4.10. Grid Connection and Strategic Landfall Assessment

4.10.1.              Grid Connections

81. The Applicant has three signed grid connection agreements with the network operator. Two agreements are for connection at the Branxton substation, with a third additional connection (the Cambois connection) at Blyth, Northumberland. The Cambois connection was confirmed in June 2022 following National Grid’s Electricity System Operator (ESO) Holistic Network Review (HNR)[2]. This third additional connection will enable the Project to reach full generating capacity (4.1 GW) by early 2030’s. The Cambois connection (offshore export cables and landfall) is being consented separately and has been considered cumulatively with the Proposed Development as part of this application (see volume 2, chapters 7 to 21).
82. The onshore works required as part of the Branxton Connection for the Proposed Development have been assessed as part of the Berwick Bank Wind Farm Onshore EIA Report for the Project (SSER, 2022a).

4.10.2.              Strategic Landfall Assessment

83. In parallel to the development of the Berwick Bank Wind Farm, subsequent boundary change and resulting Proposed Development, as described above, the Applicant progressed a strategic landfall assessment to identify a preferred landfall in the vicinity of the Branxton grid connection. As part of this assessment, a number of landfall options within the vicinity of Branxton (landfall sites 1, 2, 3, 4, 5, 6 and 7A, 7B) (see Figure 4.6   Open ▸ ) were evaluated from an engineering, consents (planning and environment) and land perspective.
84. Potential landfall options were identified based on their ability to connect to the various onshore substation options which were also being considered at the time. Key consideration for the locations of the onshore substation options were:

• proximity to the Branxton grid connection;
• environmental constraints;
• land constraints; and
• engineering feasibility.
  85. For more information on the onshore infrastructure site selection process, refer to volume 1, chapter 4 - Site Selection and Analysis of Alternatives, in the Berwick Bank Wind Farm Onshore EIA Report (SSER, 2022a).
  86. Nine onshore substation options were considered in parallel with the landfall sites. Later on in the process two further substation sites were considered within the vicinity, one at Oxwellmains, Dunbar and the other west of Torness Nuclear Power Station, also Dunbar. Refer to volume 1, chapter 4 of the Onshore EIA Report (SSER, 2022a) for detail on the onshore infrastructure site selection process including justification for the preferred Branxton Substation site.

Figure 4.6: Offshore Export Cables Landfall Options and Designations

4.10.3.              Identification of the Preferred Landfall Location

87. Various studies and surveys were undertaken between 2018 and 2021 to inform the landfall site selection process. The studies considered a range of factors such as intertidal and onshore infrastructure requirements, engineering and environmental constraints, including (but not limited to), geology, thermal, land use, nature designations (e.g. Barns Ness SSSI) and Scheduled Monuments, ancient woodland, battlefield sites, former coal working areas, as well as human receptors such as visual impacts, air quality and proximity to dwellings, recreational areas and greenspace.
88. The key outcomes of these studies and the Applicant’s site selection process allowed for decisions to be made on which landfalls could be deemed unfeasible and therefore discounted from the site selection process. The main reasons for discounting landfall locations from the site selection process are set out below.

• Landfall 1 – this option was discounted due to the long onshore cable route and challenging landform, which made it unfeasible from an engineering perspective;
• Landfall 2 – this option was considered to be unfeasible due being sited on part of Tarmac’s operational quarry. This area of land would be required to enable trenchless techniques (e.g. Horizontal Directional Drilling (HDD)) underneath the Barns Ness SSSI. In addition, access to the site would require the construction of a new road;
• Landfall 4 – This option was discounted due to the landfall being within the boundary of the Torness Nuclear Power Station licenced area;
• Landfall 6 – This option was discounted due to the presence of a cliff which would require extensive engineering earthworks, and constraints presented by the road and rail infrastructure; and
• Landfall 7 (7a and 7b) – This option was discounted based on engineering feasibility. The depth of cable under the cliff (approximately 30 m) would have led to potential thermal issues such as overheating.
  89. The remaining preferred options (Landfall 3 - Skateraw and Landfall 5 - Thorntonloch) were both included in the Berwick Bank Wind Farm Offshore EIA Scoping Report (October 2021) (SSER, 2021a). The locations of these preferred landfall sites and key environmental constraints are shown in Figure 4.6   Open ▸ .
  90. A summary of the key opportunities and constraints for both Skateraw (Landfall 3) and Thorntonloch (Landfall 5). Landfalls are presented in Table 4.11   Open ▸ .

Table 4.11: Skateraw and Thorntonloch Landfalls - Key Opportunities and Constraints

91. The landfall site selection study concluded in November 2021 with selection of Landfall 3 – Skateraw as the preferred option on the basis that, compared to Landfall 5 – Thorntonloch, the Skateraw landfall is a more technically viable option from an engineering perspective and allows for a shorter and less challenging and environmentally constrained onshore cable route to connect to the preferred Branxton Substation location.

4.11. Stage 5 – Refinement of Offshore Export Cable Route Options

4.11.1.              Offshore Export Cable Route Options

92. The Proposed Development export cable corridor included in the Berwick Bank Wind Farm Offshore EIA Scoping Report (October 2021) (SSER, 2021a) allowed for connection from the array area to either Landfall Option 3 – Skateraw or Landfall Option 5 – Thorntonloch. The Proposed Development export cable corridor is based upon the full metocean surveys of the former Firth of Forth Zone undertaken in 2010 and 2011, as well as data from a further study carried out by the Applicant in 2020 - the Indicative Export Cable Corridor Design (SSER, 2020b).
93. In addition to this, the Applicant in 2020 completed geotechnical surveys of both the Berwick Bank Wind Farm and Landfall 5 – Thorntonloch. Data from this survey identified potential technical challenges associated with Landfall 5. As such, the Applicant completed the Indicative Export Cable Corridor Design (SSER, 2020b). The objective of this study was to provide more precise offshore export cable route options for connections to Landfall 3 within the wider Proposed Development export cable corridor.
94. The Indicative Export Cable Corridor Design study involved a preliminary assessment of potential constraints to the development of offshore export cable route options using various open-source data layers (e.g. EMODnet and Joint Nature Conservation Committee (JNCC)). Information considered during the offshore export cables selection included bathymetry, seabed slope, seabed infrastructure and known shipwrecks together with seabed geology data. A list of the data sources considered in this study is included in Table 4.12   Open ▸ .
95. The data sources and associated constraints are listed in Table 4.12   Open ▸ . These were categorised as hard and soft constraints. Hard constraints were to be avoided, and soft constraints were to be avoided unless no other option was available.
96. Other technical considerations included;

• cable lengths to be minimised; and
• to ensure appropriate project scope and suitable micro-siting was achieved, a 1 km cable corridor width was maintained for all proposed routes within the offshore cable route boundary.
  97. A key consideration during the offshore export cables selection was the presence of the Firth of Forth Banks Complex Marine Protection Area (MPA). MPA’s and SSSI’s were avoided by the offshore export cable route optioneering GIS assessment (SSER, 2020b). SAC’s, SCI’s and spawning and breeding grounds were avoided where possible. As part of this analysis a rock ridge was identified which the cable route has been widened southwards to a width of 3 km in the centre of the cable route to ensure availability of engineering solutions to minimise the challenges presented by it ( Figure 4.7   Open ▸ ).

4.11.2.              Deep Water Options

98. As part of the Proposed Development export cable corridor selection, two indicative deep water (DW) options were identified, namely DW1 and DW2 ( Figure 4.7   Open ▸ ). 
99. The two deep water options connect the Proposed Development array area to landfall at Branxton, taking the most efficient routes whilst also taking into account identified hard constraints. Furthermore, the Proposed Development export cable corridor options sought to avoid the Firth of Forth Banks Complex MPA, where reasonably practicable, to minimise potential impact on this designated site. However, as illustrated in Figure 4.7   Open ▸ , it was not possible to avoid the MPA for DW1, as this deep water option overlaps with the MPA at the south-east part of the Proposed Development array area.
100. Although the Firth of Forth Banks Complex MPA is considered the most significant constraint at this stage of development, consideration was also given to bathymetry, slope and socio-economic influences when selecting the final deep water option of Proposed Development export cable corridor.

4.11.3.              Near Shore Options

101. Four indicative near shore options for the Proposed Development export cable corridor were identified, namely Nearshore A, Nearshore B, Nearshore C and Nearshore D ( Figure 4.8   Open ▸ ).
102. A study was then completed to assess the near shore options. It should be noted that at the time of this study, Landfalls 7A and 7B had not yet been eliminated from the possible landfall options so were included within the study. Please refer to sections 4.10.2 and 4.10.3 on the Strategic Landfall Assessment and Landfall Options for further detail on landfall selection. The near shore options identified connect the modified cable route originally provided to Landfalls 3, 5, 7A and 7B, taking the most efficient route whilst also respecting hard constraints.
103. The NnG cable corridor, Barns Ness SSSI, hard substrate areas and the Torness Power Station intake and outfall pipes are considered the most significant constraints at this stage of development, consideration was also given to bathymetry, slope, and socio-economic influences when selecting the final near shore option Proposed Development export cable corridor.
104. Following selection of Landfall 3 (Skateraw) the Proposed Development export cable corridor option Nearshore A to the Thorntonloch Landfall was removed from the site boundary. The Proposed Development export cable corridor has been defined as shown in Figure 4.8   Open ▸ .

Table 4.12: Constraints and Parameters Considered within Offshore Export Cables Option Site Selection

Figure 4.7: Offshore Export Cable Route Options

Figure 4.8: Nearshore Export Cable Route Options and Constraints

4.12. Overview of Project Design Envelope (PDE) Refinements

105. In addition to the boundary change and selection of the preferred landfall location and offshore export cable route, there have also been a number of refinements made to the PDE since October 2021 (upon the completion of the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) and the Offshore HRA Screening Report (SSER, 2021b)). These refinements are summarised below:

• selection of the Skateraw Landfall option in December 2021 (and abandonment of the Thorntonloch Landfall option) resulting in the modification of the Proposed Development export cable corridor ( Figure 4.7   Open ▸ );
• trenchless techniques are the only PDE option for the Skateraw Landfall to avoid open trenching through Barns Ness SSSI;
• reduction in the extent of boulder clearance along the offshore export cables (High Voltage Alternating Current (HVAC) and High Voltage Direct Current (HVDC options) has been reduced from 5,360,000 m2 to 4,360,000 m2;
• increase in the offshore export cables voltage from 320 kV to 525 kV;
• the option of suction caissons for the Offshore Substation Platforms (OSP)/Offshore convertor station platform foundations was added to the PDE, alongside the option of piled jackets;
• reduction in the number of offshore export cables from 12 to eight (HVAC/HVDC);
• reduction in the extent of sand wave clearance (along Proposed Development export cable corridor) from 9,360,000 m2 to 4,360,000 m2; and,
• reduction in the number of vessels and return trips.

4.13. Consultation and Stakeholder Engagement

4.13.1.              Scoping and Screening Documents Submitted

106. Table 4.13   Open ▸ nbelow provides a summary of the key EIA screening and scoping documents submitted to date as part of the development and refinement of the Proposed Development.

Table 4.13: Documents Submitted for the Initial Berwick Bank Wind Farm and the Berwick Bank Wind Farm

4.13.2.              Community Roadshow

107. The community roadshow took place 25 - 29 October 2021. Members of the project team were available to answer questions at 17 locations throughout East Lothian, as detailed below:

• 25 October 2021:

–           North Berwick High Street; and

–           North Berwick Community Centre, 8 Law Road, EH39 4PN.

• 26 October 2021:

–           Tesco, Tantallon Rd, North Berwick EH39 5NF;

–           Dirleton, Main Road, EH39 5EP;

–           Gullane, Main Street; and

–           North Berwick Sports Centre, Grange Rd, Eh39 4QS.

• 27 October 2021:

–           Dunbar High Street;

–           Skateraw;

–           Thorntonloch; and

–           Innerwick, Village Hall.

• 28 October 2021:

–           Melbourne Rd, outside Scottish Seabird Centre;

–           Aldi, Dunbar Rd, North Berwick EH39 4DQ;

–           Whitekirk; and

–           East Linton, Community Hall.

• 29 October 2021:

–           Hallhill Sports Centre, Kellie Road, Dunbar, EH42 1RF;

–           Broxburn, Main Street; and

–           West Barns, Edinburgh Road.

108. During the roadshow members of the Project team presented project maps including distances to shore, indicative 3D models of the Proposed Development array area, Proposed Development export cable corridor, potential landfall locations, onshore cable corridors and onshore substation infrastructure. On each day the Project team were also on hand to answer any queries or concerns members of the public had regarding our proposals.

4.13.3.              Consultation Events

109. The change from 2020 Berwick Bank Project to the 2021 Berwick Bank Wind Farm and the subsequent boundary change (Proposed Development) was notified to key consultees, stakeholders, and the public through various communication streams, including the Project website.
110. An early informal in-person and virtual public exhibition was held in October 2021. For this, the combined Proposed Development array areas were presented. At this exhibition, the Project had progressed the site selection phase and provided information on:

• the selected Skateraw Landfall and the associated Proposed Development export cable corridor from the Proposed Development array area; and
• the selected onshore Skateraw Substation site and selected onshore cable route from landfall to the onshore substation and then onwards to SP Energy Networks (SPEN)’s Branxton 400 kV Substation (proposed substation).
  111. The formal public exhibition for the Project took place in March 2022. This exhibition was both in-person and virtual as detailed in volume 1, chapter 5. At this exhibition, details of the final stage of the site selection process, as assessed as part of the Onshore and Offshore EIA Reports were presented.
  112. In July 2022, an extensive leaflet drop was undertaken notifying key consultees, stakeholders, and the public of the boundary change and providing additional information on other measures being introduced by the project to address climate change and nature emergencies.

4.14. Conclusion

113. The site selection process explained within this chapter of the Offshore EIA Report has culminated in the Application for the Proposed Development. The Applicant has endeavoured to take on board points raised by stakeholders during the offshore EIA scoping phase for the Proposed Development, in relation to the site selection and/or design.
114. As discussed in volume 2, chapter 6, a maximum design scenario approach has been implemented when assessing any impacts arising from the Proposed Development as part of this Offshore EIA Report. The final design will fall within the maximum PDE parameters to ensure that it is compliant with the Proposed Development as assessed in the Offshore EIA Report.

4.15. References

CCC (undated). Advice on reducing the UK’s emissions. Available at:https://www.theccc.org.uk/about/our-expertise/advice-on-reducing-the-uks-emissions/. Accessed on 14 April 2022

Department for Energy and Climate Change (DECC) (2009a). Offshore Energy – Strategic Environmental Assessment – Post Public Consultation Report. Available at: Microsoft Word - OE SEA Post Consultation Report.doc (publishing.service.gov.uk). Accessed on: 06/01/2022.

Department for Energy and Climate Change (DECC) (2009b). Future Leasing for Offshore Wind Farms and Licensing for Offshore Oil and Gas and Gas Storage. Non-Technical Summary. Available at: Microsoft Word - Non Technical Summary Final 260109.doc (publishing.service.gov.uk). Accessed on: 20 September 2021.

Department for Energy and Climate Change (DECC) (2011a). Overarching National Policy Statement for Energy (EN-1). Available at: 1938-overarching-nps-for-energy-en1.pdf (publishing.service.gov.uk). Accessed on: 21 September 2021.

Department for Energy and Climate Change (DECC) (2011b). National Policy Statement for Renewable Energy Infrastructure (EN-3). Available at: 1940-nps-renewable-energy-en3.pdf (publishing.service.gov.uk). Accessed on: 21 September 2021.

JNCC (2019). Southern North Sea MPA | JNCC - Adviser to Government on Nature Conservation. Available at www.jncc.gov.uk/our-work/southern-north-sea-mpa/#site-timeline. Accessed on 22 December 2021.

JNCC (2022). Outer Firth of Forth and St Andrews Bay Complex SPA. Available at: Outer Firth of Forth and St Andrews Bay Complex SPA | JNCC - Adviser to Government on Nature Conservation. Accessed on: 23 February 2022.

MacDonald, A., Speirs, D.C., Greenstreet, S.P.R. and Heath, M.R. (2018). Exploring the Influence of Food and Temperature on North Sea Sandeels Using a New Dynamic Energy Budget Model. Front. Mar. Sci. 5:339. doi: 10.3389/fmars.2018.00339. Available at: Exploring the influence of food and temperature on North Sea sandeels using a new dynamic energy budget model - Strathprints. Accessed on: 23 February 2022.

Marine Scotland (2021). Marine Licence – Construction of Export Cable – Seagreen 1A Export Cable Corridor, Firth of Forth – 00009291. Available at: Marine Licence – Construction of Export Cable – Seagreen 1A Export Cable Corridor, Firth of Forth - 00009291 | Marine Scotland Information. Accessed on: 23 February 2022.

Marine Scotland Licensing Operations Team (2021a). Scoping Opinion for Berwick Bank Offshore Wind Farm. Available at: Scoping Opinion – Berwick Bank Offshore Wind Farm | Marine Scotland Information.

Marine Scotland Licensing Operations Team (2021b). HRA Screening Report Response for Berwick Bank Offshore Wind Farm. Available at: HRA Screening Report Response - Berwick Bank Offshore Wind Farm | Marine Scotland Information.

RSPB (2017). Kittiwake joins the red list of birds facing risk of global extinction. Available at: https://www.rspb.org.uk/about-the-rspb/about-us/media-centre/press-releases/kittiwakeredlist/. Accessed on 17 January 2022.

Scottish Government (2018). Sectoral Marine Plan for Offshore Wind Energy (encompassing Deep Water Plan Options). Context Report, June 2018. Available at: Sectoral Marine Plan for Offshore Wind Energy (encompassing Deep Water Plan Options): Context Report (www.gov.scot). Accessed on: 21 September 2021.

Scottish Government (2019a). The Global Climate Emergency - Scotland's Response: Climate Change Secretary Roseanna Cunningham's statemen. Available at: The Global Climate Emergency - Scotland's Response: Climate Change Secretary Roseanna Cunningham's statement - gov.scot (www.gov.scot). Accessed on 31 August 2022.

Scottish Government (2019b). Draft Sectoral Marine Plan for Offshore Wind Energy (2019). Available at: Draft Sectoral Marine Plan for Offshore Wind Energy (2019) (www.gov.scot). Accessed on: 21 September 2021.

Seagreen (2010a). Zone Appraisal and Planning Firth of Forth Zone Characterisation. Seagreen Document No. A6SW/SEAG-Z-DEV260-SWR-017-A2. Seagreen, Glasgow.

Seagreen (2010b). Zone Consenting Strategy. Seagreen Document No. A4MR/SEAG-Z-MGT110-SST-029. Seagreen, Glasgow.

Seagreen (2011). Zone Appraisal and Planning: Update December 2011. Seagreen Document No, A4MR/SEAG-Z-DEV260-SRP-118 (December 2011).

Seagreen (2014). Zone Appraisal and Planning: Update 2. Seagreen Document No. A4MR-SEAGZDEV260-SRP-279 (April 2014).

SSER (2020a). 2020 Berwick Bank Wind Farm Scoping Report. Available at: https://www.sserenewables.com/media/0t5n05b4/berwick-bank-wind-farm-offshore-scoping-report.pdf

SSER (2020b). Indicative Export Cable Corridor Design. Seagreen Charlie Wind Energy Limited and Seagreen Delta Wind Energy Limited.

SSER (2020c). 2020 Berwick Bank Wind Farm: HRA Screening Report. Available at: https://www.berwickbank.com/planning-and-consent

SSER (2021a). Berwick Bank Wind Farm Offshore Scoping Report. Available at: https://www.berwickbank.com/planning-and-consent

SSER (2021b). Berwick Bank Wind Farm Offshore HRA Screening Report. Available at: https://www.berwickbank.com/planning-and-consent

SSE Renewables Developments (UK) (2021c). Berwick Bank Wind Farm Berwick Bank Blade Tip to Sea Clearance Sensitivity Study.

Trinder (2017). Estimates of Ornithological Headroom in Offshore Wind Farm Collision Mortality. Unpublished report to The Crown Estate (submitted as Appendix 43 to Deadline I submission Hornsea Project Three: TCE Ornithology Headroom Estimates FINAL 24_02_2017 CLEAN (planninginspectorate.gov.uk)

UK Parliament (2019). "The most important issue of our time," Opposition calls to declare climate emergency - UK Parliament. Accessed on: 01/10/2022

UK Government (2022). Major acceleration of homegrown power in Britain’s plan for greater energy independence - GOV.UK (www.gov.uk). Accessed 01/10/2022

van Deurs, M., Hartvig, M. and Steffensen, J.F (2011). Critical threshold size for overwintering sandeels (Ammodytes marinus). Mar Biol 158, 2755–2764 (2011). Available at: Critical threshold size for overwintering sandeels (Ammodytes marinus) | SpringerLink. Accessed on: 23 February 2022.

[1] Headroom is the difference between predicted levels of mortality based on worst case parameters used at the application stage and mortality rates based on ‘as built’ project designs (built v assessed or consented wind farm designs) (Trinder, 2017).

[2] Results from the NGESO Holistic Network Review were published in July 2022 (NGESO, 2022)