Chapter 4 Site Selection and Assessment of Alternatives
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Norfolk Boreas Offshore Wind Farm Chapter 4 Site Selection and Assessment of Alternatives Environmental Statement Volume 1 Applicant: Norfolk Boreas Limited Document Reference: 6.1.4 RHDHV Reference: PB5640-006-004 Pursuant to APFP Regulation: 5(2)(a) Date: June 2019 Revision: Version 1 Author: Royal HaskoningDHV Photo: Ormonde Offshore Wind Farm Date Issue Remarks / Reason for Issue Author Checked Approved No. 12/02/2019 01D First draft for Norfolk Boreas Limited review DT CD/RD/AH/JL AD/JL 27/02/2019 02D Second draft for Norfolk Boreas Limited Review DT RA/DT/JL/AH AD/JL 16/04/2019 01F Final for DCO submission DT RA/CD JL Environmental Statement Norfolk Boreas Offshore Wind Farm 6.1.4 June 2019 Page i Table of Contents 4 Site Selection and Assessment of Alternatives ......................................................... 1 4.1 Introduction ........................................................................................................... 1 4.2 Key Components of Norfolk Boreas ......................................................................... 3 4.3 Legislation and Guidance ........................................................................................ 4 4.4 Site Selection Process ............................................................................................. 5 4.5 Project Alternatives ................................................................................................ 9 4.6 Identification of the Offshore Wind Farm Location ................................................ 10 4.7 Identification of Provisional Offshore Cable Corridor and Landfall Area .................. 13 4.8 Identification of National Grid Connection Point .................................................... 16 4.9 Identification of Landfall Location ......................................................................... 18 4.10 Identification of Onshore Cable Corridor ............................................................... 21 4.11 Identification of Onshore Cable Route ................................................................... 23 4.12 Identification of Cable Relay Station Locations ...................................................... 24 4.13 Identification of Onshore Project Substation Location ........................................... 25 4.14 Identification of National Grid Extension Works Location ...................................... 32 4.15 Onshore Project Infrastructure Refinement ........................................................... 33 4.16 Identification of the Project Interconnector Cable Corridor .................................... 37 4.17 Summary .............................................................................................................. 38 4.18 References ........................................................................................................... 40 Environmental Statement Norfolk Boreas Offshore Wind Farm 6.1.4 June 2019 Page ii Tables Table 4.1 Norfolk Boreas PEIR Consultation responses 0 Table 4.2 Key strategic project alternatives considered 9 Table 4.3 Landfall ranking results 15 Table 4.4 Application of Horlock Rules to onshore project substation 25 Table 4.5 Summary of site selection decisions 38 Plates Plate 4.1 Site selection process for Norfolk Boreas and Norfolk Vanguard 8 Figures (Volume 2) Figure 4.1 The Former East Anglia Zone Figure 4.2 Offshore constraints Figure 4.3 Provisional offshore cable corridors to three landfall locations Figure 4.4 Ranking of indicative landfall sites Figure 4.5 Landfall search area Figure 4.6 Landfall site options Figure 4.7 Landfall location Figure 4.8 Onshore Infrastructure as presented at PEIR Figure 4.9 Substation search area Figure 4.10 Refined substation search area Figure 4.11 Onshore project substation footprint options Figure 4.12 Onshore project substation location under Scenario 1 Figure 4.13 Onshore project substation search area under Scenario 2 as presented at PEIR Figure 4.14 Onshore project substation location under Scenario 2 Figure 4.15 National Grid substation extension under Scenario 1 Figure 4.16 National Grid substation extension under Scenario 2 Figure 4.17 Project interconnector cable search area Appendices (Volume 3) Appendix 4.1 Initial HDD Feasibility Report Appendix 4.2 Cable Constructability Assessment Appendix 4.3 Strategic approach to selecting a grid connection point Appendix 4.4 Preferred Landfall Location Technical Note Appendix 4.5 Norfolk Vanguard and Norfolk Boreas Coastal Erosion Study Appendix 4.6 HDD Feasibility Reports for Happisburgh and Bacton Green Landfall Sites Appendix 4.7 Identification of Onshore Cable Corridor Appendix 4.8 Identification of Cable Relay Station Locations Appendix 4.9 Identification of Onshore Project Substation Search Sectors Appendix 4.10 Onshore Project Substation Site Selection Environmental Statement Norfolk Boreas Offshore Wind Farm 6.1.4 June 2019 Page iii Glossary of Acronyms AfL Agreement for Lease AHOB Ancient Humans of Britain AONB Area of Outstanding Natural Beauty CRS Cable Relay Station CWS County Wildlife Site DCO Development Consent Order EAOW East Anglia Offshore Wind EIA Environmental Impact Assessment ES Environmental Statement EU European Union GMSL Global Marine Systems Limited HDD Horizontal Directional Drilling HVAC High Voltage Alternating Current HVDC High Voltage Direct Current kV Kilovolt MCZ Marine Conservation Zone MW Megawatt NCC HES Norfolk County Council’s Historic Environment Service NETS National Electricity Transmission System NGET National Grid Electricity Transmission NHER Norfolk Heritage Environment Record NPS National Policy Statement NV Norfolk Vanguard OESEA Offshore Energy Strategic Environmental Assessment O&M Operations & Maintenance OWF Offshore Wind Farm PEIR Preliminary Environmental Information Report PEXA Practice and Exercise Area PRoW Public Right of Way SAC Special Area of Conservation SPA Special Protection Area SPR ScottishPower Renewables SSSI Site of Special Scientific Interest VWPL Vattenfall Wind Power Limited ZAP Zonal Appraisal and Planning ZDP Zonal Development Plan Environmental Statement Norfolk Boreas Offshore Wind Farm 6.1.4 June 2019 Page iv Glossary of Terminology Cables which link wind turbine to wind turbine, and wind turbine to offshore Array cables electrical platforms. Installation of cables within pre-installed ducts from jointing pits located along Cable pulling the onshore cable route. Primarily comprised of an outdoor compound containing reactors (also called inductors, or coils) and switchgear to increase the power transfer capability of Cable Relay Station the cables under the HVAC technology scenario as considered in the Scoping Report. This is no longer required for the project as the HVDC technology has been selected. GIS desk based exercise where a range of environmental data sets within a Constraints Mapping defined study area are mapped and buffers applied to aid in the process of selecting siting options for onshore electrical infrastructure. A duct is a length of underground piping, which is used to house electrical and Ducts communications cables. A voluntary consultation process with specialist stakeholders to agree the Evidence Plan Process approach to the EIA and information to support the HRA. Offshore cables which link offshore electrical platforms within the Norfolk Interconnector cables Boreas site. Underground structures constructed at regular intervals along the onshore cable Jointing pit route to join sections of cable and facilitate installation of the cables into the buried ducts. Landfall Where the offshore cables come ashore at Happisburgh South. Landfall compound Compound at landfall within which HDD drilling would take place. Underground chambers or above ground cabinets next to the cable trench Link boxes housing low voltage electrical earthing links. Areas approx. 100 x 100m used as access points to the running track for duct installation. Required to store equipment and provide welfare facilities. Located Mobilisation area adjacent to the onshore cable route, accessible from local highways network suitable for the delivery of heavy and oversized materials and equipment. Mobilisation zone Area within which a mobilisation area would be located. National Grid new / replacement overhead line New overhead line towers to be installed at the National Grid substation. tower National Grid overhead line The works to be undertaken to complete the necessary modification to the modifications existing 400kV overhead lines. National Grid substation The permanent footprint of the National Grid substation extension. extension Land adjacent to the Necton National Grid substation which would be National Grid temporary temporarily required during construction of the National Grid substation works area extension. Necton National Grid The grid connection location for Norfolk Boreas and Norfolk Vanguard. substation Norfolk Vanguard Norfolk Vanguard offshore wind farm, sister project of Norfolk Boreas. Norfolk Vanguard East and The Norfolk Vanguard project includes two offshore wind farm (OWF) sites. Norfolk Vanguard West Norfolk Vanguard East and Norfolk Vanguard West The corridor of seabed from the Norfolk Boreas site to the landfall site within Offshore cable corridor which the offshore export cables will be located. A fixed structure located within the Norfolk Boreas site, containing electrical Offshore electrical platform equipment to aggregate the power from the wind turbines and convert it into a Environmental Statement Norfolk Boreas