Socio- economic characteristics of user households
Cattle holding size
About 55.4%, 32%, 5.4%, and 6.8% of the households had cattle holding size ranging from 1–3, 4–5, 6–7 and > 7, respectively. The average cattle holding size was three cattle per household, which is less than the minimum standard set by the National Biogas Program of 4 cows for installing biogas plants (Table 3). One sample T- test result showed that livestock size has a significant (p < 0.05) positive association with the adoption of biogas technology. Field observations of biogas plants also showed that the availability of sufficient cattle dung, which is the primary feedstock for biogas plants, is the most important factor in daily biogas operation. Thus, the quantity of dung available per day is critical in realizing the benefit and viability of biogas technology. Eshete et al. (2006) indicated that rural households in Ethiopia would need at least four cattle stabled during the night to get a minimum of 20 kg of fresh animal dung per plant per day, which is the size required to produce enough biogas energy for cooking or lighting (EREDPC and SNV, 2008). Other findings from previous studies indicated that cattle size has a significant positive association with adoption of biogas technology (Walekhwa et al., 2009, Kabir et al., 2013, Shallo and Sime, 2019).
Table 3
Cattle holding size of biogas user households
Number of cattle | Frequency | Percent | One sample T-test result |
1–3 | 41 | 55.4 | p-value = 0.00 |
4–5 | 24 | 32.4 |
6–7 | 4 | 5.4 |
7 | 5 | 6.8 |
Total | 74 | 100.0 |
*. Significant at p-value ˂ 0.05 |
In terms of cattle grazing systems, about 31.1% of the households used free grazing on open field, 40.5% controlled grazing (zero grazing practice) and the remaining 28.4% used combined together free grazing on open field and controlled grazing. On the other hand, about 59.5% of the households got sufficient cattle dung while 40.5% lacked sufficient cattle dung for feeding biogas plants. The latter households had their cattle grazing freely moving on open fields. Furthermore, 40.5% of the households collected dung from various sources while the remaining 59.5% did not. Among those households collecting cow dung, 26.6% collected dung from field, 43.3% from stall (locally called Beret) and the remaining 30% from stall and field (Table 4). Field observation also showed that households practicing controlled grazing method have better potential of adopting biogas technology than those practicing other methods of grazing types. Controlled grazing was observed to ease dung collection, lessening labor and time. Mwirigi et al. (2009) reported a significant positive relationship between grazing system and adoption of biogas technology in Kenya.
Table 4
Grazing types and dung collection
Variable What grazing type do you use for feeding your cattle? | Type of grazing | Frequency | Percent |
Free grazing on open field Controlled grazing Free grazing on open field and controlled grazing Total | 23 30 21 74 | 31.1 40.5 28.4 100.0 |
Do you have sufficient cattle dung for biogas plants? | Yes No Total | 44 30 74 | 59.5 40.5 100.0 |
Do you collect cattle dung from various sources? | Yes No Total | 30 44 74 | 40.5 59.5 100.0 |
If Yes, from where do you collect cow dung? | Field Stall (Beret) Both field and stall Total | 8 13 9 30 | 26.6 43.3 30.0 100.0 |
Traditional biomass energy use pattern
The energy use pattern showed that an extensive number of households use firewood (41.9%), followed by dung cake (29.7%), charcoal (17.6%) and kerosene (10.8%) before biogas technology adoption (Fig. 2). Firewood becomes an indispensable source of fuel for cooking, followed by charcoal. This shows that traditional biomass are major sources of domestic energy (89.2%) in the study areas. About 95% of the Ethiopian population relies on traditional biomass fuels for cooking (Sanbata et al., 2014). Gwavuya et al. (2012) reported that firewood holds the greatest share of energy sources for cooking in rural Ethiopia. Besides, kerosene was mainly used for lighting. Kerosene is the major energy source for lighting in rural areas in Ethiopia (Sime et al., 2020).
Quantity of firewood consumption
About 70.3% of households consumed 3–5 bundles of firewood, 23% consumed 6–7 bundles of firewood and 6.8% consumed 8–9 bundles of firewood per month. This is, on average, equivalent to the consumption of 4.8 bundles of firewood per household per month or 57.6 bundles of firewood per year before adoption. After adoption, 81.1% of the households used 1–2 bundles of firewood, 10.8% used 3–4 bundles of firewood and 8.1% used 5–6 bundles of firewood per household per month, with an average consumption of 2.0 bundles of firewood per household per month. This is a reduction of more than 50% of the bundles of firewood used per household per month or is a reduction of 33.6 bundles of firewood per year. Thus, biogas technology adoption enabled the saving of 33.6 bundles of firewood annually. This is equivalent to saving 3010.56 ETB annually at a local price rate of 89.6 ETB per bundle of firewood (Table 5). Amare (2015) reported that biogas technology adoption enabled a reduction of 70.47% of firewood per household per year. This is a reduction in annual firewood consumption, approximately of 79 bundles of firewood per household per year. In turn, this is equivalent saving 3833.22 ETB annually at local rate of 48.40 ETB per 32 kg per bundle. A reduction of 45% in firewood consumption was also reported because of partial replacement of traditional fuels with biogas energy (Abadi et al., 2017). Similarly, other previous studies also showed that biogas users tend to consume less firewood than non-users do (Christiaensen and Heltberg, 2014).
Table 5
Number of bundles of firewood consumption per household per month before and after adoption of biogas technology
| Before adoption | | After adoption |
Number of bundle | Frequency | Percent | Number of bundle | Frequency | Percent |
3–5 6–7 8–9 Total Average = 4.8 | 52 17 5 74 | 70.3 23.0 6.8 100.0 | 1–2 3–4 5–6 Total Average = 2.0 | 60 8 6 74 | 81.1 10.8 8.1 100.0 |
How much is the price of one bundle in your local market (ETB)Amare (2015)? | Price | Frequency | Percent |
80–90 91–100 101–110 Total Average = 89.6 | 42 31 1 74 | 56.8 41.9 1.4 100.0 |
Quantity of dung cake consumption
Dung cake is regularly used as traditional fuel in traditional stoves in most parts of Ethiopia. Before adoption, about 56.8% of the households consumed 6,065 dung cakes, 32.4% consumed 66–70 dung cakes and the rest 10.8% consumed 71–75 dung cakes per month, with an average consumption of 65.4 dung cakes per household per month. However, after adoption, 82.8% of the households used 15–20 dung cakes, 13.5% used 21–25 dung cakes and 4.1% used 26–30 dung cakes per household per month, with an average consumption of 18.6 dung cakes per household per month. This is a reduction of 46.8 dung cakes per household per month. Thus, the adoption of biogas technology enabled the saving of 561.6 dung cakes per household per year. This is in turn equivalent to saving 1684.8 ETB per year at a local price rate of three ETB per dung cake (Table 6). Amare (2015) reported that adoption of biogas technology enabled a saving of 600 kg of dung cakes per year, which is equivalent to saving 1,662 ETB per year in Amhara Region in Norther Ethiopia.
Table 6
Number of dung cake consumption of household per month before and after adoption of biogas technology
Number of dung cake | Before plant installation | Number of dung cake | After plant installation |
| Frequency | Percent | | Frequency | Percent |
60–65 66–70 71–75 Total Average = 65.4 | 42 24 8 74 | 56.8 32.4 10.8 100.0 | 15–20 21–25 36 − 30 Total Average = 18.6 | 61 10 3 74 | 82.4 13.5 4.1 100.0 |
How much is the price of one dung cake in your local market? Average price of one dung cake is three ETB | Price (ETB) | Frequency | Percent |
1–2 3–4 5–6 Total | 17 55 2 74 | 23.0 74.3 2.7 100.0 |
Quantity of charcoal consumption
Table 8 presents consumption of charcoal (in sacks) before and after adoption of biogas technology. Accordingly, 59.4% of the households consumed 1 sack of charcoal, 33.7% consumed 1.5-2 sacks of charcoal and 6.7% consumed 2.25–2.5 sacks of charcoal per month, with an average consumption of 1.4 sacks of charcoal per household per month or 16.8 sacks of charcoal per year before adoption. After adoption, 70.3% (majority of biogas users) of households consumed 0.25 sacks of charcoal, 28.4% consumed 0.5 sacks of charcoal and 1.4% consumed 1 sacks of charcoal per month, with an average consumption of 0.5 sacks of charcoal per household per month. This is a reduction of 0.9 sacks of charcoal per households per month or 10.8 sacks of charcoal per year (Table 7). In monetary terms, this is equivalent to saving 2872.8 ETB annually at local rate of 266 ETB per sack of charcoal. Amare (2015) reported that adoption of biogas technology enabled households replacing 12 sacks of charcoal per household per year, which is equivalent to saving 1,243.20 ETB per household per year at the local rate of 103.60 ETB.
Table 7
Quantity of charcoal consumption (in sacks) per household per month before and after biogas plant installation
| Before adoption | | After adoption |
No. of sack | Frequency | Percent | | No. of sack | Frequency | Percent |
1 1.5-2 2.25–2.5 Total Average = 1.4 | 44 25 5 74 | | 59.4 33.7 6.7 | 0.25 0.5 1 Total Average = 0.5 | 52 21 1 74 | 70.3 28.4 1.4 100.0 |
How much is the price of one sack of charcoal in your local market? | 250–260 261–270 271–280 Total Average = 266 | 17 34 23 74 | 23 45.9 31.1 100.0 |
Analysis and estimation of time requirement for traditional fuel collection
To collect firewood and cattle dung, about 58.1% of households took 8–9 h, 23.0% took 10–11 h and the remaining 18.9% took 12–13 h per household per week before adoption of the biogas technology. This is on average equivalent to12 h per household per week, 48 h per household per month or 576 h per year. After adoption, about 64.9% of user households took 3–4 h, 18.9% took 5–6 h and the remaining 16.2% took 12–13 h to collect firewood and cow dung per household per week (Table 8). This is, on average, equivalent to 4.5 h per household per week, 18 h per household per month or 216 h per year. Thus, biogas technology adoption enabled biogas user to save an average time of 7.5 h per household per week, 30 h per month or 360 h per year, which is about 38%. Among household members, primarily women and girls are the ones who collect firewood from various sources and engage in cooking activities. Thus, adoption of biogas technology predominantly enables women and girls save time to be spent for firewood collection and cooking. The saved time enhanced women’s socioeconomic engagements: petty trading, executing agricultural activities and undertaking other social obligations. Adoption also increased the number girls attending schools. The time saved following biogas technology adoption is utilized for schooling or other productive purposes (Sime, 2020). The use of biogas narrowed the gap in educational status between males and females (Arthur et al., 2011, Sime, 2020). The reduced workload from women and children in association with firewood or cow dung collection and the availability of clean household energy lead to social and economic development (Garfí et al., 2012). Domestic biogas energy reduces the workload of women by reducing the need to collect firewood, tend fires and clean soot from cooking utensils (Eshete et al., 2006, Gwavuya et al., 2012, Amare, 2015).
Table 8
Time requirement before and after adoption of biogas technology
Time requirement How long does it take you to collect firewood and cattle dung before biogas plant installation? Hour per week Average time = 12 hours/week | Hour per week | Frequency | Percent |
8–9 10–11 12–13 Total | 43 17 14 74 | 58.1 23.0 18.9 100.0 |
How long does it take you to collect firewood and cattle dung after biogas plant installation? Hour per week Average time = 4.5 hours/week | 3–4 5–6 7–8 Total | 48 14 12 74 | 64.9 18.9 16.2 100 |
Quantity of kerosene consumption
With regard to kerosene consumption, about 43.9% (the majority) of households consumed 1–2 liter of kerosene, 45.5% consumed 3–4 liters and only 10.5% consumed greater than 4 liter of kerosene per month, with an average consumption of 2.7 liter of kerosene per household per month or 32.4 liter of kerosene per year before adoption. However, after adoption, 51.5% of the households consumed 0.25–0.5 liter of kerosene, with an average consumption of 0.7 liter of kerosene per household per month (Table 9). This is a reduction of 2 liter kerosene per household per month or 24 liter kerosene per year. This shows that biogas adoption enabled saving of 24 liter of kerosene annually. This is equivalent to saving 456 ETB annually at a local rate of 19 ETB per liter of kerosene. Simur Asres (2012) estimated the daily consumption of kerosene of 0.13 liter per day per household, which is equivalent to saving 47.43 liter of kerosene per household per year and saving 617 ETB based on local price of 13 ETB per liter in Amhara Region in Northern Ethiopia.
Table 9
Consumption of kerosene per household per month before and after adoption of biogas technology
Question Do you purchase kerosene? | Variable | Frequency | Percent |
Yes | 66 | 89.2 |
No | 8 | 10.8 |
Total | 74 | 100.0 |
If yes, at what price do you buy one liter of kerosene? Average price was 19 ETB per liter | | | |
16–18 | 26 | 39.4 |
19–21 | 33 | 50.0 |
22–23 | 7 | 10.6 |
Total | 66 | 100.0 |
| Before adoption | | | After adoption |
Liter | Frequency | Percent | Liter | Frequency | Percent |
1–2 3–4 > 4 Total Average = 2.7 | 29 30 7 66 | 43.9 45.5 10.5 100.0 | 0.25–0.5 0.75-1.0 1.5–1.75 Total Average = 0.7 | 34 18 14 66 | 51.5 28.3 21.2 100.0 |
Quantity of chemical fertilizer consumption
There are two kinds of chemical fertilizers that are widely used in Ethiopia. They are DAP and urea, the former is phosphorus fertilizer while the later one is nitrogen fertilizer. Before adoption, about 41.9% of the households used chemical fertilizer only while 47.3% of them used both chemical fertilizer and manure. The rest of the households used compost, manure or their combination. However, after adoption, 50% of the households used chemical fertilizer and bio-slurry, 35.1% used bio-slurry and compost and the remaining used chemical fertilizer only, manure and compost and chemical fertilizer and manure (Table 10). The use of chemical fertilizer was reduced from 41.9–2.7%, which is equivalent to 94% reduction. Similarly, the combined use of chemical fertilizer and manure was reduced from 47.3 to 4.1%, which is again equivalent to 91% reduction. Furthermore, field observations showed that the use of bio-slurry has increased following adoption. The majority of adopter households, which is about 65.4%, also used combination of bio-slurry and chemical fertilizer together. Debebe and Itana (2016) reported that 15.4% biogas adopter households used chemical fertilizer only, 11.5% used cow dung, compost and chemical fertilizer, while the remaining 7.7% used bio-slurry, compost and chemical fertilizer.
Table 10
Fertilizer use pattern before and after adoption of biogas technology
Question What type of fertilizer do you use before biogas adoption? | Fertilizer type | Frequency | Percent |
Chemical fertilizer only | 31 | 41.9 |
Compost | 5 | 6.8 |
Manure | 2 | 2.7 |
Chemical fertilizer and manure | 35 | 47.3 |
Chemical fertilizer and compost | 1 | 1.4 |
Total | 74 | 100.0 |
What type of fertilizer do you use after biogas adoption? | Fertilizer type | Frequency | Percent |
Chemical fertilizer only | 2 | 2.7 |
Bio-slurry and compost | 26 | 35.1 |
Manure and compost | 6 | 8.1 |
Chemical fertilizer and manure | 3 | 4.1 |
Chemical fertilizer and bio-slurry | 37 | 50.0 |
Total | 74 | 100.0 |
Likewise, about 62.2% of households, which is the majority, used 4 sacks of DAP and 1sack of urea, 37.8% used 5 sacks of DAP and 2 sacks of urea per hectare per year, with an average consumption of 4.5 sacks of DAP and 1.5 sacks of urea before adoption (1 sack weighs 50 kg). Whereas, after adoption, about 45.9% of the households used 1sack of DAP and 0.25 sack of urea. About 54.1%, which is the majority, used 2 sacks of DAP and 0.5 sack of urea per hectare per year, with an average consumption of 1.5 sacks of DAP and 0.37 sack of urea per household per hectare per year (Table 11). This is a reduction of 3 sacks of DAP and 1 sack of urea per household per hectare per year. Thus, adoption enabled the saving of 3 sacks of DAP and 1 sack of urea per hectare per year. In terms of monetary returns, this is equivalent to saving of 2265.00 ETB from DAP and 695.00 ETB from urea purchase annually per hectare at local rate (1 sack or 50 kg DAP = 755 ETB, 1 sack per 50 kg urea = 695 ETB, at the time of data collection). Thus, the adoption has remarkably reduced the quantity of chemical fertilizer consumption. Debebe and Itana (2016) stated that chemical fertilizer is very expensive as compared to bio-slurry, 80.8% of the bio-slurry users saved 1000–2000 ETB per year and 19.2% saved 2000–3000 ETB per year. Similarly, Amare (2015) reported that the use of biogas offered an annual saving of 717.65 ETB and Claudia and Addis (2011) of 682 ETB from replacing inorganic chemical fertilizer with chemical fertilizer. The difference in the amount of money saved might infer to soil fertility, type of crop grown, and tradition of using chemical fertilizer and bio-slurry.
Table 41
Amount of chemical fertilizer used before and after biogas technology adoption
Question How many sacks of chemical fertilizer do use before biogas technology adoption per hectare per season? Average = 4.5 sack DAP and 1.5 sack urea | Amount and type of fertilizer | Frequency | | Percent |
4 sack DAP and 1 sack urea | 46 | | 62.2 |
5 sack DAP and 2 sack urea | 28 | | 37.8 |
Total | 74 | | 100.0 |
How many sacks of chemical fertilizer do use after biogas technology adoption per hectare per season? Average = 1.5 sack DAP and 0.37 sack urea | | | | |
1 sack DAP and 0.25 sack urea | 34 | | 45.9 |
2 sack DAP and 0.5 sack urea | 40 | | 54.1 |
Total | 74 | | 100.0 |
How much is the price of one sack (50 kg) chemical fertilizer in your local market? Average = 755 ETB DAP and 695 ETB urea | Price | Frequency | | Percent |
750 ETB DAP and 690 ETB urea | 51 | | 68.9 |
760 ETB DAP and 700 ETB urea | 23 | | 31.1 |
Total | 74 | | 100.0 |
Access to water sources
Though about 29.7% of the households had access to water sources around their home, the majority of the households, which is about 70.3%, lacked access to such water sources. The water resource was mostly reached within 50 minutes of walking distance from their residence. Consequently, the majority of the households, which is 62.5%, use water from rivers and 16.7% from water tap, and 12.5% from rain -water harvesting (Table 12). According to the standard set in the National Biogas Program document, for daily feeding of biogas plants, the source of water should be reached within walking distance of 20 minutes to 30 minutes away from home in Ethiopia (Eshete et al., 2006, EREDPC and SNV, 2008). Distant water source had negative influence on the functionality of biogas plants (Shallo and Sime, 2019). Tucho et al. (2016) also reported that meeting biogas plant’s water requirement remained a great challenge when distant water sources are considered. Since water is a basic substrate for biogas production, access to water sources is instrumental for the sustainable adoption of biogas technology. Thus, limited water availability is a basic constraint for biogas operation in some African countries (Parawira, 2009, Wawa, 2012, Surendra et al., 2014).
Table 12
Accessibility and type of sources of water
Accessibility | Source of water | Frequency | Percent |
Do you get water at your home/residence? or | | 22 | 29.7 |
away from residence area? | | 52 | 70.3 |
| Total | 74 | 100.0 |
If you do not get water in the nearest, from where do you fetch? | River | 30 | 62.5 |
Water well | 4 | 8.3 |
Water tap | 8 | 16.7 |
Rainwater | 6 | 12.5 |
Total | 48 | 100.0 |
Connection of toilet to biogas plants
All biogas user households had toilets. About 89.2% of them connected their toilets to the biogas system while 10.8% of them lacked such a connection. Before adoption, the trend of using toilet were poor (39.2%), very poor (41.9%), good (10.8%) and very good (8.1%). Nevertheless, after adoption, the trend was soundly changed where about 40.5% were good, 36.5% were very good, 14.9% were poor and 8.1% were very poor (Table 13). Biogas technology adoption helped the majority of biogas users to construct toilets and reduce defecation in the field, with massive potential of improving environmental sanitation and human health.
Table 5
Trend of using toilets and connection of toilets with biogas system
Trend of using toilet | | Before adoption | | After adoption |
Frequency | Percent | | Frequency | Percent |
Good | 8 | 10.8 | 30 | 40.5 |
Very good | 6 | 8.1 | 27 | 36.5 |
Poor | 29 | 39.2 | 11 | 14.9 |
Very poor | 31 | 41.9 | 6 | 8.1 |
Total | 74 | 100.0 | 74 | 100.0 |
Is your toilet connected to biogas operational system? | Variable | Frequency | Percent |
Yes | 66 | 89.2 |
No | 8 | 10.8 |
Total | 74 | 100.0 |
Biogas technology improves health of rural households by providing a cleaner cooking fuel and a waste handling solution, thus, avoiding health problems (Amigun et al., 2012; Sime 2020). Cooking with clean and odorless flame of biogas enabled reduction of in-door pollution caused from the smell of kerosene or smoke of firewood burning (Bajgain and Shakya, 2005).