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.

A.6. Energy Generation

A.6.1 Sector Definition

This sector is concerned with the generation of energy through wave, tidal and wind devices and the transmission of this power through submarine export cables to land.

Wind energy

Wind energy can be produced anywhere in the world where the wind blows with a strong and consistent force. Wind turbines are used to convert kinetic energy in the wind into electrical energy, in this context, in the offshore environment. For large scale sources of wind energy, turbines are usually built close together to form a wind farm that provides grid power.

Wave energy

Ocean wave energy technologies rely on the motion of waves to generate electricity. They are placed either on the sea surface or on the seabed (to harness near shore surge energy). Energy output is determined by wave height, wave speed, wavelength and water density.

Tidal energy

Tidal energy is produced through the use of tidal energy generators. Tidal technologies include tidal range (barrages and lagoons that rely on the static pressure differential created by the rise and fall of tides) and tidal stream technologies (which utilise the flow of water generated by the change of tidal height). Both tidal range and tidal stream energy generation opportunities are limited to a few locations around the UK e.g. funnels and headlands (tidal stream) and estuaries with specific dynamics (tidal range).

Export cables

Export cables are needed to bring the energy generated offshore to land to connect with onshore electricity distribution networks.

A.6.2 Overview of Activity

Wave, tidal stream and tidal range

The development of wave and tidal infrastructure is spatially restricted to areas with an appropriate water depth, geology, met ocean conditions and resource availability. As shown in Figure A.6.1, all wave and tidal draft plan options and planned tidal developments in Scotland are located off the west coast of Scotland, the far north east coast of mainland Scotland, Orkney and the Shetland Islands. A dedicated renewable device test area ( EMEC) has been in operation in Orkney since 2003 allowing developers to install single or multiple machines in a variety of site conditions.

There are two operational commercial tidal stream projects in Scotland, MeyGen in the Pentland Firth, and Bluemull Sound in Shetland. Phase 1A of the Meygen tidal array at Pentland Firth build out has been completed and has resulted in four turbines exporting electricity to the grid. Phase 1B will involve the deployment of an additional four 1.5 MW turbines (Atlantis Resource Ltd, 2017). The first turbine of the Shetland tidal array was fully commissioned and exporting power to the grid in May 2016. Two further turbines have been installed since (4COffshore, 2017).

There are currently no tidal barrages/lagoons located within Scottish waters, although the potential for tidal range energy generation has been recognised within the Solway Firth (Celtic Seas Partnership, 2016). At present there are no commercial wave arrays in Scotland. Wave Energy Scotland ( WES) was created in 2014 (at the request of the Scottish Government), to facilitate the commercialisation of the wave energy sector through supporting projects focused on Wave Energy Converter technology, with the aim of producing reliable technology which will result in cost effective wave energy generation (Wave Energy Scotland, 2017).

The establishment of a wave and tidal energy industry could bring economic benefits for Scotland. The industry estimates that marine renewables (wave and tidal) could support 10,000 direct jobs in 2020 and the Carbon Trust has estimated that there could be as many as 68,000 UK-based jobs by 2050 ( DECC, 2012).


Current offshore wind projects in waters around Scotland includes 211 MW in operation, including Robin Rigg (Solway Firth) and Hywind Scotland (Moray Firth), and 680 MW in construction, including Beatrice (Crown Estate Scotland, 2017).

Figure A.6.1 shows offshore wind farms and lease areas which are predominately located off the east coast of Scotland and the existing draft plan option areas for offshore wind (Marine Scotland, 2013).

Employment generation as a result of renewables developments is dependent on the supply chain (particularly for offshore wind equipment) and the extent to which components are manufactured in the region. Within the offshore wind sector, manufacturing has the potential to provide the single biggest contribution to GVA, with operations and maintenance the next biggest contributor (ORE Catapult, 2014). Currently, a large proportion of the materials and components for offshore windfarms are outsourced from China and mainland Europe and thus associated employment is focused outside the UK (Celtic Seas Partnership, 2016).

Export cables

Offshore wave, tidal and wind developments are connected to onshore grid infrastructure through export cables. The presence of these is therefore associated with the amount of these activities in a particular marine plan area.

Future trends for wave, tidal and wind

The Scottish Government's proposed key energy target is that half of Scotland's heat, transport and electricity energy needs are met by renewables by 2030 (Scottish Government, 2017).

Figure A.6.1 shows an overview of energy generation activity in Scotland. Information sources that can be used in the assessment are listed in Table A.6.1.

Figure A.6.1 Energy generation activity in Scotland
Figure A.6.1 Energy generation activity in Scotland

Table A.6.1 Information sources for the energy generation sector

Data Available Information Source
Information on wave, tidal and wind energy in Scotland The Crown Estate 2017;
Offshore renewables and cables and pipelines activity in Scotland The Crown Estate, 2017
Wind, wave and tidal lease areas in Scotland Marine Scotland NMPi

A.6.3 Potential Interactions with Offshore Wind

Table A.6.2 shows potential interaction pathways between energy generation and offshore wind arrays and export cables. Based on the approach to scoping described in Section 2 in the main report, the table also records whether the interaction:

  • Is not likely to result in a significant socio-economic impact on the sector; or
  • Is likely to result in a significant socio-economic impact on the sector and hence will require a detailed assessment.

The rationale underlying this expert judgement is provided in the table. Where it is not currently possible to make a judgement regarding the likelihood of a significant socio-economic impact due to insufficient information (for example, in relation to the extent of overlap between a sector activity and the DPO Areas) the table indicates that scoping will be required to be undertaken once sufficient information becomes available. Furthermore, as described in the main report, there is currently no information regarding the likely location of export cable routes/corridors and as such, it is not possible to undertake a meaningful assessment of the potential for any sector activity/export cable interaction to give rise to significant socio-economic effects. Rather, the potential for any interaction will be identified in Regional Locational Guidance.

Table A.6.2 Potential interaction pathways

Potential Interaction

Technology Aspect and Phase

Potential Socio-economic Consequences

Initial Scoping Assessment

Competition for space (offshore) within DPO areas

All arrays

Reduced renewable energy capacity

Potential significant interactions to be considered likely where there is spatial overlap between newly identified DPO areas with existing wind, wave and tidal DPO areas, where the area of overlap is greater than 10% of the combined DPO areas. If the overlap represents less than 10% of the combined DPO areas, it is considered significant interaction can be avoided through spatial planning of arrays within the DPO areas.

Scoping assessment to be completed once DPOs defined.

Competition for transmission capacity

All arrays

Either reduced energy output from other energy sources (due to displacement by renewables) or reduced renewable energy capacity

Potential significant interactions may occur where there is competition for export cable corridors from arrays for suitable landing locations that meet all the technical and environmental criteria for connection to a substation with available capacity. A shortage of suitable locations could lead to cables being brought onshore several kilometres from the connection point, thus significantly increasing the scope, costs and consenting risks of the onshore transmission works being developed. Hence, when determining DPO areas for further development, the financial and consenting risks associated with grid capacity, the location of connection points with spare capacity and availability of suitable landing points should all be considered.

Scoping assessment to be completed once DPOs defined.

Increased difficulty of access at cable crossing points with existing/planned export cables

Export cables

Increased maintenance costs for cable owners; loss of revenue for asset owners; loss of revenue for dependent businesses/customers

Export cable routes are uncertain. Constraints inshore of DPOs will be identified in the RLG.

No detailed assessment possible.

Cable crossings with potential future export cables

Export cables

Increased maintenance costs for cable owners; loss of revenue for asset owners; loss of revenue for dependent businesses/customers

Export cable routes are uncertain. Constraints inshore of DPOs will be identified in the RLG.

No detailed assessment possible.

A.6.4 Scoping Methodology

The spatial overlap between offshore wind DPOs and existing wind, wave and tidal DPO areas to be assessed, once the offshore wind DPO areas are available.

A.6.5 Assessment Methodology

If a significant interaction between deep water wind and existing wind, wave and tidal DPOs is identified through scoping, further consideration will be given to the potential socio-economic impacts in consultation with Scottish Renewables and Renewables UK.

A.6.6 Data Limitations

Offshore renewables (particularly wave energy) are not yet well established industries and therefore it is difficult to determine their interactions with each other and the degree to which any spatial overlap will affect energy generation. The future of transmission capacity will depend on where and when the Scottish Government's projections for investment and improvement works occur (£7 billion investment between 2013 and 2021; Scottish Government, 2017).


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