Quality and Usage of Biogas Digesters in Uganda

• Main Author: Lutaaya, Fred
• Format: Others
• Language: English
• Published: KTH, Energiteknik 2013
• Subjects: biogas; greenhouse gases; methane
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133484

Global concerns of climate change, increased greenhouse gas emissions and security of energy supply have accelerated the search for alternative energy sources both indeveloped and developing countries. Developing countries are now embracingutilization of biogas as a renewable energy option to meet some of their cooking andlighting needs. In Uganda, despite the introduction of biogas in the 1950’s, thetechnology has not received considerable acceptance and as a result its penetrationhas remained relatively low.  Several installed biogas plants have failed and those working are not working to theexpectation of the technicians and their owners. This research presents results of thestudy carried out to establish the performance of farm based biogas systems so as toassess the challenges faced by the users and to identify the possible causes of failurefor the non-operational systems.  A survey of 144 biogas plants was carried out after which performance monitoring ofselected digesters in the districts of Luwero, Kampala, Wakiso, Mbale, Jinja andMukono. It was found that 55% of the surveyed  biogas  plants  were  not  operational and  others  not  performing  to  the  users expectations. Most of the plants monitoredwere operating in the temperature range of 18°C-25°C with the gas quality rangingbetween 50-60% methane. Most digesters showed evidence of high organic loadingrates indicated by traces of biogas at the expansion chamber. The identified  causes of  failure  were  poor  system  maintenance, poor workmanship during constructionworks, poor  operation  practices, availability of other cheap fuel alternatives, lazinessand lack of interest amongst  the users, lack of alternative sources of feedstock andsystem blockages. Furthermore, there is need to sensitize people on the need for using alternativesources of energy such as biogas and improved cooking stoves for fuel saving as mostof them use wood and charcoal as supplementary fuels. This would reduce globalwarming through reduced deforestation and bring about environmental sustainabilityas a whole.