Attitude towards biogas technology, use and prospects for greenhouse gas emission reduction in southern Ethiopia

Abstract

In developing countries, fuelwood extraction is one of the main drivers of deforestation, forest degradation, and greenhouse gas (GHG) emissions. This study aimed to investigate the use, management, and attitudes towards biogas technology in rural communities in Ethiopia and assess its’ potential in reducing the consumption of biomass fuels and emissions of GHG. A questionnaire survey sampled from 40 biogas user and 40 non-user households was used to collect data. The biogas flow rate was measured using a gas flow meter from three random biogas digesters. Biogas and non-biogas user households reported similar socioeconomic perspectives. Our results showed that 92.5% of biogas user households and 77.5% of non-users had a positive attitude towards biogas technology, however, 52.5% of the non-users lacked information about the technology while 25% of the non-users were deterred by biogas installation costs. The average biogas consumption of each household was from 496 to 566 m3 yr−1 for cooking and from 106 to 124 m3 yr−1 for lighting. Biogas user households consumed fuelwood and crop residue to the same extent as non-user households for baking foods. However, biogas user households differed significantly from non-user households in biomass fuel use for non-baked foods owing to the suitability of biogas stoves. Each biogas user household reduced their fuelwood and charcoal use by about 2410 kg yr−1 and 379 kg yr−1, respectively, and decreased their kerosene use (for lighting) by about 9.5 L yr−1. The GHGs emitted by each household was estimated at 10,242 kg CO2e yr−1 and 16,266 kg CO2e yr−1 for biogas user and non-user households, respectively. Thus, each household with a biogas digester has the potential to reduce 6024 kg CO2e yr−1 of GHG emission. Biogas energy can offer an opportunity to mitigate GHGs emissions through reduced pressure on forests. Its’ contribution can more than double by improving the biogas stove design to fit the traditional baked foods.