Design and modeling of an energy village for rural communities in Uganda

Abstract

Rural energy planning needs an integrated technical, economic, and social model for sustainability. In this work, a rural energy village concept was adopted. In this context, an energy village referred to a small town or community comprising of between 100 to 12000 households. Development of the energy village for the selected community of Bidibidi Refugee Camp involved characterization of the settlement for energy uses, potential and formulation of optimal energy supply option. From household surveys, a typical household in the settlement comprised of an average of 6 persons who depend predominantly on biomass (92%) to meet their key energy demand for cooking. Cooking accounted for 84% of the energy uses in the settlement. Total energy demand for cooking, electrical appliances and water pumping was 3,610 MWh/year with peak load of 410 kW, respectively. Renewable energy potential indicated average hourly wind speed of 2.6 m/s, average solar irradiation for an 8-hour sunshine hour of 0.7 kW/m² and biogas potential of 246 × 10⁶ m³/year. Considering the daily equivalence of the biogas potential, this can be used as fuel for the biogas generators to meet up to 39.7% of the total demand. Optimal generation capacity for solar and biogas systems obtained using MATLAB optimization modeling were 341.4 kW and 225.0 kW, respectively. The configured solar photovoltaic (PV) system had a rating of 0.40 kWp and three 75 kW rated biogas generators able to meet the load demand of the community. The total investment cost to realize this project was estimated as $ 1,185,805. Considering a subsidized tariff of 0.10 $/kWh and 0.15 $/kWh for systems operation at 100%, 75%, 50% and 30% capacities, payback period, Net Present Value (NPV) and Cost Benefit Ratio (CBR) were calculated. A positive NPV for 17 years project lifespan and CBR values greater than 1 showed economic feasibility of the project. More so, the average Levelized Cost of Energy (LCOE) was 0.04 $/kWh as compared to 0.34 $/kWh for bioenergy sources. This low LCOE value is advocated to the energy subsidy in the funding projection of the project and tariff over the entire project lifespan with an annual CO₂ saving of 68.4%. Therefore, harnessing the renewable energy sources from the community has the potential of ensuring attainment of energy independence as well as improving livelihoods and creating jobs for the people.