TREP accelerates Tonga’s commitment to 70% renewable target by 2030 ^Featured

The Tonga Renewable Energy Project (TREP) implemented by MEIDECC’s Department of Energy is enabling Tonga to reduce its dependency on imported fossil fuel and shift to renewables.

The project is divided into three main outputs.

Output 1: Installation of large scale battery storage in Tongatapu

Due to the Covid-19 travel restrictions, the installation and commissioning which would have been undertaken by European technical staff was completed by a local labour and a technical expert from New Zealand.

The storage is required for Tonga Power Limited (TPL) to absorb higher renewable energy percentage by minimizing the impacts due to the intermittent nature of renewable solar and wind generation.

The output was completed in December 2021 and the battery is now assisting TPL to keep the lights on due to the damages sustained by two of their largest diesel generators.

Linkage to Power Purchase Agreement (PPA)

The commissioned batteries allows the grid to accept more renewable energy.

TPL have a 6MW of solar generation commissioned under PPA with a company from New Zealand. The batteries help the existing renewable energy projects such as 2.1 MW wind and additional solar projects currently underway. While these projects, enabled by the batteries, significantly increase the renewable energy percentage there will still be a shortfall to the government’s 50% target.

Output 2: Installation of renewable energy system in ‘Ohonua, ‘Éua and Neiafu, Vava’u

With the travel restrictions all works on the outer islands have been undertaken to date using local labour.

A solar and storage plant is on target for completion in August 2022 in Vava’u and a similar solar and storage system is on target for completion in ‘Eua on September 2022.

Output 3: Installation of mini-grid systems on the islands of Niuafoóu and Haápai Outer Islands

The final part of the original project scope is to install solar mini-grid systems on the islands of Niuafo’ou and Ha’apai (Tungua, Mo’unga’one, Kotu and ‘O’ua).

These will be the first fully renewable island systems with all the power being supplied from solar power with significant storage to ensure 24/7 renewable power to all households.

The New Zealand contractor will mobilise in August with all islands currently scheduled for completion by May 2023.

Despite the pandemic and escalating costs additional scope was included in the project through savings. Solar mini-grid will be installed in four additional outer island villages in Vava’u.

These potential villages are Hunga, Ofu, Falevai and Otea.

This package is currently out for bids and the installation is scheduled for completion around October 2023.

The project has also funded transaction advisors who along with project consultants have developed a procurement option that will set Tonga to reach its 70% target by 2030.

The procurement of solar, wind and storage was endorsed by the Ministry of Finance and will go out to the international market in August 2022 having already been shortlisted through an expression of interest process completed in 2021.

The development, installation and operation of the required renewable generation will be undertaken by the successful bidder with the energy being sold to Tonga Power through a Power Purchase Agreement (PPA).

The off take of this energy would require reasonable upgrades to the grid and ADB has expressed its interest to provide funding support of the upgrades once TPL along with help from TREP consultants Entura have determined the level of upgrades required.

Increasing the renewable energy percentage, which is at a fixed cost for 20 years, will reduce the dependency on diesel minimising the effect of diesel price fluctuation creating a more stable tariff.

TREP is funded by the Asian Development Bank (ADB), Green Climate Fund (GCF) and the Australian Department of Foreign Affairs and Trade (DFAT).