Draft Sectoral Marine Plans for Offshore Renewable Energy in Scottish Waters: Socio - Economic Assesment

The study reported here provides a high level socio-economic appraisal of the potential costs and benefits to activities that may arise as a result of offshore wind, wave or tidal development within the Draft Plan Options as part of possible future Scotti

B6. Energy Generation

B6.1 Overview

This sector is concerned with the generation of energy through harvesting the power of the wind, waves and tide and the transmission of this power through submarine export cables to land. In the future, biofuel production (from seaweed) may occur in offshore areas. However, this concept is still at research stage and therefore has not been considered further in this assessment.

Wind Energy

Wind energy technologies use the energy in wind to generate electricity. Wind energy can be produced anywhere in the world where the wind blows with a strong and consistent force. 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. These large underwater turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity.

Export Cables

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

Figure B6 shows the overlap of the wind, wave and tidal Draft Plan Option areas and their associated cable corridors. Information sources used in the assessment are listed in Table B6.1.

Table B6.1 Information Sources


Information Available




Amount of electricity generated by energy source in Scotland (Scottish Environmental Statistics Online)


Scottish Government Statistics


National Renewables Infrastructure Plan


SE & HIE (2010)


Blue Seas - Green Energy - A Sectoral Marine Plan for Offshore Wind Energy

in Scottish Territorial Waters


Scottish Government


Potential Development Scenarios for Scottish Offshore Wind Supply Chain


Scottish Renewables (2010)


Scotland's Offshore Wind Route Map - Developing Scotland's Offshore Wind Industry to 2020


Offshore Wind Industry Group


The Offshore Valuation - A valuation of the UK's offshore renewable energy resource


Public Interest Research Centre on behalf of The Offshore Valuation Group (2010)


Scottish Offshore Wind: Creating an Industry to Scottish Renewables


IPA Energy + Water Economics (2010)


Information and analysis of wave and tidal market in Scotland


Pure Marine Gen Ltd (2011)


Draft Electricity Generation Policy Statement 2010


Scottish Government


A Low Carbon Economic Strategy for Scotland


Scottish Government

Pentland Firth and Orkney Waters

Supply Chain Demand - PFOW Round 1 Wave and tidal Projects


BVG Associates (2011)

West Coast

Scottish Offshore Renewables Development Sites


Scottish Development International, Highlands and Islands Enterprise, and Scottish Enterprise (2011)


Scotland's Renewable Energy Potential: realising the 2020 target


Scottish Executive (2005), Future Generation Group Report


Scottish Renewable Energy Generation Capacity


Scottish Renewables


Interim Great Britain Seven Year Statement


National Grid (2004)


Scottish and Southern Energy plc Annual Report 2011


Scottish and Southern Energy plc (2011)


Electricity Generation Policy Statement


Scottish Government (2012)


Our Electricity Transmission Network: A Vision for 2020


ENSG (2012)

B6.2 Future Trends

B6.2.1 Electricity Generation

It has been suggested that significant reductions in Scotland's electricity generating capacity would occur as coal and nuclear power stations closed and the importance of renewables grew (Allan et al, 2006). However, in the next few decades, Scotland has the capacity to install offshore renewable generation devices which could produce over 60 GW of generating capacity (Scottish Development International et al, 2011). Renewable energy is being promoted as an economic opportunity (Verso Economic, 2011). Indeed, the Scottish Government's target is to meet the equivalent of 100% of gross annual electricity consumption from renewables by 2020.

Based on the offshore wind, wave and tidal developments currently in planning, there is likely to be a significant increase in installed capacity in the period up to and beyond 2020 with potentially up to 9.2 GW of offshore wind capacity, 720 MW of wave capacity and 1 GW of tidal energy capacity.

There are currently no specific targets for offshore renewables development although Scottish Government (2012) provides projections for 'offshore and onshore' wind of 13,000 MW installed capacity by 2020 and 16,500 MW installed capacity by 2030.

SeaGreen estimate that the first phase of the Firth of Forth Round 3 Offshore Wind Farm (1 GW capacity across two wind farms) would inject £315m - £788m to the Scottish economy. Additional ongoing economic benefits would arise over the 25 year operating life of the wind farms. Development of an additional 2.5 GW generation capacity in the Firth of Forth Zone would have a further very significant contribution to the Scottish economy.

B6.2.2 Marine Biomass

There is currently no clear development plan for marine biofuels, although a number of trials are underway in Scotland (Black, 2011). The Crown Estate estimates that up to 1.5% of the seabed area could be used for macroalgae cultivation. This could give an annual biogas yield equivalent to around 5% of the natural gas consumed in the UK in 2009 (The Parliamentary Office of Science and Technology, 2011). A number of Scottish initiatives are currently underway to demonstrate the viability of producing biofuels from macroalgae and to facilitate the cost effective exploitation of currently under-utilised seaweed resources, notably the Seaweed Anaerobic Digestion and the BIOMARA programmes ( FRM, 2010).

B6.2.3 Transmission Capacity

National Grid's Electricity Ten Year Statement ( ETYS) indicates that there is likely to be a need for new infrastructure/reinforcement in many areas of Scotland to ensure that generated power can be transmitted to where it is required, for example, new transmission infrastructure will be necessary to connect power generation around the Western Isles, Orkney and Shetland to the mainland transmission network (National Grid, 2012). Indeed, problems have already occurred in some areas. Within Scotland, wind connection is restricted due to insufficient transmission capacity across the Scottish border, with 16 GW of wind awaiting connection in 2007 (Public Interest Research Centre, 2010). There are also issues with congestion in the power transmission network between the North and the South of the UK (Public Interest Research Centre, 2010). However, plans do exist to increase the capacity of power interconnections from Scotland to both England and Northern Ireland, as well as for a new major interconnector to Norway (Scottish Development International et al, 2011). In addition, there are plans for around 1,800 MW of subsea interconnectors along the West and East coasts of Scotland (Scottish Development International et al, 2011), whilst plans for a strategic set of grid upgrades across Scotland are already progressing (Scottish Government, 2010b). It is therefore likely that the future trend in transmission capacity will be upwards.

It should however be noted that transmission capacity is complicated by the variability in generation which renewables provide (Public Interest Research Centre, 2010). Despite this, it is stressed by the Scottish Executive (2005) that transmission capacity has to be built on the basis of firm development proposals, rather than on the expectation that new or developing technologies will eventually be put in place. Stakeholder responses to this study indicate that there is the hope that energy generation companies can collaborate rather than compete on grid connection to ensure economies of scale are achieved. This is likely to be critical given that the best sources of renewable energy are typically located at the edges of the current grid network, rather than the centre (Scottish Government, 2011).

B6.2.4 Supply Chain for Renewables

It is believed that there is already a strong supply chain due to the well-established and experienced oil and gas sector (Scottish Development International et al, 2011). However, although several locations can deal with operations and maintenance, the future requirements of the renewables supply chain cannot yet be fully met at any one of Scotland's ports (Scottish Enterprise and Highlands and Islands Enterprise, 2010a; 2010b). Plans are currently being developed for offshore wind manufacturing facilities at Leith and Ardersier, together with the creation of an offshore wind O&M facility at Dundee.

For wave and tidal development, facilities have already been developed at Scrabster and Lyness to support developments within the Pentland Firth. Further local development is also likely to occur to support development on the West Coast.

B6.2.5 Transmission Capacity

Scotland's transmission grid is mainly made up of 400 kV and 275 kV lines which join the major nuclear and coal fired power stations in the central belt with the Peterhead plant in North East Scotland (National Grid, 2012). The Scottish grid is connected to the English grid with four transmission lines which form two double circuits; on the East, the circuit operates at 400 kV, whilst on the West part of the circuit operates at 400 kV and the remainder runs at 275 kV (ibid). Connection between Scotland and Northern Ireland is via the 450 MW Moyle Interconnector which joins Ballantrae with Ballylumford (National Grid, 2012).

B6.3 Potential for Interaction

Table B6.2 shows potential interaction pathways between wind, wave and/or tidal arrays.

Explanation of column content:

Column 1: Describes the potential interaction between the activity and any renewable technology;

Column 2: Identifies the types of offshore renewable development (wind, wave or tidal) for which the interaction may arise;

Column 3: Identifies the potential socio-economic consequence associated with the interaction identified in Column 1;

Column 4: Indicates whether detailed assessment will or will not be required if activity is scoped in;

Column 5: Identifies how the socio-economic impact will be assessed.

Table B6.2 Potential for Interaction






Potential Interaction

Technology Relevance (Wind, Wave, Tidal)

Potential Socio-economic Consequence

Requires Detailed Assessment (√) or Does Not Require Detailed Assessment (X)

How the Economic Impact Will be Assessed

Competition for space (offshore) within Draft Plan Option areas

All arrays,

Reduced renewable energy capacity

- only where there is spatial overlap between Draft Plan Option areas and each technology occupies >5% of Draft Plan Option areas

See Section B6.4

Competition for transmission capacity

All arrays

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

See Section B6.4

Cable crossings with existing/planned export cables

Export cables

Additional costs to construct cable crossings

X - costs of crossings will be borne by developer.

Not required.

Cable crossings with potential future export cables

Export cables

Additional costs to construct cable crossings

X - costs of crossings will be borne by developer.

Not required.

B6.4 Scoping Methodology

B6.4.1 Competition for Space

A spatial analysis of potentially overlapping interests between offshore wind, wave and tidal energy Draft Plan Option areas was undertaken in GIS. For the purpose of this assessment, a potentially negative effect was only considered to be likely where the overlap of wind, wave or tidal Draft Plan Option area was greater than 10% of the combined Draft Plan Option areas.

B6.4.2 Competition for Transmission Capacity

It has been assumed that there will be competition for transmission capacity between all wind, wave and tidal developments.

The results of the scoping exercise are presented in Appendix C6.

B6.5 Assessment Methodology

B6.5.1 Competition for Space

At four sites the wind, wave and/or tidal Draft Plan Option areas overlap by more than 10% and thus spatial overlap of different technologies is considered a potential issue within these areas. Consultation was undertaken with Scottish Renewables and Renewable UK to discuss the issue of spatial overlap on future offshore energy development.

B6.5.2 Competition for Transmission Capacity

Industry and Government plans and policies for increasing transmission capacity across Scotland were reviewed.

Scottish Renewables and Renewable UK were consulted to determine their views on competition for transmission capacity between renewable energy sectors and whether this will hinder wind, wave and/or tidal development in the future.


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