## 3 Results and Discussion
### Direct Impacts of Gasifier Uptake on Household Livelihoods  
#### 3.2.1 Reduced Fuel Consumption and Time Spent in Collecting Firewood  
Since the start of gasifier use, 94% of the households reported a decrease in the amount of firewood used (measured as headloads). A headload of firewood in the study area weighs 35 kg on average [23]. These households reported using eight headloads (280 kg) and five headloads (175 kg) on average per month prior to and after gasifier introduction, respectively, and thus a significant reduction in firewood use of on average 38% (\(t\)-test, \(p=0.0002\)). Fuel saving by the gasifier extended the period of households' fuel supply. Before having the gasifier, 94% of households used a headload of firewood  
Figure 4: Three-stone open fire in use at Kwale, Kenya.  
for five days on average and for eight days after receiving the gasifier. Thus, the length of time that firewood lasted in the household was increased by 60%.  
Similarly, improvements in fuel savings by improved stoves have been reported previously. In rural Kenya, participatory cooking tests showed a reduction in fuel consumption by 40% compared with the three-stone open fire [20]. A study undertaken in Ethiopia reported a 38% fuel saving after switching from three-stone open fire to an improved cook stove [27]. Moreover, in Khairatpur village in rural India, the use of improved cook stoves lowered annual consumption of fuel by 41% compared to traditional stoves [28].  
Due to reduced fuel consumption, the time spent on firewood collection was also reduced for 98% of the households. The firewood sources included natural forests, with households sourcing from it spending 3 h on average to collect one load of firewood, friends' farms (2.8 h), community land (4.5 h), private plantations (2 h) and on-farm (1.4 h). Even though fuel collection is not a daily activity, the use of inefficient cook stoves like the three-stone open fire by households can mean many hours spent on collecting fuel. Households spent on average 11 h per month collecting firewood (eight headloads) before the introduction of the gasifier and 7 h (five headloads) after the gasifier was introduced. Similar findings on saving time spent on firewood collection had been reported previously. For instance, after switching to improved cooking stoves from three-stone fires in the Dadaab refugee camp in Kenya, the number of times women needed to walk for 4 h to the forest to collect firewood per week was reduced by 2 times [29]. Further, a 32% reduction in the annual time spent collecting firewood has been reported in Idifu village in Tanzania as a result of using improved cook stoves rather than three-stone open fires [30], while in Chamwino and Kongwa districts in Tanzania 50% saving of fuel collection time was reported [31]. The differences in time saved in various geographic locations are dependent on the distribution of firewood sources and the wealth of appropriate vegetation. The women in the study area are main firewood collectors (Table 1) and they carry the loads of firewood from the various sources [23] on their heads (Figure 5). Firewood collection is hard work for women, is dangerous, and limits the time for productive activities [8]. However, users reported spending more time preparing fuel for the gasifier compared with the three-stone open fire, so there could be trade-offs in time spent in fuel collection versus fuel preparation.  
Figure 5: Women at Kwale, Kenya carrying headloads of firewood from a private plantation.