At the heart of this transformation is the Outer Island Renewable Energy Project (OIREP), supported by the Asian Development Bank (ADB) and co-financed by the European Union and other donors. The “on-grid” portion will be allocated to Ha'apai and 'Eua, while the “off-grid” portion will incorporate 'Uiha, Nomuka, Ha'ano, Ha'afeva, as well as Niuatoputapu and. Tonga's Energy Transition to Renewable Energy and Clean Technologies Objectives Sites Significance Literature Review Mini-Grid Solar System – How it works Case Study: Pacific, Zambia, and India Mini-Grid Systems – Tonga Outcome Challenges Encountered Conclusion, Policy Recommendations, Future Study. Tonga is making tangible progress toward its renewable energy targets with the rollout of solar-powered mini-grid systems across its outer islands, in a bold move to reduce its dependence on expensive diesel imports and improve electricity access for remote communities. The review considered issues related to the overall project's relevance, effectiveness. What is the Tonga solar project? 1. The project will construct and install solar power systems with a total capacity of 1. 32 MWp on the outer islands of Tonga, and the existing grid network on the islands of Vava'u and 'Eua rehabilitated by TPL.