sea space may give rise to synergistic impacts. For example, above a certain threshold of impact, it may no longer be economic to continue with an activity and the whole of the activity may be lost. However, there is little if any evidence that indicates what the relevant thresholds might be, above which impacts may become synergistic.

2.12.3 Given these constraints, the study generally proposed to adopt an additive approach to assessing the cumulative economic impact associated with multiple offshore renewables development locations and multiple offshore renewables technologies within a region and nationally. However, if the impacts are predicted to be particularly concentrated and intense at a local or regional level, specific consultation will be undertaken with the relevant sectoral interests to seek to evaluate the combined effect using expert judgement.

2.12.4 The approach to estimating the combined social effects and distributional impacts will be based on assigning a significance rating to impacts on different groups from changes to access and experiences from the interactions associated with each sector. The number of each rating assigned has been summed to give an indication of not just the number of impacts, but also their likely overall cumulative significance for each group and each key area. The approach has followed the principles of the additive approach used across other sectoral interests, while retaining information on the range of significance of social impacts in a semi-quantitative manner. The following ratings have been applied:

  • Very significant: almost all people in this location/group are likely to be affected;
  • Significant: the most vulnerable people are likely to be affected;
  • Slightly significant: some people or those who are more vulnerable are likely to be affected; and
  • Not very significant: few people or those who are least vulnerable are likely to be affected.

Figure 5 Scottish Offshore Renewable Energy Regions
Figure 5 Scottish Offshore Renewable Energy Regions


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