This study is to further develop a project proposal submitted by the Government of Tonga to transform its solar electrification programme into a financially sustainable one. This is to be carried out through the electrification with solar PV of the outer islands of the Ha'apai Group, utilising the lessons learnt from previous projects and using the project as a leverage for change to the existing projects and a model and funding incentive for new ones. The electrification of the target islands is decentralised solar home systems is crucial for effecting changes to the existing solar electrification projects in the country.

The study confirmed that the proposed Tonga Sustainable Solar Electrification Project is in line with the priorities of the Tonga Government. Decentralised solar home systems have been identified as the best power generation option for the target islands. This study is based on the project proposal submitted by Tonga for funding under the PREFACE Programme.  The proposal is called the Tonga Sustainable Solar Electrification Project (TSSEP) aimed at transforming the existing Tonga Outer Islands Solar Electrification Programme into a financially sustainable one.