Independent or complementary power system configuration: A decision making approach for sustainable electrification of an urban environment in Sierra Leone

Providing quality and reliable power to grid-isolated areas has long been a difficulty in Africa, particularly in Sierra Leone, where government regulations are either weak or non-existent to assist the developing endeavour. Hybrid off-grid systems have grown in popularity as a way to offer electricity to people who live remote from power grids. This strategy, on the other hand, is capital demanding and prone to interruptions. This paper considers a decision-making process based on the Government of Sierra Leone's initiative to undertake a project to provide sustainable electricity to the people of Bo and Kenema in Sierra Leone's South-eastern region, with the assistance of the Africa Development Bank (ADB) and the Department for International Development (DFID). Two operating scenarios were modeled, and a comparative study was performed to determine which of the two should be considered. The results showed that the complementary scenario's proposed optimized hybrid configuration performed best in terms of technical, economic, and environmental features. Technically, it produced an excess energy of 2.29 %, compared to the combined total of the independent scenarios with 49.4 % (15.3 % excess energy from Bo and 34.1 % from Kenema). In terms of cost, it has a net present cost (NPC) of $45.6 million (M), compared to a combined NPC of $52 M ($37.8 M for Bo and $14.2 M for Kenema) for the independent networks. In terms of the environment, it generated 2,402,380 kg/yr of CO₂ which is 42 % less than the combined total produced by Bo and Kenema (3,408,018 kg/yr). Sensitivity analysis revealed that the overall system cost is heavily reliant on the diesel fuel price and average annual stream flow rate, as well as the hydro turbine's deplorable efficiency status, with the intention of project leaders' ignoring the impact of variations in the PV derating factor.