Sustainability-based economic and ecological evaluation of a rural biogas-linked agro-ecosystem

Biogas-linked agro-ecosystems provide economic and environmental benefits by using resources in a multipurpose manner. They utilize an energy consumption pattern that has prominent advantages in relieving energy shortages and reducing environmental pollution. To better understand the effects of these multiple aspects, it is important to study how much of the energy flow is extracted and available through the biogas-linked agro-ecosystem using an economic input–output evaluation or ecological and social influence assessments. It is also equally important to understand the conversion efficiency during the life cycle of biogas production, and how humans influence the whole process of the biogas-linked agro-ecosystem. This paper attempts to establish a life cycle-based accounting model of a household biogas system using different economic and ecological metrics for multiple objective considerations, to provide a powerful and comprehensive perspective to illustrate sustainability problems. In this study we use a typical household biogas system in Gongcheng Autonomous County (Guangxi Province, China) as a case study to reveal an effective route and strategy to relieve energy shortage, reduce environmental pollution, and improve human productivity. In this way, we can construct an exemplary example of how to realize sustainable development in a rural area with positive objective conditions.