​Biogas Technology Practices and Opportunities in Selected Districts of Hadiya Zone, Southern Ethiopia

Description of the study area
 
This study was conducted in 2019-20 at the selected districts of Hadiya Zone, Southern Ethiopia (Fig 1). It has thirteen districts and four cities administrative while its geographic location lies between 7°.22" to 7°.45’00" Latitude and 37°.40" to 38°.00’ Longitude with an altitude range of 1271-2800 m.a.s.l. The mean annual rainfall varies between 1001 mm to 1200 mm and the mean annual temperature varies between 15°C and 20°C. It is bordered by Gurage Zone in the North, Kembata Tembaro Zone in the South, Yem special woreda and Oromia region in the West, Silte zone in the North East and Alaba special woreda in the East. According to the 2008 national census of Ethiopia, the total population of the Hadiya zone is 1,300,000. The average population density is 470 persons per kilometer square. The population is increasing at a rate of 2.6%/year. Wood fuel is the most important energy source for cooking and kerosene for lighting purposes. Charcoal burning is also an important economic activity in some parts of the zone. The high population density and the dependence on wood fuel as the major energy source are the cause of deforestation and other forms of environmental degradation in the zone. Hadiya zone is classified into three climatic zones: Dega or the highland (33%), Weina Dega or midland (50%) and kola or lowland (17%). The soil type of the area is loam soil. Types of crops grown in the area are wheat, bean, Enset, maize, coffee and pea.
 

 
Data collection
 
Hadiya zone has thirteen districts and four city administrations including the newly added districts and city administration. To collect the data, seven districts namely Shashogo, Annalemmo, Misrak Badawaccho, soro, Gombora, Gibe and Lemmo districts were selected purposively based on the existence of small-scale biogas plants. Fourteen kebele (peasant association) i.e. two peasant associations from each district were purposively selected based on which one has biogas plant and has no biogas plant. Moreover, 56 respondents that mean two-biogas user and two non-user farmers were selected from each peasant association, in addition to these, one energy office expert from each district were purposively selected as a key informant because they are knowledgeable and experienced in this specific sector. Gay and Airasian (2003) define purposive sampling as one which involves selecting a sample based on experiences or knowledge of the group to be sampled.
 
Data collection was done by using different methods depending on the specific objectives. To gather the appropriate and reliable data, this research has relied on both primary and secondary sources of data. The primary data is derived from the field surveys using questionnaires and key informant discussion. The questionnaires were self-constructed based on the study objectives and the questions. Additional investigation tools include field observations, especially on the use of biogas and bio-slurry at the farm level. The secondary data were also synthesized in Wachemo University from reports, journals, newsletters and electronic media.
 
Data analysis
 
The quantitative data were subjected to the computer for analysis using Statistical Package for Social Sciences SPSS Version 11.5 computer package and Microsoft excel-2010. Moreover, tables and figures summarized the findings as appropriate.

Socio-economic characteristics of the respondents
 
This survey revealed that only 29% of the sampled (56) households were female-headed while 71% were male-headed (Table 1). Most of the biogas users in the study area were male-headed households. It suggests that the accepting status of biogas technology of male-headed households was higher than that of the female-headed household in the study area. On the other hand, the majority of the respondents were over 40 years (89%). this indicates that there were no farmers under the age of 18 because most young people are migrating from rural areas to town to get the daily payer job. Of the respondents, in the study area, 50% and 32% were attended primary and secondary school respectively (Table 1). Whereas a few numbers of farmers had a University degree. Accordingly, in a study carried out by Wakaje (2008) in Tanzania, the likelihood of receiving biogas energy increased with more years of formal education of the household head. This does not coincide with the results of this study.
 

 
Biogas practices in the study area
 
According to this survey, small-scale biogas technology in the study area is recent and it needs certain requirements for its installation. In this regard, respondents revealed that to construct a Biogas plant it must fulfill several requirements such as owning at least 6 cows/oxen, near access to water supply, sufficient area for biogas plant installment, access to construction materials (sand, crushed and dry stone) and physical capability to excavate the pit for a biogas plant, to mix-up the manure with water, to enter the manure and put out the slurry from the digester. This result suggests that the average cattle herd size used to produce sufficient quantities of cow dung to generate adequate amount of gas for both cooking and lighting while the other requirements are very essential to successful construction of the biogas plant. Similarly, insufficient dung (cattle number) often resulted in households abandoning the technology because of their inability of the biogas plants to generate adequate cooking energy (Gautam et al., 2009).
 
All types of biogas plant that constructed in the study area were fixed dome while their size was (6-10 m³) which depended on the number of cattle and labor in the household level. In Uganda, the fixed dome and floating drums were the most preferred types of biogas digesters due to their longer life spans when compared to the plastic tubular design Walekhwa et al., (2009). Relative to the other district, the highest numbers of biogas plants were constructed in the Lemo district (Table 2). This is because of lemo district is located near to hosana town. Furthermore, the farmers in this district had access to information about biogas, construction material and the government’s technical support. After all, the situations maximize the expansion of biogas in the Lemo district.
 

 
According to the field observation, the significant numbers (72.7%) of biogas plants in the study area were not functional (Table 2). The main reasons for the non-functionality of the biogas might be stopped feeding and poor quality of construction. So far, most of the biogas owners were non-willing to maintain their biogas plant because of feeding problems and others. The results of this study agrees with the research findings of Karanja and Kiruiro (2004), where 100% of the respondents in Central Kenya Highlands reported, low quality in construction reduce the productivity and finally lead to cease operation of biogas plant. Moreover, the most challenging maintenance for the biogas users comprises removing sludge from the digester, blocking possible cracks in the fixed digesters and repairing damages Ferrer-Martí et al., (2018). Therefore, the installed digesters’ functionality depends on continuous management and supervision of operation and maintenance Breitenmoser et al., (2019).
 
Opportunities of biogas in the study area
 
The data in (Fig 2) shows, the informants were revealed that there are many favorable opportunities for biogas expansion in the study area. Prominently, the identified opportunities by them were the presence of many cattle and organic wastes, the suitability of climate of the area, the availability of labor and nearby water, open area and access to building materials. Consequently, the result indicates all the distinguished opportunities are very important without any significant difference for biogas distribution because most of these are natural and available resources in the study area. Therefore, identification of prospects before and during the actual implementation of the different biogas development programmes could play remarkable role in mass dissemination of the domestic biogas digesters (Amigun, 2012).
 

This study shows that small-scale biogas technology in hadiya zone is recent and there are several naturally available opportunities to expand its distribution in the study area. In this regard, the availability of organic waste, cattle, water, construction materials and suitable climate were considered as good opportunity for its construction. However, the previously constructed biogas digesters in the study area were poor in quality and most of them were non-functional. Consequently, the sustainability of biogas sector needs multi-stakeholder approach, which requires the active participation and support of governmental organizations, non-governmental organizations and community based organizations. Therefore, the farmers and other stakeholders should use these opportunities effectively to maximize the distribution of biogas in the study area while assist to recover the non-functional biogas plants by providing maintenance and creating awareness for those who stop cow dung feeding to the biogas plant.

The authors would like to thank friends for their support.

None.