Can small-scale biogas projects mitigate the energy crisis of rural Bangladesh? A study with economic analysis

Energy usage disparity is burgeoning across the world. Therefore, biogas can be promising towards energy solution in bucolic regions of Bangladesh. Exploiting small-scale plants (3.45, 2.4, 2.7, 3 and 3.3 m(3)), this study elucidates the economic congruity of gasification through cost-benefit analysis. The estimated mean investment cost was BDT 39260/plant, whereas an average BDT of 8792.85 and 6856/year/plant return obtained from biogas and bio-fertiliser. All plants yielded positive net present value (NPV) in both 10% and 15% discount rates. Complacent internal rate of return (average 33.2%), positive benefit-cost ratio and lower PBP (average 2.5) debunk the feasibility of a capital-intensive investment like biogas. Sensitivity analysis elicits discount rate as the most sensitive and endorses inverse relationship between cost items and NPV. The average value of the biogas/plant is approximately tantamount to 1650 kWh electricity/year/plant which is sufficient for the energy demand of seven people. Therefore, this study espouses galvanising rural households to confide more on renewable energies like biogas.