Asset Management Plan

Transcription

1 Asset Management Plan March 2013 safe, reliable, hassle free service

2 COPYRIGHT 2013 Northpower New Zealand Limited. All rights reserved. This document is protected by copyright vested in Northpower New Zealand Limited (Northpower). Any breach of Northpower s copyright may be prevented by legal proceedings seeking remedies including injunctions, damages and costs. Any material prepared in breach of Northpower s copyright must be delivered to Northpower immediately upon request by Northpower. DISCLAIMER. The information in this document is provided in good-faith and represents Northpower s opinion as at the date of publication. Northpower does not make any representations, warranties or undertakings either express or implied, about the accuracy or the completeness of the information provided; and the act of making the information available does not constitute any representation, warranty or undertaking, either express or implied. This document does not, and is not intended to; create any legal obligation or duty on Northpower. To the extent permitted by law, no liability (whether in negligence or other tort, by contract, under statute or in equity) is accepted by Northpower by reason of, or in conjunction with, any statement made in this document or by any actual or purported reliance on it by any party. Northpower reserves all rights to alter, in its absolute discretion, any of the information provided in this document. Head Office: 28 Mt Pleasant Road, Raumanga, Whangarei 0110, New Zealand Postal Address: Private Bag 9018, Whangarei Mail Centre 0148, New Zealand. Ph: Fax: info@northpower.com Web: safe, reliable, hassle free service

3 Table of Contents Table of Contents Section 1: Summary Section 2: Background and Objectives Section 3: Assets Covered Section 4: Service Levels Section 5: Network Development Plan Section 6: Life Cycle Asset Management Plan Section 7: Risk Management Section 8: Evaluation of Performance Section 9: Expenditure Forecast and Reconciliation Appendix A: Glossary of Terms Appendix B: EDB Disclosure Schedules Appendix C: Disclosure Certification

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9 Section 1 Summary 1-1 Section 1: Summary 1.1 Northpower Company Profile Overview Our purpose Who we are Our values Key Industry Metrics Ownership and Governance Northpower Electricity Distribution Network Asset Management Plan Structure Summary Background and Objectives Assets Covered Service Levels Network Development Plan Life Cycle Asset Management Planning Risk Management Evaluation of Performance Expenditure Forecasts and Reconciliation Appendix A: Glossary of Terms Appendix B: EDB Disclosure Schedules Appendic C: Disclosure Certification Key Stakeholder Information Customer Service Levels Significant projects currently underway or planned to start in the next 12 months Stakeholder Feedback 1-10

10 1-2 Section 1 AMP Summary Section 1: Summary 1.1 Northpower Company Profile Overview Northpower Limited ( Northpower ) is proudly New Zealand owned and is the largest service provider to New Zealand s electrical distribution sector. With a history steeped in community, innovation, engineering expertise, award winning safety initiatives, renewable energy and electricity network ownership and management, Northpower has matured immensely from humble beginnings in rural New Zealand early last century. It has expanded from a consumer-owned and operated Northland electricity distribution network to become one of the largest multi-utility contractors in New Zealand, with a demonstrated commitment to safety, delivery and innovation. In the last decade alone, Northpower s growth has been illustrated by the establishment of business units in Western Australia and Melbourne, along with forays into electrical distribution and renewable energy project work in the Pacific Islands. Added to this is expertise in fibre network design and build, signified by Northpower securing New Zealand s first Government-backed Ultra-Fast Broadband contract - to construct Whangarei s fibre network. Northpower had first established its own award winning, world class fibre network in Others now seek Northpower s guidance on fibre network infrastructure design and build. Exporting Northpower s expertise, project management, IP and engineering capability has been a logical step for a company that has grown so quickly and captured such a large slice of the New Zealand electricity contracting market in little over a decade. Yet Northpower continues to own, operate and maintain the electrical distribution network within the Whangarei and Kaipara Districts. The Northpower Network is made up of almost 55,000 connected consumers - from Topuni in the south, to Bland Bay in the north - with an asset replacement value of $434M. With a number of sizeable industrial and process customers, Northpower understands implicitly the needs of major corporations - here and abroad. In addition to the electrical distribution network, Northpower owns, operates and maintains a 5MW hydroelectric power plant, is trialling various solar PV units and is also investigating other renewable opportunities and the impacts of electric vehicles on the grid. Northpower is recognised within the New Zealand, Australian and Pacific Island s electricity sectors as a trusted and reliable service provider, with a strong ethos of safely delivering on commitments backed by an innate understanding of network ownership and management, along with the implicit need for efficiencies. With long term contracts to four of NZ s five largest electricity distribution companies Wellington Electricity and Vector included Northpower has captured over 30% of NZ s outsourced service market in the electricity distribution sector. Northpower Contracting provides a competitive multi-disciplinary contracting service in design, construction and maintenance for electrical transmission, distribution, and telecommunication networks. Outside of the distribution sector, Northpower also performs capital works and maintenance services for many industrial customers (e.g. Pacific Steel, Auckland District Health Board) and transmission utilities like New Zealand s national grid owner Transpower.

11 Perth Melbourne Section 1 AMP Summary 1-3 Wellington All of Northpower s contracting operations assist with contributing to best practice, security of electricity supply and industry productivity and ultimately plays a part in economic prosperity of those countries in which d Office 28 Mt we Pleasant work - ensuring Road Raumanga the longevity Whangarei of critical 0110 infrastructure Private Bag for the 9018 communities Whangarei we Mail work Centre in. Whangarei 0148 New Zealand Ph: Fax: info@northpower.com With revenue topping $240 million annually, Northpower s growth path is solid. A vision to become a $500 million company is in sight and with over 1000 employees sharing that belief; the Northpower journey is an exciting one. Pacific Auckland Waikato Whangarei Head Office Coromandel Bay of Plenty Central Plateau Perth Melbourne Our purpose Northpower s purpose is to generate a commercial return from its business activities, invest in profitable growth and distribute profits to our shareholders. Through our business activities we support the development, prosperity and well being of the people of Whangarei and Kaipara Districts Who we are Wellington We are a dynamic infrastructure management and services company that delivers exceptional value through exceptional people and processes. We believe that safety is critical to our success. We have expanded from a Northland-owned and operated electricity distribution network to become one of the most capable utility contractors in New Zealand, with a demonstrated commitment to safety, delivery and innovation.

12 1-4 Section 1 AMP Summary Northpower has two distinct activities: NETWORK OWNERSHIP, OPERATION AND ASSET MANAGEMENT CONTRACTING SERVICES Northpower owns, operates and maintains the electrical distribution network within the Whangarei and Kaipara Districts. The Northpower Network is made up of almost 55,000 connected consumers from Topuni in the south to Bland Bay in the north - with an asset replacement value of $434M. In addition to the electrical distribution network, Northpower owns, operates and maintains a 5MW hydroelectric power plant. Northpower is also a prominent player in NZ s growing fibre optic sector. Northpower has built a Next Generation Fibre Optic Network in Whangarei, wholly designed and constructed in 2008 by the company s own engineers and technicians. In 2010, Northpower was the first company in New Zealand to enter into a joint venture with the Crown as part of the government s Ultra Fast Broadband initiative. Northpower contracting provides a competitive multi-disciplinary contracting service for design, construction and maintenance for electrical transmission, distribution, and telecommunication networks. Northpower has over 1000 full time staff, including 150 staff in Australia. Our capability and experience ranges from engineering and project management through to multi-skilled field staff for distribution/transmission sub-station and lines activity and fibre design and installation. Northpower s depots are located across the North Island of New Zealand with 15 depots in total and a further two depots based in Perth and Melbourne in Australia Our values Heart HEART We show care, respect, loyalty, openness and empathy towards one another and those that interact with our family. Trust and integrity underpin all that we do. FUTURE Future We will secure our future by creating value for our shareholders through providing customers with hassle free service, investing in our people and taking a proactive approach. BALANCE Balance We believe in balance in all we do from our business goals and commercial objectives, to our personal aspirations and our community responsibilities. DELIVERY Delivery We strive to be the best we can be. This means delivering consistently reliable performance and adding value for our customers. FAMILY Family We treat people like a family. We support each other's needs, accept our differences, take personal responsibilty for our actions and are always fair and just in our interactions. RELATIONSHIP Relationship Through our actions we strive to build good will in our relationships with customers and employees.

13 Section 1 AMP Summary Key Industry Metrics The table below provides further information on the Northpower network according to key industry metrics: Metric Description Value (2009) Value (2010) Value (2011) Value (2012) Trend Consumers Total Installation control points 53,331 53,707 54,416 54,933 connected (ICP s) connected to the network System length (km) Total length of livened circuits 5,627 5,829 5,829 6,054 Sub-transmission length (km) Distribution system length (km) Low voltage system length (km) Percentage underground Asset value Faults per 100km SAIDI SAIFI CAIDI Electricity supplied (GWh) Loss factor Capacity utilisation Total length of livened 33kV circuits Total length of livened 11kV circuits Total length of all livened LV circuits. The proportion of total system length that is undergrounded. Optimised Deprival Value (ODV) of Northpower s asset base. Average number of unplanned interruptions per 100km of high voltage circuits per annum. System Average Interruption Duration Index. A measure of the number of minutes per year the average consumer is without electricity supply. System Average Interruption Frequency Index. A measure of the number of interruptions per year that affect the average consumer. (Regulatory target in parentheses). Consumer average interruption duration index. A measure of the average length of an interruption that affects the average consumer (the quotient of SAIDI and SAIFI). Electricity entering system for supply to consumers. Proportion of electricity lost on the high voltage network. Maximum demand on distribution transformers as a proportion of installed capacity ,424 3,615 3,697 3,722 1,968 1,977 1,890 2, % 14.2% 17.2% 14.9% $186,000 $194,000 $208,632 $214, % 3.6% 3.6% 3.5% Northpower Network as per key industry metrics

14 1-6 Section 1 AMP Summary Ownership and Governance Northpower is 100% owned by the Northpower Electric Power Trust (NEPT) on behalf of the electricity consumers in the Whangarei and Kaipara Districts. The company s Board of Directors is appointed by the NEPT Northpower Electricity Distribution Network Northpower owns, manages and maintains the electricity distribution network in the Whangarei and Kaipara Districts in Northland supplying 54,933 customer installations over 6,000km s of network. The current replacement cost of the network is $434 million and the depreciated replacement cost of the network is $214 million. Approximately 50% of the electricity supplied via the network is consumed by five major loads which include heavy chemical, timber and dairy processing. In addition, there is one relatively large urban centre, and seven smaller urban centres. The balance of the network is primarily rural with some small coastal settlements, which experience seasonal loadings. The majority of the electricity supply is from Transpower at five grid exit points (GXP s) located at Bream Bay, Dargaville, Kensington, Maungatapere and Maungaturoto. Northpower s 5MW Wairua Hydro Power Station and two privately owned generation plants are connected to the Northpower network which is connected to the Transpower grid. The electricity is distributed from these points through 239km of 33kV sub-transmission network which links 19 zone substations. Ninety three 11kV distribution feeders totalling 3,722km in length provide a supply to 7,000 distribution transformers. These transformers in turn feed into 2,093km of 400V line and cable from which the majority of the 54,933 premises are supplied. There are 5 customers supplied at 33kV and 3 customers supplied at 11kV. 1.2 Asset Management Plan Structure This Asset Management Plan is prepared in accordance with the Electricity Distribution Information Disclosure Determination 2012 under part 4 of the Commerce Act Summary This section provides an overview of Northpower and its distribution network, reviews performance trends against key industry metrics and summarises the content of each section of the AMP. The summary also includes an overview of key stakeholder information Background and Objectives The background and objectives section outlines the purpose of the AMP and clearly depicts how the AMP is interrelated to Northpower s strategic and operational planning processes. In this section, stakeholder interests are identified, the responsibilities for the delivery of the asset management within the business are described and a high level overview of the systems and processes used in asset management is provided Assets Covered This section provides details on the assets that make up the Northpower Network. A high level overview of the network footprint and a description of the network configuration are provided. Detailed information on the diverse groups of assets including, age, value and condition is provided along with the technical and financial justification for these assets Service Levels The service levels section details Northpower s customer orientated service targets, asset performance and efficiency targets and provides justification for these targets.

15 Section 1 AMP Summary Network Development Plan This section details the planning criteria, the prioritization of network projects and the demand forecasting process. Details of zone substation loading and expected growth forecasts are provided together with a 10 year demand forecast and expected future capacity constraints. Northpower s distributed generation policy and alternative options to addressing network constraints are presented as well as an analysis of the network options available and decisions made to satisfy and meet the service level targets. A description of the current or planned projects for the next 12 months, a summary of the planned projects for the next 4 year period and an outline of projects being considered for the remainder of the period is provided together with a 10 year capital expenditure forecast Life Cycle Asset Management Planning The Life Cycle Asset Management Planning section describes Northpower s maintenance and renewal programme, outlining the planning criteria and assumptions, the inspection condition monitoring and routine maintenance processes and Northpower s asset renewal and refurbishment policies. A 10 year asset maintenance expenditure (OPEX) forecast is also provided Risk Management This section provides an overview of Northpower s risk policies, assessment and mitigation strategies. The company s network planning risk assessment criteria and a number of network specific risks are considered Evaluation of Performance The Evaluation of Performance section reviews Northpower s physical progress against the capital and operational expenditure plans and compares actual expenditure against forecast expenditure. Service level key performance indicator actual versus target values are compared and a gap analysis and review of the quality of asset management planning is provided Expenditure Forecasts and Reconciliation This section details forecast expenditure by category for the next 5 years (financial years 2013 to 2017) and actual versus forecast expenditure per category for the most recent financial year (2012) with percentage variance and reasons for the variance. Significant assumptions upon which the expenditure forecasts are based are included in this section Appendix A: Glossary of Terms Appendix A provides a Glossary of Terms used in the AMP Appendix B: EDB Disclosure Schedules Schedule 11a - Forecast Capital Expenditure Schedule 11b - Forecast Operational Expenditure Schedule 12a - Asset Condition Schedule 12b - Forecast Capacity Schedule 12c - Forecast Network Demand Schedule 12d - Forecast Interruptions and Duration Schedule 13 - Report on Asset Management Maturity (AMMAT) Appendix C: Disclosure Certification

16 1-8 Section 1 AMP Summary 1.3 Key Stakeholder Information Northpower believes that the AMP should be accessible to readers of varying levels of technical understanding and that all stakeholders should be able to extract the information they require. For many stakeholders, including the majority of our consumers, key asset management information includes the level of service that can be expected and projects that have been initiated to improve the quality of electricity supplied in the region. This section provides an overview of these three areas. Under each subheading a reference to the more detailed discussion later in the plan is provided Customer Service Levels In order to provide a service, Northpower is required to understand the stakeholder expectations and where possible deliver a cost effective solution to meet these expectations. Service standards include not only quality of electricity supplied but also health and safety, account management, project management, environmental outcomes, general communication and all interactions with Northpower. This philosophy is supported by the mission statement, which has as a cornerstone goal providing excellence in customer service. Customer service standards that Northpower monitors its performance against are grouped into two categories namely customer oriented performance targets and asset and business oriented targets Customer Oriented Performance Targets The delivery of a safe, reliable hassle free electricity supply of appropriate quality to consumers is Northpower s core business. In order to measure effectiveness in achieving this goal, a number of performance targets are used. These include network average reliability indices (SAIDI, SAIFI and CAIDI), faults per 100km of circuit, improvement of worst performing feeders, consumer grouping targets and quality of supply on individual feeders. Further detail on Northpower s Consumer Oriented Performance Targets is provided in section 4.2. Evaluation of performance against targets for the previous year is provided in Section 8. The table below summarises Northpower s consumer orientated performance targets Service Standard Measure Target Overall Customer Satisfaction Score Network Reliability Rating (SAIDI) Colmar Brunton Customer Perceptions Survey combined overall customer satisfaction level System average interruption duration index measures the number of minutes per year the average customer is without electricity. > 85% <145 mins LTI FR Lost time injury frequency rate 0 Overdue Unsafe Service Lines Internal Customer Satisfaction Score The number of unsafe service lines that are overdue for repair Internal service provider performance ranked monthly over various service aspects (KPI Score) 0 >1

17 Section 1 AMP Summary 1-9 Service Standard Measure Target Faults per 100km Faults per 100km by voltage level <10 (33kV network) < 10 (11kV network) Shutdown Restoration Times Annual number of shutdowns that exceed the advertised restoration times by more than 15 minutes < Asset and Business Oriented Performance Targets As well as delivering a high quality of supply, Northpower must prove to its shareholders and the regulator that it is operating in an efficient and cost effective manner. Asset and Business Oriented Performance Targets are used to measure the efficiency of Northpower s asset management practices. Measures employed include network losses, load factor and capacity utilisation Significant projects currently underway or planned to start in the next 12 months The planning period considered in this AMP sees a continuation of capital investment in the network to meet customer driven growth, maintain network security, meet customer service levels and network reliability targets and ensure compliance with regulatory requirements. The following table lists significant projects currently underway or planned to start in the next 12 months. Project Name Description Completion Year Maungatapere 33kV circuit breaker upgrade Replace 1x33kV outdoor circuit breaker 2013 Bream Bay NZR 33kV feeders 2x33kV feeder cables 2014 Western Hills Drive 11kV OHUG Maungatapere 110/50kV transformer replacement Kamo zone substation 6th 11kV feeder Fourth Avenue-Maunu Road 11kV cable link Overhead to underground conversion of section of feeder along S.H Replace EOL transformers 2014 Install new 11kV cable feeder 2013 Install new 11kV cable link 2013 Kioreroa additional 11kV feeder Installation of a new 11kV feeder panel and cable kV earth fault switch replacement Remote control 11kV pole mounted switches Replace 33kV earth fault switches with circuit breakers Installation of SCADA communications and switch control at selected switch sites 33kV CT and VT upgrades Replacement of end of life equipment 2014 Communications and RTU upgrades 11kV O/H line conductor replacement Replacement of EOL communications assets 2014 Replacement of EOL HDBC and corroding ACSR conductor 2017

18 1-10 Section 1 AMP Summary Project Name Description Completion Year 11kV ABS upgrades 33kV ABS upgrades Zone substation security improvement Zone substation transformer oil containment Replacement of air break type switches with enclosed type switches Replacement of air break type switches with enclosed type switches Installation of electronic security equipment 2015 Construction of transformer oil bunds Stakeholder Feedback Northpower encourages feedback on all aspects of the AMP to enable continued improvement in meeting the needs of consumers and stakeholders. Feedback should be addressed to: Russell Watson, Network Planning Manager, Northpower, Private Bag 9018, Whangarei Mail Centre, Whangarei, russell.watson@northpower.com

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23 Section 2 Background and Objectives 2-1 Section 2: Background and Objectives 2.1 Purpose Purpose of the Asset Management Plan (AMP) Objectives of Asset Management Planning Relationship with Other Business Plans and Goals Our purpose Who we are Our focus Our vision Documented Plans Produced in Annual Planning Process Relationships between Plans, Processes, Models and Stakeholders Period Covered by the Plan Stakeholder Interests Identification of Stakeholders Accommodating the Interests of Stakeholders into Asset Management Planning Managing Conflicting interests Accountabilities and Responsibilities Governance of Asset Management Northpower Asset Management Executive Team Managing Field Operations Asset Management Systems and Processes Asset Management Systems Geospatial Information system (GIS) EMS WASP OSISoft PI Data Historian Siemens PowerTG SCADA Power system modelling and analysis Gentrack Outage Recording Integration Services Data Completeness and Accuracy Data Quality Initiatives Plans for improvement in information quality Network Communications Network Control Business Processes Managing routine asset inspections and network maintenance Planning and implementation of network development processes Measuring network performance (SAIDI, SAIFI) for disclosure purposes 2-24

24 2-2 Section 2 Background and Objectives Section 2: Background and Objectives 2.1 Purpose Purpose of the Asset Management Plan (AMP) The primary purpose of the AMP is to make visible Northpower key objectives, network planning techniques and asset maintenance practices to key stakeholders. The AMP addresses goals and objectives which relate to asset management by focusing on levels of service, life cycle asset-management planning and the resulting long term cash flow requirements. The AMP also establishes and evaluates performance, benchmarks and demonstrates responsible ownership and management of assets to the wider community. Public comment and feedback is both welcomed and valued. Northpower s Annual AMP is published to satisfy the regulatory requirement, describing the methodology adopted to manage the assets in accordance with information disclosure requirements under Part 4 of the Commerce Act for EDB s. Northpower s asset management philosophy is encapsulated in the vision of improving the prosperity and wellbeing of the people of Whangarei and Kaipara through our business activities, investment in profitable growth and distribution of profits to our shareholders. The relationship between this philosophy, planning processes and company objectives collectively forms the Northpower concept of best practice asset management. This is achieved by: Ensuring that the performance of the assets meets the needs of broad customer groups. Ensuring that the long term functionality and value of the assets is maintained. Treating all customers with respect and being responsive to individual customer s needs. Maintaining ongoing price stability. Focusing on operational efficiency and performance improvement Objectives of Asset Management Planning From an internal perspective Northpower s AMP is a living document which undergoes continuous adjustment in response to environmental changes which may affect the lines business or the assets it manages. The AMP along with the Development and Maintenance plans (which are based on future network capacity and performance requirements) and associated budgets and spend forecasts are updated quarterly and published annually. Northpower has a continuous improvement philosophy and is a process driven organisation. The company is ISO9001 and ISO14001 certified. The asset management processes are aligned within these standardised frameworks. Planning is supported by the ongoing development and integration of core information systems together with the continuous improvement of the asset data (including type, volume, age and condition). Specialist asset management software is used to trigger, monitor and support maintenance management activities.

25 Section 2 Background and Objectives 2-3 Vision Mission Strategic Issues Stakeholder Interests Regulatory Demands Strategic Plan AMP Guiding Principles Annual Plan Development Plan Maintenance Plan AMP Planning Process 2.2 Relationship with Other Business Plans and Goals Our purpose Northpower s purpose is to generate a commercial return from its business activities and will invest in profitable growth and distribute profits to our shareholders. Through our business activities we support the development, prosperity and wellbeing of the people of Whangarei and Kaipara Who we are We are a dynamic infrastructure management and services company that delivers exceptional value through exceptional people and processes. We believe that safety is critical to our success. We have expanded from a Northland-owned and operated electricity distribution network to become one of the most capable utility contractors in New Zealand, with a demonstrated commitment to safety, delivery and innovation Our focus Northpower is present in New Zealand, Australia and the Pacific Islands providing services to and investing in key infrastructure within the following industries: distribution, transmission, generation, telecommunication and retailing Our vision Northpower s goal is to secure profitable growth within the Australasian utility sector.

26 2-4 Section 2 Background and Objectives Our Purpose Through our business activities we improve the prosperity and well-being of the people of Whangarei and Kaipara, as well as supporting those communities within which we operate. We will generate a fair commercial return from our business activities, investing in profitable growth and distributing profits to our shareholder Values Heart, Family, Balance, Future, Delivery and Relationship Our Focus Northpower is present in New Zealand, Australia and Pacific Island providing services to and investing in key infrastructure within the following industries: distribution, transmission, generation, telecommunication and retailing Our Immediate outcomes Consolidation Platform for Growth Growth Impacts Consistent achievement of performance targets Development of opportunities for future profitable growth Increased revenue from new or existing clients or in new or existing markets Documented Plans Produced in Annual Planning Process The relevant documented plans that Northpower produces as part of the annual business planning process are: Annual Planning Document Description Relationship with AMP Statement of Corporate Intent (SCI) Strategic Plan Annual Network Management Plan (NMP) Company Risk Register Northpower s SCI is published annually and approved by the Northland Electric Power Trust on behalf of the consumers. The SCI sets out the goals and objectives for the business. The Strategic Plan sets goals, objectives and key performance indicators for the business. The Network Asset Management Team annually produces the internal NMP which includes policies, standards and strategies. The Risk Register is a live database that is used to document key business risks. Risk mitigation strategies are reviewed annually. The AMP describes the way in which the goals and objectives embodied in the SCI will be achieved from an asset management perspective. The forecasts in the AMP are based upon the forecasts approved annually by the Board of Directors. The NMP informs Sections 5 and 6 of the AMP (network development and lifecycle asset management planning). Risks related to asset management within the Risk Register inform Section 7 of the AMP. Annual Planning Process Plans

27 Section 2 Background and Objectives Relationships between Plans, Processes, Models and Stakeholders GOVERNANCE Central /Local Government GOVERNANCE GOVERNANCE PLAN Consumers Regulation NEPT Statement of Corporate Intent Board of Directors Vision, Mission, Objectives, Policies and Risk STRATEGIC Resource Constraints Strategy Long Term Cashflow Modeling Gap Analysis Network Business Plan Technical requirement and specifications Load Forecasts Risk Assessment Asset Management Plan Technology Health and Safety Environmental Stakeholder Interests Annual Maintenance and Development Plans and Budgets (O d C ) Service Levels Systems and Processes OPERATIONAL Maintenance and Construction Network Operations Engineering and Costing Works scheduling and material procurement Project Management and Work execution Information System Update Monitoring and Control Operations Permits Faults Resolution Review and Feedback Relationship between plans, process and stakeholders

28 2-6 Section 2 Background and Objectives 2.3 Period Covered by the Plan The planning period covered by this AMP is the 10 year period from 1 April 2013 to 31 March This version of the AMP was completed in February 2013, approved by Northpower s Board of Directors during February 2013 and made available for public disclosure 31 March Specific projects and activities included in this AMP represent Northpower s best estimates of optimal solutions based on projections of present day drivers, issues technologies and available network data. Given that drivers and network data will change over time, inclusion of specific activities and projects, particularly toward the far end of the planning horizon, does not represent a firm commitment by Northpower to proceed with those activities and projects. Rather it is to be recognised as a demonstration of a robust methodology for addressing long term capacity, reliability and security of supply requirements. Network development plans and associated financial forecasts and budgets are essentially determined by load growth. Developments at subtransmission level tend to have more long term inertia and therefore tend to be less dynamic and more predictable than those at distribution level, with the result that projects relating to the former tend to have longer planning lead times and can normally be fairly accurately defined 5 years out. On the other hand, projects at distribution level are more closely linked to short term economic activity, with the result that confidence beyond the two to three year mark is difficult to achieve. Network maintenance related activity is far more predictable than development needs, and plans can be developed with a fair degree of confidence as there is a direct relationship with historical expenditure and present network performance. However, to ensure optimal long term maintenance planning it is essential that a good asset knowledge base exists, together with appropriate maintenance regimes, and Northpower is busy increasing resources in this area. 2.4 Stakeholder Interests Identification of Stakeholders Stakeholders are persons, groups, organisations, or systems, who affect or can be affected by Northpower actions, activities and or performance. Northpower s key principles listed below are derived from the fundamental values and business behaviours and apply to all actions and activities: Health and Safety. Financial Strength. Customer Satisfaction. People and Commitment. Environment and Communities. Operational Excellence.

29 Section 2 Background and Objectives 2-7 Consideration of these key principles in relation to identities that interact with the company defines their level as a stakeholder. The following table identifies the major stakeholders in the electricity lines business and which series of the six key principles are applicable to the stakeholder. Stakeholder Health / Safety Customer Satisfaction Financial Strength Environment / Communities People and Commitment Operational Excellence Customers Northpower Trust and Board Energy retailers Suppliers Staff and Contractors Public and Communities Land owners Territorial Authority Regional Authority New Zealand Transport Agency Teleco s Commerce Commission Electricity Authority Transpower Grid owner Transpowersystems operator Regional/ District Council Identification of Stakeholders Table There is no single policy or documented process which fully captures every situation where stakeholders should be identified. Rather, the importance of stakeholders and their interests is entrenched within many processes for many activities across several disciplines. The underpinning principles are the same, in all projects and activities consideration of who and what will be affected and how is necessary. Any issues identified are to be addressed in a respectful and considerate manner.

30 2-8 Section 2 Background and Objectives The following table provides an overview of what each stakeholder s interest is and how the stakeholder s interests are identified. Stakeholder Key Interest Method of Interest Identification Consumers Includes: Domestic, Commercial, Lifeline groups, Large Consumers (Oil Refinery, Cement Works, Milk Production etc.) Northpower Trust Northpower Board of Directors Electricity Retailers Suppliers Network reliability. Quality of supply. Speed of restoration. Hassle free service. Line charges. Reliability/price balance. Tariff options Fair commercial return on investment. Sustainability of business. Performance of Directors. Achievement against the Statement of Corporate Intent. Security of supply to region. Protection of shareholder s interests. Performance of business operation. Long term business direction and outcomes. Performance of Chief Executive and Executive Management Team. Creation of shareholder value. Contractual relationship. Clear data to support billing. Accurate and timely billing. Minimisation of line losses. Risk mitigated network. Timely response to service and information requests. Network standards. Advance notice of Network requirements. Payment in accordance with the terms of trade. Partnership approach. Annual Northpower Customer Perceptions Monitor survey. Formal and informal feedback Dedicated Customer Advisor. Dedicated Communications Manager. Dedicated Network Commercial and Operations Manager. Trade shows. Direct line function service agreements with large industrial sites. Faults free phone directly to dispatch/ network system operators. Pentennial ownership review. Triennial Trustee elections. AGM. Annual review with Directors. Six monthly meetings with Directors and Executive Team. Monthly meetings. Direct feedback from consumers. Annual review by Trust. Annual review with CEO. Annual business strategy sessions. Quarterly risk reviews. Quarterly field visits. Monthly meetings with Executive Team. Use of System Agreement. Annual relationship meetings. Direct consultation periodically throughout the year. Regular relationship meetings with Logistics Manager. Supply agreements. Structured terms of trade. Survey feedback.

31 Section 2 Background and Objectives 2-9 Stakeholder Key Interest Method of Interest Identification Staff Contractors Communities and Public Land owners District Councils Regional Council Risk mitigated network and work practices. Forward visibility of requirements. Involvement in company direction. Challenging work. Fair reward. Visibility of forward work load. Standards. Risk mitigated network. Return on investment. Partnership approach. Risk mitigated network. Responsible corporate citizen. Protection of property values. Protection of areas with cultural or historical significance. Risk mitigated network. Capability of network to service growth. Forward visibility of significant Network additions/alterations. Environmental impact of the network is in accordance with district plans and is minimized. Environmental impact of the network is in accordance with regional plans, the Resource Management Act and is minimized. Emergency response capability. Biennial Best Places to Work survey. Annual strategic planning sessions. Open forums at biannual Safety Days. Monthly Safe Team meetings. Hazard ID and Near Miss process. Weekly team meetings. Regular relationship meetings with Union representatives. Annual employment contract negotiations. Biennial Contractor review process. Annual service level agreement* negotiation. Open forums at biannual Safety Days. Monthly Safe Team meetings. Monthly relationship meetings with major contractors. Regular relationship meetings with minor contractors. Annual Northpower Customer Perceptions Monitor survey. Formal and informal feedback from interest groups. Dedicated Customer Advisor. Joint support of community sponsorship initiatives such as the Rescue Helicopter and Native Bird Recovery Centre. Public meetings. Direct consultation with interest groups. Consultation with affected or potentially affected landowners. Dedicated lines inspectors and vegetation officers in the field. Direct consultation between CEO s. District plan. Joint planning sessions. RMA. Growth strategy documentation. Direct consultation. Member of Northland Lifelines Group (Civil Defense and infrastructure disaster relief planning).

32 2-10 Section 2 Background and Objectives Stakeholder Key Interest Method of Interest Identification NZ Transport Agency Telco s Commerce Commission Electricity Authority Transpower - Grid Owner Transpower - System Operator Risk mitigated asset. No harm to public from actions of Network contractors. Value added propositions. Protection of their assets from electrical interference. Protection of their assets from physical interference. Synergies regarding access and asset placement. Legislative and regulatory adherence. Information disclosure. Legislative and regulatory adherence. Information disclosure. Payment in accordance with commercial terms. Provision of connection assets. Response to operating requests and conditions. Regulations. Direct consultation and co-operation. Regulatory and legislative protection. Relationship meetings. Information sharing sessions. Legislation laws and regulation. Disclosure documentation. Published rules. Electricity Commission updates published weekly. Annual notification of prices. Relationship meetings. Price/quality trade off consultation. Relationship meetings. Annual plan. Monthly monitoring. Direct contact with local network System Operators. Stakeholder interests and method of interest identification *the Service Level Agreement details the requirements and expectations for the level of service provided by Northpower Contracting. The content is similar to the Service Level Agreements Northpower Contracting has with other Network companies throughout New Zealand Accommodating the Interests of Stakeholders into Asset Management Planning Northpower has a number of systems which assist the accommodation of stakeholder interests; these are supported by satisfaction surveys and meetings with stakeholders. These include plans, policies and procedures along with relevant standards legislations and regulations. Of particular significance is the Northpower risk register (which details stakeholders and potential risks to sections of the business) and the interest s register (which details other interests that Northpower directors have, thus protecting against conflicting interests within decision making). Northpower is ISO 9001 and ISO certified, ISO14001 is new and significant as it focuses on environmental stakeholders in a climate of increasing environmental concern. Northpower is working towards certification for Asset Management. A gap analysis using international standard PAS 55 has been completed and work is currently underway to improve alignment with PAS 55. Northpower uses the guides in the table below to aid sound decision making, Northpower understands that good decision making processes are required to support both best practice asset management and the needs of stakeholders.

33 Section 2 Background and Objectives 2-11 Category Description of guide Type of decisions to be guided Policies Plans Procedures Vision Mission Non-asset solutions Distributed generation Redeployment & upgrade of assets Acquisition of new assets Adoption of new technology Disposal of assets Statement of Corporate Intent Strategic Plan Asset management Plan Risk management Plan Business Continuity Plan Internal manuals and specifications All organisational decisions All organisational decisions Whether non-asset solution should be used Whether DG should be installed and on what terms and conditions Whether and how assets should be redeployed or upgraded Whether new assets should be acquired Whether new technology should be adopted How assets should be disposed of High level direction for the company High level corporate decisions such as growth and investment Asset investment, maintenance and operational decisions Whether the level of risk implicit in decision options is acceptable to Northpower Responses to defined events, allocation of resources in preparation for events Operation and maintenance requirements Standards ISO 9001 ISO NZS 7901 AS/NZS Risk Application Guide AS/NZS Risk Management Various technical standards (IEC, BS etc) Various financial reporting standards PAS 55 Quality assurance decisions Environmental decisions Public safety Risk assessment Risk assessment Operation and maintenance of network assets What information needs to be reported to various entities, and when Network improvement

34 2-12 Section 2 Background and Objectives Category Description of guide Type of decisions to be guided Legislation Regulations Codes Commerce Act 1986 Electricity Act 1992 Energy Companies Act 1992 Companies Act 1993 Electricity Act 2010 Electricity Industry Reform Amendment Act 2001 Health & Safety In Employment Act 1992 Resource Management Act 1992 Electricity Industry Participation Code Electricity Distribution Information Disclosure Determination 2012 Electricity Governance Regulations NZECP s Disclosure of information, anticompetitive behavior, setting tariffs that comply with the price path thresholds, ensuring reliability does not materially decline Organisational and operational decisions Organisational and operational decisions Requirement to file various returns Requirement to separate line and energy activities Organisational and operational decisions Organisational and operational decisions Organisational and operational decisions Distributed generation requirements What needs to be disclosed to the Commerce Commission and the public, and by when Metering and supply quality requirements Guides to ensure compliance with regulations Guides to aid sound decision making Managing Conflicting interests Northpower understands the importance of appropriate consultation of stakeholders in order to ensure proper planning coordination, dissemination of information and maintenance of good relationships. Conflict of interest is treated seriously at Northpower. Wherever possible, Northpower will endeavour to resolve conflict of interest in a responsible and amicable way. In the event of a major conflict of interest, where an amicable solution cannot be found, Northpower is obliged to follow approved policy and process in order to discharge its responsibilities and obligations with regard to electricity supply. In general when there is a conflict between the interests of stakeholders, Northpower will prioritise interests in the following way: Decisions and actions required to ensure safety take priority over other interests at all times. Electricity distribution is a core activity. Northpower is committed to delivering quality to consumers, therefore decisions and actions which protect supply quality are fundamental. Decisions taken to protect supply quality must be financially responsible and meet compliance requirements. These interests form the parameters around which supply quality is prioritised.

35 Section 2 Background and Objectives 2-13 Financial interests will be considered on their merits and outcomes will depend on overall best position for Northpower. Northpower is committed to 100% compliance with the law and relevant industry regulations. The only acceptable reason for a compliance breach is action necessary to ensure safety in unforeseen circumstances. 2.5 Accountabilities and Responsibilities Board of Directors Chief Executive General Manager Network Assets Network Planning Manager Network Contracts Manager Network Commercial/ Operations Manager Accountabilities and Responsibilities Structure The responsibilities for asset management at Northpower are shown in the above. Accountability of the positions is described below Governance of Asset Management The Board of Directors is ultimately responsible for governance at Northpower. A significant proportion of the responsibility for governance and related decision making is delegated to the chief executive. However, board approval is required for: High level plans including: 10 year AMP. Maintenance Plan. Development Plan. Annual budgets including: Proposed preventative maintenance. Follow up and remedial maintenance. Asset renewal expenditure.

36 2-14 Section 2 Background and Objectives Sanction for expenditure approval for significant individual projects and expenditure that exceeds budget. Board sign off is required for projects over certain values or for unusual projects. Examples include: Switchboard upgrades. Power transformer upgrades. New zone substations. New technologies. Research and development projects. Safety, reliability and security of supply initiatives. The Chief Executive provides a business report to the Board Meeting each month. The report includes an outline of the Asset Management Division performance, business status and other significant issues. Specific examples include: Overall Network division financial position. Wairua power station (note that although not part of the lines business, Northpower network division is responsible for managing this asset). Network performance. Sub-divisional reports including: º º Network Planning. º º Commercial. º º Operations º º Contracts. Fibre network (note that although not part of the lines business, Northpower network division is responsible for managing this group of assets). Metering (note that although not part of the lines business, Northpower network division is responsible for managing this group of assets) Northpower Asset Management Executive Team The Network Assets division carries responsibility for the Asset Management functions at Northpower. Responsibilities within the division are as follows: The General Manager for the Network Assets division is the principal point of day-to-day responsibility for the asset management function which includes improving and managing Northpower s image and relations with the Northpower Trust, community and other key stakeholders. The General Manager for Network Assets is accountable to the Chief Executive for meeting the network operational and financial targets. The Network Planning Manager (which encompasses Network Planning, Development and Information Analysis) is responsible for network policy, standards and asset management systems, together with the network development and maintenance plans (and associated annual budgets) which form part of the Asset Management Plan. The Network Commercial and Operations Manager is responsible for the operations of the network and manages the interface between Northpower s network and the Transpower grid, Northpower s larger customers and the energy retailers. He also manages the interface with the Electricity Authority and determines the line charges Managing Field Operations The Network Contracts Manager is the interface with the in-house field services division. This relationship is managed by way of a Service Level Agreement. A significant function of this role is to monitor and audit key projects and required outcomes but, within the parameters of the Service Level Agreement.

37 Section 2 Background and Objectives 2-15 Northpower Contracting is the primary contractor operating on the Northpower network. This is advantageous firstly because the values, standards and operating practice are aligned with Northpower s asset management practice; the two operations share the same governing factors. Secondly, a wide and mobile workforce is available if additional resources are necessary. From time to time other contractors carry out work. These contractors are subject to the same safety and work criteria expected of Northpower Contracting. They are required to demonstrate this for approval to work on the Northpower network. External contractors are also engaged to carry out services that are not available internally. Examples include civil engineering and construction services. 2.6 Asset Management Systems and Processes Asset Management Systems Network Data is managed in five core systems (OSISoft PI, Siemens SCADA, Intergraph GIS, EMS Works, Maintenance Management and Gentrack Billing) supported by a number of MS SQL Server databases. Data from each of the above repositories is loaded in a data warehouse environment with analysis and operational visibility provided via an enterprise data warehouse environment. Northpower has adopted a de-coupled integration philosophy based on Microsoft BizTalk Server, use of a service oriented architecture (SOA) and industry standard tools and protocols. The net result is a configurable, reusable and scalable integration architecture that has lower cost of ownership. Leveraging this framework enables Northpower to continue with a best of breed approach without compromising systems inter-operability. The ongoing bedding in of these systems particularly the GIS, together with related applications development projects, will continue to extend into the medium term. Integration Layer Network Topology Asset Data Works Data ICP Data (batch) Asset and Operations Data Works Data ICP Data Operations Data Sincal GIS Bespoke Applications WASP GenTrack SCADA (Historian) Asset Data Faults Data Maintenance Data ICP Data Events and Status Extract Transform Load ICP Data Works History Data Warehouse Structured Reports Analysis Systems Integration Structure

38 2-16 Section 2 Background and Objectives Users also use a wide range of structured and ad-hoc reports available via an Intranet portal which interrogates the data in the aforementioned data stores. Specialised geospatial software is used to support advanced analysis Geospatial Information system (GIS) System Purpose Data Stored GIS Repository for Master Asset Data and Electrical Connectivity to support Records Management, Planning and Analysis. Zone Substation assets, Sub Transmission, HV and LV Distribution Assets The GIS system is of primary importance to Northpower as it acts as the master repository of asset data which provides the basis for asset planning. Northpower has invested heavily in recent years in upgrading the GIS system and improving the data stored within it. The GIS data now forms the basis of the systems that sit downstream providing planning, design, analysis and maintenance functionality. A web based front end (GNet Viewer) provides users with access to the underlying data through a wide range of search features. Asset Data for distribution assets is mastered in GIS with the following assets replicated in WASP via an interface. WASP stores a subset of the distribution assets and associated data required to support maintenance regimes: Capacitors Distribution Switchgear & Reclosers Distribution Substations Distribution Transformers Regulating Substations Regulating Transformers Pillars Poles Distribution Earthing Of the zone substation assets the following are now mastered in GIS and interfaced to WASP. It is the intention to bring the balance into GIS and interface them to WASP as resources permit over the next two years Circuit Breakers Current Transformers Tap Changers and Controllers Voltage Transformers Zone Transformers Network Representation Asset data is maintained in the GIS database and two views are available schematic (11kV only) and geographic (all voltages). Both are views of the same feature in GIS. 11kV Schematic The 11kV schematic displays the source substation, circuit breaker, switching nodes, distribution substations, in-line links, critical sites and some basic location detail and is the primary source of information for control room operations.

39 Section 2 Background and Objectives kV Schematic View Geographic View This displays the geographical location, electrical connectivity, and provides essential data for poles, conductor spans, cable sections, pillars, distribution substations, distribution transformers, switches, links, fuses and other network assets. 11kV Geographic View

40 2-18 Section 2 Background and Objectives 33kV Schematic The 33kV schematic is currently maintained in MicroStation and displays network interconnection, switching nodes and conductor circuit length details. 33kV Schematic EMS WASP The primary system used to support asset maintenance is EMS WASP (Works, Assets, Solutions, and People). System Purpose Data Stored EMS WASP Asset Management Assets and associated data required to drive maintenance. Condition data, test and inspection results. Maintenance/ inspection regimes, triggers and tasks. Maintenance history. Capital projects WASP has been configured to support the following functions: Storage of maintenance history for individual Network assets Forward planning of capital works programmes Automatic generation of regular tasks including preventative maintenance, inspections and testing tasks Recording test and inspection data Defect capture from asset inspections Task planning, packaging and scheduling using various criteria Data held in WASP includes condition data, test and inspection results as well as that required to drive maintenance management regimes, including manufacturer, type and model. Condition data from inspections is fed back into WASP and used to generate asset replacement and repair type tasks. Routine tests, inspection and maintenance regimes are held in relevant quality system documentation. Earth test results are stored in WASP to ensure that regulatory and safety requirements for the operation of the Network are met. Where test results are not loaded directly into WASP, scanned copies of these records (together with consultant s reports and manufacturer certificate/test sheets) are linked to the asset record in WASP.

41 Section 2 Background and Objectives 2-19 Over the next one to two years Northpower will review its options for Asset Management systems as the current WASP product approaches maturity OSISoft PI Data Historian System Purpose Data Stored PI Server Real time System Data Acquisition and Analysis. System events, plant status and loading, busbar voltages The PI system provides an improved Data Historian and analysis tool kit. Interfaces have been setup between the Siemens SCADA system, Communications Systems and other data repositories which provide an efficient historical capture of information. The information is mainly used for reporting and network planning/modelling purposes Siemens PowerTG SCADA System Purpose Data Stored SCADA Real time System Control & Data Acquisition System events, plant status and loading, busbar voltages The SCADA system records and stores time stamped event, status, loading and voltage data for the purpose of analysing system events (e.g. faults) and capturing network loading and voltage conditions for network modelling purposes. A tool has been setup to allow the 11kV schematic captured and updated in GIS to be imported in the Siemens SCADA system. The objective of the project is to improve the operations resilience in the event of a disaster. Having a digital snapshot of hand dressed and telemetered system status will allow operations staff to operate from any connected SCADA workstation. Siemens PowerTG SCADA Single Line Diagram

42 2-20 Section 2 Background and Objectives Power system modelling and analysis System Purpose Data Stored PSS/Sincal Network load flow and fault level analysis Network models and case studies PSS/Sincal is a power system analysis software tool used to model the subtransmission and distribution networks. Network models are developed from GIS extracts and populated with rating and other data from equipment name plates and manufacturer s specifications. Loading data obtained from the SCADA system is then used to simulate actual network conditions to identify capacity constraints, calculate fault levels and determine optimum distribution transformer tap settings. The software is also used to simulate future loading scenarios and network strengthening options in order to identify optimum solutions. The results of these studies ultimately determine the nature of the 10 year development plan. Many other applications such as motor starting, generation, backstopping capabilities, determination of available capacity for new customer connections, calculation of network losses and protection settings are also undertaken with this software. Sincal is currently being extended to hold all the protection information and provide discrimination tools for coordinating protection across the network Gentrack System Purpose Data Stored Gentrack Network Billing ICPs & Billing information Gentrack maintains detailed ICP records for billing purposes and automatically synchronises its installation data with the national registry. Also, retailer s customer data for each ICP is received via the national registry to automatically notify customer and retailer changes (start dates and end dates). Retailers send a file of Northpower network ICPs for monthly billing which contains dates, tariffs, consumption (kwh units). Gentrack bills the retailer for daily fixed charges applicable to each tariff for the correct number of days (taking retailer switching and customer changes into account). Energy is charged according to consumption or demand notified by the retailer, and the rate applicable for each tariff. Gentrack also keeps a dated record of meter type and serial number at each installation, together with details of all relays deployed. The Northpower customer service team maintains a log for each ICP in Gentrack to record all requests for service, events and outcomes concerned with metering, connections and disconnections from the network Outage Recording System Purpose Data Stored HV & LV Faults Database (MS SQL Server) Network Performance Data Capture Fault records and outage imperials Northpower currently measures and reports certain performance results for disclosure purposes on a routine basis. To do this, all planned and unplanned outages are entered into these databases The HV Faults database produces network performance reports which include: SAIDI, SAIFI and CAIDI results for any selected time period The daily outage and incident report which is circulated to interested parties and key managers Outage causes sorted by various selected parameters

43 Section 2 Background and Objectives 2-21 All unplanned outage causes are categorised as per the Electricity Industry Information Disclosure Regulations. Northpower s disclosure information and process is audited annually by PricewaterhouseCoopers for accuracy and consistency. The audit covers both planned and unplanned work. An outage management system has been budgeted for Financial Year This outage management system uses the telemetered system status points along with the hand dressed points mentioned in to determine outage statistics and track performance Integration Services System Purpose Data Stored Systems Integration Support the use of best of breed approach to systems. Business rules to ensure data integrity. Systems Integration Northpower s integration philosophy relies on a de-coupled approach using a middleware layer for data exchange. This architecture is supported by the use of service oriented architecture (SOA) and industry standard tools and protocols. The net result is a configurable, reusable and scalable integration architecture that has lower cost of ownership. Leveraging this framework enables Northpower to continue with a best of breed approach without compromising systems interoperability Data Completeness and Accuracy Retrospective capture of data has slowed in the last 12 months as GIS resources have been diverted from this project. However at the close of 2012, almost 70% of the network had been reviewed and data populated by desktop and field investigation. Data completeness and accuracy targets were set in December 2007 and are compared with the position at 27 November 2012 below. Overall Northpower is still behind target for all categories. As part of the Service Level Agreement with Northpower Contracting the payment of work undertaken is dependent on the accurate updating of network data in the various systems. The situation has been improving and the linkages between the various systems are being tightened. Audits are undertaken based on job status with results being fed back to the data updaters to continually improve the process. Northpower has rolled out a project where contracting Field staff are now utilising tablet based PC s to enter field data Subtransmission Lines and Cables The target for data completeness and accuracy has been set at 100%. This is due to the high value and strategic importance of these assets. The target has almost been achieved High Voltage Lines and Cables The target for data completeness has been set at 98% with accuracy at 90% for overhead lines vs 95% accuracy for cables reflecting added safety requirements. At November 2012 conductor type had improved from 95% to 98% complete while age completeness had improved from 50% the year before to 52% Low Voltage Lines and Cables The target for data completeness and accuracy have been set at 95% and 90% respectively Ongoing retrospective data capture from desktop investigation and field verification has completely eliminated the quantity of Northpower owned assumed LV network. Around 90% of conductor types have been captured and over 40% aged Subtransmission and Distribution Switchgear Given the criticality of this group of assets, targets for data completeness and accuracy have been set at 100%. These assets have been fully captured and conductor type fully populated while almost 90% have been reliably aged (up from 75% the year before).

44 2-22 Section 2 Background and Objectives Distribution Substations and Transformers As critical assets, the targets for data completeness and accuracy have been set at 100% for this group of assets. Essential data for these assets is now fully complete and almost all have been reliably aged Poles Data completeness and accuracy targets reflect the voltage of conductors carried on the pole. Across all voltages however the target for completeness is 95%+ with accuracy at 90%. Key pole data completeness and accuracy remains variable (and dependent on conductor voltage) however almost 60% are now reliably aged (up from 57% last year) Pillars The target for this group of assets is 95% completeness with 90% accuracy. Data for LV Link pillars in the CBD is good while for service pillars the completeness of key data also remains at a high level Zone Substation Assets A zone substation data capture project early in 2010 yielded a significant improvement in the quality of data for these assets. As a result, data completeness had improved across all zone substation assets to over 90%. Higher valued, strategic assets including circuit breakers and zone transformers now approach 100% data completeness and accuracy Data Quality Initiatives To improve the efficiency and accuracy of data capture, in-field technology is preferred over traditional manual paper-based systems. To this end electronic form capture is being progressively rolled out. To date this approach has been extended to cover pillar and ground mounted distribution substations while electronic data capture has been introduced for overhead lines inspections. Asset data retrieved from the field is validated against existing data and transferred directly to the core system, either GIS or Asset Management. Defects are transferred to the asset management system The ongoing development and integration of information systems including GIS, Works Management and Network Billing in conjunction with a centralised data repository has greatly improved distribution of, and access to, asset data. Data is extracted from these core systems, aggregated in a data warehouse, and deployed via an internet portal to a combination of structured and ad-hoc reports with the result that users now access the one version of the truth often with no sense of data source. The success of these initiatives going forward will depend on the ongoing integration between core systems and reduced reliance on feral databases and islands of information Plans for improvement in information quality The GIS database (and underlying data model) has provided the platform for a comprehensive data capture programme aimed at improving both completeness and accuracy. The overall goal of this project is to provide comprehensive and reliable data to support regulatory reporting and the Company needs for asset management. At 31 December 2012 almost 70% of the network had been visited by desktop investigation and data updated by a dedicated resource using historical records wherever possible. Unresolved data issues are flagged and followed up by a combination of targeted and routine field inspection. The majority of these have since been resolved.

45 Section 2 Background and Objectives Network Communications Due to the aging nature of the analogue based radio systems and copper based communications systems and the advent of modern communications technologies such as fibre/microwave Northpower has been upgrading the existing communications network infrastructure. The fibre/microwave systems extent Northpower s wide area network to remote sites providing geographic agility, reliability and speed improvements. Some of the protection schemes employed by Northpower use fibre differential schemes to protect the important ST conductors. These fibre schemes provide greater reliable than the radio or copper based systems due to their resilience to interference and minimal attenuation during transmission Network Control Network control is tasked with 24/7 monitoring of the electricity network. Northpower have focused on developing a fully equipped backup control room to provide a geographically separated control location in the event of failure of the main control room. This control room is fully equipped with corporate and SCADA network access, RT s and phones. This backup control room will leverage the PowerTG SCADA Schematic to provide a snapshot of the network configuration Business Processes Managing routine asset inspections and network maintenance Northpower uses specialist asset management software to support routine asset inspections and network maintenance management activities. The system, EMS WASP, automates repetitive manual tasks and ensures standardisation. WASP is primarily driven by cyclical triggers which initiate work requirements. Event related data is also used to trigger work. The system captures and manages asset condition data and defect tasks. WASP operates as a slave to the GIS master data repository and generates event driven maintenance triggers based on data provided from the SCADA system. Section 6 of the Asset Management Plan specifically addresses the routines and related policy Northpower employs to manage network inspection and maintenance Planning and implementation of network development processes Network development projects are grouped according to the following 3 main categories: Growth (new customer connection and growth of existing load). The network load forecast is used to identify future capacity constraints and possible solutions are identified. Technical and financial analyses are carried out in order to identify the most suitable long term solution. Projects are then defined and planned. Replacement and renewal (asset deterioration or obsolescence). Assets requiring upgrading or replacement due to end of life or condition (safety, performance, maintenance costs) are identified and their replacement planned. Improvement (safety, reliability, environmental). Projects required to improve public and employee safety, network reliability and performance as well as reducing environmental impact where possible are identified, defined and planned. Optimum solutions are based on minimising capital outlay and life cycle costs without compromising safety, quality and performance. A long term network development plan (10 years) comprising of planned projects is developed from these requirements with projects prioritised according to safety, performance and capacity requirements.

46 2-24 Section 2 Background and Objectives Individual projects (or groups of projects) are required to be justified in order to obtain sanction for expenditure (SFE) following which a project brief is generated. SFE approval is given at Board or executive management level depending on project value. Large projects with long lead times (detailed design, equipment procurement and construction) are required to be initiated well in advance. Annual capital projects budgets are compiled from the development plan and the financial system tracks individual project expenditure against budget. Northpower has a process for planning and implementing network development project (Capital Projects). Capital Projects Process System Design Engineer/Project Manager Network Planner Start Develop project definition Capital Projects Schedule Develop design from project definition Review design and cost estimate Estimate cost Asset Management Plan Obtain budget approval Finance One Develop project justification & submit sanction for expenditure (SFE) Prepare project brief Call for tenders for major equipment & obtain required permissions Prepare final design & review cost estimate SFE Template in Process Central Request budget extension if required Budget Template in Process Central Approve project Procure equipment, schedule and construct Test and commission Update records End Review project & sign off Northpower Network/Contracting Service Level Agreement Capital Projects Process Measuring network performance (SAIDI, SAIFI) for disclosure purposes Northpower currently measures and reports certain performance results for disclosure purposes on a routine basis. To do this, all planned and unplanned outages are entered into the Northpower Faults Database. The database produces network performance reports which include: SAIDI, SAIFI and CAIDI results for any selected time period The daily outage and incident report which is circulated to interested parties and key managers Outage causes sorted by various selected parameters All unplanned outage causes are categorised as per the Electricity Industry Information Disclosure Regulations. Northpower s disclosure information and process is audited annually by Price Waterhouse Cooper for accuracy and consistency. The audit covers both planned and unplanned work. Northpower is evaluating the use of an outage management system which will provide accurate SAIDI, SAIFI and CAIDI calculations on a per customer basis. This outage management system is budgeted for the next two years and will interface to the dispatch team and obtain information from the SCADA system and operations staff.

47

48 safe, reliable, hassle free service Asset Management Plan

49 Section 3: Assets Covered

50 safe, reliable, hassle free service

51 Section 3 Assets Covered 3-1 Section 3: Assets Covered 3.1 Distribution Area Area Covered Northpower s Large Customers Load characteristics for different parts of the network Peak demand and Total Electricity Delivered Description of Network Assets Supply Points and Embedded Generation Subtransmission Network Distribution Substations Low Voltage Network Secondary Assets Network Assets Sub Transmission Overhead Lines HV Overhead Lines LV Overhead Lines Underground Sub Transmission Cable Underground HV cables Underground LV cables Poles Distribution Switchgear Distribution Earthing Voltage Regulators Distribution Substations/Transformers Low Voltage Pillars Zone Substation Sites Zone Substation Battery Banks Zone Substation Transformers and Tap Changers Circuit Breakers Zone Substation Earthing Protection Relays Ripple Plant SCADA and Communications Supporting and Secondary Systems Metering Systems Power Factor Correction Plant Mobile Substations and Generators Generation Plant Backup Control Room Fibre Network Justification of Assets Justification Process 3-42

52 3-2 Section 3 Assets Covered Section 3: Assets Covered 3.1 Distribution Area Area Covered As at 31 December 2012, Northpower supplies 54,933 connected customers spread over an area of some 5,700 square kilometres covered by the Whangarei and Kaipara Districts. This area includes Whangarei City and the towns of Dargaville, Hikurangi, Kaiwaka, Maungaturoto, Ruawai and Waipu. The main depot and head office for Northpower is located in Whangarei. Sub-depots are located in Dargaville and Maungaturoto. The map below shows the geographical area supplied by Northpower as well as the location of the five Transpower grid exit points to which Northpower s network is connected. Kensington Maungatapere Bream Bay Dargaville Maungaturoto Northpower geographical area of supply and GXP s Northpower s Large Customers Customers with high consumption (in terms of either maximum demand or energy or both) are defined as large customers. These customers usually have special requirements with regard to security of supply (typically duplicate transformers and lines or cables) as their loads are too large to supply with emergency standby or backup generation. These loads are normally supplied directly from the sub-transmission system at 33kV or by one or more dedicated 11kV distribution feeders emanating from a nearby zone substation.

53 Section 3 Assets Covered 3-3 Northpower currently has five large loads and together they consume approximately 50% of the electricity supplied via the Northpower network. Key industries in the Northpower distribution area include: Heavy chemical processing Wood processing Dairy processing Northpower considers the identity of individual consumers drawing major loads to be commercially sensitive, so does not publicly disclose this in the Asset Management Plan Load characteristics for different parts of the network Grid Exit Point (GXP) Bream Bay Dargaville Kensington Maungatapere Maungaturoto Load Characteristics Fairly constant load throughout the year Predominantly industrial load High reactive power component Peak load in winter Predominantly rural dairy, residential and commercial load Peak load in winter Predominantly residential and commercial load Load transferred between Kensington and Maungatapere Fairly constant load throughout the year Mixture of all load types High reactive power component Load transferred between Maungatapere and Kensington Peak load in spring Predominantly dairy load Increasing coastal settlement load Northpower s electricity network is predominately rural. Apart from the major loads mentioned above, the major urban centre of Whangarei, and the smaller urban centres of Dargaville, Kaiwaka, Ruawai, Maungaturoto, Mangawhai, Ruakaka, Hikurangi and Waipu, sees the balance of the load comprising of dairy farming, townships and small coastal settlements. Typically the load peaks in winter, usually late July or early August. The exception is the Maungaturoto Grid Exit Point (GXP) which peaks in spring due to the dominance of dairy industry in the area. The Mangawhai coastal area load is growing with the highest loads occurring during the Christmas and New Year holiday period followed by Easter. Mangawhai is also showing cyclic load peaks during weekend periods due to its relatively close proximity to and ease of access from Auckland. Generally, daily peaks for the network are cyclic and predictable. Residential and rural areas have highest demand during the mornings and evening hours while commercial areas and the central business districts demand are highest during the day. Hikurangi Zone substation is also noteworthy as it has a significant amount of flood pumping connected. In periods of very wet weather this can place extra demand on the substation.

54 3-4 Section 3 Assets Covered A typical daily profile is shown below and is a snapshot from the 12 th May Kensington GXP is a typical urban profile showing peaks in the morning and evening whereas Bream Bay GXP is a typical commercial/ industrial load. 60 Typical GXP Load Profile (12/05/2012) Bream Bay MW/MVAr :00: Peak demand and Total Electricity Delivered Peak Demand 02:00:00 04:00:00 06:00:00 08:00:00 10:00:00 12:00:00 14:00:00 16:00:00 18:00:00 20:00:00 22:00:00 00:00:00 Dargaville Kensington Maungatapere Maungaturoto Peak demand on the network is due to coincident consumer activity. For example, demand will increase in residential areas in the mornings as the majority of residents wake and switch on appliances. Residential demand is also highest in winter as consumers use more electricity to power heating devices. Peak demand is an important consideration when managing electricity assets because the electricity network must have the capacity to meet that demand to ensure uninterrupted delivery of electricity. Northpower employs ripple control systems to interrupt supply to hot water cylinders during peak load periods in order to reduce the peak load. This helps to reduce/defer investment in increased capacity of substations and lines / cables, which ultimately benefits the customers in the long term. The peak demand on Northpower s network for 2012 was 162.8MW which occurred on 15 th Aug 2012 at 7:04pm) and the total energy delivered to the end of October 2012 was 826.8GWh. The 2012 maximum half hourly demand and total energy supplied for the five Grid Exit points is shown in the table below. The output from Northpower s 5MW Wairua hydro power station and Trust Power s 9MW Peaking Plant have been included for reference. The maximum demand at Kensington and Maungatapere appears high due to shifting significant amounts of load between the two GXP s for maintenance, fault or load management reasons. Note that the peak loads and reactive power are not coincident.

55 Section 3 Assets Covered 3-5 Station Financial Year Firm Capacity 2011/12 (Financial Year) energy supplied and peak demand MVA GWh MW MVAr Bream Bay GXP 2011/ / Kensington GXP 2011/ / Maungaturoto GXP 2010/ / Maungatapere GXP 2011/ / Dargaville GXP 2011/ Generation Stations Northpower s - Wairua Power Station Ballance Agri Nutrients Cogen Trustpower Peaking Plant 2010/ GWh The following charts show the active (MW) and reactive (MVAr) daily peak demand profiles for each of the 5 grid exit points for the 10 month period January 2012 to October 2012: Daily Peak MW/ MVAr for Kensington GXP MW/MVAr Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Daily Peak MW/MVAR for Kensington GXP 2011 Active Power 2011 Reactive Power 2012 Active Power 2012 Reactive Power

56 3-6 Section 3 Assets Covered 55 Daily Peak MW/MVAr for Mangatapere GXP MW/MVAr Active Power 2011 Reactive Power 2012 Active Power 2012 Reactive Power 5-5 Jan Feb Mar Apr May Jun Jul Aug Daily Peak MW/MVAR for Mangatapere GXP 20 Sep Oct Nov Dec Daily Peak MW/MVAr for Mangaturoto GXP 15 MW/MVAr Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Daily Peak MW/MVAR for Mangaturoto GXP 2011 Active Power 2011 Reactive Power 2012 Active Power 2012 Reactive Power

57 Section 3 Assets Covered 3-7 Daily Peak MW/MVAr for Bream Bay GXP MW/MVAr Active Power 2011 Reactive Power 2012 Active Power 2012 Reactive Power 10 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Daily Peak MW/MVAR for Bream Bay GXP 14 Daily Peak MW/MVAr for Dargaville GXP MW/MVAr Active Power 2011 Reactive Power 2012 Active Power 2012 Reactive Power 2 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Daily Peak MW/MVAR for Dargaville GXP

58 3-8 Section 3 Assets Covered 3.2 Description of Network Assets Supply Points and Embedded Generation Northpower receives most of its electricity supply from Transpower via the Grid Exit points at Bream Bay, Dargaville, Kensington, Maungatapere and Maungaturoto. Northpower s 5MW Wairua power station is connected to the Northpower network which is connected to the Transpower s grid at Maungatapere GXP. A privately owned 1MW generation plant is also connected to the Northpower Network supplied from the Maungatapere GXP. In July 2011, a diesel powered peaking station owned by TrustPower was commissioned at Bream Bay and connects to the Northpower Zone Substation adjacent to the Bream Bay GXP. Small privately owned embedded generators, solar and wind are being established across the network. The figure below is an extract from Transpower s North Island Network Map showing Transpower s transmission network throughout Northpower s distribution region. Transpower s Transmission network as of 31 st October Subtransmission Network Northpower s Subtransmission network is shown schematically in the diagram below. The Kensington and Maungatapere Grid Exit Points are linked at sub-transmission level, whereas Bream Bay and Maungaturoto Grid Exit Points supply isolated sub-transmission networks. Dargaville Grid Exit Point does not have an associated sub-transmission network; rather, supply is taken at 11kV from the Transpower GXP. Key features of Northpower s sub-transmission network include a 33kV ring between Kensington GXP and Maungatapere GXP via Tikipunga, Onerahi, Kioreroa and Whangarei South zone substations and a 33kV link from Tikipunga substation through Alexander Street substation to Whangarei South substation. A new 33kV cable link was installed between Kensington and Alexander Street in 2010 to off-load the Kensington-Tikipunga 33kV cables. These circuits provide a high security of supply to the Whangarei district customer base. There is also a significant amount of inter-connections within the 11kV network in the main urban areas. Northpower has nineteen zone substations (including Dargaville where the 50/11kV transformers are owned by Transpower). In addition there is one 33/11kV substation which provides a dedicated supply to an industrial load shown as Chip Mill below. The substations are connected to the grid exit points by the 33kV subtransmission network. Zone substations typically comprise of one or two 33/11kV transformers with on load tap changers, 33kV and 11kV bus bars and switchgear, associated protection and tap change relays and SCADA remote terminal units.

59 Section 3 Assets Covered 3-9 The development planning section provides detailed information about capacity and security of supply at Northpower s zone substations (below is a high level comparison of the security of supply situations at each of the zone substations). Zone Substation Subtransmission Security Transformer Security Peak Load Security Alexander St N-1 N-1 N-1 Bream Bay N-1 N N Dargaville No Subtransmission N-1 N-1 Hikurangi N-1 N-1 N Kaiwaka N N N Kamo N-1 N-1 N-1 Kioreroa N-1 N-1 N-1 Mangawhai N N-1 N Mareretu N-1 N N Manungatapere N-1 N-1 N Maungaturoto N-1 N-1 N-1 Ngunguru N N N Onerahi N-1 N-1 N Parua Bay N N N Poroti N N N Ruakaka N-1 N-1 N-1 Ruawai N N N Tikipunga N-3 N-1 N-1 Whangarei South N-3 N-1 N Subtransmission and Substation Transformer Security Subtransmission Network Single Line Diagram Distribution Network

60 3-10 Section 3 Assets Covered Electricity is distributed to customers via ninety-three 11kV feeders emanating from zone substations, with the exception of a number of large customers who are supplied directly at 33kV. Some customers are supplied directly at 11kV but the majority are supplied via 11,000/415V distribution transformers (either pole or ground mounted) ranging in size from 5kVA to 1,000kVA. Northpower s 33kV Network Shown Geographically

61 Section 3 Assets Covered 3-11 The map above shows the Northpower distribution area and geographical location of zone substations and communication sites. Please refer to section 5 for maps showing the geographical areas serviced by each zone substations and its associated 11kV distribution feeders. Most remote zone substations are fed by a single 33kV line with sufficient back-feeding capability on the 11kV network. Where back-feeding capacity is not adequate for major outages, portable generation is used for voltage support purposes. Northpower has acquired a 500kVA purpose designed mobile generating system (including transformer) for this purpose. Description Quantity (km) Underground (km) Overhead (km) High Voltage Lines , (6.4%) 3,485 (93.6%) High Voltage Lines , (6.9%) 3,467 (93.1%) Distribution Substations Distribution substations comprise of an 11,000/415V transformer with an off-load tap changer, high and low voltage fuses, associated earth mats and in some cases high voltage surge arrestors. Fuses on the high voltage side of the transformer provide fault protection for the transformer. Fuses on the low voltage side provide both transformer overload and downstream fault protection for cables or lines. Transformers with a rating exceeding 150kVA are normally ground mounted due to their weight and size. Transformers with a rating of 50kVA and below can be either 2 phase or 3 phase while those larger than 50kVA are all 3 phase. The number of customers supplied by a distribution substation typically range from 1 to 100. Shown below is Northpower s transformer s grouped by kva rating and orientation. There are a large number of overhead 30/50kVA units in service due to the high proportion of overhead network kva Ratings of Distribution Transformers Count Ground Mounted Overhead kva Ratings of Distribution Transformers kva Rating ,000 1,500

62 3-12 Section 3 Assets Covered Low Voltage Network The Northpower low voltage (LV) network is comprised of overhead lines and underground cables (feeders) operating at 400/230V. The LV feeders distribute power from distribution transformers connected to the 11kV network to consumers who are connected to the LV feeder via a service line or cable. In most cases this will be from poles or pillars near property boundaries. Each LV circuit is protected by fuses at the transformer and at (or as near as practical to) each customer point of supply (POS). Electricity meters and ripple relays or pilot control contactors (for control of water heating load) are generally located at the end of the service line or cable on the premises. Where there are significant numbers of customers or where increased security of supply is required, the LV network is configured in a ring. Normally open links in the ring can be closed to allow an alternative supply should it be required. This type of arrangement is common in the central business district and residential areas. The preference is for new network extensions to be underground in urban environments (this is a District Council policy requirement in the Whangarei urban area), however cost is a significant factor. Description Quantity (km) Underground (km) Overhead (km) Low Voltage Lines , (30.7%) 1,450(69.3%) Low Voltage Lines , (33.9%) 1,220(66.1%) Note: Northpower have been in the process of improving the data quality and correcting previous ownership issues. This explains the substantial changes to the quantities Secondary Assets Sophisticated metering equipment is in operation at Transpower GXP s to continuously measure, record and control the Northpower network load on the Transpower transmission system. Northpower s six ripple signal generation plants (located at Maungatapere, Tikipunga, Bream Bay, Maungaturoto, Dargaville and Ruakaka) transmit at 283Hz and inject into the 33kV network, except for 3 plants which inject into the 11kV network. Ripple control is used to manage GXP loadings by means of hot water and priority channel load control, street lighting, automatic load shedding and time of use metering. The ripple system is also made available to the Northland Regional Council to use as a Tsunami warning system. As Northpower is charged for reactive power demand which is supplied by Transpower, reactive power compensation (power factor correction) in the form of fixed capacitor banks are utilised. At present Northpower has 19 x 750kVAr, 5 x 150kVAr and 2 x 200kVAr capacitor banks (15.6MVAr) connected to the network and more will be installed in future as the load grows to manage the reactive power imported from the national grid. Northpower owns a 500kVA mobile generator (with associated 400/11,000V transformer) which is used to reduce the number of planned maintenance and fault shutdowns on the 11kV network. The purchase of larger 1MVA machines is being investigated for use at zone substations. Similarly, 400V generators are used on the low voltage network to maintain supply to customers where possible. Northpower operates a supervisory control centre in Whangarei, which is attended 24 hours a day. A state of the art SCADA system continuously monitors load pulses, alarms and indication from equipment in the 33/11kV zone substations as well as reclosers, sectionalisers and switches on the network. This equipment, as well as street lighting and all load-shedding plant, are under direct supervisory control. In addition to this, load pulses, alarms and indication of the state of outgoing circuit breakers at the five GXP s are returned to the Control Centre via the SCADA system.

63 Section 3 Assets Covered 3-13 The communications network makes use of microwave, UHF and VHF radio links, as well as copper and optical fibre cable links. 3.3 Network Assets Notes: 1) Where the word fair is used to describe the condition of an asset or group of assets, the term is used in the context of good, fair, poor (or new, mid-life, end of life) 2) Northpower has an ongoing data improvement program. When asset age data is invalid or nonexistent then associated assets are used to determine a possible age. If this technique fails then a default value is used and this is highlighted in associated graphs Sub Transmission Overhead Lines The following chart details the conductor cross sectional areas for reference. Conductor Sizing Conductor Cross Sectional Area (mm2) Jaguar Caracal Dog Weke Helium Mink 19/0.083 Cu Ferret Fluorine Gopher 7/0.104 Cu Squirrel 7/0.080 Cu 7/0.064 Cu Conductor Size Comparison Description of Asset Description Quantity (km) in 2012 Quantity (km) in 2011 Subtransmission lines Electricity is transmitted at high voltages to reduce the energy lost in long distance transmission. The subtransmission network connects the GXP s to the zone substations. Further interconnections may exist with sub-transmission lines or cables between zone substations. Northpower s sub-transmission network is operated at 33kV. The 219km of line is made up of three wires of conductor varying in size from Jaguar ACSR to Helium AAC.

64 3-14 Section 3 Assets Covered Age Profile 35 Age Profile of Sub Transmission Lines Default Value of 39 Years used for 11.2km of Unknown Age Sub Transmission Lines (5.1%) Length (Kilometers) Default Known Age Sub Transmission Lines Age Profile Age (Years) Sub Transmission Line Length and Average Age Length (Kilometers) Average Age (Years) Length Average Age Dog ACSR Jaguar ACSR 7/.104 Copper Caracal ACSR Helium AAAC Unknown/Other 0 Sub Transmission Lines Length/Age by Conductor Type

65 Section 3 Assets Covered Condition The condition of the sub-transmission network varies between fair to good. Regular preventative maintenance inspections which include a helicopter patrol of the lines provide regular condition assessments and follow up maintenance is carried out with some urgency given the strategic importance of this portion of the network HV Overhead Lines Description of Asset Description Quantity (km) in 2012 Quantity (km) in 2011 High Voltage Lines 3,485 3,467 Aluminium conductor steel reinforced (ACSR) makes up the majority of the distribution network (Gopher 32%, Ferret 14%, Mink 10% and Dog 9%) although there is still a relatively high proportion of copper conductor in service (7/ %, 7/ % and 7/ %). The ACSR conductor sizes vary from Squirrel to Caracal. Increasing volumes of all aluminium alloy conductor (AAAC) (currently only 6.1% of total) are being used with Helium and Iodine conductor being preferred Age Profile Length (Kilometers) Age Profile of HV Lines Default Value of 39 Years used for 410km of Unknown Age HV Lines (11.78%) Default Known Age HV Lines Age Profile Age (Years)

66 3-16 Section 3 Assets Covered HV Line Length and Average Age 1, , Length (Kilometers) Average Age (Years) Length Average Age 0 Gopher ACSR 7/.064 Copper Ferret ACSR Mink ACSR Dog ACSR 7/.080 Copper Flourine AAAC HV Lines Length/Age by Conductor Type 7/.104 Copper Squirrel ACSR Caracal ACSR 7/.080 Copper HDBC 19/.083 Copper Weke AAC 19/.064 Copper Unknown/Other 0 40 HV Line Change in Length Length (Kilometers) Gopher ACSR 7/.064 Copper Ferret ACSR Mink ACSR Dog ACSR 7/.080 Copper Flourine AAAC 7/.104 Copper Squirrel ACSR Caracal ACSR 7/.080 Copper HDBC 19/.083 Copper Weke AAC 19/.064 Copper Unknown/Other HV Lines Change in Length by Conductor Type

67 Section 3 Assets Covered Condition The more proactive and robust inspection regimes have seen an increased level of maintenance spend. This increased level of maintenance has provided some short term benefits helping to achieve the medium term goal of improved reliability and system performance. Northpower s overhead lines generally are in better condition than the average network worldwide; they are safe, fit for purpose, serviceable and have capacity to accommodate growth. Risk mitigation drivers have seen the development of a long term conductor replacement strategy. The graphs detail the population and age profile of conductors. Combined, ACSR Gopher and 7/.064 HDBC make up 48.2% of the distribution network. Initially the focus will be on the 7/.064 HDBC and the coastal ACSR Gopher conductor. The results of a conductor sample analysis were received at the end of 2010 and these have been used to map out a an ongoing conductor replacement program which commenced in Northpower has a test regime for measuring the tensile strength of aging conductors. The regime tests broken and replaced conductors to get an accurate picture of the conductor s ability to perform and allows replacement to be targeted. Northpower has a proactive vegetation clearance program that has seen a reduction in the number of tree related faults on feeders that have been cleared to date LV Overhead Lines Description of Asset Description Quantity (km) in 2012 Quantity (km) in 2011 Low Voltage Lines 1,230 1,220 Similar components to those used on the HV network have been used on the LV network with regard to poles. The majority of the network consists of all aluminium conductor (AAC) (Rango 29%, Kutu 12% and Weke 4%), Copper (7/ %, 19/.083 6% and 7/.080 3%) and ACSR (Ferret, Mink and Gopher 2% respectively). There is 8.5% in the unknown category.

68 3-18 Section 3 Assets Covered Age Profile Age Profile of LV Lines Default Value of 39 Years used for 344km of Unknown Age LV Lines (23.8%) Length (Kilometers) Default Known Age 10 5 LV Lines Age Profile Age (Years) LV Line Length and Average Age Length (Kilometers) Average Age (Years) Length Average Age 0 Rango AAC 7/.064 Copper Kutu AAC 19/.083 Copper Unknown Weke AAC Unknown Copper NS 7/.080 Copper Ferret ACSR 35mm² Aluminium ABC 19/.064 Copper Gopher ACSR 16mm² Copper NS Mink ACSR Unknown/Other 0 LV Lines Length/Age by Conductor Type

69 Section 3 Assets Covered 3-19 LV Line Change in Length Length (Kilometers) Rango AAC 7/.064 Copper Kutu AAC 19/.083 Copper Unknown Weke AAC Unknown Copper NS 7/.080 Copper Ferret ACSR 35mm² Aluminium ABC 19/.064 Copper Gopher ACSR 16mm² Copper NS Mink ACSR Unknown/Other LV Lines Change in Length by Conductor Type Condition The LV network is in many places contiguous with the HV network. The age profile and condition therefore is very similar to that of the HV network, similar inspection and maintenance regimes are applied for corresponding improvements in performance. A program of works comparable to that of the HV network is to be undertaken on the LV network Underground Sub Transmission Cable Description of Asset Description Quantity (km) in 2012 Quantity (km) in 2011 Subtransmission cables The sub-transmission cables comprise 19.4km of the sub-transmission network. There are a number of configurations with some three core cable installed as well as some runs consisting of three single cores. Aluminium and copper conductors have been used with the copper conductors varying in size from 120mm 2 to 130mm 2 and the aluminium conductors ranging from 95mm 2 to 500mm 2.

70 3-20 Section 3 Assets Covered Age Profile by Insulation Type 6 Age Profile of ST Cables 5 4 Length (Kilometers) 3 2 Oil Filled PILC Default XLPE/PVC Age (Years) Sub Transmission Cables Age Profile 6 ST Cable Length and Average Age Length (Kilometers) Average Age (Years) 1 10 Length Average Age 0 130mm² Copper 500mm² Aluminium 300mm² Aluminium 1200mm² Copper 400mm² Aluminium 185mm² Aluminium 95mm² Aluminium 50mm² Aluminium 70mm² Aluminium 120mm² Copper 0 Sub Transmission Cable Length/Age by Conductor Type

71 Section 3 Assets Covered Condition The sub-transmission cable routes are also regularly patrolled and checked for any excavation or fill activity and to ensure access is maintained in the event of a cable fault. Sub-transmission cable condition has been assessed as good to fair. The cables are also tested on a 3 yearly cycle. Standard electrical testing is carried out by Northpower s contractors and PDC (Polarisation/Depolarisation and Partial Discharge) tests are carried out by a consultant engineer involving the use of specialist equipment. This ensures that the integrity or rating of the system has not been compromised Underground HV cables Description of Asset Description Quantity (km) in 2012 Quantity (km) in 2011 High Voltage Cables The type of underground cable used on Northpower s network has varied over time. Typically for HV cables it was common for paper insulated lead covered (PILC) multi-core with copper conductors to be installed. As gains were made in manufacturing technology, cross linked polyethylene (XLPE) cables became more prevalent. These cables were either single or multi-core and had copper or aluminium conductors Age Profile by Insulation Type Age Profile of HV Cables Default Value of 39 Years used for 56km of Unknown Age HV Cable(23.8%) Length (Kilometers) Oil Filled PILC Default XLPE/PVC HV Cables Age Profile Age (Years)

72 3-22 Section 3 Assets Covered HV Cable Length and Average Age Length (Kilometers) Average Age (Years) Length Average Age 0 35mm² Aluminium 16mm² Copper 25mm² Aluminium 95mm² Aluminium 185mm² Aluminium 70mm² Copper 19/.064 Copper 95mm² Copper 25mm² Copper Unknown/Other 0 HV Cable Length/Age by Conductor Type Condition The 20km s of PILC 11kV cables installed years ago are still providing reliable operation. It is expected that these cables will last for 60 years plus. Issues experienced to date largely concern joint or termination failures but not at levels to suggest a systemic failure issue. Terminations and joints are replaced as opportunity maintenance in conjunction with other planned work on adjacent assets. There is currently 236km of unknown age HV cable, of this 100km is of unknown type to reduce the chances of surprises a default age has been used Underground LV cables Description of Asset Description Quantity (km) in 2012 Quantity (units) in 2011 Low Voltage Cables Cables on the LV network consist of single core PVC sheathed cables with either aluminium or copper conductors typically run inside a PVC duct. Latterly XLPE sheathed sector cables have been used. These cables typically have aluminium conductors.

73 Section 3 Assets Covered Age Profile by Insulation Type 50 Age Profile of LV Cables Default Value of 39 Years used for 154km of Unknown Age LV Cable (23.9%) Length (Kilometers) Default XLPE/PVC LV Cables Age Profile Age (Years) LV Cable Length and Average Age Length (Kilometers) Average Age (Years) Length 50 5 Average Age 0 Unknown <240mm Aluminium Copper >=240mm Aluminium 0 LV Cable Length/Age by Conductor Type

74 3-24 Section 3 Assets Covered 4.00 LV Cable Change in Length Length (Kilometers) LV Cables Change in Length by Conductor Type Condition As with the 11kV cables, the 400V cables have proven to be very reliable. Failures, when they do occur tend to be at terminations or joints. The expected life of 45 years is applied to this asset category. Underground tee joints are showing an increasing incidence of failure due to an ingress of moisture through the epoxy joint; the volume of faults is however being closely monitored. There is nothing to suggest that it is a widespread issue and replacement occurs as a result of failure or in conjunction with other work on the asset Poles Unknown <240mm² Aluminium Description of Asset Description Quantity (Units) in 2012 Quantity (units) in 2011 Wood 1,288 1,358 (1,605*) Concrete 50,683 50,883 (56,990*) Steel (78*) Unknown 2,570 2,559 (2,760*) *These were reported incorrectly in the 2011 AMP due to incorrect assumptions resulting in duplicate records. Northpower s distribution of overhead conductor is supported predominately by Concrete poles produced from Northpower s pole factory or latterly by BUSCK Industries. The wooden poles in use on the network are largely hardwood. The crossarms used to separate and support the insulators/conductors are typically 100mm x 75mm hardwood on the HV network and 75 x 75mm hardwood on the LV network. The crossarms vary in length depending on the pole spacing to provide sufficient conductor spacing. Northpower have recently begun a trial of a custom designed galvanised steel cross arm for use in coastal environments with the aim of reducing the failure rates and corrosion issues. Copper >=240mm² Aluminium

75 Section 3 Assets Covered Age Profile Age Profile of Poles 2,000 1,800 Default Value of 39 Years used for 14,463 of Unknown Age Poles (26.4%) 1,600 1,400 Count 1,200 1, Default Unknown Material Wood Steel Concrete Age (Years) Poles Age Profile Condition The relatively small population of wood poles installed from the early 1950 s through to the mid 1990 s are actively being replaced with increasing replacement volumes over the past six years. The preference is for new aerial lines to be constructed with concrete poles. The concrete poles on the network have a standard life of 60 years; however inspections have shown that the condition of the concrete poles in the Northland environment will likely exceed this by a significant margin. In conjunction with the conductor replacement program mentioned earlier other associated fittings and hardware such as crossarms and insulators are being replaced. Additional opportunity maintenance will also be carried out and is likely to include pole replacements where required Distribution Switchgear Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Disconnectors/Air Break Switches Load Break Switches (Sectos) Fuse links (sets) 7,102 6,908 Reclosers Ring Main Units Overhead switches are typically used on the distribution network to facilitate the isolation or sectionalisation of lines as a result of faults or planned outages. They can also be used to alter the network configuration (normally open points) in response to changes in loadings. There are four categories of overhead switches on the network and within each category (excluding load break switches) variants are found due to the presence of different manufacturers in the market dependent upon the timeframe of installation.

76 3-26 Section 3 Assets Covered There are three makes of air break switch (ABS) in service on the network; Canterbury Engineering, Mahunga and Schneider. These switches use a set of knife links or contacts (with flicker blade) and an air gap and are operated from the ground by way of a mechanical lever system to provide an open circuit. This type of switch is inherently unreliable and is not designed to break significant load current. For these reasons, air break type switches are no longer being installed on the network and those in service are being replaced (5 year program) with enclosed gas filled switches. All enclosed gas (SF6) filled switches in service and currently being installed as replacements for air break switches or new switch points are ABB Sectos units. This type of switch is far superior to the traditional air break switch in terms of reliability, safety and long term maintenance costs. The sectos switch is also available in a motorised form which supports remote control operation of switches to speed up fault isolation and reduce operating costs. Single phase fuse links are primarily installed on distribution transformers and spur lines as a means of isolation and protection. When the fuse blows due to fault current or overload, the fuse carrier drops down, providing a visual sign as well as electrical isolation. As with other network hardware, there have been a number of different manufacturers who have supplied this type of component to Northpower. There are populations of Gough, Dominion, AB Chance and JTS branded product on the network. A recloser is a self controlled device with a preset sequence of opening and closing followed by a reset, hold closed or lockout condition dependent upon the fault circumstance. These units are employed on the network typically at the mid point of a rural feeder to limit the outage area and provide a more rapid restoration time after a fault. As with other network hardware, there have been a number of different manufacturers who have supplied this type of equipment to Northpower. Two manufacturers, Cooper Power Systems (KFME and Nova models) and Nulec (N and U series) are the types used. A ring main unit is a component of switchgear installed in the Underground HV network to facilitate the isolation or sectionalisation of lines as a result of faults or planned outages. They can also be used to alter the network configuration in response to changes in loadings. In addition they can contain fuse units for protection of ground mount distribution substations Age Profile Age Profile of Distribution Switches Default Value of 39 Years used for 719 of Unknown Age Switches (8.8%) 400 Count Default Fuse Link Ring Main Unit Air Break Switch Sectionaliser Recloser Overhead Enclosed Disconnectors/ABS Age (Years) Distribution Switches Age Profile

77 Section 3 Assets Covered Condition Northpower embarked on an ABS replacement project largely due to the age and condition of the existing 3 phase disconnectors on the network. As well as the planned replacements, opportunity maintenance as a result of faults or in conjunction with other planned maintenance on associated assets, a target of approximately 100 switches replaced on an annual basis was initially set. The target has been exceeded thus far with 181 ABS switches replaced in 2009, 134 in 2010, 131 in 2011 and 101 were replaced between January and October The reclosers are in good condition given that the population age is relatively low and this assessment is supported by the regular preventative maintenance checks carried out. As with the ground mounted distribution substations, the ground mounted ring main units are also regularly inspected and their condition is listed as good to fair. There has been a phase out of the Series 1 oil filled Andelect RMU due to a known issue of possible catastrophic failure on operation. These units were replaced with SF6 filled units which are specified for any new installation. Regular maintenance will see the existing oil filled units last for at least their expected 40 year life Distribution Earthing Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Distribution earthing 8,897 8,731 Effective grounding or earthing of the distribution system neutral is necessary to achieve several objectives, the most important of which is the safety of the public and network utility personnel. This is achieved through the installation of a system of interconnected copper clad earth rods and bare copper conductors under the surface of the ground at the site of each distribution substation. Typically the series of driven rods are 13mm in diameter and 1.8m in length and are connected to each other with 70mm 2 bare copper conductor where used in a zone substation earthing system and 50mm 2 bare copper conductor in other locations Age Profile Age Profile of Distribution Substation Earthing Default Value of 39 Years used for 1704 of Unknown Age Distribution Substation Earthing (19.2%) Count Default Known Age Age (Years) Distribution Substation Earthing Age Profile

78 3-28 Section 3 Assets Covered Condition The current data on distribution substation earths is incomplete as shown by the large number of sites for which the precise date of installation is unknown. However there is an active program in place to visit each site and conduct a test of the resistance of the earthing system. The earthing system is upgraded at those sites that do not comply with the regulatory resistance requirement. The age profile graph shows the numbers of earthing upgrades have risen in recent times. There have also been improvements in data validity as a result of the preventative maintenance site visit Voltage Regulators Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Regulator Stations 4 4 An automatic voltage regulator is a tap changer equipped autotransformer that maintains the voltage level within a certain range, regardless of the load variations. The units in place on the network are typically on long, predominantly rural feeders that have a relatively high load characteristic. As with other network hardware, there have been a number of different manufacturers who have supplied this type of equipment to Northpower. Units manufactured by Cooper Power Systems and Turnbull and Jones are currently in use Age Profile Of the 4 regulator stations 1 is 7 years old, 1 is 10 years old and the other 2 are 40 years old Condition Given the low numbers of assets in this category, condition monitoring is uncomplicated. The overall condition of these units is considered to be good and the 55 year expected life should be achievable Distribution Substations/Transformers Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Pole Mount 5,693 5,663 Ground Mount 1,307 1,296 The purpose of a distribution substation is to reduce the primary voltage of the electrical distribution system (11kV - HV) to the utilisation voltage (400V or 230V - LV). Distribution transformers are installed to have sufficient capacity to meet peak electrical load requirements. They are located on the HV network and can be situated on or above the ground near the load. The transformer may supply a number of electrical installations via the LV network. As with other network hardware, there have been a number of different manufacturers who have supplied this type of component to Northpower. Latterly distribution transformers have been manufactured by ABB or ETEL although given the longevity of the asset, units manufactured by Tolley, Turnbull and Jones, Ferranti, ASEA, CANZAC and Tyree Power Construction are still in use on the network. Ground mounted transformers are usually installed in plastic or metal cubicles or in dedicated enclosures or rooms within buildings. They can range in capacity from 30kVA through to 1MVA.

79 Section 3 Assets Covered 3-29 The purpose of a pole mounted distribution substation is the same as that of a ground mounted substation. All rural distribution substations (with some exceptions) utilise pole mounted transformers due to lower cost and ease of installation and vary in size from 1kVA through to 200kVA units (which need to be mounted on double pole structures due to their size and weight). Pole mounted distribution substations have traditionally also been installed in urban environments where the transformer size is 200kVA or less but they are gradually being replaced by ground mounted stations. New substation installations in high density urban environments are ground mounted Age Profile Age Profile of Distribution Substations Count Ground Mounted Overhead Distribution Substations Age Profile Condition Age (Years) Regular preventative maintenance inspections capture the condition of the distribution substations. The ground mounted substation inspections show that the general condition is fair given the spread of age of the asset. There are 183 ground mounted transformers in service that are older than the 45 year standard expected lifespan. The pole mounted substation inspections show that the general condition is fair to poor given the spread of age of the asset. There are approximately 1,037 overhead transformers in service that are older than the 45 year expected life. Replacement is typically triggered due to loading changes either increasing or decreasing the required capacity; failure due to lightning strikes; physical damage from third party interference or the onset of corrosion possibly causing an oil leak.

80 3-30 Section 3 Assets Covered Low Voltage Pillars Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Link Pillar (659*) Service Pillar 9,810 9,403 (12,759*) *These values were reported incorrectly in the 2011 AMP. Low voltage underground cables are typically terminated in pillars adjacent to the boundary of a premise. The pillar usually contains the fusing and is the termination point for the customer owned service cable for the electrical installation. Pillars can often contain fuses for more than one installation as they are typically located on the boundary of two lots. The unit is usually made of plastic although a number of different materials such as concrete and metal have been used in the past. In addition to service pillars, the network contains a number of low voltage link pillars which are common points between two runs of low voltage conductors from different transformers. Link pillars may be used to back feed low voltage from one transformer into the circuits from an adjacent transformer when one of the transformers is removed from service Age Profile 1000 Age Profile LV Pillars Default Value of 39 Years used for 2,347 of Unknown Age LV Pillars (29.4%) 700 Count Default Link Pillar Service Pillar Age (Years) LV PIllars Age Profile Condition A visual inspection of all service pillars is undertaken on a biennial cycle and annually for the link pillars. The visual inspection identifies any safety issues which are remedied in a timely manner. Overall the condition of the pillars is fair. A number of the older concrete type pillars have been identified as having a potential issue due to corrosion failure of the cable termination studs. The active program to replace this type of pillar continues.

81 Section 3 Assets Covered Zone Substation Sites Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Zone Substation Land Zone Substation/GXP Buildings Most of Northpower s zone substations typically consist of two sections. There is the outside switch yard which contains the transformer or transformers to convert the sub-transmission voltage (33kV) to the distribution voltage (11kV) and the 33kV switchgear. The switchyard also contains the bus work that interconnects the sub-transmission network, the transformers and the distribution network along with the sensing devices for the control of the system. In addition there is a building which usually contains the 11kV circuit breakers, the control systems and the communication systems. Further details on the circuit breakers are contained within the section below. The more modern zone substations in urban environments do not have an external HV switchyard and all components are enclosed in the building. As the electrical demand has increased over the years, additional zone substations have been added to the network giving the widespread age profile Age Profile 6 Age Profile of Zone Substation Buildings 5 4 Units Age Zone Substation Buildings Age Profile Condition Monthly inspections of the zone substation buildings and equipment ensure that they are maintained in an overall fair condition. As with other buildings in the Northland area, 50 years is considered to be the standard life. Given the construction techniques employed in the buildings, the preventative maintenance inspections and the follow up maintenance undertaken as a result of the inspections, it is anticipated that the zone substations will provide a longer life than the standard assumed lifespan.

82 3-32 Section 3 Assets Covered Zone Substation Battery Banks Description of Asset Description Quantity (units) in 2012 Quantity (units) in V Battery Bank V Battery Bank V Battery Bank V Battery Bank 2 2 All zone substations contain a series of 9 x 12V lead acid batteries providing an 110V DC supply. This supply is used to operate certain components of both the 33kV and 11kV circuit breakers such as closing coils, tripping coils and spring release charging motors as well as transformer tap changer motors Age Profile 16 Age Profile of Battery Banks Default Value of 11+ Years used for 9 Battery Banks(22%) Default Units 8 12V 6 24V 48V V Age Battery Banks Age Profile Condition The condition of the 110V battery banks overall is considered to be good largely due to the two monthly impedance and condition checks that are carried out and any remedial work as a result of those checks. On average a battery bank will last seven years although those installed in substations and that get infrequent use will last much longer.

83 Section 3 Assets Covered Zone Substation Transformers and Tap Changers Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Transformers + OLTC As stated above, the sub-transmission transformers convert the sub-transmission voltage (33kV) to the distribution voltage (11kV). As with other network hardware, there have been a number of different manufacturers who have supplied this type of component to Northpower in the past. All of the transformers are oil filled for insulation and cooling purposes. Those units whose load is close to their rated capacity may have additional cooling facilities through the installation of oil circulating pumps and fan forced cooling. The power transformers have ratings between 1MVA and 20MVA. In addition, the transformers have sensors and transducers fitted that monitor the condition and loading of the transformer. These signals are transmitted back to the control room for monitoring and will raise alarms if they exceed their normal operating parameters. This data is also stored for system analysis and profiling to assist in planning for the future development of the distribution network. The on-load tap changer (OLTC) is used to change the tapping connection of the transformer winding while the transformer is energised. This regulates the output voltage to keep it within required levels Age Profile Age Profile of Sub Transmission Transformers Units kV Distribution Zone Sub Age Sub Transmission Transformers Age Profile

84 3-34 Section 3 Assets Covered 80 Age Profile of On Line Tap Changer Relays Units On Line Tap Changer Relays Age Profile Condition 6-10 The transformers are subject to both bi-monthly and bi-annual checks. The bi-monthly inspections are to ascertain their physical condition with regards to paint work, rust, oil leaks, breather/silica gel units and any obstructions to the cooling fins. The bi-annual checks are two-fold; firstly the condition of the oil is checked by analyses of oil samples and secondly electrical testing of the transformers. The oil samples are tested externally by a reputable analyst who evaluates the condition of the oil. The resulting test report provides any recommendations for future/ additional testing and/or maintenance. The electrical testing of the transformers covers both the basic tests completed by Northpower and PDC (Polarisation/Depolarisation and Partial Discharge) tests is carried out by a consultant engineer which involves the use of specialist equipment. These reports cover the current condition of the transformer and report on its expected remaining life usage at full power. All test results are collated and summarised into a prioritised list indicating the next preferred transformer to be released for mid-life refurbishment maintenance. The mid-life refurbishment involves a full de-tank inspection of the transformer core with a complete dry out in a vacuum oven. Adjustment and repairs to the transformer and tap changes are carried out during this process. If any significant problems are indentified during the testing, they are notified to all internal stakeholders to enable the correct safety and commercial decisions to be made. The mid life maintenance priority list is regularly updated and scrutinised, as the latest test data becomes available, to highlight any sudden changes in a transformer s condition. A number of the older transformers are free breathers and are subject to moisture ingress which needs to be closely monitored in order to maintain the transformers within acceptable operating limits. Due to the robust condition monitoring program in place this group of assets the overall condition is rated as good and the standard life expectancy of 45 years will be exceeded Circuit Breakers Description of Asset Age

85 Section 3 Assets Covered 3-35 Description Quantity (units) in 2012 Quantity (units) in 2011 Indoor circuit breakers Outdoor circuit breakers Isolators/switches High-voltage breakers are broadly classified by the medium used to extinguish the arc: Bulk oil Minimum oil Air blast Vacuum SF6 The older breakers installed in Northpower s substations were either bulk oil or minimum oil breakers. Bulk oil breakers have a tank or reservoir of oil to maintain the levels of oil over the switch contacts. Minimum oil breakers contain a minimum amount of oil in each pole of the breaker. Both types need regular servicing due to potential contamination of the oil from the switching arc. Improvements in technology have seen the introduction of air blast, vacuum and SF6 circuit breakers. Northpower does not have any air blast circuit breakers. In the SF6 type breaker, pressurised sulphur hexafluoride gas is used to extinguish the arc across the breaker contacts. In the vacuum type breaker, the contact is within a vacuum so the arc is not maintained. Northpower has a number of the vacuum and SF6 type breakers installed. As with other network hardware, there have been a number of different manufacturers who have supplied this type of component to Northpower in the past. The following graph shows the populations of 33kV and 11kV circuit breakers by type. In addition there are air break switches (ABS) installed at substations primarily for use in isolating parts of the substation for maintenance. These use a set of knife links and an air gap; they are operated from the ground by way of a mechanical lever system to provide an open circuit Age Profile 35 Age Profile of Zone Substation Circuit Breakers Default Value of 39 Years used for 2 Unknown Age Circuit Breakers(0.9%) Units Default 11 kv Indoor CB - SF6/VAC 11 kv Indoor CB 33 kv Outdoor CB 33kV Indoor CB Circuit Breaker Age Profile Age

86 3-36 Section 3 Assets Covered Condition The preventative maintenance program including inspections and follow up maintenance have maintained the condition of circuit breakers as fair however due to the age and the increasing fault levels they are exposed to, the condition of the older oil breakers could be considered to be poor. For this reason they will be phased out as part of the zone substation switchboard upgrade projects over the next 10 years. The SF6 units are obviously much newer and are considered to be in very good condition Zone Substation Earthing Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Zone Substation Earthing The function of the zone substation earthing and bonding system is to provide an earthing connection to which transformer neutrals and other earthing equipment may be connected in order to pass the maximum fault current and allow the protection systems to operate. The earthing system also ensures that no thermal or mechanical damage occurs to the equipment within the substation. In addition, the earthing system also guarantees equipotential bonding such that there are no dangerous step and touch potential gradients developed within and surrounding the substation. The low impedance path is achieved by installing a grid under the substation site consisting of a series of 1.8m x 16mm driven earth pins connected with 70mm2 bare copper conductor. All exposed metalwork in the vicinity is connected to the earth grid. There are a number of nominated test points located at various places around the grid to facilitate the testing of the resistance of the earth mat Age Profile As the earth mat was installed at the time of the construction of the zone substation, the age profile is the same as that of the zone substation Condition The preventative maintenance inspections and any follow up maintenance undertaken as a result of the inspections have maintained the condition of the zone substation earthing as good Protection Relays Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Numeric Relays Electric/Static Relays The function of a protection relay is to initiate the disconnection of any faulty section of the power system from service. The protection relay senses the abnormal condition and the task of isolation of the faulty section is achieved through a circuit breaking device which is capable of disconnecting the faulty section. Northpower runs three categories of protection; line (point to point on the 33kV sub-transmission network), transformer (looking for fault conditions on the 33/11kV transformers) and feeder (looking for fault conditions on the 11kV outgoing feeders).

87 Section 3 Assets Covered 3-37 There are two distinct types of protection relays used on the system. There is the electro-mechanical type which tends to be older and which can be set to detect one particular abnormal condition so requiring a greater number of units to be installed per system element. The other type is numeric which is a fully programmable electronic unit providing greater functionality in a single unit. As with other network hardware, there have been a number of different manufacturers ranging from Reyrolle, GEC, SEL and Basler who have supplied this type of component to Northpower in the past Age Profile Age Profile of Protection Relays Default Value of 39 Years used for 30 of Unknown Age Protection Relays (9.2%) 25 Count Default Elect/Stat Numeric Protection Relays Age Profile Condition Similar to the circuit breakers, there is a wide range of age profiles and therefore a spread of condition ranging from good to poor. The biennial testing ensures that the relays continue to function within their prescribed limits and as required for the installation situation. As the asset has aged, Northpower has replaced the older electro-mechanical types with the numeric types. This replacement has been in conjunction with other associated work at the substations. Going forward, the protection relays will be upgraded in conjunction with the 11kV switchboard upgrades in the substations planned over the next 10 years Ripple Plant Description of Asset Age (Years) Description Quantity (units) in 2012 Quantity (units) in 2011 Ripple injection plants 6 6 A ripple plant generates a 283Hz signal which is then injected into the system to carry out load shedding and bulk control. The injected signal activates ripple receivers installed in the low voltage system of the network through which load such as water heating and streetlights are controlled. This ensures that the electrical load of the system is less than the volume of energy available to be consumed. Northpower operates three ripple plants that inject into the 33kV system and three ripple plants that inject into the 11kV system. All six plants are electronic solid state units.

88 3-38 Section 3 Assets Covered Age Profile Age Profile of Ripple Plant Units Age Ripple Plant Age Profile Condition The newer plants are in very good condition however the two older plants are approaching the end of their designed life and their condition is described as fair. The oldest unit was replaced in The plant that is removed will then be kept for spares to be used on the other plant to provide a longer life and delay the capital expenditure required for replacement SCADA and Communications Description of Asset Description Quantity (units) in 2012 Quantity (units) in 2011 Zone Substation RTU s Radio Stations (23*) *note this value was reported incorrectly in the previous year and didn t include all the radio stations; this should have also been 40 in the 2011 AMP. SCADA stands for Supervisory Control and Data Acquisition. In the context of Northpower, it refers to the computer system used to monitor and remotely control the electricity network. It consists of a master station located in the control centre at Northpower s Head Office which is monitored by system operators 24 hours a day. The remote stations (located primarily at zone substations) collect information about the system s condition or status and return that information to the master station via dedicated communications links. Northpower s communication system utilises optical fibre and radio communications in the microwave, UHF and VHF (for remote switches and voice) bands. In 2007 Northpower s master station was upgraded and work is currently underway to replace the existing remote stations, which have reached the end of their service life.

89 Section 3 Assets Covered Age Profile Due to the nature of the electronic hardware and changes in technology, the SCADA system together with the associated radio stations and remote terminal units have a wide spread of age profiles Condition The condition of these assets ranges from good to fair owing to the wide spread of age profiles. The older stations do not provide the functionality required to efficiently operate a modern electricity distribution network and as a result are nearing end of life from that respect. Northpower embarked on a three year program to replace the solid state equipment with micro-processor based systems. This will see an increase in the performance, reduction in outages and provide Northpower with a platform to build on for substation automation. Approximately 10 years ago a practice of replacement of equipment over a defined age was introduced and this has seen the older communications stations being updated. The overall condition of the communications system is therefore described as fair. Further advances in technology now provide the ability for Ethernet communications over microwave or fibre optic cabling. This technology has been adopted by Northpower and migration to these systems along with digital UHF is being carried out over the period of the AMP. As more and more zone substations are connected with fibre/microwave the penetration of Ethernet connectivity will increase providing geographic agility. The communication backbones also offer increased bandwidth for a greater level of monitoring which will include security cameras/proximity locks and network performance data. 3.4 Supporting and Secondary Systems Metering Systems Power Quality Metering Northpower has five sets of Power Quality Meters installed at the Transpower points of supply. These units provide the following functions: The recording of system power quality and events The recording of system voltage, frequency, current and power A comparative check of the Transpower metering impulses that are the basis for determining Transpower s billing to Northpower Revenue Metering Northpower owns in excess of 102,192 revenue meters fitted in customer s installations Power Factor Correction Plant Northpower currently has 18 x 750kVAr 11kV fixed capacitor banks installed at zone substations.

90 3-40 Section 3 Assets Covered Mobile Substations and Generators Northpower owns and maintains a 500kVA 400V mobile distribution substation with a 500kW generator. This unit is used to provide supply in the event of either an unplanned shutdown or planned shutdown. There are three modes of operation: Direct connection onto the LV network. In parallel with 11 kv network via transformer supplying an islanded 11 kv network via a transformer Generation Plant Northpower owns, operates and maintains a 5MW output hydro power station at Wairua. All generation plant has a preventative maintenance regime to ensure the most efficient use of the asset Backup Control Room Northpower has a backup control room which has been setup in case of emergency situations. The backup control room is fully featured scaled down version of the primary control room and includes a SCADA workstation, communication equipment and basic amenities Fibre Network With the development of the fibre network Northpower s communications and protection schemes have been migrated from older copper and wireless circuits where possible and cost effective. This has resulted in improved reliability and performance of these links. 3.5 Justification of Assets Northpower owns and manages existing assets and acquires new assets in order to carry out the core business activity of electricity distribution. The following table categorises network assets which Northpower justifies on technical and economic grounds to meet the requirement to provide affordable electricity of sufficient capacity (allowing for reasonable load growth) and reliability to consumers. Category of Asset 33kV switchgear within Transpower GXP s 33kV sub-transmission lines and cables Zone substations 11kV distribution lines and cables* 11kV distribution switches 11kV distribution substations 400V distribution network Justification Provide switching and fault interruption functionality at the source end of sub-transmission assets. Power transfer requirements are beyond that of distribution lines or cables. Interface power transfer capability of the 33kV network with the flexibility and cost effectiveness of distribution network. Power transfer requirements are beyond that of 400V lines or cables, but the use of 33kV would present physical and cost constraints. Provide operational flexibility and supply security. Interface power transfer capability of the distribution network with the cost-effective delivery of 400V supply to low capacity (domestic) customers. Most cost-effective way of delivering 400V supply to low capacity (predominantly domestic) customers. * As it is possible that the distribution system will be operated at both 11kV and 22kV in future, 22kV rated assets are technically justified.

91 Section 3 Assets Covered 3-41 Ideally the total network assets should not exceed the minimum required to provide the levels of service mentioned above at least cost i.e. they should be optimum. Northpower has some assets that exceed the theoretical optimum level. The value of these assets at replacement cost (2004) is shown in the table below which is an extract from the last Northpower ODV valuation carried out in The total replacement cost of Northpower system fixed assets at this date was $283million. The following are some reasons for the existence of these assets: The minimum rating available of some electrical equipment is significantly greater than the loads imposed, particularly in remote and rural areas. Some lines between existing zone substations and sites or areas identified as requiring a zone substation in the future were built to 33kV standard but are currently used at 11kV. One of the two 33kV circuits between Maungatapere GXP and Whangarei South zone substation was built as a single pole double circuit line (used currently as a single circuit line) for future capacity and security. The network grew incrementally over many decades. If the present-day network was being entirely constructed over a short period of time, it would probably look quite different as many assets would be optimised out. However, the present day network represents an accumulation of incremental investment decisions that were quite probably very efficient at the time they were made. A large part of the network was built in an era when investment criteria were different to those of today.