«Prepared for the Government of the Cook Islands Foreword Thank you to all those that have assisted in the preparation of this report particularly the ...»
Rakahanga Power Study
Report December 2006
Prepared for the Government of the Cook Islands
Thank you to all those that have assisted in the preparation of this report particularly the Director
and staff of the Energy Division, MFEM Aid Management Division and particularly the residents,
Council and Administration of Rakahanga who showed tremendous hospitality and a willingness to
help gather information for this power sector report. I hope this report helps to further the
development of a sustainable power system on Rakahanga.
Bruce Clay December 2006 ii
ACRONYMS and ABBREVIATIONS
$ = NZ$ unless stated otherwise iv
TABLE OF CONTENTS1 SUMMARY OF FINDINGS AND RECOMMENDATIONS
2.1 PROJECT BACKGROUND AND OBJECTIVES
3 RAKAHANGA BACKGROUND
3.1 PHYSICAL DESCRIPTION AND POPULATION
3.2 LOCAL GOVERNMENT
4 RAKAHANGA ENERGY
4.1 STRUCTURE AND ORGANISATION
4.2 POWER STATION
4.4 LOW VOLTAGE DISTRIBUTION
4.5 FUEL HANDLING
4.6 POWER QUALITY AND LOAD PROFILE
4.7 CUSTOMER DISTRIBUTION AND TARIFF
Developments and Load Growth
4.8 PRESENT RECOVERY TARIFF
5 POWER SECTOR PLAN
5.1 INSTITUTIONAL ARRANGEMENTS
5.2 LOAD FORECASTS
5.3 SHORT TERM RECOMMENDATIONS
5.3.1 Power Station
5.3.2 LV Distribution
5.3.3 Administration and Personnel
5.3.4 Demand Side Management (DSM)
5.3.6 Renewable Energy
5.4 MEDIUM TERM RECOMMENDATIONS
5.4.1 Power Station
5.4.2 LV Distribution
5.4.3 Administration & Personnel
5.4.4 Demand Side Management
5.4.6 Renewable Energy
5.4.7 Renewable Energy Power System
Project Engineering Considerations
Personnel and Organisational Considerations
Optimal Renewable Energy System
5.5 LONG TERM RECOMMENDATIONS
5.5.1 Power Station & LV Distribution
5.5.2 Administration & Personnel
5.5.3 Demand Side Management
1 SUMMARY FINDINGS RECOMMENDATIONSOF AND This report investigates the current power system on Rakahanga and considers short, medium and long term options for the development of the system to include local renewable energy sources. A field visit was carried out in April 2006 to assess current system status, personnel and island development.
Rakahanga’s existing diesel generation plant is in a poor state of repair and requires replacement or overhauling to provide power security. The power station switchboard requires replacement and the LV distribution network needs maintenance. Technicians will need to be brought on island to assist the local energy personnel in servicing the system to bring it to an acceptable level of quality.
In the short term a wind and solar monitoring programme should be initiated to quantify the local renewable energy resource. This could be carried out on Manihiki as the results derived would be applicable to both islands.
Medium term integration of renewable energy utilising solar photovoltaic (PV) is recommended to provide 24hour power subject to quantification of the local resource through a monitoring program in the short term. Modelling suggests that installation of a solar/battery/diesel hybrid system would provide all of the islands power requirement from a local renewable resource at a full recovery cost 20% less than the existing diesel system. Based on the assumed solar resource, current fuel price and an installed cost of approximately $1,000,000 the hybrid system is financially viable.
Should funds not be available for a full renewable energy based system in the Medium term a staged approach with a diesel/battery hybrid installed first at a cost of approximately $300,000 would reduce the full recovery cost to $1.92/kWh and subsequent stages could add solar PV and/or wind power generation as funds become available.
Long term it is anticipated that wind and/or solar could replace virtually all diesel power generation and provide Rakahanga with a power system whose operating costs are not significantly affected by variations in fuel prices and provides the island with a high degree of power self sufficiency.
Table 1-1 summarises the major findings and recommended interventions which form the basis of an overall power sector plan for Rakahanga Energy.
The ADB Cook Islands Power Development Study of 1998 carried out an extensive evaluation of outer island power supplies and provides a baseline for comparison to current systems. Key statistics and a comparison to the current situation are shown in Table 1-2. Of particular importance is the 82% increase in the current landed fuel price and full cost recovery tariff requirement of more than double over the 1998 figures whilst the billed tariff has not increased. Operating recovery cost has more than doubled over the 1998 figures reflecting the fuel price increase. On an annualised basis the fuel price increase since 1998 has added close to $10,000 p.a. to the operating cost of RE.
Whilst population has decreased approximately 40% total power consumption has increased 45% since 1997. Interestingly the number of connected consumers has barely changed indicating that the 6 number of people per dwelling has dropped by close to 40%. Supply hours have increased to 14 hours however this would probably attribute less than 15% to increased consumption. The increase in power consumption can really only be attributed to the increased use of household appliances such as TV’s, radios, fans and electric cooking.
This power study has been executed by the Energy Division, Ministry of Works, GoCI to asses the current power status on Rakahanga, provide a power sector plan and investigate the feasibility of supplementing and in the long term replacing the present diesel generation system with local renewable energy. The goal of the Government of the Cook Islands (GoCI) for renewable energy, as stated in its National Energy Policy (2003), is to increase the utilisation of renewable energy technologies in the Cook Islands energy supply.
This project has the following objectives:a) Determine short term improvements of the existing power system In view of the current serious limitations in generation capacity and distribution recommend short term interventions to ensure reliability of supply and address longer term capacity requirements.
b) Determine medium to long term feasibility of supplementing current diesel power systems with renewable energy Investigations of appropriate feasible renewable energy technologies which could supplement the diesel power system.
c) Power Sector Plan Formulation of a plan encompassing project recommendations which addresses short, medium and long term development of the power system. Issues addressed include:Operational Costs and Budgets Capital Budgets Tariff Structure Demand Growth Organisational requirements Human resources development Demand side management strategies
Project execution was undertaken in the following four stages.
Stage 1: Inception Note/Project Preparation.
• Review of relevant background material, studies and investigations already undertaken.
• Identify key stakeholders.
• Preparation of inception note.
• Develop field visit schedule in consultation with stakeholders.
Stage 2: Field Visit Consultant Bruce Clay participated in the field visit to Rarotonga and Rakahanga. The field visit encompassed the following;
Visit to Rarotonga:
• Discussions with the Energy Division, Ministry of Works; Aid Management and relevant Government Ministries on current status of Rakahanga Energy.
• Following up Stage 1 information gathering with relevant Government Departments, organisations and project stakeholders.
Visit to Rakahanga:
• Meeting with stakeholders including Rakahanga Island Council, Rakahanga Island Administration, Rakahanga Energy (RE) personnel and the community to discuss and survey qualitatively the socio-economics of the various consumers and how these impact Energy services.
• Compiled a listing of existing power generation and control equipment, grid composition and their operating status.
• Gather available power system data for existing diesel power systems. Specifically looking at operational regime information, power production, daily load structure and its variability, and fuel consumption.
• Using a power quality analysis recorder log power data during the island visit. Data logged included phase voltages and currents, active and reactive power and energy and power factor. Collected data is used in substantiating/correlating existing data.
• Investigated potential local energy resources and their technical feasibility for using in future power generation development.
• Assessed relevant physical and institutional conditions that may impact power generation development. These included; geographic characteristics, existing infrastructure, utility capabilities, workforce and construction equipment availability.
Stage 3: Debriefing
• Debrief Director of the Energy Division, Ministry of Works, Aid Management, OIC of RE, Rakahanga Island Secretary and Rakahanga Island Mayor on conclusions based on preliminary analysis and findings.
Stage 4: Detailed Analysis and Power Sector/Feasibility Report Preparation
• Description of project background and immediate objectives, based on the Government of the Cook Islands recognition of the potential contribution renewable energy technologies can make toward economic and social development and the environment. Reference was made to the project’s objectives, concept and beneficiaries and how it ties in to relevant studies and those currently in process.
• Socio-economic consequence description that is based on field qualitative survey and where available, existing survey data.
• A power Sector description was generated after analysis of gathered data. This description highlights the various roles on a national and local community level of relevant public authorities, institutional and legal frameworks in place for the power sector, standards, ownership, Government policies, plans, budgets and objectives.
• Examined, described and assessed the trends in electricity tariff and demand based on gathered information including the Cook Islands National Energy Policy (2003) and its influence on the feasibility of introducing renewable energy technologies to Rakahanga.
Procedures for accommodating changes in tariff structure were investigated.
• Analysed existing power and load structure data in association with field recorded power analysis logged data and investigated present and potential power demand and loading structure. Forecasts were prepared relating to medium and long-term power requirements to assist in further feasibility studies.
• Based on the field visit and collected data relating to existing power generation, short term options were examined to improve efficiencies in diesel generation and distribution. Options include supply sided, distribution and demand side management activities.
• Local energy resource preliminary assessment that was based on available resource data and field visit and evaluated solar thermal, solar photovoltaic, wind and biomass and their future potentials for Rakahanga power generation.
• Assessment of project engineering for Rakahanga’s power system when considering short, medium and long term options. These will consider not only the technologies applicable to generation and distribution but also civil, operational and maintenance requirements with particular consideration to difficulties in operating and maintaining power systems in remote locations.
• The consultant will investigate organisational requirements for power plant construction/upgrade, operation and maintenance.
• Training and technical assistance programmes will be outlined. These will include training programme target groups, content and delivery.
• For each Energy option, capital and operational budgets will be prepared. Based on budgets and cash flows, an economic and financial analysis (including sensitivity analysis) will be performed on the various options as part of the overall feasibility assessment. The consultants will undertake analysis of associated assumptions and risks.
• As a major project outcome, the consultants will develop a power sector plan for Rakahanga. This plan will encompass the synthesis of project recommendations and Energy options feasibilities consistent with the Cook Islands National Energy Policy.
Several previous studies and reports are particularly relevant to this project and were relied on among others for information regarding power sector, institutional structure, background to power systems on each of the islands and renewable energy resource data. These include but were not
• Cook Islands National Energy Policy 2003
• Environment Act 2003