Planning Scotland's Seas: 2013 - The Scottish Marine Protected Area Project – Developing the Evidence Base tor Impact Assessments and the Sustainability Appraisal Final Report

C.12. Power Interconnectors and Transmission Lines

C.12.1 Introduction

This appendix provides an overview of existing and potential future activity relating to power interconnectors and transmission lines in Scottish waters and outlines the methods used to assess the impacts of potential MPAs on this sector.

C.12.2 Sector Definition

This sector is concerned with the transmission of power through submarine cables, including international, national and inter-island links. This assessment excludes power cables to/from individual developments ( e.g. power supplies to oil and gas installations, export cables from offshore wind farms).

C12.2.1 Overview of Existing Activity

A list of sources to inform the writing of this baseline is provided in Table C12.1.

Table C12.1 Information Sources

Scale	Information Available	Date	Source
Scotland	All pipelines and cables	Current	SeaZone Solutions Ltd
Scotland/UK	Power interconnectors and Transmission Lines	Current	SeaZone
Scotland	Power cables (submarine electricity cables)	Current	Baxter et al. (2011)
Scotland	Potential future subsea cable developments / reinforcements	2009	National Planning Framework for Scotland Annex National development 11 (Scottish Government, 2009b)

C12.2.2 Location and intensity of activity

There are approximately 900km of submarine power cables in Scottish waters (Baxter et al, 2011) predominately created to connect island communities to the mainland national grid infrastructure (UKMMAS, 2010). This is reflected in Figure C15 which shows subsea grid infrastructure connections in inshore waters between areas of mainland Scotland and between the mainland and islands. Note, subsea power cables to/from developments ( e.g. oil and gas platforms) are not shown.

C12.2.3 Economic value and employment

There is no agreed methodology for calculating the economic value of subsea power cables. In the absence of information on economic value, the capacity of interconnector cables may be used as an indicator of both value and activity (UKMMAS, 2010).

C.12.3 Future trends

The location of offshore renewables resources, often remote from locations of power demand, and the large proposed expansion of offshore renewables development may drive the development of an offshore grid network and interconnectors.

UKMMAS (2010) reported that over the period 2007-12 the Office of the Gas and Electricity Markets (Ofgem) provided for capital investment of up to £4.3 billion in the electricity transmission network, an increase of 160% over the previous 5-year price control period, with much of this investment planned for Scotland.

The Scottish National Planning Framework 2 (Scottish Government, 2009b) identifies 'electricity grid reinforcements' as one of the fourteen national developments essential to the delivery of the spatial strategy set out in the second National Planning Framework. The strategic grid reinforcements are essential to provide the transmission capacity necessary to realise the potential of Scotland's renewable energy sources, maintain long-term security of electricity supply and support sustainable economic development. This development would occur throughout Scotland, from the English border to the Shetland Islands and, in relation to marine power interconnectors and transmission lines, would include:

• Reinforcement of the sub-sea cable link between Orkney and the Scottish mainland; and
• New sub-sea cable links for the Outer Hebrides and the Shetland Islands.

In addition, there are a number of proposed marine power interconnector developments in the UK at various stages of maturity in the planning process. Those that are relevant to Scotland are shown in Table C12.2 and Figure C15. If these developments proceed, they would significantly increase the length and capacity of interconnector and offshore grid cables compared to the current baseline. However, the nature and form of the overall development of the offshore grid remains uncertain particularly in the long-term (Saunders et al, 2011).

Table C12.2 Potential Future Power Interconnector Cables and Transmission Lines

Project	Description	Current Project Stage*	Earliest Completion Date
Western HVDC Link	West Coast 1.8GW High Voltage Direct Current (HVDC) link between Hunterston and Connah's Quay in North Wales	Construction	2015
Eastern HVDC Link	1.8GW HVDC link between Peterhead and Hawthorne Pit in Humberside	Optioneering	2018 (Q2)
Shetland HVDC Link	Island link connecting Shetland Islands to Moray Firth offshore hub	Design	2017 (Q4)
Orkney 132kV Subsea Link	Island link connecting Orkney and Pentland Firth Subsea Link	Design	2015 (Q4)
Western Isles HVDC Link	Island Link	Planning	2015 (Q4)
Hunterston-Kintyre 240MVA AC subsea link	AC subsea link between Hunterston and Carradale in Argyll and Bute	Planning	2015 (Q4)
Caithness-Moray HVDC reinforcement	HVDC Link: from Caithness to the Moray Coast via the Moray Firth Offshore hub	Design	2016 (Q4)
UK-Norway NorthConnect	Interconnector between Norway (Sima and Samnanger) and Scotland (landfall Peterhead).	Co-operation agreement signed in February 2011	Expected to be operational before 2020
HVDC Norway -England	Hylen, Sundal in Norway to Blyth in the United Kingdom. Expected to be operational by 2020. (Source: Wikipedia)	Optioneering	Expected to be operational by 2020. (Source: Wikipedia)

*Current Project Stage:

Optioneering - Transmission Operator believes that the need case is firm, number of design options provided for public consultation so that a preferred design solution can be identified;
Design - designing the preferred solution into greater level of detail and preparing for the planning process;
Planning - continuing with public consultation and adjusting the design as required through the planning process application process;
Construction - planning consent has been granted and/or contracts have been awarded and manufacturing underway.

C.12.4 Assumptions on Future Activity

It has been assumed that all currently planned and proposed interconnector projects (see Table C12.2) will be constructed in the period to 2020.

C.12.5 Potential Interactions with MPA Features

The installation and operation of submarine power cables will have similar effects on MPA features as that of telecom cables, and is discussed in detail in the Telecom Cables appendix. In addition to these impacts, interconnecting power cables induce electromagnetic changes in the local environment that are detectable by some electro-sensitive and magneto-sensitive species, notably elasmobranchs. The significance of these effects for individuals and populations remains uncertain ( JNCC & NE, 2011).

C.12.6 Assumptions on Management Measures for Scenarios

It is assumed that the impact of power interconnectors and transmission lines on MPA features will be managed under the existing marine licensing framework within 12nm (there is no requirement for cables beyond 12nm to apply for a licence). Two scenarios ('lower' and 'upper') have been developed to capture the possible costs of proposed MPAs to the sector. These include a range of possible management measures, as detailed requirements will need to be based on site-specific factors.

It has been assumed that there will be no review of existing consents or licences, although where existing power interconnectors and transmission lines within 12nm apply for new consents or licences, these applications will be considered against the conservation objectives for features for which MPAs may have been designated.

The intermediate ('best') estimate for each site has been based on SNH/ JNCC current views on management options and judgements made by the study team. The assumptions do not pre-judge any future site-specific licensing decisions. After MPA designation, the management of activities in MPAs will be decided on a site-by-site basis and may differ from the assumptions in this assessment.

Management measures applied under the lower and upper scenarios are detailed below. Specific management measure assumptions for each scenario (including the intermediate scenario) are defined in the MPA Site Reports (Table 4, Appendix E).

Lower Scenario

• Additional costs will be incurred for new licence applications within 12nm in assessing potential impacts to MPA features within the proposed development footprint; and
• Mitigation measures may be required for non- OSPAR/BAP features within 12nm ranging from:
  ˉ No additional mitigation required for existing power interconnectors and transmission lines beyond existing good practice;
  ˉ No additional mitigation required for new developments beyond good practice; and
  ˉ Re-routeing of cables to avoid highly sensitive MPA features.

Upper Scenario

• Additional costs will be incurred for new licence applications within 12nm in assessing potential impacts to MPA features within 1km;
• Additional survey costs will be incurred to inform new licence applications (within 12nm) for cables intersecting features proposed for designation within potential NC MPAs;
• Additional post-licence monitoring of any features proposed for designation within potential NC MPAs within 100m of cable within 12nm; and
• Mitigation measures may be required for some OSPAR/BAP features ^[50] for which adequate protection is not currently achieved and all non- OSPAR/BAP features within 12nm ranging from:
  ˉ No additional mitigation required for existing power interconnectors and transmission lines beyond existing good practice;
  ˉ No additional mitigation required for new developments beyond good practice;
  ˉ Seasonal controls on new cable laying to minimise impacts to highly sensitive MPA features - site specific assessment; and
  ˉ Re-routeing of cables to avoid moderately and highly sensitive MPA features.

C.12.7 Assessment Methods

Additional Licensing Costs

Where required, it is assumed that the additional costs will be as follows:

• Additional assessment costs for licence application - £5k per licence application; and
• Additional survey costs - £5k per km of cable route within potential MPA.

Additional Post Licensing Costs

Where required, it is assumed that additional costs will be incurred as follows:

• Additional monitoring costs £5k per km of cable route within potential MPA, three years after construction.

Mitigation Measures

Where required, it is assumed that the following additional costs may be incurred:

• Seasonal controls on new cable laying to minimise impacts to highly sensitive MPA features - site specific assessment; and
• Re-routeing of cables to avoid moderately and highly sensitive features - £1.01m/km (based on Annex H14 of Finding Sanctuary et al, 2012).

Cost of Uncertainty and Delays

The designation of NC MPAs has the potential to increase the time taken to determine licence applications and to negatively affect investor confidence. It has not been possible to quantify these potential impacts.

C.12.8 Limitations

• The number and location of interconnectors that may be constructed up to 2020 is uncertain and beyond 2020 is unknown; and
• The requirements for management measures are uncertain.

C.12.9 References

Baxter, J.M., Boyd, I.L., Cox, M., Donald, A.E., Malcolm, S.J., Miles, H., Miller, B., Moffat, C.F., (Editors), 2011. Scotland's Marine Atlas: Information for the national marine plan. Marine Scotland, Edinburgh.

Finding Sanctuary, Irish Seas Conservation Zones, Net Gain and Balanced Seas, 2012. Impact

Assessment materials in support of the Regional Marine Conservation Zone Projects' Recommendations. Annex H14 Renewable Energy.

JNCC and NE, 2011. General advice on assessing potential impacts of and mitigation for human activities on MCZ features, using existing regulation and legislation. Advice from the Joint Nature Conservation Committee and Natural England to the Regional MCZ Projects. June 2011. 107pp.

Saunders, J., Tinch, R., Ozdemiroglu, E. & Hull, S., 2011. Valuing the Marine Estate and UK Seas: Dynamic Baseline Assessment (draft). Marine Estate Research Report for The Crown Estate.

Scottish Government, 2009. National Planning Framework for Scotland 2.

United Kingdom Marine Monitoring and Assessment Strategy (UKMMAS), 2010. Charting Progress 2 Feeder Report Productive Seas. Department for Environment Food and Rural Affairs on behalf of UKMMAS (Eds. Saunders, J. and McKie, J.) 472pp Available online: http://chartingprogress.Defra.gov.uk/