7.3 Strategic Options Report

The North Wales Wind Farms Connection Project

Strategic Options Report

Application reference: EN020014 March 2015

Regulation reference: The Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 Regulation 5(2)(q)

Document reference 7.3

The Planning Act 2008

The Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009

Regulation 5(2)(q)

The North Wales Wind Farms Connection Project

Strategic Options Report

Document Reference No. 7.3

Regulation No. Regulation 5(2)(q)

Author SP Manweb

Date March 2015

Version V1 Planning Inspectorate Reference EN020014 No.

SP Manweb plc, Registered Office: 3 Prenton Way Prenton CH43 3ET. Registered in England No. 02366937

SUMMARY The North Wales Wind Farms Connection Project is a major electrical infrastructure development project, involving several wind farm developers and the local Distribution Network Operator – SP Manweb plc (SP Manweb). The development of on-shore wind generation in Wales is guided by the Welsh Government’s energy strategy, initially published in 2003. In their Technical Advice Note (TAN) 8: renewable energy (2005) the Welsh Government identified 7 Strategic Search Areas (SSAs) as potential locations for wind generation, of which area A is in North Wales.

During the past 20 years, approximately 220 MW of wind generation (both onshore and offshore) have been connected to the SP Manweb distribution network in North Wales. Within the TAN 8 SSA A, SP Manweb is currently contracted to connect a further four wind farms[1] which have received planning consent and total 170 MW of generation. SP Manweb has a statutory duty to offer terms to connect new generating stations to its distribution system. The options presented in this Report address those connection offers.

The wind farms vary in size from approximately 22 MW up to 80 MW and are dispersed over a fairly wide area, so to collect electricity from the wind farms and transport it to the transmission system requires a combination of 33 kV and 132 kV connections. New 33 kV circuits have a typical maximum capability of about 25 MVA2 (depending on length), whereas single circuit 132 kV wood pole line capacities range from 89 MVA to 176 MVA in capacity. Single circuit 132 kV steel tower lines can transport up to 245 MVA, whilst double circuit 132 kV steel tower lines can transport up to 490 MVA.

The Report back-checks and reviews several connection options, at both 33 kV and 132 kV, to the existing network infrastructure. It updates the first Strategic Options Report dated May 2013 and concludes that the preferred option is for a 132 kV circuit to be constructed from SSA A northwards to the St Asaph BSP substation (Option SA).

1 Clocaenog Forest (80 MW), Llyn Brenig (45 MW), Nant Bach (22 MW) and Derwydd Bach (23 MW)

2 Older circuits can be typically assumed to be rated at 20MVA

This option is technically capable of accommodating all the contracted generation and has the shortest 132 kV connection of all the technically viable options that do not require any development at 400 kV. Shorter options are generally preferred on the basis of minimising both impacts and costs, unless a longer alternative offers sufficiently reduced environmental impact compared with the shorter route.

CONTENTS PAGE No.

GLOSSARY 1 INTRODUCTION 12 BACKGROUND 13 NEED 17 DESIGN PROCESS 23 BUSINESS PROCESS 30 OPTIONS IDENTIFICATION AND EVALUATION 31 CONCLUSIONS 39 ABBREVIATIONS 41

Appendices

Appendix A – Options Evaluation

GLOSSARY 132kV Overhead 132,000 volts overhead line from the Collector Substation to the Line Terminal Point Above Ordnance Elevation of land above sea level (at Newlyn) Datum (AOD) Agricultural Land The classification system used by the Department for Classification Environment Food and Rural Affairs based on its quality and (ALC) versatility. The classification ranges from Grade 1 (the best and most versatile) through Grades 2, 3a, 3b, 3 c and 4, down to Grade 5 (least versatile) Agri-environment A UK government undertaking in which farmers are paid to farm scheme / in an environmentally sensitive way agreement Alluvium Material transported by rivers and deposited along its course Air Quality Declared by local authorities for areas where objectives specified Management Area in the national Air Quality Strategy are not predicted to be met (AQMA) Air Quality Action Produced by local authorities for AQMAs, setting out measures to Plan (AQAP) improve air quality Ancient Semi- Woodland composed of native tree species that have not Natural Woodland obviously been planted (ASNW) Aquifer A body of permeable rock that is capable of storing significant quantities of water; is undertaken by impermeable material, and through which groundwater moves Area of Non statutory designation to categorise sensitive landscapes - Outstanding designated by Denbighshire County Council Beauty (AOB) Area of An area designated under the National Parks and Access to Outstanding Countryside Act 1949 for its particularly attractive landscape and Natural Beauty unspoilt character, which should be protected and enhanced as (AONB) part of the national heritage Area of Search The term given to a wide area within which the route corridors are identified and for the purposes of the Proposed Development is shown on the Location Plan (document reference 2.1) Assessment of the A method of assessment of the effect of a development on Significance of Historic Landscapes Impacts of Development on Historic Landscape areas (ASIDOHL) Associated Development which is associated with a Nationally Significant Development Infrastructure Project as defined by the Planning Act 2008 Authority The Gas and Electricity Markets Authority established under Section 1 of the Utilities Act 2000

Baseline Existing environmental conditions which are described in the ES Best and most Defined by the ALC as Grades 1, 2 and 3a. Provisional versatile (BMV) reclassification has removed sub-classifications within Grade 3, considering Grades 1 and 2 as ‘Best and Most Versatile’ (BMV) land Biodiversity The variety and abundance of species, their genetic composition, and the natural communities, ecosystems, and landscapes in which they occur Biodiversity Action A strategy for conserving and enhancing wild species and wildlife Plan (BAP) habitats in the UK. Now replaced by Country Biodiversity Strategies British Trust for Ornithology (BTO) Broad Route Initial strategic corridors identified for the Proposed Development Corridor(s) and shown on Figure 3.1 in the ES (document reference 6.16) Cable An insulated conductor designed for laying underground Cadw The historic environment service of the Welsh Government Collector The new collector substation which will be located in the Substation Clocaenog Forest and will connect the wind farms into the electricity distribution network Conductor Overhead wire(s) attached to wood poles which conduct electricity Connection and Defined within Transmission Licence Standard Conditions. use of system code Condition C1 and C10 states the meaning of the Connection (CUSC) and Use of System Code (CUSC) as: The licensee shall establish arrangements for connection and use of system in respect of matters which, other than those to which standard conditions C14 (Grid Code) and C5 (Use of system charging methodology) to C9 (Functions of the Authority) relate are calculated to facilitate the achievement of the following objectives: (a) the efficient discharge by the licensee of the obligations imposed upon it under the Act and by this licence; (b) facilitating effective competition in the generation and supply of electricity, and (so far as consistent therewith) facilitating such competition in the sale, distribution and purchase of electricity; and (c) compliance with the Electricity Regulation and any relevant legally binding decision of the European Commission and/or the Agency

Conservation Area Designated by local authorities on account of their special architectural or historic interest, the character and appearance of which it is intended to preserve and enhance Construction Sets out management measures required of contractors for any Environmental construction works associated with the Proposed Development Management Plan

(CEMP) Construction phase Is when preparatory works or construction works are taking place until commissioning of the Proposed Development Consultation 100m wide corridor(s) within which 132 kV Overhead Line could Corridors be constructed and which were the subject of pre-application consultation pursuant to the Planning Act 2008 Consultation zone For the purpose of the pre application consultation pursuant to the Planning Act 2008 a broad geographic consultation zone was defined and is shown in Appendix 7.1 of the Consultation Report (document reference 5.2.1) Countryside and Act, dated 2000, which provides for public access on foot to Rights of Way Act certain types of land (CROW) Cumulative Effects The effects of other development schemes (whether under construction, consented, or there are firm proposals for) assessed cumulatively with the Proposed Development and the Wider Scheme. These effects can be temporal (e.g. construction phases occur at the same time) or spatial (e.g. the same area is affected) Decibel (dB) The scale on which sound pressure level is expressed. It is defined as 20 times the logarithm of the ratio between the root- mean-square pressure of the sound field and a reference pressure (2x10-5Pa) Decommissioning The final phase of the Proposed Development covering all phase activities to remove the Proposed Development from the environment once it is no longer in operational use and the undertaking of restoration works Designated area Area designated and protected by national or international law for its landscape, biodiversity, or historic interest Development The order made when an application has been made pursuant to Consent Order section 37 of the Planning Act 2008 for a NSIP and the Secretary (DCO) of State determines that the order should be made Distribution Code A code required to be prepared by a DNO pursuant to condition 9 (Distribution Code) of a Distribution Licence and approved by the Authority as revised from time to time with the approval of, or by the direction of, the Authority. Distribution A distribution licence granted under Section 6(1)(c) of the Act. Licence

Distribution Distribution Network Operators own and operate the electricity Network Operator distribution network that brings electricity from the national (DNO) transmission network to the consumer. SP Manweb is the DNO for North and Mid Wales, Cheshire and Merseyside Easement Allowing another person to use your land for a specific purpose, such as installing utilities Ecological Impact Ecological Impact Assessment is part of an EIA and assesses the Assessment (EcIA) potential effects of a development on habitats and species, particularly those protected national and international legislation 3

or considered to be of particular nature conservation importance Electromagnetic Electric and magnetic fields generated by electricity Fields (EMFs) Electricity Act 1989 The Electricity Act 1989 (as amended by the Utilities Act 2000 (The 1989 Act) and the Energy Act 2004).

EN-1 National Policy Statements set out national policy against which proposals for major infrastructure projects will be assessed and decided by the Secretary of State. EN-1 is the Overarching National Policy Statement for Energy EN-5 National Policy Statements set out national policy against which proposals for major infrastructure projects will be assessed and decided by the Secretary of State. EN-5 is the National Policy Statement for Electricity Networks Infrastructure Environment Environment Agency Wales, now part of NRW, was the Agency Wales environmental regulator for Wales (EAW) Environmental A statutory process whereby a project is assessed through the Impact collection and consideration of environmental information with the Assessment (EIA) aim of taking account of the predicted effects of the proposed development on the environment in the decision making process. The findings are published in an Environmental Statement Environmental Report documenting the outcome of an Environmental Impact Statement (ES) Assessment Environmentally An agricultural area which needs special protection because of its Sensitive Area landscape, wildlife or historic value (ESA) Final Route Current pole positions along the centreline of the Limits of Alignment Deviation identified following consultation, technical and environmental appraisal Flood Required for developments in flood zones. It is an assessment of Consequence the potential impact of a development on flooding Assessment (FCA) Flood Zone (FZ) Areas at risk of flooding, divided into subcategories / zones Floodplain The area that would naturally be affected by flooding if a river rises above its banks Grid Code The code which NGC is required to prepare under its Transmission Licence and have approved by the Authority as from time to time revised with the approval of, or by the direction of, the Authority. Grid Supply Point Any point at which electricity is delivered from the National (GSP) Electricity Transmission System to the DNO’s Distribution System

Groundwater Water flowing through or contained beneath the ground surface Guidelines for Guidelines for Landscape and Visual Impact Assessment (Third Landscape and Edition) published by the Landscape Institute and Institute of Visual Impact Environmental Management & Assessment

Assessment (GVLIA) Habitat Suitability A numerical index that represents the capacity of a given habitat Index (HSI) to support a selected species. Most commonly used for great crested newts Habitats Directive EC Directive on the conservation of natural habitats of Wild Fauna and Flora (92/43/EEC) Habitats Assessment undertaken of the impacts of a project on Natura Regulations 2000 sites in accordance with the requirements of The Assessment (HRA) Conservation of Habitats and Species Regulations 2010 Heavy Goods A good vehicle greater than 3.5 tonnes gross weight Vehicle (HGV) Historic A register of known archaeological sites, monuments and finds Environment Record (HER) Holford Rules A series of planning guidelines for the routeing of overhead lines first developed in 1959 by Lord Holford, advisor to the then Central Electricity Generating Board (CEGB) on amenity issues. They were reviewed in the 1990s by National Grid Institute for The Chartered Institute for Archaeologists Archaeologists (IfA) Insulator Used to safely connect the conductors to wood poles or pylons International Provides scientific advice and guidance on the health and Commission on environmental effects of non-ionizing radiation Non-Ionizing Radiation Protection (ICNIRP) kV kilovolt (1000 volts) LANDMAP LANDMAP a tool developed by CCW (now NRW) to assess the diversity of all landscapes within Wales, identifying and explaining the characteristics and qualities Landscape and Assessment methodology used to assess the potential effects of Visual Impact a proposed development on the landscape Assessment (LVIA) Landscape A standard methodology for identifying, describing, classifying Character and mapping what is distinctive about our landscapes Assessment (LCA) Landscape The Chartered Institute for Landscape Architects Institute (LI) Light Goods Goods vehicles not exceeding 3.5 tonnes gross vehicle weight Vehicle (LGV)

Limits of Deviation Works 1A and 1B of the Proposed Development will be carried (LoD) out within Limits of Deviation which are shown on the Works Plans. The LoD provide a degree of flexibility which is required because following the making of the DCO, micro-siting may take place in response to detailed technical survey information, particularly for unconfirmed ground conditions and / or minor alterations requested by landowners LoD have been defined laterally and vertically Listed Building A building of special architectural or historic interest which has been included on a list approved by the Secretary of State under the Planning (Listed Buildings and Conservation Areas) Act 1990 (known as the ‘Statutory List of Buildings of Special Architectural or Historic Interest’). Buildings are classified in grades (I, II* and II) and to show their relative importance Local Biodiversity A set of action plans for habitats and species Action Plan (LBAP) Local Development A statutory document which guides future development Plan (LDP) Local Nature A site with features of nature conservation interest controlled by a Reserve (LNR) local authority Local Planning Is defined by S.1 of the Town and Country Planning Act 1990 Authority and, in the case of the Proposed Development is Denbighshire County Council and Conwy County Borough Council Local Wildlife Site Sites identified and selected for their local nature conservation (LWS) value Magnitude of The degree of change that a receptor is anticipated to experience potential effect as a result of the Proposed Development Megawatts (MW) Energy generated by wind farms is described in MW Mitigation Measures to avoid, reduce and offset environmental effects National Grid A system of grid references used in Great Britain Reference (NGR) National Unscheduled archaeological sites and features recorded by Cadw Monuments Record (NMR) National Nature A protected area of importance for wildlife, flora, fauna reserved Reserve (NNR) and managed for conservation National Policy Sets out national policy against which proposals for major Statements (NPS) infrastructure projects will be assessed and decided by the Secretary of State National Classification and description of the plant communities of Great Vegetation Britain Classification (NVC) Nationally Means a project designated under the Planning Act 2008 Significant Infrastructure Project (NSIP)

Natura 2000 sites A European-wide network of sites protected under the Habitats and Birds Directives, and made up of Special Areas of Conservation and Special Protection Areas Natural Resources An amalgamation of CCW, EAW and Forestry Commission Wales or Cyfoeth Wales, operational from 1st April 2013 Naturiol Cymru NGC National Grid Electricity Transmission plc

Nitrate Vulnerable Areas where land drains and contributes to the nitrate found in Zones (NVZ) “polluted” waters North Wales Wind Means the Proposed Development and the Wider Scheme Farms Connection NSP Noise sensitive premises Order Limits Means the limits shown on the works plans within which the Proposed Development may be carried out Palaeo-channel Ancient relict watercourse Permitted Part III of the Town and Country Planning Act provides that the Development Secretary of State may grant planning permission by way of development order. The principal development order is the Town and Country Planning (General Permitted Development) Order 1995 which provides that planning permission for certain developments is granted subject to specified conditions. It provides specified permitted development rights for statutory undertakers Persons with an Section 57 of the Planning Act 2008 defines persons with an Interest in the Land Interest in the Land which includes: (PILS) (1) owners, lessees, tenants or occupiers of land; (2) persons with an interest in land or who have a power to sell land or to release land; and (3) persons who may be able to make a claim for compensation as a result of the DCO being made and implemented.. Land for these purposes means land to which the application for development consent relates Photomontage A collection of images used to create an overall image. The objective of a photomontage is to simulate the likely visual changes that would result from the Proposed Development, and to produce printed images of a size and resolution sufficient to match the perspective in the same view as would occur in reality Planning Act 2008 The legislation for Nationally Significant Infrastructure Projects (the Act) and the requirements for development consent Planning The Planning Inspectorate administers the examination of Inspectorate applications for development consent (PINS) Planning Policy The document that sets out the Welsh Government’s policies on Wales different aspects of land use planning (PPW)

Preferred Route Is identified as the preferred route corridor for the Proposed Corridor Development and is set out in the Route Corridor Study Preliminary The report of the initial environmental impact assessment findings Environmental for the Proposed Development Information Report (PEIR) Prescribed Means persons to be consulted pursuant to the Planning Act Consultees 2008 and set out in Schedule 1 of the Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 Proposed The 132kV Overhead Line together with required pedestrian and Development vehicular accesses, temporary construction compound, construction laydown areas, mitigation planting and other integral works PRoW Public Right of Way which is a footpath or track over which the public have a right of access Ramsar sites Wetlands of international importance designated under the Ramsar Convention (Convention on Wetlands of International Importance, especially as Waterfowl Habitats) (1971) and ratified in the UK in 1976). The convention was held in the town of Ramsar, Iran Red Data book The IUCN (International Union for Conservation of Nature) Red List of threatened bird species categorised as Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened or Least Concern Regionally Designated sites of local, regional and national importance for Important geodiversity in the UK Geological Site (RIGS) Registered Park Parks and gardens which have been classified by grade to show and Garden (RPG) their relative importance: Grade I – international historic interest, Grade II* - exceptional historic interest, Grade II – national historic interest Reinstatement The actions undertaken to return a temporary working area to its previous condition, as far as reasonably practicable Requirement A requirement in Schedule 2 of the Development Consent Order Residual effects Effects remaining after mitigation measures have been taken into account Route corridor Search area used to provide a degree of flexibility in which to develop a route alignment, usually approximately 1km wide and shown in respect of the Proposed Development in Figure 3.1 of the ES (document reference 6.16) Route Corridor An appraisal to identify potential route corridors within a defined Study (RCS) study area Royal Commission Records and interprets built and landscape heritage on the Ancient and

Historical Monuments of Wales (RCAHMW) Royal Society for Large nature conservation charity the Protection of Birds (RSPB) Scheduled Ancient An archaeological site of national importance, which is included Monument on a schedule compiled by the Secretary of State for National Heritage under the terms of the Ancient Monuments and Archaeological Areas act 1979 (as amended by the National Heritage Act 1983) Scoping An early stage within the Environmental Impact Assessment (EIA) process where the scope of the environmental studies are determined Scoping Opinion A person who makes an application for an order granting development consent may ask the Secretary of State his opinion as to the information to be provided in an ES and this is known as a Scoping Opinion Scoping Report The scoping report prepared by SP Manweb and submitted to the Secretary of State to support its application for a Scoping Opinion

Screening Initial process by which project proposals are assessed to decide whether they require a formal Environmental Impact Assessment Secretary of State The Secretary of State for Energy and Climate Change (SOS) Significance The significance of effects considers the value (or sensitivity) of the receptor and the magnitude and likelihood of potential effects Site of Importance Sites of substantive local nature conservation value for Nature Conservation (SINC) Site of Special An area of land of special interest by reason of its flora, fauna, Scientific Interest geology or physiographical features notified under Section 28 of (SSSI) the Wildlife and Countryside Act 1981 Sites and List of known archaeological sites Monuments Record (SMR) Source Protection A zone surrounding an aquifer where the contamination of the Zone (SPZ) groundwater flow due to surface spills could pollute the aquifer SP Manweb The DNO for North and Mid Wales, Cheshire and Merseyside. The promoter of the Proposed Development

Special Area of Sites chosen to conserve the natural habitat types and species of Conservation wild flora and fauna listed in Annex I and II of the Habitats (SAC) Directive. They are the best areas to represent the range and variety of habitats and species within the European Union.

Special Landscape Non statutory designation to categorise sensitive landscapes - Area (SLA) designated by Conwy County Borough Council

Special Protection Area designated under article 4 of the European Communities Area (SPA) Council Directive on Conservation of Wild Birds for the protection of particularly sensitive bird species, or for regularly migrating birds: to help protect and manage areas which are important for rare and vulnerable birds because they use them for breeding, feeding, wintering or migration St Asaph Means the substation located in St Asaph and which the North Substation Wales Wind Farms Connection will connect into Statement of A statement setting out how the applicant proposes to consult the Community local community in respect of the Proposed Development and as Consultation required by section 47 of the Planning Act 2008 (SOCC) Statutory Organisations that SP Manweb is required to consult by virtue of consultees the Planning Act 2008 Statutory Companies with regulatory powers and duties, such as gas, undertakers electricity, water and transport providers / transmitters Strategic Options Sets out the initial technical options for the Proposed Report (SOR) Development, and an appraisal of each option identifying the preferred technical option for the Proposed Development Strategic Search Associated with Welsh Government Technical Advice Note 8 Area (SSA) Substation Generated electricity is fed into the electrify distribution network through substations. Substations control the flow of power through the network by means of transformers and switchgear, with facilities for control, fault protection and communications Technical Advice Welsh Government Technical Advice Notes provide Note (TAN) supplementary guidance document on a number of planning policy matters. Welsh Government Technical Advice (TAN) 8: Planning for Renewable Energy (2005) sets out renewable energy, planning, technologies and design considerations Terminal Point Location at which the 132 kV Overhead Line terminates and is shown on Work Plan Sheet 13 (document reference 2.3.13) The Wider Scheme The Wider Scheme incorporates the Collector Substation, underground cables from the Terminal point to St Asaph Substation, proposed works at St Asaph Substation, temporary storage areas within St Asaph Substation and the Collector Substation and diversions of existing lower voltage overhead line crossings Traffic Impact Examines the potential impact of a development on the Assessment surrounding transport network

Tree Preservation Made by a local planning authority if it appears that it is expedient Order (TPO) in the interests of amenity to make provision for the preservation of trees or woodlands in their area in order to protect such trees,

groups of trees or woodlands as may be specified in the order Undergrounding Electricity cables laid underground United Kingdom Describes biological resources and provides detailed plans for Biodiversity Action conservation Plan (UKBAP) United Kingdom Describes habitats and provides detailed plans for conservation Habitat Action Plan (UKHAP) Vantage Point A survey method designed to record flight activity of bird species Survey (VPS) Wales National Cadw National Monuments Record of sites and events Monument Record (WNMR) Wind Farms the four wind farms at Nant Bach, Derwydd Bach, Clocaenog Forest and Brenig Wireframe Computer generated line drawing based on a digital terrain model, that illustrates the three dimensional shape of the landscape and any features within it Wood poles Wooden poles used to support an overhead electricity line (either single or double) World Health The United Nations public health arm Organisation (WHO) Written Scheme of A method statement setting out archaeological investigations Investigation (WSI) Zone of Theoretical A map which illustrates the potential (or theoretical) visibility of a Visibility (ZTV) development

INTRODUCTION Purpose of Report

1.1 This Strategic Options Report (“the Report”) describes the process of developing and assessing options which have led to a proposal to create new network infrastructure within the North Wales area. It is an update on the previous Strategic Options Report which was published in May 2013 and is a back-check and review of the original options to confirm that no new information is available that would change the original decisions. The proposal is promoted by SP Manweb plc (SP Manweb).

1.2 The Report presents options which have been developed in response to connection contracts entered into by SP Manweb with the developers of new wind farms in North Wales. The back-check and review updates information on the SP Manweb distribution network, generation and identifies one new option that has arisen since the publishing of the first Strategic Options Report in May 2013.

1.3 The Report first considers the background to the development of new electricity distribution infrastructure, and then addresses the need for new connections in North Wales. The process of option development and assessment is described and finally an updated range of options is described and evaluated.

BACKGROUND Planning Context

2.1 In 2003, the then Welsh Assembly Government launched the Welsh Energy Strategy identifying five key energy objectives including renewable energy targets of 4 TWh (terawatt-hours) by 2010 and 7 TWh by 2020. It subsequently issued Planning Guidance Technical Advice Note (TAN) 8 in July 2005, which identified seven Strategic Search Areas (SSAs) for the location of wind generation in Wales. The Proposed Development is to connect wind farms in SSA Area A near Clocaenog Forest.

2.2 Following the publication of TAN 8, North Wales became an area of developer activity. In TAN 8, SSA A has an ‘indicative’ target generation of 140 MW with an estimated potential of 210 MW. However, it is clear from the connection and planning applications received to date that the potential for wind power generation in North Wales is greater. This is primarily attributed to the development of turbines with larger individual capacities. Previously, individual wind turbines were typically 850 kW to 1.3 MW in size, as with the existing Welsh wind farms, whereas turbines of 2 MW to 3 MW are now more typical for most large-scale on-shore wind farm applications.

2.3 2 MW to 3 MW machines are considered to be the largest optimum rating for on-shore machines; larger ratings are only practically achievable at present via off-shore turbines.

National Policy Statements

2.4 The Proposed Development is a Nationally Significant Infrastructure Project (NSIP) for the purposes of the Planning Act 2008 (the Act) and therefore a development consent order (DCO) is required. Section 104(3) of the Act states that the decision maker must determine an application for a DCO in accordance with any relevant National Policy, except in certain circumstances. These include

where the adverse impact of the proposed development would outweigh its benefits.

2.5 Six National Policy Statements (NPSs) for energy infrastructure were published by the Secretary of State for Energy and Climate Change in July 2011. The most relevant NPSs for electricity infrastructure are the Overarching National Policy Statement for Energy (EN-1) and the National Policy Statement for Electricity Networks Infrastructure (EN-5), which must be read in conjunction with EN-1. The NPSs are also a material consideration for decisions on other types of development consent in England and Wales (including offshore projects).

SP Manweb Network

2.6 SP Manweb is a distribution network operator (DNO) and holds the electricity distribution licence for North and Mid Wales, Cheshire, Merseyside and parts of Shropshire. SP Manweb is part of the ScottishPower group, which is in turn owned by Iberdrola, Spain’s number one energy group, one of the largest utility companies in the world. SP Manweb is responsible for distributing power between the National Grid Supply Entry/Exit Points and load/generation customers connected within the distribution network.

2.7 The SP Manweb distribution network operates at 132,000 volts (132 kV), 33,000 volts (33 kV), 11,000 volts (11 kV), 6,600 volts (6.6 kV) and 400 volts (230 volts single phase). The SP Manweb 132 kV network comprises some 1,286 km (kilometres) of overhead lines, 253 km of underground cable and approximately one hundred 132/33 kV Grid substations. Within North and Mid Wales there are about 468 km of 132 kV overhead line circuits and approximately 37 km of 132 kV underground cables. Less than 10% of the total 132 kV circuit length in Wales is underground cable. These cable sections are typically located either within particularly sensitive landscape environments, such as the Snowdonia National Park or at the entry/exit point of some 132 kV substations, to facilitate circuit access to the substations.

2.8 The network of 132 kV distribution overhead lines is focussed on historic generation locations and urban areas where demand for electricity is high. Typically, there is little or no existing 132 kV infrastructure close to the main wind farm development areas, since these tend to be in remote, upland areas. That which does exist is predominantly overhead as this is the most efficient and cost effective network design for distributing power over long distances.

Regulations and Legal Requirements

2.9 Under the Electricity Act 1989, SP Manweb has a statutory duty to offer terms to provide connection to its distribution system. The form which these connections might take will depend on a number of factors including the location, capacity, timing and requirements of new generating stations. In particular it should be noted that wind farms are often remote from the main centres of electricity demand and the existing distribution network. In order to connect this additional generation, reinforcement of the distribution system, including uprating and re- conductoring existing lines, new overhead lines, new underground cables and new or extended substations may be required. Due to the interconnected nature and topology of the existing SP Manweb distribution network, system reinforcement or enhancement works may be required some distance away from the new generating stations which are to be connected.

2.10 When they were privatised, and as required by its distribution licence, SP Manweb and the other UK DNOs implemented the Distribution Code, which is designed to permit the development, maintenance and operation of an efficient, coordinated and economical system for the distribution of electricity, to facilitate competition in the generation and supply of electricity and to promote the security and efficiency of the power system as a whole. This reflects SP Manweb’s statutory duties under the Electricity Act 1989. It does this by providing a clear technical basis for its requirements for suitable performance from electrical equipment connected to the distribution system, and by specifying clear levels of expected performance from the distribution system on which the design of other parties' equipment may be based or reviewed. By application of these standards,

material damage to other parties' equipment, resulting from credible events in the development, maintenance and operation of the distribution network, may be avoided. Additionally, the technical interface between SP Manweb and National Grid is governed by the Grid Code, whilst the commercial interface is dictated by the Connection and Use of System Code (CUSC).

2.11 In terms of the relevant legislation, Section 9(2) of the Electricity Act 1989 requires SP Manweb:

(a) “to develop and maintain an efficient, co-ordinated and economical system of electricity transmission; and

(b) to facilitate competition in the supply and generation of electricity.”

2.12 Section 38 and Schedule 9 of the Electricity Act 1989 requires that SP Manweb, when formulating proposals for new lines and other works:

“(a) shall have regard to the desirability of preserving natural beauty, of conserving flora, fauna, and geological or physiographical features of special interest and of protecting sites, buildings and objects of architectural, historic or archaeological interest; and

(b) shall do what he reasonably can to mitigate any effect which the proposals would have on the natural beauty of the countryside or on any such flora, fauna, features, sites, buildings or objects”.

NEED Existing Network

3.1 Two National Grid 400 kV double circuit steel tower lines run east-west across North Wales: one circuit is north of TAN 8 SSA A, close to the coast; and the other is to the south of SSA A. These circuits form a ring around North Wales and connect to the SP Manweb distribution system via Grid Supply Points (GSPs) at Connah’s Quay, Legacy (near Wrexham), Pentir (near Bangor), and Trawsfynydd. In addition, a new GSP has recently been established at Bodelwyddan near St Asaph, where it connects to the SP Manweb 132 kV network.

3.2 Bodelwyddan is now the closest GSP to TAN 8 SSA A, superseding Legacy, which is a 400/132kV GSP near Wrexham shown as Legacy Local Grid on Fig 2 one of the main supply points into both North and Mid Wales.

3.3 The maximum demands for the Connah’s Quay / Pentir / St Asaph 132 kV group over the past five years have been: . 2009/10 444.07 MVA . 2010/11 438.62 MVA . 2011/12 408.93 MVA . 2012/13 424.32 MVA . 2013/14 447.25 MVA

3.4 The maximum demands for the Connahs Quay / Pentir / St Asaph 132kV group are illustrated below in Figure 1. These show that there is a steady increasing level of system demand for the underlying group and is not untypical:

Figure 1 - Connahs Quay / Pentir / St. Asaph, Maximum Group Demands (Historic and Forecasted) - MVA

3.5 The 33 kV network in and around TAN 8 SSA A is supplied from 132/33 kV transformers at Supply Points located at St Asaph, Holywell, Hawarden, Brymbo, Maentwrog, Dolgarrog and Colwyn Bay. The design of the SP Manweb network means that BSPs are interconnected through the 33 kV network, and effectively operate in groups. Four grid groups include the BSPs listed above, these are[3]: . Brymbo T2A, Hawarden T2, Holywell T2 . Colwyn Bay, Dolgarrog . Four Crosses, Maentwrog . Holywell T1, Rhyl, St Asaph

3.6 Within these four groups, the minimum and maximum demands that occurred over the last three years are shown in the following table:

3 Information on the grouping of Supergrid, Grid and Primary transformers can be found in the SP Manweb Long Term Development Statement (http://www.spenergynetworks.co.uk/pages/long_term_development_statement.asp)

Annual Minimum Annual Maximum Year Time MW Time MW 2011/12 Sun 19-Jun-11 05:30 88.46 Thu 02-Feb-12 18:00 286.12 2012/13 Sun 22-Jul-12 06:00 87.59 Thu 13-Dec-12 17:30 290.04 2013/14 Sat 22-Jun-13 05:30 92.64 Mon 25-Nov-13 17:30 263.81

3.7 Existing generation (nearly all renewable) within the area currently totals just over 300 MW, and is mainly a mix of hydro and wind generation. The two offshore wind farms[4] of North Hoyle and Rhyl Flats both feed onto the 132 kV network and total 150 MW; and the hydro stations at Dolgarrog, Cwm Dyli and Maentwrog total 76.9 MW. Although connected at 33 kV, Dolgarrog and Maentwrog are located at BSPs and therefore effectively feed into the 132 kV network. Several on-shore wind farms (see Table 1 below), all connected to the 33 kV network, total 65.0 MW of generation; with 12.4 MW of generation (a mix of landfill gas, wind and hydro) connected at 11 kV, and 5 MW of natural gas fuelled generation connected at 33 kV.

4 A third off-shore wind farm, Gwynt y Mor, is currently under construction. However, this generation feeds directly into the National Grid 400 kV network near St Asaph and will not connect to the SP Manweb network.

Generation [5] Voltage Capacity Num Type (on-shore) (kV) (MW) In Operation Rhyd-y-Foel Landfill 11 4

Carmel Landfill 11 1

Hafoty Ucha Wind 11 3.15 1, 2 & 3 Llyn Cleyn (Bala) Hydro 11 4.2

Maentwrog Hydro 33 30

Dolgarrog Hydro 33 37

Cwm Dyli Hydro 33 9.9

Hamil BHP Natural 33 5 Petroleum Gas Cemmaes Wind 33 15

Mawla, Moel Maelogan + 1 Wind 33 15.6

extension Wern Ddu 2 Wind 33 9.2

Braich Ddu 3 Wind 33 3.9

Tir Mostyn and 4 Wind 33 21.25 Foel Goch 5 Contracted Future connection? Clocaenog Forest 6 Wind 80 Yes

Llyn Brenig 7 Wind 45 Yes

Nant Bach 8 Wind 22 Yes

Derwydd Bach 9 Wind 23 Yes

Conwy Falls Hydro 4.5 No

Other enquiries Totals Existing 159.2 Received connection offer from SPEN 170 Table 1: North Wales Generation – status and capacities at 1 December 2014

5 These numbers identify the location of the wind farms on the maps in Figure 3 and Appendix A. Cemmaes wind farm is not shown on the maps; it is located between Dolgellau and Machynlleth to the south of Maentwrog Grid to which it is connected via the 33 kV network.

Connection Agreements

3.8 As shown in Table 1 above, there is currently a total of 170 MW of new generation contracted to connect to the SP Manweb distribution system within TAN 8 SSA A. The wind farms are: Clocaenog Forest (80 MW), Llyn Brenig (45 MW), Nant Bach (22 MW) and Derwydd Bach (23 MW), whose connections are due to be made from 2017 onwards.

3.9 The general location of the TAN 8 SSA A relative to the existing SP Manweb network is shown in Figure 2 and in Figure 3, which also shows wind farm locations; whilst the details of the status (as of 1 December 2014) of the various wind farm capacities are given in Table 1. In Figure 2, green and blue represent the SP Manweb 33 kV and 132 kV networks respectively. The red is the 400 kV National Grid Network.

Figure 2 - TAN 8 SSA A and the Existing SP Manweb Network

3.10 The connection to the network of significant levels of contracted generation in North Wales will require new electrical infrastructure, since it is not possible to accommodate this amount of additional generation on the existing network. As can be seen from Figure 2 and Figure 3, SP Manweb has limited network in the vicinity of SSA A: no 132 kV circuits and effectively three (perhaps four) 33 kV circuits. Existing 33 kV circuits are limited to about 20 MVA and there are already 34.35 MW of wind generation directly connected[6] to the 33 kV circuits close to SSA A. Clearly another 170 MW cannot be connected without significant network reinforcement. This Report examines the connection options available to meet the current contracted position in North Wales, and these are presented in paragraphs 6.8 onwards.

National Policy Statements

3.11 Part 3 of EN-1 sets out Government policy on the need for new nationally significant energy infrastructure projects. Paragraph 3.1 confirms that the UK needs all the types of energy infrastructure covered by the NPS to achieve energy security at the same time as dramatically reducing greenhouse gas emissions. It states that "substantial weight" should be given to the contribution which projects would make towards satisfying this need. Paragraph 3.7 confirms the need for new electricity network infrastructure and notes that they “will add to the reliability of the national energy supply, provide crucial national benefits, which are shared by all users of the system”. A need for new electricity infrastructure is set out in EN-1 and EN-5, and a need for new nuclear and offshore/onshore wind generation (i.e. the type of generation giving rise to the need for new electricity infrastructure for this project) is set out in EN-1, EN-3 and EN-6.

6 Wern Ddu (9.2 MW), Braich Ddu (3.9 MW), Tir Mostyn and Foel Goch (21.25 MW). See Table 1.

DESIGN PROCESS 4.1 There are various issues relating to the existing distribution system, regardless of cable or overhead line, which are considered when reviewing the need for system reinforcement. In summary the principal issues considered include: . Thermal Conditions: lines, cables and transformers must normally operate within their rating; . Fault Levels: lines, cables and transformers must normally operate within their fault rating; . Voltage Levels: system voltages must be kept within statutory limits; . Security of Supply : the network must operate within the security standards; . Losses: network losses should be minimised as far as is practicable. These issues are considered in more detail in the following sections.

4.2 Given the reasons outlined in the underground cable section of the Report (paragraphs 4.17 to 4.22 below) the starting point for 132kV connections is an overhead line design. The above key issues have been considered within this overhead context only for this Proposed Development.

Thermal Conditions

4.3 Overhead line conductors are designed for a certain operating temperature, and safe clearances between the conductors and the ground/structures are based on this assumption. The thermal rating translates into standard seasonal current ratings. Overloading causes conductors to overheat which will increase the sag of the conductors and reduce safety clearances. Operating at a temperature greater than their design temperature could also lead to a reduction in conductor strength.

4.4 Most existing 132 kV overhead line conductors within the SP Manweb network are ACSR 175 mm2 ‘Lynx’, which has a summer rating of 389 A (89 MVA) at 50°C[7]. New or replacement conductors are 200 mm2 AAAC ‘Poplar’, which has a higher summer rating of 542 A (124 MVA) at 75°C. 132 kV Poplar conductors

7 The line ratings quoted here are as specified in National Grid TGN 26

can be accommodated on either wood pole or steel lattice tower construction. In certain circumstances, it is possible to place 300 mm2 AAAC ‘Upas’ conductors (770 A, 176 MVA) on new wood pole construction, although this has a tendency to reduce the span lengths between poles, introducing more poles per km. ‘L4’ construction steel towers can accommodate two 132 kV circuits with 300 mm2 conductors (i.e. a rating of 176 MVA per circuit), whilst ‘L7’ construction steel towers can accommodate double circuits with 500 mm2 AAAC ‘Rubus’ conductors, with a summer rating of 245 MVA (1071 A per circuit).

4.5 SP Manweb has been investigating and trialling the use of Dynamic Line Rating (DLR). The temperature rise of an overhead line depends not only on its electrical loading, but also on the weather conditions; the conductors being heated by sunlight, and cooled by wind. Seasonal line ratings need to be somewhat conservative, and therefore dynamically determined ratings are often (though not always) higher. It is clear that connections to wind farms could benefit from the application of DLR since high line loading inevitably coincides with windy conditions. Completed trials indicate that in suitable circumstances an up to 30% increase in line loading can be achieved, and these findings are presently being evaluated by SP Manweb.

Fault Levels

4.6 The SP Manweb 132 kV design fault level limit is 20 kA (4570 MVA) for three phase faults and 25 kA (5700 MVA) for single phase faults. A high fault level improves the quality of supply by reducing the magnitude of short-term voltage fluctuations, but the fault level must also be kept within the capability of the plant and switchgear, otherwise catastrophic equipment failure can result during a network fault. Therefore, the design approach is generally to keep the fault levels as high as possible, whilst also maintaining sufficient design margins relative to the plant rating.

Voltage Levels

4.7 The statutory voltage level limits at 132 kV are ±10%. This allows for a voltage gradient along the length of a 132 kV circuit. The voltage gradient is directly related to the current flowing in the conductor and it is primarily this voltage gradient that limits the practical length of a 132 kV circuit. In fact, on a power network, particularly at the higher voltages levels, voltage drop is caused by reactive power (MVAr) flow to a much greater degree than active power (MW) flow.

4.8 Since most elements of a power system absorb reactive power, operation of a power network requires the input of reactive power, and this is mainly provided by the generators. The UK Grid Code[8] specifies the reactive power import/export levels that generators are required to be capable of delivering. Although the exact requirements depend on the size and type of generation, typically a generator must be capable of delivering/absorbing reactive power down to a power factor of 0.95[9]

4.9 As a consequence of Ohm’s Law, as applied to alternating current (AC) circuits, there is an upper limit to the electric power that can be transported over any electrical circuit; but even this theoretical capacity for a circuit cannot be reached in practice. The resulting network would be unstable to operate and would have voltages outside statutory limits.

4.10 In AC systems the two main factors determining the power flow limit on any circuit (irrespective of its thermal rating) are the line voltage and series reactance of the circuit. The power flow limit is proportional to the square of the voltage, so a 132 kV circuit has of the order of sixteen times the capacity of a 33 kV circuit (all

8 http://www.nationalgrid.com/uk/Electricity/Codes/gridcode/

9 Power factor is defined as the ratio of real power (MW) to apparent power (MVA), i.e. PF = MW/MVA. Since MVA2 = MW2 + MVAr2, at 0.95 power factor the reactive power (MVAr) is about one third the magnitude of the real power (MW). E.g. 100 MVA at 0.95 PF is the same as 95 MW and 31.225 MVAr.

other things being equal). On the other hand, the higher the line reactance, the lower the maximum power transmission, so this limits the length of any overhead line.

4.11 Line resistance is inversely proportional to the conductor cross sectional area, so 500 mm2 Rubus has approximately 40% of the resistance (per unit length) of 200 mm2 Poplar conductor. However, line reactance and line capacitance are a function of conductor spacing and they are similar across the L7 tower and wood pole designs.

4.12 If there is an instantaneous change in power flow (for example as a result of a wind farm disconnecting itself from the network or a circuit or transformer being switched out) this will cause an instantaneous step change in voltage. Plant and equipment can be sensitive to sudden changes in voltage, therefore events that cause instantaneous changes in power flow are avoided as much as possible (for example, the wind farm ramps up and down its export in a ‘slow’ and controlled manner). Therefore, voltage step change is considered as part of the design process.

Security of Supply

4.13 Distribution networks in the UK are generally designed according to the security standard defined within the ENA Engineering Recommendation P2/6 ‘Security of Supply’. The basic principle of P2/6 is based on the need to provide greater levels of supply security as the size of the group load increases. Network security is created by a combination of plant redundancy and load transfer capability. In other words, for large load groups, it should be possible to maintain supplies to customers following an outage of any single item of plant or to restore supplies by transferring the load into another load group by network switching.

4.14 However, the standard does not apply to individual (large) customers if:

(a) the customer requests a security different from that defined in P2/6 (either better or worse); and

(b) it is possible to provide the level of security that the customer requests.

Losses

4.15 Losses occur in the circuits and transformers used within the distribution network as a result of the power flowing through them. One of the dominant loss mechanisms is Ohmic losses, which are proportional to the circuit resistance, R, and the square of the current (I2). These are generally referred to as the ‘I squared R’ losses. The ‘R’ in any circuit is proportional to its length, therefore, the longer the circuit, the greater the losses. One way to reduce the losses for a given circuit length is to operate at a higher voltage. For example, for a given power transfer, if the voltage is increased by a factor of four (say, from 33 kV to 132 kV), the current is reduced by a factor of four and the I2R losses are reduced by a factor of sixteen for the same conductor size and power transfer.

4.16 As distance and the amount of energy increase it becomes more efficient to use higher voltage circuits. It is for these fundamental reasons that the transmission of large amounts of power is achieved with higher voltage infrastructure.

Underground Cable

4.17 In addition to the above design process considerations, so far as underground cabling is concerned, SP Manweb has a licence obligation to develop an efficient, coordinated and economical system It also has a duty under Schedule 9 of the Electricity Act (see 2.10) in relation to conserving and protecting amenity It is therefore required to balance these duties when developing a new project and in doing so, it notes that the National Policy Statement for Electricity Networks (EN- 5) says in section 2.8 that Government does not believe the development of overhead lines is generally incompatible with this (Schedule 9) duty. Overhead wood pole line solutions can facilitate compliance with these obligations in that they generally result in lower impacts on the environment and enable more sensitive routeing through the landscape.

4.18 Taking into account Government has not laid down any general rule about when an overhead line should be considered unacceptable, SP Manweb considers the justification for underground cable on a case by case basis. These considerations include lifetime costs (based on capital cost, cost of electrical transmission losses and operational and maintenance costs calculated over the asset lifetime, which for the purposes of this report is assumed to be 25 years) in addition to the system design requirements described above, and the specific factors involved in each particular proposal, such as areas of high technical or environmental constraints and areas of the highest recognised amenity value.

4.19 In this case, SP Manweb considered a fully undergrounded solution, which would follow a route of approximately 24km, and assessed the lifetime costs. In terms of capital costs these have been determined to be approximate £1.1M to £1.6M per km plus the costs of associated cabling equipment such as termination structures. With the additional substation infrastructure added, this rises to an overall cost range of £48M to £60M. Operations and maintenance costs have been estimated at approximately £18k per km per year. Transmission losses have been estimated to be approximately £1M. The total costs would be in the range of £59.6M to £71.3M.

4.20 In terms of the system design requirements, it must be recognised that the use of cable circuits within a power system introduces additional reactive power (VAr) within the network. This is due to the additional capacitance and the lower reactance of underground cable circuits compared to that of an equivalent overhead line.

4.21 Long circuit routes further exacerbate these capacitance and reactive power issues. To address these, additional reactive power compensation equipment is often required. This increases cost, inefficiencies and footprint of the network solution. Furthermore, the introduction of high levels of reactive power into a system limits or reduces the level of maximum power transfer through a network.

4.22 However, the technical design requirements do not have a material impact on the choice of solutions considered due to the overall length of the connection.

4.23 Overall, the costs of a fully underground solution were unacceptable to SP Manweb and therefore this solution was not taken forward for the Proposed Development.

4.24 In progressing an overhead line solution and to protect amenity SP Manweb developed a routeing methodology with the objective of avoiding areas of highest environmental sensitivity wherever possible.

4.25 SP Manweb has considered the environmental impact of the Proposed Development against a range of factors and policy provided in the NPS (EN-5). Further information is provide in Appendix 1 of the Planning Statement (document reference 7.5) The assessment has taken a precautionary approach and looked at a number of areas for undergrounding based on significant effects and comments received during consultation. SP Manweb concludes that the benefit of an underground cable as an alternative to an overhead line in this area would not outweigh any extra economic, social or environmental impacts.

BUSINESS PROCESS Background to Connection Applications

5.1 As stated in paragraph 2.10, SP Manweb has a statutory duty to develop and maintain an efficient, coordinated and economical system of electricity distribution under the Electricity Act 1989. This includes a duty to connect new generating stations to the distribution network.

5.2 For the purposes of providing connection offers to developers and prior to carrying out detailed engineering and environmental assessments, a preliminary network design is prepared by SP Manweb as the basis for any connection offers.

5.3 The subsequent strategic options exercise as set out in the Report is driven by the resulting accepted connection offers. Key assumptions include:

. the design of the generators being in accordance with the connection applications received (or as subsequently amended); . the contracted position (i.e. accepted connection offers); and . the need to maintain the appropriate level of security of supply.

5.4 Therefore the trigger for the commencement of the strategic options process is the connection offers made to the four wind farms (Clocaenog Forest, Brenig, Nant Bach, Derwydd Bach) which make up the Project.

5.5 The strategic options are described in Chapter 0 and illustrated in Appendix A.

OPTIONS IDENTIFICATION AND EVALUATION 6.1 In identifying and evaluating the options which were considered prior to each connection offer, due regard was given to the key criteria of developing and maintaining an ‘efficient, co-ordinated and economical system of electricity transmission’ as well as SP Manweb’s duties under Schedule 9 of the Electricity Act 1989. The National Policy statements were also considered, in particular EN- 1 and EN-5.

6.2 For the purposes of strategic options, the cost estimates for individual options for contracted schemes are based on unit costs for the key elements of the option. This is sufficient to allow a broad order of relative costs to be established and compared for the options, as necessary at the strategic level, and is not intended to provide an accurate cost for each option which can only be obtained at the more detailed design and connection offer stage.

6.3 Issues of system compliance and deliverability were addressed by SP Manweb’s internal System Design and Asset Engineering Departments, whilst environmental issues were advised by the internal Environmental Planning Department and external environmental consultants.

6.4 Additional information on individual options is provided in Appendix A, along with diagrammatic representations.

6.5 The options presented in this Report deal with the main shared elements and core infrastructure required for the Project. The peripheral collector network, to facilitate connection from the respective wind farms has been chosen to be omitted for clarity. The design of the main infrastructure endeavours to minimise this collector network, which will be of similar extent for all of the main options.

6.6 The strategic options evaluation also considers landscape and visual implications and other environmental constraints at a high level. This consideration was assessed in relation to the two options considered most likely to be adopted (SA and CQ).

6.7 As part of SP Manweb’s iterative design process, and in preparation for the submission of the Development Consent Order (DCO), the options evaluation has been back-checked and reviewed to confirm there have been no underlying changes that affects the Report’s conclusions.

Reinforcement Requirements

6.8 Figure 3 shows the existing network infrastructure in North Wales and its relationship to the wind farms in and around the TAN 8 SSA A area. The wind farms (existing and future) are shown as an open square containing an identifying number which is listed in Table 1. As shown in the table, 68.1 MW of wind generation is already connected to the 33 kV network in the area (wind farms 1 to 5, dark green squares in the figures, plus Cemmaes and 11 kV connected wind farms).

Figure 3 - North Wales network infrastructure relevant to SSA A[10]

Figure 4 - Map legend

6.9 SP Manweb is contracted to connect 170 MW of wind generation, which significantly exceeds the capability of the 33 kV network. A single 33 kV circuit is

10 Circuits that are remote from SSA A may not be shown on the map. The open squares containing numbers denote wind farm locations; the key to the numbering is in Table 1.

capable of exporting up to 25 MW of generation and, given the existing level of connected generation (circa 70 MW), this new level of generation clearly exceeds what can be met using only the current 33 kV network.

6.10 The nearest 132 kV network is to the north (20 km) and east (25 km), and 170 MW is within the capability of a (suitably sized) 132 kV circuit. Various 132 kV options are evaluated in the following sections.

6.11 Figure 3 shows that a National Grid 400 kV circuit passes close to the south side of TAN 8 SSA A. Although a new GSP somewhere near Corwen could provide a connection point for all the proposed generation, it would be uneconomic for such a level of generation. The option has been included for clarity.

Option ‘DN’: Do nothing (Figure A1)

6.12 The Do Nothing option is discounted because it would be a clear breach of SP Manweb’s distribution licence statutory obligation to provide and honour terms for connections to its distribution network. Furthermore, failure to provide any connection would have wider consequences for the overall UK electricity supply, and could adversely impact on achieving government targets for renewable and low carbon generation.

Option ‘CEN’: Connect to existing network (Figure A2)

6.13 Table 1 shows that 68.1 MW of wind generation is already connected to the 33 kV network in and adjacent to SSA A. The capacity of the existing network to connect generation is already substantially used up, and the 33 kV network is not capable of connecting the 170 MW of pending generation. Most of the existing generators have ‘unfirm’ connections, which means they are constrained to reduce or cease generation in the event of a single network contingency, such as maintenance or loss of a circuit.

6.14 Given the significant existing generation connected to the local 33 kV network, the connection of 3 to 4 times this level of generation would cause significant thermal issues and risk local security of supply.

6.15 This option is therefore discounted because it would be a breach of SP Manweb’s distribution licence statutory obligations. The option would not be compliant with the Electricity Act 1989 as connection to the existing network of such levels of contracted generation would breach thermal, quality and security of supply.

Option ‘GC’: New Grid Supply Point near Corwen (Figure A3)

6.16 The National Grid Deeside/Legacy to Trawsfynydd 400 kV circuit passes close to the south of SSA A, and if a new Grid Supply point were established on this circuit somewhere near Corwen, it could accommodate the generation in SSA A. As well as the new GSP, which would be provided by National Grid, SP Manweb would also have to establish a BSP for such a connection.

6.17 Although this is a viable option, the construction of both a GSP and a BSP is a major development. The cost for both a GSP and BSP must be taken into account as the associated equipment and construction costs for both would be much greater than a 132 kV overhead line. This option has not been taken forward because of its very high cost in relation to the amount of generation requiring connection; since Section 9(2) of the Electricity Act 1989 requires SP Manweb to develop and maintain an economical system of electricity transmission.

Option ‘BL’: 132 kV connection to Brymbo or Legacy (Figure A4)

6.18 The 132 kV substations at Brymbo and Legacy are both to the east of SSA A, and are the same distance from it. A single wood pole 132 kV circuit with 300 mm2 AAAC conductor has a summer rating of 176 MVA, and is therefore capable, at unity power factor (UPF), of exporting the contracted generation from SSA A.

6.19 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 35 km of 132 kV wood pole line would need to be constructed. However, the route of this line would cross the Clwydian Range Area of Outstanding Natural Beauty (AONB) which is considered a strategic environmental constraint to the establishment of an overhead line route.

6.20 If the connection is to Brymbo, it would also be necessary to uprate an existing 132 kV circuit between Brymbo and Legacy.

Option ‘CQ’: 132 kV connection to Connah’s Quay (Figure A5)

6.21 The 132 kV substation at Connah’s Quay is to the north east of SSA A. A single wood pole 132 kV circuit with 300 mm2 AAAC conductor has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.22 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 36 km of 132 kV wood pole line would need to be constructed. However, the route of this line would cross the Clwydian Range AONB which is considered a strategic environmental constraint to the establishment of an overhead line route.

Option ‘H’: 132 kV connection to Holywell (Figure A6)

6.23 The 132 kV substation at Holywell is to the north east of SSA A. A single wood pole 132 kV circuit with 300 mm2 AAAC conductor has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.24 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 30 km of 132 kV wood pole line would need to be constructed. However, the route of this line would cross the Clwydian Range AONB which is considered a strategic environmental constraint to an overhead line route. 36

6.25 It would also be necessary to uprate the existing 132 kV circuit between Holywell and Connah’s Quay.

Option ‘SA’: 132 kV connection to St Asaph (Figure A7)

6.26 The 132 kV substation at St Asaph is to the north of SSA A. A single wood pole 132 kV circuit with 300 mm2 AAAC conductor has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.27 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 25 km of 132 kV wood pole line would need to be constructed.

6.28 National Grid has recently established a GSP at Bodelwyddan which is adjacent to SP Manweb’s BSP at St Asaph. Therefore any subsequent reinforcement of the 132 kV network to accommodate the SSA A wind farms is likely to be minimal when compared to the other options presented here.

Option ‘D’: 132 kV connection to Dolgarrog (Figure A8)

6.29 The 132 kV substation at Dolgarrog is to the north west of SSA A. A single wood pole 132 kV with 300 mm2 AAAC conductor circuit has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.30 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 35 km of 132 kV wood pole line would need to be constructed. It would also be necessary to reinforce the existing 132 kV system at Dolgarrog by establishing a 132 kV substation and uprating the 132 kV circuit between Dolgarrog and St Asaph.

Option ‘T’: 132 kV connection to Trawsfynydd (Figure A9)

6.31 The 132 kV substation at Trawsfynydd is to the west south west of SSA A. A single wood pole 132 kV circuit with 300 mm2 AAAC conductor has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.32 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 45 km of 132 kV wood pole line would need to be constructed. Trawsfynydd is situated within the Snowdonia National Park which is considered a strategic environmental constraint to an overhead line route.

Option ‘MW’: 132 kV connection to the future mid Wales GSP (Figure A10)

6.33 As part of the development of the mid Wales wind farms (SSAs B, C and D), National Grid propose to developed a 400/132 kV substation near Bryngwyn, which is to the south of SSA A. A single wood pole 132 kV with 300 mm2 AAAC conductor circuit has a summer rating of 176 MVA, and is therefore capable at UPF of exporting the contracted generation from SSA A.

6.34 In addition to the network infrastructure required to connect to the wind farms in SSA A, approximately 60 km of 132 kV wood pole line would need to be constructed.

6.35 This option would require an additional 35 km of 132 kV overhead line compared to Option ‘SA’ to St Asaph. SP Manweb considers that this would result in the potential for additional environmental effects due to the longer length of overhead line.

CONCLUSIONS 7.1 This Report has reviewed options for connecting the 170 MW of wind generation that is planned for development in TAN 8 SSA A in North Wales, and which is contracted to connect to the SP Manweb electricity network. This information has been updated and back-checked since the original strategic options assessment was carried out in 2013. No new information has emerged that would result in a change to the original conclusions made in the May 2013 Strategic Options Report.

7.2 A summary of the options evaluation is provided in Appendix A, with a more detailed description in Appendix Tables A1 to A10 of this Report.

7.3 The preferred option is confirmed as the 132 kV circuit to be constructed from SSA A northwards to the St Asaph BSP substation (Option SA). This option is technically capable of accommodating all the contracted generation and has the shortest 132 kV connection route of all the technically viable options. Shorter options are generally preferred on the basis of minimising both environmental impact and cost.

7.4 The option also has the benefit that the 132 kV circuit route does not affect either the Snowdonia National Park or the Clwydian Range AONB. When comparing the other options which also avoid the Snowdonia National Park and Clwydian Range AONB, on the basis of the high level early routing option investigations, it is not considered that environmental performance is sufficiently different to justify taking forward an option other than the shortest, lowest cost option. Option ‘D’, which avoids Snowdonia National Park and the Clwydian Range AONB, does not provide any additional benefit at an amenity level when compared to the preferred option.

7.5 Options ‘GC’, ‘BL’, ‘CQ’, ‘H’, ‘T’ and ‘MW’ are all deemed technically viable options but have not be taken forward for further study due to additional costs and/or environmental concerns such as new infrastructure within nationally designated sites.

7.6 Since the Strategic Options Report was originally published in May 2013, the options selection process has been back-checked and reviewed as part of SP Manweb’s iterative design process, This review has confirmed that the factors which led to the selection of the preferred option remain valid and that no new factors have emerged which alter this assessment. Therefore the previous conclusions from the May 2013 Strategic Options Report remain unchanged.

ABBREVIATIONS A Ampere, a unit of electric current AAAC All Aluminium Alloy Conductor ACSR Aluminium Conductor Steel Reinforced AONB Area of Outstanding Natural Beauty BSP Bulk Supply Point CUSC Connection and Use of System Code DCO Development Consent Order DGIM Distributed Generation Incentive Mechanism DLR Dynamic Line Rating DNO Distribution Network Operator ENA Energy Networks Association GSP Grid Supply Point GW Gigawatt (one thousand megawatts or 109 watts) kA Kiloampere (one thousand amperes) km Kilometre kV Kilovolt (one thousand volts) mm2 Square millimetre MVA Mega Volt Ampere (one million volt amperes) MVAr Mega Volt Ampere reactive (one million volt amperes reactive) MW Megawatt (one million watts or 106 watts) MWh Megawatt-hour NG National Grid NGET National Grid Electricity Transmission plc NPS National Policy Statement SPEN ScottishPower Energy Networks SP Manweb ScottishPower Manweb plc SGT SuperGrid Transformer TAN Technical Advice Note TW Terawatt (one million megawatts or 1012 watts) TWh Terawatt-hour UPF Unity Power Factor V Volt, a unit of electric potential Welsh Government WG (formally the Welsh Assembly Government, WAG) Wh Watt-hour, a unit of energy measurement (1 Wh = 3,600 joules) XLPE Cross-linked Polyethylene

Appendix A – Options Evaluation

Option Description Additional Comments Option Status Summary DN Do Nothing Does not connect any of the Option discounted contracted wind farms. because breach of SP Manweb’s licence obligation to offer terms for connection. CEN Connect to Existing network is already close to Option discounted Existing its limit with existing/contracted because breach of SP Network generation connections, and there is Manweb’s licence insufficient spare 33kV capacity to obligation to preserve connect the contracted generation. the integrity of the distribution system and offer terms for connection. GC New GSP Construction of a new GSP on the Although technically near 400 kV circuit near Corwen, and a satisfactory, this option Corwen new BSP adjacent to it is discounted because of its higher cost and the time needed to establish 400 kV infrastructure. BL 132 kV 35 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to Legacy or but not the lowest cost to Brymbo Brymbo. The 132 kV line crosses option. Environmental or Legacy the Clwydian Range AONB. For constraints. connection at Brymbo, the Brymbo to Legacy 132 kV circuit requires uprating. CQ 132 kV 36 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to Connah’s but not the lowest cost to Connah’s Quay. The 132 kV line would cross option. Environmental Quay the Clwydian Range AONB. constraints. H 132kV 30 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to Holywell. but not the lowest cost to Holywell The 132 kV line would cross the option. Environmental Clwydian Range AONB. The constraints. Holywell to Connah’s Quay 132 kV circuit requires uprating SA 132kV 25 km of 132 kV wood pole line The lowest cost option connection required from SSA A to St Asaph. that is also technically to St Asaph satisfactory.

D 132kV 35 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to Dolgarrog. but not the lowest cost to Dolgarrog 132 kV substation required at option. Dolgarrog. The Dolgarrog to St Asaph 132 kV circuit requires uprating. T 132kV 45 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to but not the lowest cost to Trawsfynydd. The 132 kV line option. Environmental Trawsfynydd would go through the Snowdonia constraints. National Park. MW 132 kV 60 km of 132 kV wood pole line Technically satisfactory, connection required from SSA A to Bryngwyn but not the lowest cost to mid option. Wales GSP

Key to symbols on maps

Table A1

Scheme: North Wales Option Reference Option ‘DN’ Option Title Do Nothing

Scope of Works None.

Evaluation Criteria Issues Economy n/a

Discount System • This is a breach of SP Manweb licence obligation to offer and Compliance honour terms for connection to the SP Manweb distribution network. Discount  Deliverability n/a

Discount Environmental • Prevents renewable generation from being connected to the network, thereby limiting potential contributions of renewable energy to reducing carbon dioxide emissions and failing to Discount  address environmental effects associated with climate

Recommendation: Option to be discounted because it is a clear breach of SP Manweb’s licence obligation to offer terms for connection.

Figure A1 DN: Do nothing, the existing network and wind farm sites

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A2

Scheme: North Wales Option Reference Option ‘CEN’ Option Title Connect to existing network

Scope of Works • No network reinforcement. • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical n/a

Discount System • Insufficient capability within the existing network to provide Compliance the necessary capacity to connect the required levels of contracted generation; • This is a breach of SP Manweb licence obligation to design the network in accordance with the Distribution Code Discount  (preserve the integrity of the Distribution System); Deliverability n/a

Recommendation: Not a viable option. Option discounted because it is a breach of SP Manweb’s licence obligation to preserve the integrity of the distribution system and to offer terms for connection.

Figure A2 CEN: Connect to existing network

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A3

Scheme: North Wales Option Reference Option ‘GC’ Option Title New GSP near Corwen

Scope of Works • National Grid to construct new GSP near Corwen • SP MANWEB to construct new BSP near Corwen • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Very high cost in relation to the amount of generation being connected

Discount System • Compliance

Discount Deliverability • Development of 400 kV infrastructure will delay the connection of the wind generation significantly

Discount Environmental • Minimises requirements for 132kV circuit and associated environmental effects. Potential for environmental effects associated with the development of a large GSP and BSP Discount sites within a rural setting.

Recommendation: A viable option. Option not to be taken forward because of high cost and long time required for development

Figure A3 GC: New GSP near Corwen

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A4

Scheme: North Wales Option Reference Option ‘BL’ Option Title 132 kV connection to Brymbo or Legacy

Scope of Works • Construct 35 km of 132 kV wood pole line from SSA A to Brymbo or Legacy, and the connection into Bymbo or Legacy substations • Uprate the Brymbo to Legacy 132 kV circuit if the connection is into Brymbo • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 10 km more 132 kV circuit required than Option SA • If connection is to Brymbo, the Brymbo to Legacy 132 kV Discount circuit requires uprating System • Compliance

Discount Deliverability •

Discount Environmental • Any new 132kV overhead line would be required to cross the Clwydian Range AONB. AONBs are nationally designated areas of high sensitivity to new development. Increases Discount 132kV circuit length and associated potential environmental

Recommendation: A viable option. Option not to be taken forward because of cost and potential environmental issues.

Figure A4 BL: 132 kV connection to Brymbo or Legacy

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A5

Scheme: North Wales Option Reference Option ‘CQ’ Option Title 132 kV connection to Connah’s Quay

Scope of Works • Construct 36 km of 132 kV wood pole line from SSA A to Connah’s Quay, and the connection into Connah’s Quay substation • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 11 km more 132 kV circuit required than Option SA

Discount System • Compliance

Discount Deliverability •

Discount Environmental • 132 kV wood pole line crosses the Clwydian Range AONB. AONBs are nationally designated areas of high sensitivity to new development. Increases 132kV circuit length and associated potential environmental effects. Discount

Recommendation: A viable option. Option not to be taken forward because of cost and potential environmental issues.

Figure A5 CQ: 132 kV connection to Connah’s Quay

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A6

Scheme: North Wales Option Reference Option ‘H’ Option Title 132 kV connection to Holywell

Scope of Works • Construct 30 km of 132 kV wood pole line from SSA A to Holywell, and the connection into Holywell substation • Uprate the Holywell to Connah’s Quay 132 kV circuit • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 5 km more 132 kV circuit required than Option SA • The Holywell to Connah’s Quay 132 kV circuit requires Discount uprating System • Compliance

Discount Deliverability •

Discount Environmental • 132 kV wood pole line crosses the Clwydian Range AONB. AONBs are nationally designated areas of high sensitivity to new development. Increases 132kV circuit length and Discount associated potential environmental effects.

Recommendation: A viable option. Option not taken forward because of cost and potential environmental issues.

Figure A6 H: 132 kV connection to Holywell

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A7

Scheme: North Wales Option Reference Option ‘SA’ Option Title 132 kV connection to St Asaph

Scope of Works • Construct 25 km of 132 kV wood pole line from SSA A to St Asaph and the connection into St Asaph • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • The shortest 132 kV connection, other than Option GC (which requires substantial substation development at both BSP and GSP level) Discount System • Compliance

Discount Deliverability •

Discount Environmental • Minimises 132kV circuit length and therefore associated potential environmental effects. Can make use of existing topography and landform. Minimal existing electrical Discount infrastructure in the area.

Recommendation: The preferred option. The lowest cost option that is technically satisfactory.

Figure A7 SA: 132 kV connection to St Asaph

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A8

Scheme: North Wales Option Reference Option ‘D’ Option Title 132 kV connection to Dolgarrog

Scope of Works • Construct 35 km of 132 kV wood pole line from SSA A to Dolgarrog and the connection into Dolgarrog • Establish a 132 kV substation at Dolgarrog • Uprate the Holywell to Connah’s Quay 132 kV circuit • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 10 km more 132 kV circuit required than Option SA • A 132 kV substation would need to be established at Discount Dolgarrog System • Compliance

Discount Deliverability •

Discount Environmental • Increases 132kV circuit length and associated potential environmental effects. Close proximity to Snowdonia National Park. National Parks are nationally designated Discount areas of high sensitivity to new development.

Recommendation: A viable option. Option not taken forward because of cost and potential environmental issues.

Figure A8 D: 132 kV connection to Dolgarrog

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A9

Scheme: North Wales Option Reference Option ‘T’ Option Title 132 kV connection to Trawsfynydd

Scope of Works • Construct 45 km of 132 kV wood pole line from SSA A to Trawsfynydd and the connection into Trawsfynydd • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 20 km more 132 kV circuit required than Option SA

Discount System • Compliance

Discount Deliverability •

Discount Environmental • A 132 kV wood pole line would be required through Snowdonia National Park. Increases 132kV circuit length and associated potential environmental effects. National Discount Parks are nationally designated areas of high sensitivity to

Recommendation: A viable option. Option not taken forward because of cost and potential environmental issues.

Figure A9 T: 132 kV connection to Trawsfynydd

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend

Table A10

Scheme: North Wales Option Reference Option ‘MW’ Option Title 132 kV connection to the future mid Wales GSP

Scope of Works • Construct 60 km of 132 kV wood pole line from SSA A to Brynwyn and the connection into Bryngwyn • Construct wind farm network infrastructure

Evaluation Criteria Issues Economical • Approximately 35 km more 132 kV circuit required than Option SA

Discount System • Compliance

Discount Deliverability •

Discount Environmental • Increases 132kV circuit length and associated potential environmental effects.

Discount

Recommendation: A viable option. Option not taken forward because of cost.

Figure A10 MW: 132 kV connection to the future mid Wales GSP

See Table 1 (Page 20) for wind farm site numbering key See Figure 4 (Page 33) for the map legend Note: 33 kV network remote from SSA A (in particular in mid Wales) is not shown.