Okello, Collins (2014) ASSESSING SUSTAINABILITY OF BIOENERGY SYSTEMS IN DEVELOPING COUNTRIES: METHODOLOGICAL DEVELOPMENT AND APPLICATION. [Tesi di dottorato]

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Abstract

Close to a half of the global population is currently deprived of clean and reliable energy for cooking. Majority of the energy poor live in developing countries where use of traditional biomass is prevalent and associated with several social, economic, environmental and technological challenges. Recently, United Nations General Assembly emphasised the importance of access to sustainable energy to all, most especially in developing countries. It noted that access to clean and reliable energy is critical to meeting the millennium development goals and ensuring sustainable development. This suggests the need for more efforts to incorporate sustainability concerns in planning energy systems in developing countries. This could lead to the identification of more sustainable technologies for cooking, and also provides benchmarks to help monitor progress towards sustainable development of energy systems. To achieve these objectives, availability of suitable tools to help policy and decision makers in selecting energy systems in developing countries would be very critical. However, planning for sustainability is a very intricate endeavour and presents a knowledge gap especially in developing countries where it is a relatively new concept. This study was therefore carried out with the aim of developing an appropriate sustainability assessment method for selecting bioenergy systems for cooking in developing countries. The proposed sustainability assessment framework is an integrated method that incorporates the social, economic, environmental and technological concerns of biomass energy systems to aid decision making. It is based on multi-criteria decision analysis as a tool to aid participatory ranking and selection of biomass energy systems to ensure sustainability. The framework provides for participatory appraisal of a finite set of energy alternatives at the beginning of the assessment so as to identify and eliminate options that are obviously unacceptable by stakeholders. Methods for selection, ranking and evaluation of sustainability criteria were proposed. A model based on Preference Ranking and Organisational Method for Enhanced Evaluation (PROMETHEE) and Graphical Analysis for Interactive Aid (GAIA), was proposed as a tool for final ranking of biomass cooking technologies on the basis of a set of sustainability criteria. The methodology was applied in Uganda to rank domestic biogas, briquette gasification and Jatropha plant oil cooking energy systems with charcoal system as the reference. Participatory appraisal of the energy systems resulted in Jatropha oil system as the best cooking energy system according to Ugandan stakeholders. It was followed by biogas and briquette while charcoal, ranked last. A set of 21 criteria for assessing sustainability bioenergy systems was developed under Ugandan conditions and weights assigned to them by a multi-stakeholder panel using the analytic hierarchy process. Economic criteria were ranked as most important considerations influencing sustainability of bioenergy systems in the country, while technical criteria generally ranked lowest. Results of environmental assessment of the energy systems indicated that biogas is the most environmentally sustainable alternative, while charcoal was the worst option. The environmental performances of biogas and Jatropha systems were observed to significantly improve with recycling of waste products as fertilizer. Results of multi-criteria sustainability assessment showed that under the business as usual scenario, charcoal and biogas were incomparable under PROMETHEE I partial ranking, but better than Jatropha and briquette gasification systems, which were also found to be incomparable. Biogas was ranked as the best alternative under PROMETHEE II complete ranking, while Jatropha and briquette systems performed worse than charcoal. Biogas systems was again ranked as the best alternative when by-products were recycled as fertilizer. It was followed by Jatropha and briquette systems, which performed worse than charcoal. The study further showed that the charcoal cooking is inefficient and pose high health risks to users compared to the other three energy alternatives. In summary, the study showed that economic factors play a predominant role in the decisions by households to adopt more sustainable bioenergy technologies for cooking in Uganda. Also, the environmental performance of biogas and Jatropha energy systems significantly improve with increase in recycling of by-products as fertilizers, and avoidance of open air burning of residues. Recycling of by-products significantly improves overall sustainability of biogas and Jatropha bioenergy systems. Biogas energy system seems to be the most sustainable energy system for cooking in Uganda. The study further showed that the proposed method for participatory appraisal of bioenergy systems, based on strengths, weaknesses, opportunities and threats; analytic hierarchy process, and desirability functions seem to be a very promising tool. In conclusion, the proposed multi-criteria sustainability assessment framework showed a high potential to be used as a tool to aid decision-making when selecting cooking energy systems in developing countries.

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