Ethiopia
On the Design and Optimization of Distributed Energy Resources for Sustainable Grid-integrated Microgrid in Ethiopia
Apr 2023
Publication
This paper presents a study that focuses on alleviating the impacts of grid outages in Ethiopia. To deal with grid outages most industrial customers utilize backup diesel generators (DG) which are environmentally unfriendly and economically not viable. Grid integration of hybrid renewable energy systems (HRES) might be a possible solution to enhance grid reliability and reduce environmental and economic impacts of utilizing DG. In this study an optimization of grid integrated HRES is carried out for different dispatch and control strategies. The optimal power supply option is determined by performing comparative analysis of the different configurations of grid integrated HRES. The result of the study shows that grid integrated HRES consisting of photovoltaic and wind turbine as renewable energy sources and battery and hydrogen as hybrid energy storage systems is found to be the optimal system to supply the load demand. From the hydrogen produced on-site the FC generator and FCEVs consume 143 620 kg/yr of hydrogen which is equivalent to 394 955 kg/yr gasoline fuel consumption. This corresponds to saving 1 184 865 kg/yr of CO2 emissions and 605 703 $/yr revenue. Besides this system yields 547 035.4 $/yr revenue by injecting excess electricity to the grid. The study clearly shows the economic and environmental viability of this new technology for implementation.
Future Green Energy: A Global Analysis
Jun 2024
Publication
The main problem confronting the world is human-caused climate change which is intrinsically linked to the need for energy both now and in the future. Renewable (green) energy has been proposed as a future solution and many renewable energy technologies have been developed for different purposes. However progress toward net zero carbon emissions by 2050 and the role of renewable energy in 2050 are not well known. This paper reviews different renewable energy technologies developed by different researchers and their potential and challenges to date and it derives lessons for world and especially African policymakers. According to recent research results the mean global capabilities for solar wind biogas geothermal hydrogen and ocean power are 325 W 900 W 300 W 434 W 150 W and 2.75 MWh respectively and their capacities for generating electricity are 1.5 KWh 1182.5 KWh 1.7 KWh 1.5 KWh 1.55 KWh and 3.6 MWh respectively. Securing global energy leads to strong hope for meeting the Sustainable Development Goals (SDGs) such as those for hunger health education gender equality climate change and sustainable development. Therefore renewable energy can be a considerable contributor to future fuels.
Production of Green Hydrogen from Sewage Sludge/Algae in Agriculture Diesel Engine: Performance Evaluation
Jan 2024
Publication
Alternative fuel opportunities can satisfy energy security and reduce carbon emissions. In this regard the hydrogen fuel is derived from the source of environmental pollutants like sewage and algae wastewater through hydrothermal gasification technique using a KOH catalyst with varied gasification process parameters of duration and temperature of 6–30 min and 500-800 ◦C. The novelty of the work is to identify the optimum gasification process parameter for obtaining the maximum hydrogen yield using a KOH catalyst as an alternative fuel for agricultural engine applications. Influences of gasification processing time and temperature on H2 selectivity Carbon gasification efficiency (CE) Lower heating value (LHV) Hydrogen yield potential (HYP) and gasification efficiency (GE) were studied. Its results showed that the gasifier operated at 800 ◦C for 30 min offering maximum hydrogen yield (26 mol/kg) and gasification efficiency (58 %). The synthesized H2 was an alternative fuel blended with diesel fuel/TiO2 nanoparticles. It was experimentally studied using an internal combustion engine. Influences of H2 on engine perfor mance like brake-specific fuel consumption brake thermal efficiency and emission performances were measured and compared with diesel fuel. The results showed that DH20T has the least (420g/kWh) brake-specific fuel consumption (BSFC) and superior brake thermal efficiency of about 25.2 %. The emission results revealed that the DH20T blend showed the NOX value increased by almost 10.97 % compared to diesel fuel whereas the CO UHC and smoke values reduced by roughly 31.25 28.34 and 42.35 %. The optimum fuel blend (DH20T) result is rec ommended for agricultural engine applications.
Enhanced Combustion and Emission Characteristics of Diesel-Algae Biodiesel-Hydrogen Blends in a Single-Cylinder Diesel Engine
Mar 2025
Publication
With the escalating global energy demand the pursuit of sustainable energy sources has become increasingly urgent. Among these biofuels have gained significant attention for their potential to provide renewable and eco-friendly alternatives. Biodiesel is recognized for its diverse and cost-effective feedstock options. The study provides a novel approach to the production of biodiesel by employing the use of Dunaliella salina microalgae as a green source. The research suggests the blends provide a future solution to less toxic fuel sources achieving efficiency and minimizing emissions. This research emphasize on the production of biodiesel from Dunaliella salina microalgae a promising resource due to its high energy yield. The microalgae were cultivated in an f/2 nutrient medium enriched with carbon dioxide vitamins and trace metals. A total of 700 mL of bio-oil was extracted using ultrasonication at 50 Hz for 85 minutes. Then the bio-oil was transesterified in a single-stage sodium hydroxide-catalysed process with methanol as a solvent. The process yielded a high extraction efficiency of 94%. The produced biodiesel was characterized through advanced analytical techniques including NMR spectroscopy GC-MS and FTIR test studies confirming its suitability as a fuel. Combustion and emission analyses revealed that the direct substitution of biodiesel blends for diesel in engines significantly reduced hydrocarbon and carbon monoxide emissions although a slight increase in nitrogen oxide (NOx) emissions was noted. The combustion and emission characteristics were influenced by blend composition and calorific value. Additionally the study provides a detailed comparison of the performance of pure diesel biodiesel blends and hydrogen-enriched biodiesel in diesel engines offering valuable insights into their environmental and performance impacts. This study gives additional insights towards future work such as scalability (consisting large scale cultivation of algae for better studies) engine durability (studies on engine wear and tear) and integration with renewable energy sources (integrating renewable sources like solar and wind energies).
Decoupled Hydrogen Production through Hybrid Water Electrolysis Utilizing Ruthenium-tin Oxide Electrocatalyst
Oct 2025
Publication
Hybrid water electrolysis system was designed by using Ruthenium-Tin Oxide (RuSn12.4O2) electrocatalyst as anode material for efficient hydrogen production enhancing energy conversion efficiency. The RuSn12.4O2 Electrocatalyst was synthesized by hydrothermal method and exhibited exceptional activity making it an optimal choice for Iodide oxidation reaction (IOR) and enabling energy-saving hydrogen production. The two-electrode acidic electrolyzer reduced voltage consumption by 0.51 V at 10 mA cm-2 compared to oxygen evolution reaction (OER) at the same current density. This hybrid electrolysis system achieved a remarkable reduction in energy consumption of over 40 % compared to OER process. The Chrono-potentiometric test demonstrated that the RuSn12.4O2 electro-catalyst’s superior stability and low overpotential increase of 70 mV at 10 mAcm-2 . The RuSn12.4O2 electro-catalyst Tafel slope is also a crucial metric for understanding kinetic characteristics in both IOR and OER processes. Thus RuSn12.4O2 electro-catalyst in IOR has a lower Tafel slope (61 mV dec-1) than that in OER according to the Tafel slopes determined from linear sweep voltammetry (LSV) curves. Additionally at various potentials the electro-catalyst's activity toward IOR to produce hydrogen demonstrated exceptional performance in this electrolysis system without causing any catalyst degradation.
Integrated Renewable Energy Supply Architecture for Advancing Hydrogen Symbiosis and Eco Synergistic Smart Grid Interactions with Next Generation Combustion Technologies
Jul 2025
Publication
This study introduces the Smart Grid Hybrid Electrolysis-and-Combustion System (SGHE-CS) designed to seamlessly integrate hydrogen production storage and utilization within smart grid operations to maximize renewable energy use and maintain grid stability. The system achieves a hydrogen production efficiency of 98.5% indicating the effective conversion rate of electrical energy to hydrogen via PEM electrolysis. Combustion efficiency reaches 98.1% reflecting the proportion of hydrogen energy successfully converted into usable power through advanced staged combustion. Storage and transportation efficiency is 96.3% accounting for energy losses during hydrogen compression storage and delivery. Renewable integration efficiency is 97.3% representing the system’s capacity to utilize variable renewable energy inputs without curtailment. Operational versatility is 99.3% denoting the system’s ability to maintain high performance across load demands and grid conditions. Real-time monitoring and adaptive control strategies ensure reliability and resilience positioning SGHE-CS as a promising solution for sustainable low-carbon energy infrastructure.
High-performance Hydrogen Energy Generation via Innovative Metal-organic Framework Catalysts and Integrated System Design
Aug 2025
Publication
Hydrogen energy generation faces challenges in efficiency and economic viability due to reliance on scarce noble metal catalysts. This study aimed to develop platinum-doped nickel-iron metal-organic framework (Pt-NiFe-MOF) catalysts with controlled metal ratios and pore architecture for enhanced water electrolysis. The NiFe-MOF framework was first synthesized via a solvothermal method which was then subjected to post-synthetic modification to introduce controlled platinum loadings (0.5- 2.0 wt%). The pore structure was tuned using a mixed-linker strategy (H₄DOBDC ratios 1:0 to 1:1). Catalysts were characterized using PXRD HRTEM BET XPS and ICP-OES techniques. Electrochemical performance was analyzed in 1.0 M KOH. A custom-designed integrated electrolysis system at 75 °C assessed practical performance. The Pt-NiFe-MOF-1.0 catalyst with H₄DOBDC ratio of 1:0.5 achieved remarkable effectiveness requiring overpotentials of only 253 mV for OER and 58 mV for HER when operating at 10 mA/cm². This catalyst featured an optimal pore diameter of 4.2 nm and surface area of 1325 m²/g. DFT calculations revealed platinum incorporation created synergistic effects by modifying hydrogen binding energies. Furthermore DFT calculations and XPS analysis revealed that the role of platinum in the OER is not direct catalysis but rather a powerful electronic modulation effect; Pt dopants withdraw electron density from adjacent Ni and Fe centers promoting the formation of higher-valent Ni³⁺/Fe³⁺ species that are intrinsically more active and lowering the energy barrier for the rate-determining O-O bond formation step. The integrated system achieved 1.62V at 100 mA/cm² with 75.8% energy efficiency maintaining stability for 200 h with 15–30 times lower precious metal loading than conventional systems. Strategic incorporation of low platinum concentrations within optimized NiFe-MOF structures significantly enhances water electrolysis performance while maintaining economic viability advancing development of industrial-scale hydrogen generation systems.
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