Niger relies heavily on electricity imports from Nigeria. Still, recent political tensions have caused severe disruptions, leaving the country grappling with widespread energy shortages and an increased dependence on diesel generators (DGs). This study develops an optimal microgrid (MG) planning framework to enhance electricity security and sustainability in Niamey, Niger’s capital city. Using Mixed-Integer Linear Programming (MILP), the research explores two configurations: one using photovoltaic (PV) panels paired with battery storage systems (BSS) and another combining PV, BSS, and DGs in a hybrid system. A comprehensive techno-economic analysis evaluates both configurations regarding cost-effectiveness, reliability, and sustainability. The objective is to withstand the sudden import supply line cut while minimizing costs. Compared to the first scenario, the second scenario incorporating DGs is the most economically viable, with a 17.395% reduction in total life cycle cost (TLCC). The TLCC for scenario 2 is around $435,102,442, resulting in a levelized cost of electricity (LCOE) of 0.057$/kWh, marginally lower than the 0.069$/kWh in scenario 1. As well as offering data-driven insights to inform Niamey’s energy planning under severe energy disruptions, this detailed techno-economic assessment illustrates the trade-offs between economic efficiency and environmental sustainability.