Tonga: Outer Island Energy Efficiency Project

Sovereign Project | 46492-001

The impact of the project will be improved energy security in Tonga. The outcome will be increased reliability and efficiency of power on the supply side of TPL's outer islands. The outputs will include (i) power distribution network upgraded in the project area; (ii) operation and maintenance knowledge transfer program and (iii) efficient project management services.

Project Details

  • Project Officer
    Hattle, Paul S.
    Pacific Department
    Request for information
  • Country
  • Modality
    • Technical Assistance
  • Sector
    • Energy
Project Name Outer Island Energy Efficiency Project
Project Number 46492-001
Country Tonga
Project Status Closed
Project Type / Modality of Assistance Technical Assistance
Source of Funding / Amount
TA 8296-TON: Outer Island Energy Efficiency Project
Clean Energy Fund under the Clean Energy Financing Partnership Facility US$ 400,000.00
Strategic Agendas Environmentally sustainable growth
Inclusive economic growth
Drivers of Change Gender Equity and Mainstreaming
Governance and capacity development
Sector / Subsector

Energy / Renewable energy generation - solar

Gender Equity and Mainstreaming Some gender elements
Description The impact of the project will be improved energy security in Tonga. The outcome will be increased reliability and efficiency of power on the supply side of TPL's outer islands. The outputs will include (i) power distribution network upgraded in the project area; (ii) operation and maintenance knowledge transfer program and (iii) efficient project management services.
Project Rationale and Linkage to Country/Regional Strategy

Petroleum dependency makes Tonga highly vulnerable to oil price shocks, affecting the affordability of food, goods, electricity, and transportation. This reliance on fossil fuels exposes the economy to high electricity tariffs linked to volatile oil prices over the last decade, since more than 90% of its overall grid connected electricity demand is supplied by generators fueled by imported diesel. Between 2001 and 2011, the average ex-Singapore-based oil price increased from $25 to $98 per barrel. Linked to these fluctuations, the electricity tariff reached a peak in 2008 at $0.55 per kilowatt hour (kWh), and although the tariff has now dropped to $0.53 per kWh, it is still the most expensive in the region, partly due to an inefficient power distribution system.

The government has been seeking to reduce both the cost of electricity supply and Tonga's vulnerability to oil price increases. In 2008 the government approved The Renewable Energy Act, a regulatory instrument to promote the use of renewable energy technologies. In recognition of the vulnerability of Tonga's electricity sector to oil price rises the government has set a target to generate 50% of Tonga's grid based electricity from renewable energy resources and to achieve a 50% reduction in diesel consumption by 2020 in its National Strategic Planning Framework of 2009. The Tonga Energy Road Map 2010-2020 (TERM) is the government's development, reform and improvement plan for the energy sector, drafted in close coordination with development partners. The TERM pursues (i) enhancement of the petroleum supply chain; (ii) deployment of renewable energy technologies; and (iii) supply and demand-side energy efficiency, recommending especially loss reduction in the electricity distribution network.

The responsibility for provision of electricity services rests solely with Tonga Power Limited (TPL), the power utility, a vertically integrated public enterprise wholly owned by the government under the oversight of the Ministry of Public Enterprises (MPE) and the Cabinet. TPL has concessions to operate four independent grids in Tonga, the largest on the main island of Tongatapu, and three smaller grids on the main islands of the Vava'u, Ha'apai and Eua island groups, where it generates, distributes, and retails electricity, and provides operation and maintenance services.

The total installed grid connected power capacity managed by TPL in 2012 had about 14.3 megawatt (MW), with a yearly demand of about 52.4 gigawatt hour (GWh), and about 700 kilometers of power distribution lines. The total diesel consumption for generation of electricity in 2011 was estimated in 15 million liters to supply 98% of grid connected electricity. It is expected that the peak demand will increase to 17.2 MW by 2020.

The power distribution system is the most visible part of the electricity supply chain, which requires considerable investment, maintenance and operation efforts. According to electrical industry standards power distribution assets represents 20-30% of the required power system investments. Standard losses in rural power distribution networks are around 5 to 6%. However, in Tonga the percentage of power losses (commercial and technical) is around 20%, requiring more fuel for power generation. Therefore it is in the interest of the power utility and consumers to increase the efficiency of the power system as a whole.

The proposed project will capitalize on the results to be achieved under the proposed Outer Island Renewable Energy Development Project, the scope of which is to implement solar power connected to existing power distribution networks in the outer islands of Tonga. To maximize the distribution of the newly installed solar electricity the Government has requested Asian Development Bank's (ADB) assistance to upgrade the existing power distribution grids of (i) Ha'apai, including 'Uiha, Nomuka, Ha'ano and Ha'afeva; (ii) Vava'u; and (iii) Eua. The proposed project will replace grid assets (cable, poles, distribution transformers and switchgear) and existing street lighting with efficient street lighting powered by solar panels. It will minimize power distribution losses and reduce the fuel consumption of the existing diesel power plants, thus avoiding about 2,025 tons of carbon dioxide (CO2) per year. Before project implementation, project preparatory technical assistance (PPTA) will conduct due diligence for each project site including technical feasibility, social and environmental safeguards, and gender action plan.

The added value of the proposed project is to demonstrate that combining deployment of renewable power generation and power distribution loss reduction is an appropriate strategy to optimize existing energy matrixes and reduce their carbon output. Additional electricity will contribute to power security, create sustainable livelihoods and reduce environmental pressure. The proposed project is in line with ADB's Energy Policy 2009 which promotes energy efficiency and renewable energy; maximizing access to energy for all; promoting energy sector reform, building capacity, and improving governance. It is included in Tonga's Country Partnership Strategy (2008-2012) and Country Operations Business Plan 2012-2014

Project Outcome
Description of Outcome
Progress Toward Outcome
Implementation Progress
Description of Project Outputs
Status of Implementation Progress (Outputs, Activities, and Issues)
Geographical Location
Summary of Environmental and Social Aspects
Environmental Aspects
Involuntary Resettlement
Indigenous Peoples
Stakeholder Communication, Participation, and Consultation
During Project Design
During Project Implementation
Business Opportunities
Consulting Services

The TA will require 11 person-months of international and 6 person-months of national consulting inputs. The scope of this project is an extension of the proposed Outer Island Renewable Energy Project, therefore single source selection of the same consultancy firm (High Chem GmbH) is proposed. This fact will allow the natural continuity in the technical approach, highly qualified work, retaining experience acquired, continued professional liability, and continuation of good performance. The firm was previously engaged through quality- and cost-based selection method (quality-cost ratio of 90:10), due to the specific technological complexity of the previous project preparation using a simplified technical proposal in accordance with the Guidelines on the Use of Consultants (April 2010, as amended from time to time). The proceeds of the PPTA will be disbursed in line with ADB's Technical Assistance Disbursement Handbook (April 2010, as amended from time to time).

The cluster TA, ADB's Pilot Asia Pacific Climate Technology Finance Center, Subproject B, Assessment of Technology options for priority projects, will finance as in-kind contribution 3 person-months of international consulting inputs.

Responsible ADB Officer Hattle, Paul S.
Responsible ADB Department Pacific Department
Responsible ADB Division Transport, Energy and Natural Resources Division, PARD
Executing Agencies
Ministry of Finance
Vuna Road
Kingdom of Tonga
Concept Clearance -
Fact Finding -
Approval 17 Dec 2012
Last Review Mission -
Last PDS Update 21 Jan 2013

TA 8296-TON

Approval Signing Date Effectivity Date Closing
Original Revised Actual
17 Dec 2012 28 Jan 2013 28 Jan 2013 30 Nov 2013 31 Dec 2013 -
Financing Plan/TA Utilization Cumulative Disbursements
ADB Cofinancing Counterpart Total Date Amount
Gov Beneficiaries Project Sponsor Others
0.00 400,000.00 0.00 0.00 0.00 0.00 400,000.00 18 Nov 2021 390,000.00

Project Data Sheets (PDS) contain summary information on the project or program. Because the PDS is a work in progress, some information may not be included in its initial version but will be added as it becomes available. Information about proposed projects is tentative and indicative.

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Title Document Type Document Date
Outer Island Energy Efficiency Project Technical Assistance Reports Jan 2013

Safeguard Documents See also: Safeguards
Safeguard documents provided at the time of project/facility approval may also be found in the list of linked documents provided with the Report and Recommendation of the President.

None currently available.

Evaluation Documents See also: Independent Evaluation

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Related Publications

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The Access to Information Policy (AIP) establishes the disclosure requirements for documents and information ADB produces or requires to be produced in its operations to facilitate stakeholder participation in ADB's decision-making. For more information, refer to the Safeguard Policy Statement, Operations Manual F1, and Operations Manual L3.

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