Feasibility Study and Optimal Design of Hybrid Renewable Energy Microgrid System for Rural Electrification in Ethiopia (A Case Study: Jimma-Gera-Kola-Kinibibit)

Abstract

The introduction of a decentralized energy system in rural areas with limited or no access to electricity can improve the quality of life of people living in rural areas. Renewable energy technology plays a key role in electricity generation, as grid expansion is not cost-effective. This study mainly focused on the techno-economic feasibility and optimal design of a hybrid power system ,or the combination of micro-hydro-photovoltaic-diesel-battery-power system designed to electrify a typical remote village in southwest Ethiopia, which was called the Kola-Kinibibit kebele. It aims to achieve electrification at a low cost by considering the complexities of environmental pollution emissions. Therefore, this study determines the technical details and economic feasibility of setting up such a power system using the hybrid optimization of multiple energy resources (HOMER-PRO) simulation tool. Different combinations of energy resources, such as solar, hydro, energy storage systems, and diesel generators, were compared and analyzed. The system performance and economics used determinant factors such as the cost of energy, operation and maintenance costs, net present costs, excess electricity, capacity shortage, generator fuel consumption rates, load fulfillment, CO2, and other pollutant gas emission savings. The results and comparative analysis show that a hybrid hydro/PV/diesel/battery system is the preferred option for off-grid rural electrification with a solar power capacity of 45.1KW dc power, micro-hydropower capacity of 73.3KW, and a 15 kW diesel generator. The simulation results also indicate that the optimal system had a net present cost (NPC) and cost of energy (COE) of $862,098 and $0.0966/kWh, respectively, with a renewable fraction of 99.1%, excess electricity of 11.6%, and required initial capital of $375,151. Finally, to efficiently use the energy produced using the energy sources mentioned above installed as an island microgrid system, a fuzzy logic controller is used to make an intelligent decision by identifying the type and amount of resources available, then choosing the appropriate alternative source and implementing it. The fuzzy rule was written using a fuzzy rule editor, and each component of the proposed and entire hybrid system was modeled using MATLAB/Simulink.