Technical evaluation of the performance of solar PV mini-grids: a case study in Bunjako Island Mini-Grid Uganda

Abstract

This project evaluates the performance of a Buzaami solar PV mini-grid located on Bunjako Island, Mpigi District, Uganda. The mini-grid has an installed capacity of 40 kWp and a battery capacity of 75.4 kWh. Despite sufficient generation on this mini-grid, supply of energy remains a struggle due to limitations in energy storage. This study investigates the reasons behind the unmet demand and proposes recommendations for improvement. The analysis revealed unused energy during peak sunshine hours. To address this inefficiency in order to increase energy supply in meeting demand, the report suggests expanding the battery storage capacity by 37.7 kWh. This would enable the storage of excess energy and cater to the unmet demand at night. Additionally, incorporating productive use energy (PUE) loads that consume less than 3 kW, such as freezers and food processing equipment, is recommended. These interventions are predicted to improve the performance ratio to 80.2% and reduce unused energy to 5.2%. The economic feasibility of the proposed solutions is also explored. The payback period for the additional battery storage is estimated at 5.5 years, indicating a financially viable investment. In conclusion, this project demonstrates the potential for solar PV mini-grids to provide sustainable energy access in rural areas. By expanding the energy storage and incorporating PUE loads, these mini-grids can achieve greater efficiency and meet the growing demand for electricity