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As the Ethiopian energy demand urges for fuel options, it is essential to identify biomass fuels and estimate their energy potential. This study quantified the agricultural residues' biomass resources and their energy potential. Further analyzed and characterized the potential nature through quantitative and qualitative methodologies with descriptive, comparative, explanatory, and exploratory studies. Five-year crop yield data of 27 crops were collected from the Central Statistical Agency of Ethiopia. Conversion factors into energy were surveyed from the literature. Subsequently, the residues available and their energy potentials were estimated. Mathematical and statistical analysis methods were considered in an Excel sheet. A new measure of natural potential capacity for energy was defined in two views (resource and application). Accordingly, their potential capacities were rated and prioritized comparatively. The gross energy potential of all the residues was estimated to be 494.7 PJ. With 30% collecting efficiency, it corresponds to the imported petroleum fuel in 2018. Five major crops contributed to 80% of this gross potential. Maize and sorghum presented the highest potential due to their superior yields and good natural potential capacities. They are also well distributed in all the regions. Cotton and maize's natural potential capacities are the best in both views. Generally, commercial crops presented better capacities than the major cereal crops. However, major crops' energy potentials dominated due to their yields. These resources need mobilization into modern and commercially accessible fuel forms that await intervention. Densified and carbonized forms of consumption in nearby industries and households are most viable for the Ethiopian case. [ABSTRACT FROM AUTHOR]

The 2030 sustainable development goal (SDG7) target progress indicators show that developing countries are off track. Ethiopia's low performance to the SDG7 has endangered its economic, societal, and environmental sustainability. The performance in clean cooking has contested its policy, institutional setup, and R&D. The objective of this paper lies in evaluating four improved cook stoves against a traditional stove based on fuel consumption, cooking time, and emission. The study would contribute to solving the clean-cooking challenges by giving scientific evidence on the technological status of these stoves. The evaluation results show that the TCS consumed 2.7 kg of fuel, had a cooking time of 1:30 h, and used 4.3 kg CO2 per cooking period. Similarly, the ICSs required: 1.2 kg, 2 h, and 1.9 kg (EZY); 1.5 kg, 3 h, and 2.4 kg (Tikikkle); and 1.4 kg, 5 h, and 3.2 kg (Lakech), respectively. In addition, these stoves registered a thermal efficiency of 25, 17, and 19%, respectively. The metal body, insulation, and air inlet caused EZY to perform better. However, these technologies are low-order technologies, and their performance is found to be a major locking factor in ICS adoption. This evidence would help ICS actors to understand where to intervene for better adoption. Furthermore, the authors gave implementation fix recommendations to improve ICS programs. [ABSTRACT FROM AUTHOR]

Background: Injera is food consumed daily by Ethiopians like bread and rice in other parts of the world. Biomass stoves are used to bake Injera in most rural households. The unsustainable use of fuelwood causes deforestation. Improved cook stoves such as Mirt (name in local language) were introduced to replace traditional stoves and save fuel wood. This study presents a performance comparison of three newly developed prototype biomass stoves with traditional and Mirt stoves. The prototype stoves were made with a clay pan (designated MUC: Mekelle University prototype with clay pan), with a glass pan (MUG) and with an aluminum pan (MUA). Controlled cooking tests were conducted for each type of stove to determine the thermal efficiency and specific fuel consumption. Results: The thermal efficiencies of the traditional, Mirt, MUC, MUA and MUG stoves were found to be 14%, 17%, 21%, 29% and 32%, respectively. Similarly, the percentage fuel wood savings by Mirt, MUC, MUA and MUG compared to the traditional stove were 32%, 48%, 64% and 67%, respectively. The results indicate that the prototype stoves had significantly better performance compared to the traditional and Mirt stoves. Conclusion: The prototype stoves have the potential to reduce fuel wood consumption by more than half of that currently consumed employing traditional stoves. In addition to the economic benefit of saving fuel wood, the improved stoves will have significant environmental implication. Based on the fuel saving figures, it is estimated that 0.4, 0.5 and 0.52 tons/year of fuel wood may be saved per household adopting MUC, MUA and MUG stoves, respectively. [ABSTRACT FROM AUTHOR]

In Ethiopia, like most developing countries, the majority of households depend on wood and charcoal as their cooking energy resources. This energy has a direct impact on the forest coverage and its emissions have significant health issues. Biogas technology has introduced to address these problems and reduce energy poverty in developing countries. However, the success of this technology depends on many factors such as technology appropriateness, available skill, proper introduction, and government support to create favorable financial incentives. The objective of this paper is to make an overview assessment of biogas development programs in Ethiopia, identify development barriers and provide suggestions to mitigate these barriers. The national and regional biogas program of Ethiopia has implemented to give energy for cooking and to some extent for lighting. However, it has shown limited success over the years. The National Biogas Programme of Ethiopia has shown an overall 50% achievement while the Tigray region registered 55% achievement. In addition, the owner of the biogas facility in Tigray reported a 57% functionality rate but the lowest satisfaction level of 15%. Generally, the region has shown relatively better performance in terms of dissemination and functionality but a low satisfaction rate due to technical limitation, unsteady input, and financial factors. [ABSTRACT FROM AUTHOR]

This paper deals with PHL management of Guava fruit through small-scale juice processing in rural areas that have no access of modern energy. Guava trees cover large areas in Tigray region of Ethiopia, however, during the harvest period the consumption and yield of the fruit is not in balance. Consequently, considerable amount of the fruit spoiled in the field. In addition, during this period the market price of the fruit is very low and discourage farmers to collect the fruit as its market price could not cover the labor cost. On the other hand, the fruit is not available out of the yield season. This study has demonstrated fruit processing using locally developed solar energy technologies to improve PHL management of fruits and vegetables. The technology has sized in view of smallholding farmer's production capacity with an average power of 6kW at an average solar insulation of 800 W/m2 that boils 5 l of water in 5 min. During the experiment, uniformly sliced fruits were boiled using the solar boiler for half an hour to make it sterilized and soft. The boiled fruit was mixed with preservatives, homogenized, filtered and hot-filled into a glass bottle to avoid air traps. The juice examined regularly in 30, 60 and 90 days for its PH, TSS and total microbial load. The results have shown the average total bacteria counts of the juices is below the maximum allowable limit in foods for consumption. Accordingly, the technology would enable smallholding farmers to start equitable agroprocessing. [ABSTRACT FROM AUTHOR]

Today, many developing countries are using biomass as their primary energy supply. However, this energy affects the environment, health and safety of women and children. In addition, utilization of this energy using traditional cooking stoves is causing indoor air pollution and in turn health problems to millions of people. To overcome such problems, efforts are being made by researchers globally and are suggesting alternative safe energy sources. This paper demonstrates solar cooker with an integrated PCM thermal storage and heat transportation loop system suitable for high temperature applications. The system has designed to address Injera baking application. Injera, a fermented flat bread type, is the most common food type served three to four times a day in Ethiopia. Other countries like Eritrea, Somalia, Sudan and Yemen also use this food. The storage system has storing capacity of heat up to 2500C and it can retain this heat for about two days. The storage has coupled to a polar mounted concentrator, fixed receiver and used steam heat transfer fluid. The steam circulates naturally between the evaporator and condenser in a closed loop. The paper focuses on indirect charging, simultaneous charging-discharging and discharging of the stored heat for the purpose of Injera baking. The frying pan is a custom-made aluminum plate casted by embedding a 10mm coiled stainless steel steam pipe as heating element. The pan is 500mm in diameter and 30mm thick; and the fins are 20mm in diameter and 140mm long. The fins have immersed into a 20kg PCM, which is coupled to a 1.8m diameter parabolic dish collector. The solar fryer demonstrates Injera baking for average family size. Baking is tested from the stored heat, while storage is charging. A fully charged storage has supplied enough heat to baked average household Injera demands about 19Injeras and additional breads with the remaining heat. [ABSTRACT FROM AUTHOR]

Proper sterilization of reusable medical devices and surgical instruments are critical aspects of modern health care delivery system that can also directly affect the patients. In off grid health centers and health posts, solar autoclave can have great contribution to facilitate modern heath care delivery by sterilizing medical infected equipment and reduces associated health risks. This research has developed a solar thermal based autoclave and analyzed its performance. The numerical and experimental results have validated with standard sterilization techniques and show successful and efficient results. The laboratory and community trial of the autoclave achieved temperatures of about 145°C and it was maintained it for more than 20 minutes that complies the sterilization process and procedures that has proved by the sterilization monitoring techniques. The field trial of the system was an encouraging comment to promote the technology and disseminate the technology. [ABSTRACT FROM AUTHOR]

Latent heat storage and efficient heat transport technology helps to utilize the intermittent solar energy for continuous and near isothermal applications. However, many latent heat storages face challenges of storage charging, heat retaining, and discharging the stored heat. This paper tries to address the challenges of heat transportation and storage charging-discharging issues. The heat transportation from the receiver over some distance, from outside to the kitchen, is carried out with a stainless pipeline and water as heat transfer fluids. However, the charging-discharging process is carried by conduction method with the help of fins. In addition, the stored heat is retained for about one-two days by using aerogel insulation. The latent heat is stored in a phase change material (PCM), nitrate salt (mixture of 60%NaNO3 and 40%KNO3), which melts at 222°C and has 109 J/g specific heat of fusion. The storage has the capacity of storing up to 250°C heat and supply this heat isothermally during baking in the liquid-solid phase transition. However, the sensible heat stored in the solid and liquid form of the PCM is used to perform additional applications that do not require uniform heat which includes bread baking, kita (large pancake) baking and water boiling. The low thermal conductivity of PCM is enhanced by using extended aluminum fins that are attached to the baking plate and extruded inward to the storage. In this paper, two-phase loop thermosyphon of steam is used to manage the long distance heat transportation required between the receiver (outside) and the storage (inside a house). The steam in the thermosyphon flow has restricted to a maximum working temperature of 250°C. Steam is selected for its highest heat capacity, availability and stable nature. It carries heat from the collector focus point and condenses in a coiled pipe imbedded in aluminum plate placed on top of the storage. Many fins are solidly attached to this plate to conduct the heat down to the PCM inside the storage during charging. This design configuration avoids pressure development inside the PCM storage and the charging-discharging temperature is recorded in three zones (top, middle and bottom) of the storage. The experimental and numerical results show that the heat transportation, retention and charging-discharging methods are effective. [ABSTRACT FROM AUTHOR]

The Injera baking electrical mitad is the most energy-consuming device in every household in Ethiopia. This research presents a detail engineering study on the energy-consumption performance of existing electrical mitad in Mekelle city. The research work considered thirty-one electrical mitad from different workshops in Mekelle. Depending on the number of clay used, there are three types of electrical mitad; the single clay, the double clay and the rotating type mitad. In this research, it was found out that the average power consumption of existing mitad is in the range of 3.5 KW to 3.9 KW. The specific average baking energy is 0.82, 0.73 and 0.54 kWh/kg of injera for double clay, single clay and rotating type mitad respectively while the thermal efficiency by considering baking of 6kg of Injera on each mitad is 38%, 47% and 61% respectively. In all designs, the baking temperature is in the range of 130-140 0C. Although the rotating type mitad is more energy efficient, it has technical limitations. Due to that, the single and the double clay mitad are widely used by households hence share all the market penetration of injera baking electrical mitad. These commonly used electrical mitad have an energy loss from 50-60% of the input energy. [ABSTRACT FROM AUTHOR]