DOCUMENT 9.2 Wylfa to Pentir Preferred Route Corridor Selection Report (2015) National Grid (North Wales Connection Project) Regulation 5(2)(q) of the Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 First published October 2015 Application Reference EN020015 September 2018 - Blank Page - North Wales Connection Wylfa to Pentir Preferred Route Corridor Selection Report Table of Contents EXECUTIVE SUMMARY ............................................................................................................... iii 1 INTRODUCTION ................................................................................................................. 1 1.1 Background ......................................................................................................................... 1 1.2 Purpose of this Report ......................................................................................................... 2 1.3 Report Layout ...................................................................................................................... 5 2 NATIONAL GRID DUTIES AND POLICIES ........................................................................ 6 2.1 Introduction ......................................................................................................................... 6 2.2 Duty to Provide a Connection .............................................................................................. 6 2.3 Economic Duties ................................................................................................................. 6 2.4 Duty to Protect the Environment .......................................................................................... 7 2.5 Stakeholder, Community and Amenity Policy ...................................................................... 7 2.6 Transmission Line Route Options Appraisal Process .......................................................... 8 2.7 Other Legislation ................................................................................................................. 8 3 PROJECT CONTEXT ....................................................................................................... 10 3.1 The UK Energy Challenge ................................................................................................. 10 3.2 North Wales Transmission System .................................................................................... 10 3.3 Strategic Options Appraisal ............................................................................................... 11 3.4 Wylfa to Pentir Route Corridor Options .............................................................................. 12 4 POLICY CONTEXT ........................................................................................................... 16 4.1 National Policy Statements ................................................................................................ 16 4.2 Welsh Planning Policy ....................................................................................................... 18 4.3 Planning Consents ............................................................................................................ 21 5 ELECTRICITY TRANSMISSION DEVELOPMENTS......................................................... 22 5.1 Introduction ....................................................................................................................... 22 5.2 Overhead Lines ................................................................................................................. 22 5.3 Underground Cables ......................................................................................................... 30 5.4 Substations ....................................................................................................................... 35 6 APPRAISAL PROCESS ................................................................................................... 36 6.1 Introduction ....................................................................................................................... 36 6.2 Statutory Duties ................................................................................................................. 36 6.3 Planning Act 2008 ............................................................................................................. 36 6.4 Route Corridor Appraisal Process ..................................................................................... 38 6.5 Additional Supporting Activities ......................................................................................... 42 7 CONSULTATION .............................................................................................................. 45 7.1 Introduction ....................................................................................................................... 45 7.2 Route Corridor Consultation .............................................................................................. 45 7.3 Route Corridor Appraisal Consultation .............................................................................. 45 7.4 Summary of Stakeholder Feedback ................................................................................... 46 8 ROUTE CORRIDOR DESIGN REFINEMENT ................................................................... 47 8.1 Introduction ....................................................................................................................... 47 8.2 Main Issues for an Overhead Line Connection .................................................................. 47 8.3 High Level Mitigation Consideration for an Overhead Line within Route Corridors ............ 48 8.4 Overhead Line Mitigation Options Considered .................................................................. 51 8.5 Refined Route Corridor Options for Appraisal .................................................................... 57 9 APPRAISAL OF ROUTE CORRIDORS ............................................................................ 59 9.1 Introduction ....................................................................................................................... 59 9.2 Environment ...................................................................................................................... 59 9.3 Socio-Economic ................................................................................................................ 75 9.4 Technical ........................................................................................................................... 80 9.5 Costs ................................................................................................................................. 82 i North Wales Connection Wylfa to Pentir Preferred Route Corridor Selection Report 10 SELECTION OF PREFERRED ROUTE CORRIDOR........................................................ 84 10.1 Introduction ....................................................................................................................... 84 10.2 Stakeholder Feedback ....................................................................................................... 84 10.3 Identification of Topic Differentiators .................................................................................. 84 10.4 Selection of Preferred Route Corridor ................................................................................ 89 11 WAY FORWARD .............................................................................................................. 91 11.1 Next Steps ......................................................................................................................... 91 11.2 On-going Scheme Development ........................................................................................ 91 GLOSSARY .................................................................................................................................. 93 APPENDIX A Environmental and Socio-economic Baseline Plans ................................... 97 APPENDIX B Review of Locations for Route Corridor Design Refinement .................... 103 ii North Wales Connection Wylfa to Pentir Preferred Route Corridor Selection Report EXECUTIVE SUMMARY A new electricity connection to the mainland transmission system is needed to allow the export of power from a new nuclear power station proposed to be built at Wylfa, on the Isle of Anglesey. National Grid has contractually agreed to connect the new Wylfa Newydd Power Station to the transmission system in North Wales by 2024/25. In 2012, National Grid discussed with statutory stakeholders a number of strategic options for exporting the power generated by the proposed nuclear station to the wider transmission system. National Grid also undertook a high-level appraisal of the environmental, socio-economic, technical and cost considerations associated with each strategic option. The responses from this initial consultation and the findings of the appraisal were taken into account and used to inform the selection of a preliminary preferred strategic option before presenting the appraisal findings for wider public consultation. The preferred option involved the development of a second transmission connection overland across Anglesey between Wylfa and an existing National Grid substation at Pentir, on the mainland in Gwynedd. In parallel with the strategic options