Techno-Economic Feasibility and Energy Performance Assessment of Small-Scale Agricultural Waste-to-Energy Pathways in Nigeria

Reliable electricity supply remains a major constraint on economic activity in Nigeria, while large quantities of agricultural residues and processing wastes are generated with limited productive use. This study evaluates the techno-economic feasibility and energy performance of small-scale agricultural waste-to-energy (WtE) pathways suitable for decentralized deployment in Nigeria. Three representative conversion routes are assessed using a harmonized framework: biomass gasification coupled with an internal combustion engine, direct combustion integrated with an Organic Rankine Cycle, and anaerobic digestion with biogas-to-power. A consistent functional unit of one tonne of waste processed (as received) and common system boundaries are applied to enable technology-neutral comparison of specific electricity yield, conversion efficiency, and levelized cost of electricity (LCOE). Base-case scenarios are defined using literature-supported technical and economic parameters relevant to Nigerian agricultural residues. Results indicate that gasification-ICE delivers the highest net electricity yield (574.2 kWh/t) and the lowest LCOE (0.138 USD/kWh) under electricity-only operation, while combustion–ORC produces lower electricity output (311.4 kWh/t) but achieves the highest overall energy utilization when useful heat is recovered in combined heat and power mode. Anaerobic digestion yields lower electricity per tonne (169.2 kWh/t) but demonstrates strong compatibility with wet wastes and high conversion efficiency on a biogas-energy basis. Sensitivity analysis shows that capacity factor and capital cost are the dominant drivers of economic viability, while feedstock moisture content and methane fraction strongly influence energy output. The findings highlight the importance of aligning WtE technology choice with feedstock characteristics, heat demand, and operational conditions, and provide evidence-based guidance for decentralized agricultural waste-to-energy deployment in Nigeria.