Effects of access to renewable energy sources and technologies on rural household energy use and the environment in Ethiopia

Abstract

Access to modern, affordable, and reliable energy and clean cooking facilities is critical for Ethiopia to drive its economic development, reduce poverty and curb the negative environmental and health impacts of traditional and unsustainable use of solid biomass fuels. To that end, the government of Ethiopia has devoted considerable efforts in recent years to improving rural access to electricity, and the dissemination of household biogas systems, solar photovoltaic (PV) systems and improved biomass cookstoves (ICSs). In light of these efforts, the present thesis aims to investigate and empirically examine the effects of access to modern and renewable energy sources and technologies on the rural households’ energy use patterns, well-being, and the environment in southern Ethiopia. In doing so, the thesis seeks to shed new light on the nexus between renewable energy access and household energy transition in rural sub-Saharan Africa in the face of climate change. The research was carried out mainly in four rural districts of Southern Ethiopia and data were collected from a comprehensive cross-sectional study (survey) of sample households, direct field assessments, and energy consumption measurements.

The first paper systematically reviews and analyses existing empirical evidence on the potential environmental impacts of small-scale renewable energy technologies (SRETs): biogas, ICSs, and solar PVs in East Africa by taking Ethiopia, Kenya, Tanzania and Uganda as case studies. The results showed that SRETs have considerable potential for reducing household consumption of traditional fuels; thereby lessening forest degradation and the subsequent carbon dioxide (CO2) emission at local level. Our conservative estimates, based on the evidence, indicated that the biogas plants and ICSs disseminated in each country until 2015, had a combined potential of saving 0.31 to 3.10 million tons (Mt) of woodfuel and reducing emissions of 0.56 to 5.67 Mt of CO2 equivalent (CO2e) per country per year. However, when compared with the annual biomass energy consumptions and CO2 emissions of each country, the biogas and ICSs disseminated till 2015 did not appear to offset more than 7.2% of the total woody biomass energy consumed and 3.8% of the total CO2e emitted by the respective countries per year.

In light of the evidence from the systematic review in paper I, in paper II we analysed the current utilization rate, performance, and impact of domestic biogas systems in rural southern Ethiopia based on direct field studies and surveys in four districts. The results showed that despite growing efforts, the uptake and utilization of biogas technology is yet very low. Out of the total 32 digesters directly investigated, only 21 (65.63%) were found functional. The average quantity of biogas produced from a 6m3 functional plant was estimated to be 0.61 m3/day. This suggests that the current level of biogas use could substitute the consumption of 632 kg of fuelwood and 25 L of kerosene per household per year. However, comparative analysis of the total energy consumption of biogas user and non-user households revealed that the effect of biogas use on household fuelwood and kerosene consumptions, and energy transition was insignificant.

Paper III extended the in-depth investigation and examined the potential fuel savings, economic and environmental co-benefits of three ICSs (Mirt, Gonziye, and Tikikil from a survey of 605 sample households and direct kitchen cooking observations to 133 ICSs users. The study finds that compared with the traditional open-fire tripod, the three ICSs studied could reduce household fuelwood consumption on average by 1.72 to 2.08 tons (t)/stove/year. The fuelwood savings translate to an estimated CO2e emission reduction of 2.82 to 3.43 tCO2e per stove per year. The results from the cost-benefit analysis (CBA) showed that usage of these ICSs could provide a net economic return of between US$ 317 and $460 during the 2 to 5 years lifespan of the stoves. The study highlighted that beyond improving the energy efficiency and well-being of rural households, ICSs are an essential component of the national and global strategies for GHGs emissions abatement.

In paper IV we explored the impacts of rural electrification with solar PV systems in the study districts based on the survey data and direct field assessment of 137 solar PVs and lanterns. The findings indicated that solar-electrified households consume on average 43.68 litres less kerosene, and emit 107 kg less CO2 and 2.72 kg less Black Carbon (BC) per year compared with non-electrified households (neither grid nor solar light). This reduction in kerosene consumption and the access to electricity from the solar PVs could enable a solar user household to save between US$ 65 and $75 per year from the avoided energy expenditures and mobile charging costs. The new access to electricity and solarlighting has also reduced the health risks of rural families from kerosene wick lamps and allowed small-businesses to generate more income. The study concluded that solar PVs and lanterns are improving rural households’ wellbeing and access to clean lighting, and therefore should be further integrated into the national energy systems. However, the sustainability and effectiveness of solar PVs faces serious challenges from poor-quality and counterfeit products in the market, high cost of quality-verified products, lack of after-sales maintenance services, and limited access to credit financing services.

In paper V, we analysed the current patterns of rural households’ energy consumption and the share of modern and clean fuels to examine the overall effect of access to modern and renewable sources and technologies on rural household energy use and transition. The results showed that more than 97% of the households still rely on traditional solid biomass fuels, particularly fuelwood (90.7%) as the primary fuel for cooking and baking Injera (Ethiopian bread). In contrast, the use of biogas and electricity for cooking was limited. On the other side, 50% use kerosene, 29% grid electricity, 19% solar, and 1.98% biogas as primary energy sources for lighting. Of the total 87, 172 MJ energy estimated to be consumed by a rural household per year, energy derived from traditional biomass fuels accounted for 85, 278 MJ (97.83%); while energy from modern and clean sources (electricity, biogas and solar) combined accounted for only 830 MJ (≈ 1%). The findings indicated that the recent efforts of Ethiopia to improving the rural access to modern and renewable energy sources have led to significant lighting energy substitution and partial transition from kerosene oil-based towards clean lighting fuels. However, we found no evidence of substantive energy substitution to suggest that the heavy dependence on traditional solid biomass fuels for cooking and baking end-uses is declining.

Given the findings in paper V, in paper VI, we examined the major determinants of rural household’s energy choices for cooking and lighting by using Pearson’s Chi-square (χ2) test and Multivariate probit model. The results indicated that rural household’s primary cooking fuels are statistically significantly associated with the household size, distance to wood source, location, and income level. Empirical results of the multivariate analysis showed that rural households’ energy choices for lighting are significantly influenced by income level, family size, location, educational status, distance to market, road access. We find that wealthier and more educated households residing near road access were more likely to use clean lighting energy such as electricity and solar power; while poorer households residing in areas with limited road access use kerosene and dry-cell battery. However, the results also indicated that high-income level and grid-connection have not led households to completely forgo the use of traditional cooking and lighting fuels. This pattern appears to observe the energy-stacking model as opposed to the energy-ladder model of complete fuel-switching. While income remains a principal factor, the study finds that several non-income factors also play a major role in determining the energy choices and energy transition of rural households in developing countries.

Overall, this PhD thesis provides new empirical evidence and fresh insights to inform decision making and energy planning on the socio-economic, environmental, and energy transition effects of access to renewable energy sources and improved cookstoves; and the associated drivers, challenges, and determinants in the context of rural sub-Saharan Africa. The thesis has shown that increased access and use of modern and renewable energy sources such as electricity and solar in rural areas of developing countries can lead to significant energy substitution and transition from kerosene towards clean and quality lighting. It has also revealed that promoting the use of ICSs is a viable option and an essential component of the strategy for reducing deforestation, mitigation of climate change, and sustainable use of biomass in sub-Saharan Africa. The low rate of utilization and impact from household biogas systems, on the other hand, signifies that thorough re-examining of existing dissemination approaches and operational practices is critical. Most importantly, the thesis has highlighted that the nexus between access to modern and renewable energy; and household energy transition in rural sub-Saharan Africa is complex and non-linear. As such, traditional biomass fuels will likely remain the primary energy sources of even the wealthiest households that are connected to the grid.

The implication is that solid biomass-energy dependent countries like Ethiopia need to critically address the growing demand for biomass fuels through developing sustainable and diversified bio-energy sources, energy-saving and affordable cooking technologies, and decentralized renewable rural hybrid energy systems alongside the current efforts of improving rural access to grid electricity. Although the data for this study is primarily from rural southern Ethiopia, the conclusions and policy implications drawn can have a wider application in the broader context of rural sub-Saharan Africa.