Proposed Orkney Caithness Connection 132Kv Consultation
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Proposed Orkney Caithness Connection 132kV Consultation Document October 2011 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document Scottish Hydro Electric Transmission Limited Orkney Caithness Connection Consultation Document Comments on this document should be sent to: Lisa Kelly Scottish Hydro Electric Transmission Limited 10 Henderson Road Inverness IV1 1SN Please submit comments by Friday 2 December 2011 Published by Scottish Hydro Electric Transmission Limited October 2011 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document CONTENTS 1 INTRODUCTION 1 1.1 Background 1 1.2 The Consultation Document 3 1.3 The next stages 4 1.4 Statutory consents procedure 5 2 PROJECT DESCRIPTION 8 2.1 The Project 8 2.2 Government policy and targets for renewables 8 2.3 Background and Driver for Reinforcement 9 2.4 Design and Construction 13 3 METHODOLOGY 20 3.1 Overview 20 3.2 Substation site selection study- methodology 22 3.3 Landfall site selection study – methodology 23 3.4 Underground cable route selection study – methodology 24 3.5 Subsea cable route selection study - methodology 25 4 ENVIRONMENTAL CHARACTER 27 4.1 Introduction 27 4.2 Key elements of the landward environment 27 4.3 Physical environment 27 4.4 Ecological environment 30 4.5 Human environment 35 4.6 Key elements of the marine enviroment 41 4.7 Marine physical environment 41 4.8 Marine biological environment 44 4.9 Human marine environment 49 5 DETAILED SUBSTATION SITE, LANDFALL SITE, UNDERGROUND CABLE ROUTE AND SUBSEA CABLE ROUTE STUDIES 54 5.1 Introduction 54 5.2 Substation site selection study 54 5.3 Landfall site selection study 57 5.4 Underground cable route selection study 61 5.5 Subsea cable route selection study 63 6 OVERALL PREFERED OPTION 65 APPENDICES Appendix A Nature conservation information May 2010 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document FIGURES Figure 3.2 Search Area Figure 4.1 Drift Geology Figure 4.2 Designated Sites Figure 4.3 Cultural Heritage Figure 4.4 Landscape Figure 4.5 Subsea Constraints Figure 5.1 Options Summary Figure 6.1 Overall Preferred Route May 2010 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document 1 INTRODUCTION 1.1 Background 1.1.1 The European Union has set a target that 20% of Europe’s energy requirements shall be met from renewable resources by 2020. The UK government’s contribution towards this target is to achieve 15% energy from renewable sources by this date and the Scottish Government aims to exceed this, by achieving 20% energy generated from renewable sources, by 2020. In respect of electricity, the aim of the Scottish Government is that 100% of the demand within Scotland (demand being defined as gross consumption) for electricity should be met from renewable sources by 2020, with a milestone of 31% by 2011 (equivalent to 5,000MW of installed capacity1). Scottish Hydro Electric Transmission Limited (SHETL) is committed to playing its part in ensuring that Scotland takes full advantage of its renewable energy potential. 1.1.2 The existing transmission network in the north of Scotland was originally designed to serve a rural area and the Islands which at that time had a low demand for electricity and generation potential. The Renewables Obligation targets are leading to many renewable generation developers requesting connections to the electricity network in the north of Scotland and this is placing a significant requirement on the transmission system. 1.1.3 The amount of renewable generation that can be exported from Orkney is limited by the capacity of the two existing 33kV subsea cables that connect Orkney to the mainland transmission grid at Thurso. Taking account of the renewable generation that has already been connected or is contracted to be connected on Orkney means that the existing subsea connection has now reached full capacity. Three developers have formally applied for connection to the network on the west coast of mainland Orkney where development of tidal and wave energy generation is proposed and as such, there is now a requirement to reinforce the network between Orkney and mainland Scotland. 1.1.4 SHETL is part of SSE plc and is the transmission licence holder in the north of Scotland. SHETL has a duty, under Section 9 of the Electricity Act 1989, to facilitate competition in the generation and supply of electricity. The company also has obligations to offer non-discriminatory terms for connection to the transmission system, both for new generation and for new sources of electricity demand. 1.1.5 Where there is a requirement to extend, upgrade or reinforce its transmission, SHETL’s aim is to achieve an environmentally appropriate, technically feasible and 1 Energy Policy: An Overview, September 2008, Scottish Government (website only) Aug 2011 Page 1 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document economically viable solution which on balance will cause the least disturbance to the environment including the people who use the area. 1.1.6 SHETL is obliged to provide connections to new renewable generation into the transmission network as part of its general duties as a transmission licensee. 1.1.7 In March 2010 The Crown Estate announced the leased option areas for the Pentland Firth and Orkney Waters Round 1 Development Sites for marine generation totalling a potential 1600MW, which includes a generation potential of up to 1050MW (wave and tidal) around the Orkney isles and 550MW off the Caithness coast. Initial forecasts suggest the earliest developments will start in 2012, growing thereafter up to the full capacity potential by 2020, assuming successful proving of the technology in the early years. 1.1.8 Currently three developers have applied for a connection to the transmission system on the west coast of mainland Orkney. This will ultimately need to connect to the mainland of Scotland as the proposed generation exceeds the demand on Orkney and far exceeds the capability of the existing twin 33kV circuit link to Orkney from the mainland (Thurso) which is already fully committed to connected generation on the islands. 1.1.9 As a result, new transmission infrastructure is required between Orkney and Caithness. This will need to connect into the existing substation at Dounreay which is currently being upgraded to accommodate a number of proposed connections from this project and other developments. A new substation will also be required on the west coast of mainland Orkney to facilitate the connection of the marine generation sites to the network. 1.1.10 Given the geographical location of the connection applications, the only viable connection option for the new infrastructure will be the installation of a subsea cable from the west coast of mainland Orkney to Caithness. There will be a requirement for on-land infrastructure to connect the subsea cable to the proposed substation in Orkney and the existing substation at Dounreay. The starting assumption is that these connections would be made using underground cables given the anticipated proximity for connection. 1.1.11 SHETL’s approach is to develop and explore a range of potential substation sites on Orkney and connecting routes to Dounreay, in an environmentally led manner in order to identify, in the first instance, a ‘preferred option’ for the subsea cable, underground cable, landfall sites and substation site. Following consultation and further environmental studies a ‘proposed option’ will be selected for which consent applications will be made. Aug 2011 Page 2 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document 1.2 The Consultation Document Purpose 1.2.1 This consultation document describes the work undertaken in considering options for connection of the proposed marine wave and tidal generation sites along the west coast of Orkney. 1.2.2 The consultation document outlines the process by which the preferred substation site and cable routes have been selected (including underground cables on land and subsea cables) and gives consultees and other interested parties the opportunity to comment on the proposals. 1.2.3 All comments will then be considered as part of the next stage of the decision-making process, in order to select the proposed route for the new transmission infrastructure and the proposed site for the new substation. Consultation 1.2.4 Comments on this consultation document have been sought from a wide range of statutory authorities, key consultees, politicians and the general public. 1.2.5 Copies have also been deposited at Council offices in Thurso, Wick, Kirkwall and Stromness and will be available for public consultation from 10 October 2011. The document is also available on the SHETL website, at www.sse.com/OrkneyCaithness 1.2.6 A public consultation exhibition will be held at Harray Community Hall on Thursday 27 October 2011 Between 2pm and 7pm. 1.2.7 Owners of the land through which the preferred route passes, or on which the substation will be constructed, are also being consulted on an individual basis. Structure of the document 1.2.8 The document is divided into sections that cover the need for the project, the criteria applicable to the routeing of subsea and underground cables and the siting of substations, the route and site options being considered and compared, and the process undertaken in identifying a preferred option for Orkney Caithness Connection. These sections can be summarised as follows: Section 1: Introduction Aug 2011 Page 3 SCOTTISH HYDRO ELECTRIC TRANSMISSION LIMITED Orkney Caithness Connection 132kV Consultation Document 1.2.9 Section 1 reviews the purpose and scope of the consultation document, outlines the subsequent stages of the project and the statutory consents procedure. Section 2: Project description 1.2.10 Section 2 describes the need for the project and the design, construction and maintenance of of the various components of the project.