Westpower ASSET MANAGEMENT PLAN 2020 - 2030 1st of April 2020 to 31st March 2030 Asset Management Plan A 10 Year Management Plan for Westpower’s Electricity Network From 1 April 2020 to 31 March 2030 Westpower Limited P.O Box 375 Greymouth 7840 Website: www.westpower.co.nz Phone: +64 3 768 9300 Fax: +64 3 768 2766 1st published March 1993 © Copyright: Westpower Ltd 2020 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 2020 TABLE OF CONTENTS 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 21 2.3 Westpower’s Asset Management System 27 2.4 The Asset Management Plan (AMP) 35 3.0 LEVELS OF SERVICE 41 3.1 Introduction 41 3.2 Customer-Orientated Performance Targets 41 3.3 Other Targets 50 3.4 Justification for Targets 51 3.5 Stakeholder Needs 54 4.0 NETWORK DEVELOPMENT 55 4.1 Introduction 55 4.2 Planning Criteria and Assumptions 55 4.3 Prioritising Network Development 59 4.4 Load Forecasting 62 4.5 Distributed Generation 71 4.6 Solutions for Handling Load Increases 73 4.7 Network Development 74 4.8 Capital Projects 76 4.9 Sub-transmission Assets – Capital Projects and Programmes 77 4.10 Distribution Assets – Capital Projects and Programmes 80 4.11 Distribution Substations – Capital Projects and Programmes 83 4.12 Distribution Transformers – Capital Projects and Programmes 85 4.13 Reticulation Assets – Capital Projects and Programmes 86 4.14 Services – Capital Projects and Programmes 88 4.15 Zone Substations – Capital Projects and Programmes 90 4.16 MV Switch Gear – Capital Projects and Programmes 96 4.17 SCADA and Communications - Projects and Programmes 99 5.0 ASSETS AND ASSET LIFECYCLE MANAGEMENT 102 5.1 Assets Covered 102 5.2 Asset Lifecycle Management 103 5.3 Format of Asset Group Sections 111 5.4 Transpower Grid Exit Points (GXPs) 112 5.5 Sub-transmission – General and 110 kV Lines 117 5.6 Overhead Lines – 66 kV 118 5.7 Overhead Lines – 33 kV 121 5.8 Distribution Assets 126 5.9 Distribution Substations 133 5.10 Distribution Transformers 137 5.11 Reticulation 141 5.12 Services 145 5.13 Zone Substations 147 5.14 MV Switchgear 161 5.15 SCADA and Communications 166 5.16 Other 170 6.0 FINANCIAL SUMMARY 176 6.1 Financial Forecasts 176 6.2 Assumptions and Sensitivity Analysis 178 6.3 Actual Deviations from Previous AMPs 182 2 ASSET MANAGEMENT PLAN 2020-2030 TABLE OF CONTENTS 7.0 ASSET MANAGEMENT PROCESSES, SYSTEMS AND IMPROVEMENT PROGRAMMES 186 7.1 Introduction 186 7.2 Asset Management Processes 186 7.3 Asset and Works Management Data and Information Systems 188 7.4 Asset Management System Improvement Process 192 8.0 RISK MANAGEMENT PLAN 193 8.1 Business Risk Management Planning Framework 193 8.2 Asset Risk Management – Framework 206 APPENDIX A - GLOSSARY 214 APPENDIX B - ACTIVITY GROUP DEFINITIONS – AMP AND INFORMATION DISCLOSURE 217 APPENDIX C - NETWORK RELIABILITY BY ZONE SUBSTATION AND FEEDER 220 APPENDIX D - EDB INFORMATION DISCLOSURE REQUIREMENTS 224 APPENDIX E - WESTPOWER’S AMMAT REPORT 234 APPENDIX F - CROSS REFERENCE WITH EDIDD 243 3 TABLE OF CONTENTS Tables Table 1.1: Service Level Performance Summary 2018-2019 7 Table 1.2: AMP – Forecast Expenditure by Activity ($’000) 9 Table 1.3: Network Summary 12 Table 3.1: Planned and Unplanned SAIDI (Urban, Rural and Remote Rural) 46 Table 3.2: Planned and Unplanned SAIFI (Urban, Rural and Remote Rural) 47 Table 3.3: SAIDI Targets Projected Forward 10 Years 49 Table 3.4: SAIFI Targets Projected Forward 10 Years 49 Table 3.5: Other Customer Service Targets 50 Table 3.6: Historical and Future Targeted Performance 50 Table 3.7: Future Performance of Efficiency Targets 51 Table 3.8: SAIDI Cause of Breakdown April 2018 to March 2019 54 Table 4.1: Common Network Limitations 56 Table 4.2: Security Guidelines for Distribution Planning 56 Table 4.3: Minimum Security Levels for Distribution Networks 57 Table 4.4: Load Trends and Forecasts to 2029 63 Table 4.5: GXP Maximum Demand and Current Utilisation 66 Table 4.6: Zone Substation Forecast Demand 68 Table 4.7: Options for Handling Load Increases 73 Table 4.8: Sub-transmission Capital Expenditure by Category ($’000) 78 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 ($’000) 82 Table 4.12: Distribution Substations Capital Expenditure by Category ($’000) 83 Table 4.13: Distribution Substations Capital Expenditure Summary ($’000) 84 Table 4.14: Distribution Transformers Capital Expenditure by Category ($’000) 85 Table 4.15: Distribution Transformers Capital Expenditure Summary ($’000) 85 Table 4.16: Reticulation Capital Expenditure by Category ($’000) 86 Table 4.17: Reticulation Capital Expenditure Summary ($’000) 87 Table 4.18: Services Capital Expenditure by Category ($’000) 88 Table 4.19: Services Capital Expenditure Summary ($’000) 89 Table 4.20: Zone Substations Capital Expenditure by Category ($’000) 92 Table 4.21: Zone Substations Capital Expenditure Summary ($’000) 95 Table 4.22: MV Switchgear Capital Expenditure by Category ($’000) 97 Table 4.23: MV Switchgear Capital Expenditure Summary ($’000) 98 Table 4.24: SCADA and Communications Capital Expenditure by Category ($’000) 100 Table 4.25: SCADA and Communications Capital Expenditure Summary ($’000) 101 Table 5.1: Assets Covered in the AMP 102 Table 5.2: Maintenance Triggers by Asset Category 104 Table 5.3: GXP - Capacity and Load Profiles 112 Table 5.4: Bulk Consumers Supplied from the GXPs 116 Table 5.5: Justification of 66 kV Lines 118 Table 5.6: Quantity of 66 kV Overhead Line by Circuit Kilometre 118 Table 5.7: Justification of 33 kV Lines 121 Table 5.8: Quantity of 33 kV Overhead Line by Circuit Kilometre 121 Table 5.9: Routine Patrol and Inspection Frequencies 124 Table 5.10: Sub-transmission Maintenance Expenditure ($’000) 125 Table 5.11: Sub-transmission Maintenance Expenditure by Activity ($’000) 125 Table 5.12: Overhead Line Assets by Circuit Length 126 Table 5.13: Distribution of 11 kV Underground Cables 127 Table 5.14: Distribution Maintenance Expenditure ($’000) 130 Table 5.15: Distribution Maintenance Expenditure by Activity ($’000) 132 Table 5.16: Distribution Substation Expenditure ($‘000) 135 Table 5.17: Distribution Substation Expenditure by Activity ($’000) 136 Table 5.18: Summary of Distribution Transformers 138 Table 5.19: Distribution Transformer Maintenance Expenditure ($’000) 140 Table 5.20: Distribution Transformer Maintenance Expenditure by Activity ($’000) 140 Table 5.21: Summary of 400 V Overhead Lines 141 Table 5.22: Summary of 400 V Underground Cable 142 Table 5.23: Reticulation Maintenance Expenditure ($’000) 144 Table 5.24: Reticulation Maintenance Expenditure by Activity ($’000) 144 Table 5.25: Services Maintenance Expenditure ($’000) 146 Table 5.26: Services Maintenance Expenditure by Activity ($’000) 146 4 ASSET MANAGEMENT PLAN 2020-2030 TABLE OF CONTENTS Table 5.27: Zone Substation Capacity and Maximum Demand 147 Table 5.28: Summary of Power Transformers 151 Table 5.29: Circuit Breakers 153 Table 5.30: Zone Substation Maintenance Expenditure ($’000) 159 Table 5.31: Zone Substation Maintenance Expenditure by Activity ($’000) 160 Table 5.32: MV Switchgear 161 Table 5.33: MV Switchgear Maintenance Expenditure ($’000) 165 Table 5.34: MV Switchgear Maintenance Expenditure by Activity ($’000) 165 Table 5.35: SCADA and Communications Maintenance Expenditure