Linking household waste segregation to biogas-based energy system feasibility: A techno-economic and policy assessment in Rejang Lebong, Indonesia

Abstract

Reliable feedstock supply is critical to the feasibility of decentralised biogas-based energy systems, particularly in developing regions where municipal organic waste is largely unsegregated. This study evaluates how household waste segregation performance influences biogas-based electricity generation and energy system feasibility in Rejang Lebong Regency, Indonesia. A cross-sectional survey of 400 households was conducted to determine household waste segregation rates and behavioural conditions. Survey results were integrated into scenario-based techno-economic modelling to estimate recoverable organic waste, biogas production, electricity generation, and financial viability under three segregation scenarios: 38.5%, 60%, and 80%. Results show that improved segregation substantially increases recoverable organic waste and electricity generation and enhances financial feasibility. The model indicates a break-even segregation threshold of approximately 54%, while the 80% scenario provides greater financial feasibility. The findings demonstrate that household segregation performance is a critical determinant of decentralised renewable energy viability rather than merely an environmental behaviour. The study provides policy-relevant evidence for integrating household waste management improvements with decentralised energy planning in resource-constrained regions. Results should be interpreted in light of the planning-level engineering and economic assumptions adopted in the model.