Environmental sustainability of small-scale biomass power technologies for agricultural communities in developing countries

Highlights: • First LCA of small-scale biomass power systems in the context of Southeast Asia. • Gasification has lower impacts than combustion of crop residues in 17 categories. • GWP of biogas from animal manure can be higher than that of diesel generator. • Power from biomass has higher eutrophication and toxicity impacts than from diesel. • Anaerobic digestion has lower impacts than biomass gasification and combustion. -- Abstract: Agricultural wastes are readily available in farming communities and can be utilised for off-grid electrification as an alternative to diesel generators. This work evaluates for the first time the life cycle environmental sustainability of these small-scale systems in the context of Southeast Asia. Rice and coconut residues are considered for direct combustion and gasification, and livestock manure for anaerobic digestion. Overall, anaerobic digestion is the best option for 14 out of 18 impacts estimated through life cycle assessment. The results also suggest that gasification has up to 12 times lower impacts per kWh than combustion, except for resource depletion. Combustion and gasification have 85% to two times lower impacts than diesel generators, except for eutrophication, ecotoxicity and human toxicity. Depending on the feedstock, global warming potential of anaerobic digestion ranges from being 170% lower to 41% higher than that of the diesel generator. Overall, providing power from residual biomass in small agricultural communities would reduce environmental impacts significantly while improving waste management practices.