Westpower Asset Management Plan 2018-2028 From 1st of April 2018 to 31st of March 2028 Asset Management Plan A 10 Year Management Plan for Westpower’s Electricity Network From 1 April 2018 to 31 March 2028 Westpower Limited P.O Box 375 Greymouth Website: www.westpower.co.nz Phone: +64 3 768 9300 Fax: +64 3 768 2766 1st published March 1993 © Copyright: Westpower Ltd 2018 This document is entitled to full protection given by the Copyright Act 1994 to the holders of the copyright. Reproduction of any substantial passage from this document is a breach of copyright. This copyright extends to all forms of photocopying and any storing of material in any kind of information retrieval system. All applications for reproduction in any form should be made to Westpower Ltd Plan compiled by: Asset Management Division This issue approved by Westpower Board of Directors March 2018 Liability Disclaimer This Asset Management Plan (AMP) has been prepared and publicly disclosed in accordance with the requirements of the Electricity Distribution Information Disclosure Determination 2012. Some of the information and statements contained in the AMP are comprised of, or are based on, assumptions, estimates, forecasts, predictions and projections made by Westpower Limited (Westpower). In addition, some of the information and statements in the AMP are based on actions that Westpower currently intends it will take in the future. Circumstances will change, assumptions and estimates may prove to be wrong, events may not occur as forecasted, predicted or projected, and Westpower may at a later date decide to take different actions to those it currently intends to take. Except for any statutory liability which cannot be excluded, Westpower will not be liable, whether in contract, tort (including negligence), equity or otherwise, to compensate or indemnify any person for any loss, injury or damage arising directly or indirectly from any person using, or relying on any content of, the AMP. When considering any content of the AMP persons should take appropriate expert advice in relation to their own circumstances and must rely solely on their own judgement and expert advice obtained. This document is publicly available, and we welcome constructive comments and suggestions. Comments may be made in writing to: Rodger Griffiths General Manager-Assets and Engineering Services Westpower Limited P.O. Box 375 Greymouth 7840 New Zealand Email: [email protected] 1 TABLE OF CONTENTS Contents Liability Disclaimer 1 1.0 EXECUTIVE SUMMARY 7 2.0 OVERVIEW OF ORGANISATION STRUCTURE AND ASSET MANAGEMENT SYSTEM 14 2.1 Organisation Structure 14 2.2 Westpower’s Stakeholders 20 2.3 Westpower’s Asset Management System 27 2.4 The Asset Management Plan (AMP) 36 3.0 LEVELS OF SERVICE 42 3.1 Introduction 42 3.2 Customer-Orientated Performance Targets 42 3.3 Other Targets 52 3.4 Justification for Targets 53 3.5 Stakeholder Needs 55 4.0 NETWORK DEVELOPMENT 56 4.1 Introduction 56 4.2 Planning Criteria and Assumptions 56 4.3 Prioritising Network Development 61 4.4 Load Forecasting 63 4.5 Distributed Generation 72 4.6 Solutions for Handling Load Increases 74 4.7 Network Development 75 4.8 Capital Projects 77 4.9 Sub-Transmission Assets – Capital Projects and Programmes 78 4.10 Distribution Assets – Capital Projects and Programmes 80 4.11 Distribution Substations – Capital Projects and Programmes 82 4.12 Distribution Transformers – Capital Projects and Programmes 84 4.13 Reticulation Assets – Capital Projects and Programmes 85 4.14 Services – Capital Projects and Programmes 86 4.15 Zone Substations – Capital Projects and Programmes 87 4.16 MV Switch Gear – Capital Projects and Programmes 93 4.17 SCADA and Communications - Projects and Programmes 96 5.0 ASSETS AND ASSET LIFECYCLE MANAGEMENT 99 5.1 Assets Covered 99 5.2 Asset Lifecycle Management 100 5.3 Format of Asset Group Sections 104 5.4 Transpower Grid Exit Points (GXPs) 105 5.5 Asset: Sub-Transmission – General and 110 kV Lines 110 5.6 Asset: Overhead Lines – 66 kV 111 5.7 Asset: Overhead Lines – 33 kV 114 5.8 Asset: Distribution Assets 121 5.9 Asset: Distribution Substations 127 5.10 Asset: Distribution Transformers 131 5.11 Asset: Reticulation 135 5.12 Asset: Services 139 5.13 Asset: Zone Substations 141 5.14 Asset: MV Switchgear 155 5.15 Asset: SCADA and Communications 160 5.16 Asset: Other 163 2 TABLE OF CONTENTS 6.0 FINANCIAL SUMMARY 169 6.1 Financial Forecasts 169 6.2 Assumptions and Sensitivity Analysis 171 6.3 Actual Deviations from Previous AMPs 175 7.0 ASSET MANAGEMENT PROCESSES, SYSTEMS AND IMPROVEMENT PROGRAMMES 179 7.1 Introduction 179 7.2 Asset Management Processes 179 7.3 Asset and Works Management Data and Information Systems 180 7.4 Asset Management System Improvement Process 184 8.0 RISK MANAGEMENT PLAN 185 8.1 Business Risk Management Planning Framework 185 8.2 Asset Risk Management – Framework 195 APPENDIX A: GLOSSARY OF TERMS AND ABBREVIATIONS 202 APPENDIX B: ACTIVITY GROUP DEFINITIONS – AMP AND INFORMATION DISCLOSURE 205 APPENDIX C: NETWORK RELIABILITY BY ZONE SUBSTATION AND FEEDER 208 APPENDIX D: EDB INFORMATION DISCLOSURE REQUIREMENTS 212 APPENDIX E: WESTPOWERS AMMAT REPORT 222 3 TABLE OF CONTENTS Tables Table 1.1: Service Level Performance Summary 2016-2017 8 Table 1.2: AMP – Forecast Expenditure by Activity ($’000) 9 Table 1.3: Network Summary 12 Table 3.1: Planned and Unplanned SAIDI (Urban, Rural and Remote Rural) 48 Table 3.2: Planned and Unplanned SAIFI (Urban, Rural and Remote Rural) 48 Table 3.3: SAIDI Targets Projected Forward 10 Years 51 Table 3.4: SAIFI Targets Projected Forward 10 Years 51 Table 3.5: Other Customer Service Targets 51 Table 3.6: Historical and Future Targeted Performance 52 Table 3.7: Future Performance of Efficiency Targets 52 Table 3.8: SAIDI Cause of Breakdown April 2016 to March 2017 55 Table 4.1: Common Network Limitations 57 Table 4.2: Security Guidelines for Distribution Planning 58 Table 4.3: Minimum Security Levels for Distribution Networks 58 Table 4.4: Load Trends and Forecasts to 2027 64 Table 4.5: GXP Maximum Demand and Current Utilisation 67 Table 4.6: Zone Substation Forecast Demand 69 Table 4.7: Options for Handling Load Increases 74 Table 4.8: Sub-transmission Capital Expenditure by Category ($’000) 79 Table 4.9: Sub-transmission Capital Expenditure Summary ($’000) 79 Table 4.10: Distribution Capital Expenditure by Category ($’000) 81 Table 4.11: Distribution Capital Expenditure Summary ($’000) 81 Table 4.12: Distribution Substations Capital Expenditure by Category ($’000) 82 Table 4.13: Distribution Substations Capital Expenditure Summary ($’000) 83 Table 4.14: Distribution Transformers Capital Expenditure by Category ($’000) 84 Table 4.15: Distribution Transformers Capital Expenditure Summary ($’000) 84 Table 4.16: Reticulation Capital Expenditure by Category ($’000) 85 Table 4.17: Reticulation Capital Expenditure Summary ($’000) 85 Table 4.18: Services Capital Expenditure by Category ($’000) 86 Table 4.19: Services Capital Expenditure Summary ($’000) 86 Table 4.20: Zone Substations Capital Expenditure by Category ($’000) 88 Table 4.21: Zone Substations Capital Expenditure Summary ($’000) 92 Table 4.22: MV Switchgear Capital Expenditure by Category ($’000) 94 Table 4.23: MV Switchgear Capital Expenditure Summary ($’000) 95 Table 4.24: SCADA and Communications Capital Expenditure by Category ($’000) 97 Table 4.25: SCADA and Communications Capital Expenditure Summary ($’000) 98 Table 5.1: Assets Covered in the AMP 99 Table 5.2: Maintenance Triggers by Asset Category 101 Table 5.3: GXP - Capacity and Load Profiles 105 Table 5.4: Bulk Consumers Supplied from the GXPs 109 Table 5.5: Justification of 66 kV Lines 111 Table 5.6: Quantity of 66 kV Overhead Line by Circuit Kilometre 111 Table 5.7: Justification of 33 kV Lines 114 Table 5.8: Quantity of 33 kV Overhead Line by Circuit Kilometre 114 Table 5.9: Routine Patrol and Inspection Frequencies 117 Table 5.10: Sub-transmission Maintenance Expenditure ($’000) 119 Table 5.11: Sub-transmission Maintenance Expenditure by Activity ($’000) 120 Table 5.12: Overhead Line Assets by Circuit Length 121 Table 5.13: Distribution of 11 kV Underground Cables 122 Table 5.14: Distribution Maintenance Expenditure ($’000) 125 Table 5.15: Distribution Maintenance Expenditure by Activity ($’000) 126 Table 5.16: Distribution Substation Expenditure ($‘000) 129 Table 5.17: Distribution Substation Expenditure by Activity ($’000) 130 Table 5.18: Summary of Distribution Transformers 132 Table 5.19: Distribution Transformer Maintenance Expenditure ($’000) 134 Table 5.20: Distribution Transformer Maintenance Expenditure by Activity ($’000) 134 Table 5.21: Summary of 400 V Overhead Lines 135 4 TABLE OF CONTENTS Table 5.22: Summary of 400 V Underground Cable. 136 Table 5.23: Reticulation Maintenance Expenditure ($’000) 138 Table 5.24: Reticulation Maintenance Expenditure by Activity ($’000) 138 Table 5.25: Services Maintenance Expenditure ($’000) 140 Table 5.26: Services Maintenance Expenditure by Activity ($’000) 140 Table 5.27: Zone Substation Capacity and Maximum Demand 141 Table 5.28: Summary of Power Transformers 145 Table 5.29: Circuit Breakers 147 Table 5.30: Zone Substation Maintenance Expenditure ($’000) 153 Table 5.31: Zone Substation Maintenance Expenditure by Activity ($’000) 154 Table 5.32: MV Switchgear 156 Table 5.33: MV Switchgear Maintenance Expenditure ($’000) 159 Table 5.34: MV Switchgear Maintenance Expenditure by Activity ($’000) 159 Table 5.35: SCADA and Communications Maintenance Expenditure ($’000) 162 Table