This study assessed the feasibility of installing solar-diesel hybrid mini-grid systems on Koome Main and Damba Island (Uganda), to bridge the energy access gap in off-grid communities. Despite being economically active, these islands face significant challenges in accessing essential services such as healthcare, education and business infrastructure due to the lack of electricity. A mixed-methods approach including surveys, interviews, focus group discussions and technical modelling using STATA, Excel and Homer Pro was used to assess the technical, economic/financial feasibility as well as affordability aspects of the project. The results indicate that the installation of solar-diesel hybrid mini-grids of 650 - 950 kW and 300 - 470 kW for Koome and Damba islands respectively were feasible. The economic assessment shows favorable financial indicators, including internal rate of return (IRR) ranging between 14% - 19% and PBP between 4 - 7 years. In terms of affordability of electricity from mini-grids, a 50% subsidy would be necessary to make electricity affordable for domestic and institutional category spending between UGX10,000 - 30,000. Also, net present cost (NPC) between 1.58 million € and 2.24 million €, LCOE ranging between 0.24 - 0.27 €/kWh which was still less than 0.3 €/kWh for both islands was obtained, further highlighting attractiveness of the solar-diesel hybrid systems for Koome and Damba Islands.
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