Life Cycle Analysis Of Alternative Biomass Energy For Cooking: A Case Of Kitui, Kenya And Moshi, Tanzania

Abstract

Wood-based biomass energy remains vital in meeting local energy needs for cooking in various parts of emerging countries, particularly in sub-Saharan Africa. This is largely because wood-based biomass energy can be obtained locally and is also affordable to the underprivileged population. Currently, concerns have been raised about the undesirable effects of reliance on wood-based energy. Continued use of wood-based energy sources has created pressure on natural resources leading to degradation of land, water and forests and emission of greenhouse gases. Additionally, there has been devastating effects on human health as a result of indoor air pollution. This has provided a platform from which the continued dependence of wood-based energy sources has been argued against. This calls for development of alternative biomass energy solutions that benefit local people without damaging the environment. It is imperative that their development is grounded on identification of suitable combinations of raw material and their conversion and consumption technologies. However, the effects of sustainable development of bioenergy processing are typically focused on industrialised countries. Nevertheless, improving awareness of impacts of bioenergy processing in emerging countries is imperative. Evaluating the sustainability of biomass energy supply chains is, however, often met with challenges, one of which is lack of data. In addition, the data is often fragmented or focus on only part of the whole life cycle. The objective of the study was to evaluate the performance of selected value chains for biomass energy used for cooking in Kitui, Kenya and Moshi, Tanzania. Their performance was based on their carbon footprints, life cycle costs and eco-efficiency. This study included firewood, charcoal, biogas, jatropha oil from hedges and crop residue briquettes for cooking at the household level while focussing on particular processing and consumption technologies of biomass energy in Kitui, Kenya and Moshi, Tanzania. Life cycle analysis as a methodological tool has been applied to offer useful evidence for the process of decision making process in these data scarce contexts. This study evaluated the carbon footprints of biomass of biomass energy by applying the Life Cycle Assessment. Their economic viability was evaluated using the Life Cycle Costing methodology. The study further determined the eco-efficiency of biomass energy pathways by integrating their carbon footprints and the life cycle costs. xv The study used field data, databases (Eco-invent) and data from scientific literature to model the carbon footprint, life cycle costs and the eco-efficiency of these selected biomass value chains. The results indicate that the jatropha oil value chain holds the highest potential for carbon footprint reduction, as long as the jatropha plant is grown as hedges around the plots. Conversely, the jatropha oil value chain has the highest life cycle cost amongst the selected biomass energy value chains. Integration of the carbon footprints and the life cycle cost (eco-efficiency) of the biomass energy pathways indicate that viable options for biomass energy exist for households in Kitui and Moshi. The results presented can help stakeholders in decision making about substitute biomass energy value chains. Development and improvement of technologies used for biomass energy conversion and consumption provide significant opportunities for enhancing access to biomass energy for cooking. Additionally, they contribute to carbon footprint reduction strategies and provide a source of income especially for the rural and urban poor households.