Tonga Power Supply Solar System Model

The project achieved its proposed impact, in terms of helping Tonga reduce its dependence on imported fossil fuel for power generation with OIREP assets estimated to have reduced diesel usage by 0.5 million litres annually. Central to the project outcome was the provision of on-grid and off-grid generation solar power at reduced cost.

This means that little more than 30,000 people are spread across 35 islands, presenting acute issues in terms of the provision of modern infrastructure. At OIREP commencement, the ADB estimated that 89% of all households across Tonga had access to electricity.

Australia also has a long history of engagement in relation to helping secure Tonga's outer island energy needs. In the early 2000s, Australia funded the Ha'apai Outer Islands Electrification project (HOIEP), which involved the installation of diesel-powered generators and electrical reticulation on four islands in the Ha'apai group.

This has contributed to the Tongan economy and electricity consumers being exposed to high and volatile electricity prices due to fluctuations in the price of oil internationally. According to UK-based aggregate website Cable, Tonga's electricity is the 13th most expensive in the world, at an average cost of USD 0.35 per kilowatt hour (kWh).

However, significant needs and opportunities exist to further expand renewable energy systems on outer islands. Less tangible, but also important is the role played by OIREP in consolidating Tonga's social contract with remote island dwelling communities, by allowing for enhanced and more reliable access to electricity.

OIREP's on-grid work was always a matter of laying the foundations for further investment in renewables and enjoyed the ease of working through one implementing partner – Tonga Power Limited – who were incentivised to help ensure the program succeeded given they will manage all on-grid assets post-project.