Analysis of Biogas Technology for Household Energy, Sustainable Livelihoods and Climate Change Mitigation in Kiambu County, Kenya
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Date
2015-01-21
Authors
Muriuki, Salome Wamuyu
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
Domestic energy insecurity is a major threat to sustainable development in Sub Saharan Africa. Across the region, the fundamental role that firewood and charcoal plays in the social and economic welfare of many households cannot be overemphasized. This study aimed to assess the role of biogas technology in saving wood, mitigating green-house gases emissions, and in improving livelihoods in Kiambu County. Oral interviews, Focused Group Discussions, and Action Learning Case Studies were used on biogas adopter and non-adopter households. Participatory experimental research was carried out using selected farmers’ installed bio-digesters of different designs and sizes. Cows were fed on nine different feed combinations and the biogas yield from these cows’ dung tested for CH4, CO2 and H2S contents. Gas was analyzed using portable Biogas Analyzer 5000 (Geo-tech UK). Fuel consumption and expenditure patterns was determined using household surveys. Carbon emission reduction was calculated from fuel consumption reduction with biogas use, and presented in CO2 equivalent. Impact of the technology on livelihoods was analyzed using DFID (1999) framework on sustainable livelihoods. Data was analyzed using SPSS and SAS computer softwares. ANOVA revealed variation in gas quality from different cattle feeds. Descriptive statistics, tests of significance (t-tests and chi-square), and logistic regression were used to establish relationships between variables. There was high likelihood of biogas adoption with combination of independent variables age, education level, farm size and the number of cows owned. The technology showed great potential and real benefits for uplifting livelihoods. Significant financial savings were realized, with an average household saving about KShs 38, 676 (455 USD) annually upon shifting to biogas energy. Time savings (up to 5 hours weekly) was highly significant. Health of user households also improved tremendously with absolute reduction in smoke, and improved sanitation around the home environment. From a livelihood perspective, biogas energy technology gave adopter households’ essential assets (human, physical, natural, social and financial) that enabled the households achieve positive livelihood outcomes. Among these assets, financial capital was probably the most resourceful. Wood consumption reduced immensely with biogas use. An approximate 303.8 metric tonnes firewood and 229.4 metric tonnes of wood from charcoal being conserved annually by biogas adopters. This combined helped mitigate approximately 1,079 tonnes of CO2 equivalent from being emitted to the atmosphere. Type and size of digester did not significantly influence gas quality. However, gas quality was markedly influenced by cattle diet. A high protein feed, gave a combined optimal effect on CH4 and CO2 emissions. The highest methane yield was achieved from chicken dropping (64.2%) and fodder legumes (63.8%). The technology therefore offers a myriad of environmental benefits and is a major driver of livelihoods in Kiambu. Efforts and resources are needed to increase widespread adoption of the technology
Description
Department of Environmental Science, 169pg. 2009, TP 359 .B48M8