Micro-scale biogas systems in East Africa: Sustainable development panacea or more hot air?

摘要

Advocates of micro-scale biogas systems note that this technology should transform organic wastes into a clean-burning source of renewable energy and a valuable fertilizer. As a result, this technology should improve indoor air quality, reduce the burden of fuelwood collection on women, improve farmers' yields, and mitigate deforestation---all while delivering a modern standard of public sanitation to underserved communities. Seizing on what appears to be a relatively simple technological fix for a host of previously intractable development problems, massive investments and policy advocacy have resulted in the rapid proliferation of this technology across East Africa, particularly in Uganda where the 2007 Renewable Energy Policy set the ambitious goal of installing of 30,000 household level digesters and 100,000 institutional and industrial biogas systems by 2017, making Uganda the only nation in East Africa to have state-designated targets for biogas installations clearly outlined in national energy policy. But are these systems truly a sustainable development panacea? High rates of reported system failure and a lack of field validation of the assumptions underlying digesters' development promise raise significant concerns about the actual impact of this technology. This dissertation offers a comprehensive assessment of the capacity of urban, institutional micro-scale biogas systems to deliver on their promise of sustainable development. Chapter 1 offers a brief overview of biogas technology, explains how this technology arrived in East Africa, and describes the expected benefits of these systems. Chapter 2 examines whether institutional biogas systems have delivered improvements in public sanitation and explores how this technology compares to both traditional forms of distributed waste management and modern, centralized waste management facilities. Chapter 3 evaluates the impact of biogas systems on both indoor air quality and energy security. Chapter 4 identifies current barriers to widespread technology adoption. Chapter 5 identifies next steps and describes some of the promising technological innovations and policy interventions that could help biogas systems deliver on their development promise. This body of work offers policymakers a quantitative, evidence-based assessment of the potential of this technology, enabling informed decision-making about the future of the micro-scale biogas sector while addressing several gaps in the academic literature.