Abstract

Decentralized renewable energy systems can provide a promising pathway for improving energy access in rural regions with limited grid reliability. This study conducts a techno-economic and environmental assessment of a household-scale hybrid energy system integrating a 1.65 kWp solar photovoltaic (PV) array with a fixed-dome biogas digester. System performance was evaluated using one year of field data and a 20-year economic model. At an 8% discount rate, the system requires an initial investment of USD 1,227. It yields annual savings of USD 321.45, resulting in a net present value of USD 1,707.3, an internal rate of return of 23%, and a discounted payback period of four years. The hybrid configuration achieves a net reduction of approximately 2.16 tCO₂e yr⁻¹. Results demonstrate that integrating PV and biogas improves economic viability and energy reliability, offering a sustainable solution for decentralized rural energy supply.