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Research Article
An Advanced Modular Multilevel Inverters for
Grid-connected PV Optimization by Maximum Power Point Tracking
Issue:
Volume 1, Issue 1, March 2026
Pages:
1-13
Received:
12 October 2025
Accepted:
29 January 2026
Published:
25 February 2026
Abstract: Modular multilevel inverters (MMLIs), acknowledged not only for its modular structure, scalability and low harmonic distortion but also offers an efficient solution, for managing high-power renewable-energy applications. However, these often depends on conventional centralized control methods, which are insufficient in addressing critical challenges like scalability and hardware delays in distributed control systems. This paper emphases on the design and implementation of an advanced 3-Ph. MMLI for a 400-kW solar plant connected to a 25 kV grid. The study examines the system's performance, control strategies and operational challenges encountered during the integration with grid. To optimize energy extraction from the PV array, incorporate a DC/DC, converter featuring MPPT, through ‘Perturb and Observe’ (P & D) technique. The extracted energy is then stepped up and converted into 3-Ph. AC voltage through MMLI. The output from these, feed into a common 500V DC bus, enabling the overall system integration. Unlike earlier methods which are used open-loop control to address power imbalances among legs, this study employs closed-loop control using to correct mismatched DC loop currents. This allows, dynamic adjustment the voltage across PV array to optimize output efficiency. The efficacy of the proposed control-strategy has been validated through Mat lab/Simulink simulations, demonstrating its potential.
Abstract: Modular multilevel inverters (MMLIs), acknowledged not only for its modular structure, scalability and low harmonic distortion but also offers an efficient solution, for managing high-power renewable-energy applications. However, these often depends on conventional centralized control methods, which are insufficient in addressing critical challenge...
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Research Article
Nonintrusive Model Order Reduction Theory in a Fixed Size Domain with Particle in Fluid Flow Application
Issue:
Volume 1, Issue 1, March 2026
Pages:
14-30
Received:
4 December 2025
Accepted:
15 December 2025
Published:
25 February 2026
Abstract: High-fidelity numerical simulation of particle-in-fluid systems is critical for engineering applications such as proppant transport in hydraulic fracturing, cuttings transport in drilling, and fluidization processes, but its practical use is often limited by the high computational cost of Eulerian–Lagrangian (CFD (Computational Fluid Dynamics)–DEM (Discrete Element Method)) methods. Although reduced-physics approaches such as Eulerian–Eulerian models offer faster solutions, they typically sacrifice accuracy by oversimplifying particle dynamics. This work introduces a new nonintrusive Reduced Order Modeling (ROM) strategy that integrates Proper Orthogonal Decomposition (POD) with a previously developed nonintrusive model-order reduction framework to achieve substantial computational acceleration while preserving the fidelity of CFD–DEM simulations. Snapshot-based POD is used to extract dominant flow and particle-motion modes from high-resolution simulations, enabling projection operators that reduce the system dimension by two to three orders of magnitude without modifying the underlying solver. Nonintrusive serial and parallel bridges are constructed to link system states along and across trajectories in input space, allowing nonlinear behavior to be retained while enabling rapid prediction. Additional speed-ups are achieved by projecting these bridges into reduced space, resulting in a ROM–ROM framework. The method is validated using a particle–fluid gas blower model with 3,151 particles and a 12,604-dimensional state space. Snapshot data from four simulations are used to construct reduced bases for particle position and velocity, with 30 POD modes preserving approximately 80–85% of system energy. Predictions for a new operating condition show excellent agreement between the ROM–ROM model, nonintrusive full-space predictions, and the full CFD–DEM solution. Performance analysis demonstrates that the ROM–ROM approach is approximately 3×10⁵ times faster than the full CFD–DEM simulation and about 40 times faster than the nonintrusive full-space method. These results confirm that combining POD with nonintrusive trajectory-based reduction provides an efficient and accurate framework for accelerating multiphase particle-transport simulations, with even greater potential gains for larger systems. This study represents the first POD-enabled nonintrusive ROM applied to particle-in-fluid systems with a fixed particle count, enabling fast surrogate models suitable for real-time simulation, optimization, and uncertainty analysis in complex engineering workflows.
Abstract: High-fidelity numerical simulation of particle-in-fluid systems is critical for engineering applications such as proppant transport in hydraulic fracturing, cuttings transport in drilling, and fluidization processes, but its practical use is often limited by the high computational cost of Eulerian–Lagrangian (CFD (Computational Fluid Dynamics)–DEM ...
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Review Article
Ethiopian Coal Deposits: Resource Development and Future Prospects
Wakjira Tesfaye*
Issue:
Volume 1, Issue 1, March 2026
Pages:
31-39
Received:
4 February 2026
Accepted:
14 February 2026
Published:
26 February 2026
Abstract: This review synthesizes the current state of knowledge regarding coal deposits in Ethiopia, a nation whose energy strategy has historically prioritized large-scale hydropower development. Moving beyond superficial resource inventories, this article critically examines within the tectonic framework of Permo-Carboniferous (Karoo) graben systems and Mesozoic rift basins. This study provides a meticulous analysis of Ethiopia's coal resources, which include approximately 297 Mt of registered coal reserves identified through systematic exploration, historical resource estimates of ~600 Mt, and recent government projections suggesting potential resources exceeding 1 billion tons subject to further delineation, and evaluates their quality and suitability for applications ranging from thermal combustion to advanced conversion technologies. Furthermore, it evaluates their quality and suitability for applications ranging from thermal combustion to advanced conversion technologies. The paper delves into the historical context and contemporary status of resource development, identifying systemic technical, infrastructural, and economic bottlenecks that have hindered exploitation. Within the global and national discourse on energy transition; that the strategic, responsible, and technology-enabled development of indigenous coal resources is not an anachronism but a critical component of Ethiopia’s energy security and industrial modernization. This is contingent upon the integration of advanced clean coal technologies (CCT). While carbon capture utilization and storage (CCUS) remains economically prohibitive in the Ethiopian context presently, emission control technologies (ESP, FGD) offer immediate pathways for localized pollution mitigation. Analyzing coal’s potential role in cement manufacturing (as a kiln fuel), direct reduction iron (DRI) if washed to <15% ash, and as a feedstock for synthetic fuels via CTL technologies. Ethiopian coal, if governed under stringent environmental regulations and technological upgrading, could provide the dispatch able base load and fiscal stability required to underwrite Ethiopia's longer-term transition to a renewable-dominated energy system.
Abstract: This review synthesizes the current state of knowledge regarding coal deposits in Ethiopia, a nation whose energy strategy has historically prioritized large-scale hydropower development. Moving beyond superficial resource inventories, this article critically examines within the tectonic framework of Permo-Carboniferous (Karoo) graben systems and M...
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Research Article
Barriers to Adoption of Energy-efficient HVAC Systems in Middle-class Households in Pakistan
Muhammad Awais Javed*
Issue:
Volume 1, Issue 1, March 2026
Pages:
40-48
Received:
23 June 2025
Accepted:
20 February 2026
Published:
4 March 2026
Abstract: Buildings and additional structures utilize a significant helping of the energy in the sphere. HVAC systems are mostly responsible for building energy use in middle class households in Pakistan. This study proposes a simulation-based optimization approach for efficiently measuring HVAC systems choices in the early design stages to get the optimal configuration in middle class households in Pakistan. This strategy is applied establishing HVAC systems in middle class households in Pakistan. The ventilated Dunkel cycle performs better than the other two designs for high COP systems in all three climate zones; nevertheless, ventilation is the superior choice in middle class households in Pakistan. Systematic simulations can help with the difficult process of optimizing HVAC systems designs in middle class households in Pakistan. This invention will assist HVAC systems design are selecting the optimal systems configuration and design parameters during the early design phase by accounting for various middle-class households in Pakistan.
Abstract: Buildings and additional structures utilize a significant helping of the energy in the sphere. HVAC systems are mostly responsible for building energy use in middle class households in Pakistan. This study proposes a simulation-based optimization approach for efficiently measuring HVAC systems choices in the early design stages to get the optimal c...
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Research Article
Mechanically Actuated Water Injection for Advanced Diesel Emission Control
Berisso Woyessa Bekele*
Issue:
Volume 1, Issue 1, March 2026
Pages:
49-53
Received:
28 February 2026
Accepted:
10 March 2026
Published:
26 March 2026
DOI:
10.11648/j.sdenergy.20260101.15
Downloads:
Views:
Abstract: The research target is the significance of nitrogen oxides (NOx) and particulate matter (PM) emissions reduction of diesel-powered engines that are still significant sources of air pollution in terms of transportation and industrial activity. The suggested exhaust-driven water vapor injection system will make use of exhaust pressure to actuate a gear-cam nozzle assembly to inject water vapor in the combustion process in a controlled manner. This solution seems promising and innovative in the form of a retrofit solution to the current diesel engines. Combination of thermodynamic analysis: the thermodynamic modeling is done to consider the impact of water vapor injection on maximum flame temperature and NOx production with extended Zeldovich kinetics and first-law energy balance. The final experimental results reported show that despite the injection ratio of water being 10 and 20 per cent, the up to 42 and 44 percent of NOx emissions and particles are reduced, which is quite optimistic in its environmental improvement. Moreover, the resemblance to the latest literature allows locating the findings in the context of emission control technologies. Nonetheless, there are several things that need to be better explained and elaborated. The description does not provide sufficient details on the experimental setup, engine details, instrumentation, and measurement procedures, which makes it difficult to fully assess the reliability and reproducibility of the reported results. Moreover, there is no description of the modelling assumptions and validation approach. The rise of the brake specific fuel consumption (BSFC) is mentioned and not analysed adequately in terms of overall engine efficiency and performance trade-offs. Better articulation of the methodology and rigorous validation of the model, a more articulate discussion of performance implications, would enhance the scientific applicability and clarity of the work.
Abstract: The research target is the significance of nitrogen oxides (NOx) and particulate matter (PM) emissions reduction of diesel-powered engines that are still significant sources of air pollution in terms of transportation and industrial activity. The suggested exhaust-driven water vapor injection system will make use of exhaust pressure to actuate a ge...
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Research Article
Dodola Iron Ore as Sustainable Iron Source for Clinker Production: Quantitative Analysis of Quality, Reactivity, and Environmental Benefits in Ethiopia
Issue:
Volume 1, Issue 1, March 2026
Pages:
54-60
Received:
3 March 2026
Accepted:
12 March 2026
Published:
26 March 2026
DOI:
10.11648/j.sdenergy.20260101.16
Downloads:
Views:
Abstract: The rapid industrialization of Ethiopia, catalyzed by major infrastructure projects like the Great Ethiopian Renaissance Dam (GERD), Koysha Hydroelectric Dam, Road and Railway Expansion, and Industrial Parks has necessitated a strategic shift toward domestic raw material sourcing for cement production. This study evaluates the technical and mineralogical viability of Dodola iron ore, hosted within the Precambrian meta-gabbro suites of the Bale Administrative Region, as a sustainable iron corrective for Portland cement clinker. Quantitative geochemical analysis reveals a distinctive composition characterized by an average total iron (Fe2O3) content of 45.6% and a significant titanium dioxide (TiO2) concentration of 11.12%. While standard industrial thresholds typically limit TiO2 to less than 1.0%, this research demonstrates that at controlled concentrations, the titanium acts as a potent mineralizer that reduces the clinker melt viscosity and lowers the liquid phase formation temperature by 50°C to 100°C. This "soft burning" effect optimizes kiln efficiency, facilitates a potential 6.44% increase in alite content, and reduces the carbon footprint associated with high-heat calcination and long-range logistics. The integration of Dodola iron ore into a recalibrated raw mix offers a dual benefit of improving clinker reactivity while aligning the Ethiopian cement sector with national "Green Growth" and circular economy objectives.
Abstract: The rapid industrialization of Ethiopia, catalyzed by major infrastructure projects like the Great Ethiopian Renaissance Dam (GERD), Koysha Hydroelectric Dam, Road and Railway Expansion, and Industrial Parks has necessitated a strategic shift toward domestic raw material sourcing for cement production. This study evaluates the technical and mineral...
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