The continuous growth in electricity demand imposes increasing constraints on power transmission and distribution infrastructures, particularly in developing electrical networks. Among the key components of these systems, power transformers play a central role, while simultaneously contributing to reactive power consumption that affects voltage regulation and network efficiency. This study focuses on the compensation of reactive power absorbed by the power transformer of the Mamou electrical substation in Guinea. The investigated transformer is an oil-immersed unit rated at 15 MVA with a voltage level of 110 kV/30 kV. An analytical approach based on transformer operating characteristics is adopted to evaluate the reactive power requirements associated with magnetizing and leakage reactances. Using these formulations, the required rating of a shunt capacitor bank is determined in order to fully compensate the reactive energy consumed by the transformer. The results indicate that a capacitor bank rated at 2422.5 kVAr allows a significant reduction in apparent power and line current on the high-voltage side. Consequently, copper losses, Joule losses in the transmission line, and associated greenhouse gas emissions are reduced, leading to an annual energy saving of approximately 36,104 kWh. The findings highlight the technical and economic relevance of reactive power compensation for improving the operational performance of substations in emerging power systems.
In the context of the energy transition and Senegal’s objective to increase the share of renewable energy to 20%, this study investigates the reliability of an off-grid photovoltaic (PV) power plant located in the village of Badiari, Sédhiou region, in the south of the country. Over a three-month period (June to August), corresponding to the rainy season, the 5 kWp production system was continuously monitored using an intelligent SMA inverter, enabling minute-by-minute data collection. The analysis reveals a clear mismatch between the system’s generation capacity and the users’ energy demand. The lead-acid batteries (1,000 Ah) undergo recurrent deep discharges, occasionally reaching critical levels (21 % state of charge), significantly shortening their operational lifespan. Simultaneously, the backup generator, intended to mitigate these deep discharges, is seldom activated. Frequent overvoltage events, shutdowns due to extreme temperatures (up to 80 °C at the heat sink), and islanding phenomena highlight both system imbalance and structural vulnerability. Reliability metrics were quantified, with a Mean Time Between Failures (MTBF) of 10,907 minutes and a Mean Time To Repair (MTTR) of 43 minutes in June, compared to 8,671 minutes and 329 minutes, respectively, in August. These values underscore the irregularity of energy supply. The findings emphasize the need to reconsider the sizing and maintenance strategies of rural solar installations. Recommended measures include increasing battery bank capacity (up to 2,500 Ah), introducing power limiters for consumers, and improving the thermal management of the technical room (ventilation, insulation). Implementing these strategies is expected to enhance local energy autonomy and improve the long-term sustainability of solar infrastructures.
Hydrogen is widely regarded as a cornerstone of the global transition toward low-carbon and sustainable energy systems. However, the environmental benefits of hydrogen depend strongly on the production pathway employed. This review presents a comparative analysis of water-splitting technologies and biological methods for green hydrogen production, highlighting their operating principles, efficiencies, costs, technological readiness, and prospects. Water splitting approaches include electrolytic methods alkaline water electrolysis (AWE), proton exchange membrane (PEM), anion exchange membrane (AEM), and solid oxide electrolysis (SOEC) as well as photocatalytic and photoelectrochemical (PEC) systems. Among these, AWE and PEM are technologically mature and commercially deployed, offering high hydrogen purity and system reliability, while SOEC demonstrates superior thermodynamic efficiency at elevated temperatures. Photocatalytic and PEC techniques provide direct solar-to-hydrogen conversion but remain limited by low efficiencies, charge recombination, and material instability. Biological hydrogen production routes like biophotolysis, fermentation, gasification, and pyrolysis utilize biomass and organic waste as feedstocks, supporting circular economy principles. Gasification and pyrolysis exhibit relatively high hydrogen yields and industrial potential but require high temperatures and extensive gas cleaning. In contrast, biophotolysis and fermentation operate under mild conditions and are environmentally benign but are constrained by low production rates, oxygen sensitivity, and process instability. A critical comparison indicates that electrolytic water splitting currently offers the most viable pathway for large-scale, high-purity hydrogen production when powered by renewable electricity, whereas biological methods present attractive waste-to-energy solutions with lower technological readiness in some cases. Future development should focus on reducing capital costs, replacing precious metal catalysts, improving membrane durability, enhancing photocatalyst stability, and optimizing bioreactor performance. Integrating these advances with renewable energy systems will be essential for achieving scalable, cost-effective, and truly sustainable hydrogen production.
Monocrystalline and polycrystalline silicon-based modules are commonly used in Burkina Faso, particularly in the city of Koudougou, to generate electricity. However, climatic parameters affect the performance of these modules. It is therefore necessary to conduct a comparative study between polycrystalline and monocrystalline silicon-based photovoltaic solar modules. The objective of this work is therefore to determine the module best suited to the city of Koudougou's climatic context. In this study, climatic parameters such as sunshine and temperature were considered. Thus, based on the mathematical model of a photovoltaic module, a simulation was carried out in the MATLAB/Simulink environment an experimental study of the two types of modules was conducted. The results obtained after the simulations and experiments were compared. Analysis of the results for the two module technologies shows that during the period of the day when the temperature is high, the polycrystalline silicon-based module performs better than the monocrystalline silicon-based module. However, during periods when the temperature is lower, the monocrystalline module performs better than the polycrystalline module. Considering the average daily power output for October 2024, it appears that the monocrystalline silicon-based module performs better than the polycrystalline silicon-based module. In general, monocrystalline modules offer better technical performance than polycrystalline modules in the climate of the city of Koudougou.
One of the main challenges to the performance of photovoltaic (PV) modules is the reduction in efficiency resulting from their high working temperature. Air-based photovoltaic/thermal (PV/T) devices offer a solution. This work presents the development of a photovoltaic/thermal air heat collector to optimize the performance of PV modules: Experimental case with monocrystalline and polycrystalline silicon photovoltaic solar modules. This was accomplished by designing, constructing, and positioning a thermal collector under the solar modules that had a surface area of 0.378 m2 and a height of 0.11 m. A real-time experimental study conducted on a sunny day in the courtyard of ISABEE of university of Ebolowa, Cameroon, showed that the proposed collector maintained the temperature below the monocrystalline solar panel at 49°C and that of the polycrystalline panel at 51°C, respectively, in order to an average power of 56.24 W (a power gain of 9 W compared to conventional PV) for the monocrystalline panel and 62.4 W (a power gain of 18 W) for the polycrystalline panel. DC fans where set up at the collector’s outlet were used to control the air flow rate to optimize cooling. In terms of thermal performance, a power output of 242 W (52% efficiency) was achieved for the monocrystalline module, while the polycrystalline module reached 295.94 W (56.46% efficiency). The tests, conducted under average sunlight of 936.36 W/m2 (between nine in the morning and three in the afternoon), demonstrated the system's efficiency. This study not only validates the optimization of electrical and thermal performance using the proposed technique, but also reveals the different behavior of the two types of cells. This collector can be considered highly suitable for optimizing the efficiency of PV modules in domestic solar installations, particularly in regions with an equatorial climate (such as the southern region of Cameroon) and high ambient temperatures.
Many countries in sub-Saharan Africa, such as Cameroon, face major challenges in terms of access to electricity, particularly in rural areas. A large proportion of the rural population does not have access to a reliable source of energy, which limits the economic and social development of these regions. Existing conventional energy sources, such as hydropower or oil-fired power plants, are often unsuitable for remote areas due to high transport and infrastructure costs. Cameroon enjoys abundant sunshine throughout the year. The government of Cameroon has therefore identified solar PV as a promising option for the rural electrification of 1,000 villages. Of the 350 solar power plants already delivered, the North of Cameroon has received 92 plants, representing 72% (38341.8 kWp) of the country's solar installations and 20% of the region's electricity supply in its energy mix, if we include the 2 large solar power plants in Guider and Maroua, each with a capacity of 15 MWp. Approximately 2,21712 rural households could therefore have access to electricity, with an average per capita energy supply of between 431 and 578 kWh/inhabitant/year in the rural areas benefiting from the first and second phase installations, compared to an estimated national average consumption of 280 kWh/inhabitant/year.
This paper presents a novel approach to stabilizing the Duffing oscillator using a neural-inspired control policy based on the hyperbolic tangent function. The controller, though structurally simple, is interpreted as a one-layer neural network with explicitly defined weights and no need for training. Through this lens, we explore how artificial intelligence techniques can be adapted to deliver interpretable, energy-aware control for nonlinear dynamical systems. The system’s long-term behavior is analyzed using bifurcation diagrams, Poincare sections, and Lyapunov-based stability analysis. Simulation results show that the control law suppresses chaotic transitions, enforces global boundedness, and facilitates adaptive entrainment with external forcing. Time evolution of the Lyapunov function remains bounded and oscillatory with the function’s peaks and troughs giving no indication of runaway growth or divergence. A custom energy efficiency metric is also introduced, quantifying the system’s ability to retain input energy under feedback control. This energy efficiency metric presents an upward trend with increasing excitation, suggesting that the controller not only stabilizes the system but also facilitates more effective interaction with the external environment. Together, these results demonstrate the potential of embedded AI control to regulate nonlinear systems in a sustainable, robust, and explainable manner. The findings offer a foundation for future research in control-aware learning, physics-informed neural architectures, and real-time energy regulation.
Background: Despite the huge efforts and ambitious climate policy in the United Kingdom, the critical question remains – will the UK achieve the Net-Zero emission target by 2050? This research addresses this research question by analysing the measures, policies and actions undertaken towards the ambitious goals. Methods: The study conducts an analysis of various trends so far, and forecasts the trend to 2035 (the new target set in 2021) and by 2050 the net-zero emission target to see the outcome. The study uses secondary data on various greenhouse gas emissions. Descriptive statistics and forecasting techniques are adopted. Results: The results revealed a declining trend of greenhouse gases emission from 1990. The results indicated that on 2035, the total greenhouse gas emission in UK would be 219.95 MtCO2e while that of total CO2 would be 137.19 MtCO2e. The reduction in emission would not have been reduced by 78% as targeted by the CCC, if the same trend and effort is going to be maintained. However, considering the level of emission reduction by 2050, the results indicated that for the total C02 emissions, if the same trend and effort is maintained, the total emission was forecasted to be -74.29 MtCO2e, having achieved the net-zero emission of C02. For the total greenhouse gases emissions, the results indicated that for the year 2050, the emission would be 0.32 MtCO2e, which would be approximately net-zero. This confirms that the net-zero emission target would be achieved by 2050.
The present research aims to evaluate the level of noise pollution in different regions in Sirajganj District Town. 7 distinct zones and 40 places were identified in Sirajganj District Town according to land use criteria. A sound level meter (REED SD-4023) was utilized to assess noise levels in Sirajganj District Town from January 1, 2021, to April 30, 2021. Multiple samples were taken at each sampling location. The noise levels were assessed regularly three times at each sampling site. The mean noise pollution level and Leq of Sirajganj District Town were found to be 73.42 dBA and 98.27 dBA, respectively. The recorded mean and Leq values were 73.61 dBA and 84.13 dBA for silent areas, 71.67 dBA and 105.35 dBA for residential areas, 73.51 dBA and 100.89 dBA for mixed areas, 71.52 dBA and 80.63 dBA for commercial areas, 74.91 dBA and 100.51 dBA for industrial areas, 73.93 dBA and 86.81 dBA for road intersections, and 74.81 dBA and 86.46 dBA for village areas, respectively. The hierarchy of various land uses according to mean noise levels is as follows: Industrial Area > Village Area > Road Intersection > Silent Area > Mixed Areas > Residential Area > Commercial Area. The three places with the greatest noise pollution levels were Jubil Building (109.32 dBA), Mowla Box Daal Mill (109 dBA), and Vasani Road (97.32 dBA). Conversely, the three areas with the lowest noise pollution levels were Sirajganj Bus Terminal (69.69 dBA), Masum Para (69.82 dBA), and DC Office (70.51 dBA), as determined by Leq. The study revealed that the noise levels at all sampling locations were above the national standard.
This study evaluates reservoir performance and steam production in the Olkaria Domes Geothermal Field, Kenya, over the period 2019-2023, with a focus on key wells supplying Olkaria IV, Olkaria V, and wellhead power plants. Monitoring data from wells such asOW-914, OW-916, and OW-921 show stable wellhead pressures ranging from 6.5 to 9.8 bar, and discharge enthalpies between 1400 and 2650 kJ/kg, consistent with production from a high-temperature liquid-dominated reservoir. Reinjection rates remained above 48%, helping maintain reservoir pressure. However, evidence of cooling and dilution was observed in wells like OW-923 and OW-926, where enthalpy values dropped by up to 250 kJ/kg, and silica concentrations declined from 470 ppm to 410 ppm, suggesting the encroachment of colder reinjection fluids. Using discharge test data and pressure logging, mass flow rates, pressure trends, and thermodynamic conditions were analyzed. The findings underscore the necessity for continuous reservoir monitoring and the need to optimize reinjection design to avoid long-term pressure drawdown and thermal degradation. These insights are vital for sustaining steam supply and ensuring the long-term viability of geothermal energy production in the Olkaria Domes field.
Silicon ingots can be crystallized using a variety of processes. These lead to different qualities of crystal, and therefore of solar cell, depending on whether the silicon obtained is polycrystalline, i.e. made up of a multitude of crystals of varying size and orientation, or monocrystalline, i.e. formed from a single crystal. Like crystallization, doping is one of the steps in the silicon manufacturing process. Studying the doping level of a solar cell is crucial, as it has a direct influence on its performance, particularly its ability to convert sunlight into electricity. Doping, which consists in introducing impurities into silicon, modifies the electrical properties of the material and, consequently, the characteristics of the solar cell. The aim of this study is to assess the impact of polycrystalline crystal size and the capture effect at the contact surface of two crystals on the effect of p-layer dopant on effective diffusion length, diode current, short-circuit current and open-circuit voltage. Using the continuity equation with generation-recombination phenomena, this study found mathematical expressions for the fundamental electrical parameters needed to characterize solar cells. These mathematical expressions relate the effective diffusion length, diode current and electrical parameters such as short-circuit current and open-circuit voltage to the p-layer doping rate, crystal dimensions and carrier loss rate at the interfaces, respectively. Then, using Mathcad software, we simulated the impact of crystal size and the effect of captures at crystal interfaces on the influence of p-layer doping rate on effective diffusion length, diode current and electrical parameters such as Jsc and Voc. The results obtained from this analysis reveal that: For low values of p-layer doping rate and crystal size, the short-circuit current and effective diffusion length decrease less with low p-layer doping rates. On the other hand, for p-layer doping rates higher than 1017cm-3, the effective diffusion length and short-circuit current intensity decrease, but this decrease is faster when the crystal size is smaller. Diode current and open-circuit voltage increase with p-layer doping rate and crystal size. Growth is greatest when the p-layer doping rate is greater than 1017 cm-3 for diode current. The results of this study make it possible to design more efficient solar cells for polycrystalline silicon photovoltaic applications by keeping the doping rate at or below 1017 cm-3.
The Asia-Pacific, a global economic powerhouse, paradoxically fuels its growth through carbon-intensive practices, making it the world's leading contributor to CO2 emissions and the region most vulnerable to catastrophic weather events. This study investigates the direct relationship between the region's carbon trajectory and climatic instability. Using a mixed-methods approach, we conducted a longitudinal analysis from 1980 to 2023, correlating annual regional CO2 emissions with a composite extreme weather index comprising heatwave frequency, extreme precipitation, and tropical cyclone intensity (Accumulated Cyclone Energy). Our findings reveal a statistically significant and robust positive correlation between regional CO2 emissions and the extreme weather index (r = +0.88, p < 0.001). Regression analysis further demonstrates that rising regional emissions account for 77% of the variance in extreme weather events over the past four decades. The strongest associations were observed between emissions and heatwave frequency (r = +0.92) and tropical cyclone intensity (r = +0.75), particularly in the vulnerable Southeast Asian and Pacific sub-regions. This evidence highlights a self-defeating cycle where the region's economic model directly drives the climatic instability that jeopardizes its progress. The established statistical link provides a compelling scientific basis for immediate policy reform, strengthening the case for accelerated mitigation efforts, enhanced adaptation investment, and "Loss and Damage" claims within international climate frameworks. We conclude that a rapid and just transition from fossil fuels is not merely an environmental necessity but a fundamental prerequisite for the long-term stability and prosperity of the Asia-Pacific region.
The integration of solar cooling system into the food preservation system is an important step towards energy sustainability. Study aims are to design a cooling system combining solar thermal energy, an absorption cooling system and cooling rooms. The cooling rooms studied are containers intended to preserve fish and onions with storage capacities of 1000 kg and 2000 kg respectively. A modeling of the different subsystems was done and the energy balances established. The model simulation is done with Engineering Equation Solver (EES). The results obtained show that for solar thermal collector efficiency between 0.6 and 0.7, the area of the solar thermal field can be optimized to 45 m2 and 70 m2 respectively for the preservation of onions and fish. Similarly, for solar irradiation between 5 KWh/m2 and 6 KWh/m2, the area of the solar thermal field decreases from 100 m2 to 40 m2 and from 160 m2 to 60 m2 respectively for the cold room intended to preserve onions and fish. For thermal loads greater than 50 KWh and 80 KWh respectively for onions and fish, the area of the solar field increases linearly with the increase in thermal loads.
In many parts of Nigeria, wood remains a primary source of household and small-scale industrial energy. As fuelwood demand continues to grow, identifying species with high energy efficiency is increasingly important. This study evaluates eight commonly used wood species in Nasarawa State, Nigeria, to determine their suitability for fuelwood and charcoal production. Each species was assessed for calorific value, volatile matter, ash content, moisture content, wood density, and charcoal yield, using five replicates per species. Laboratory tests followed standard procedures, and the data were analyzed using descriptive statistics, ANOVA, and Duncan’s multiple range tests. Significant variation was observed across species, with Anogeissus leiocarpus, Khaya senegalensis, and Prosopis africana exhibiting superior energy profiles, including higher calorific values and lower ash and moisture contents. Boxplots and Duncan’s multiple range tests highlighted distinct groupings among the species. Correlation and multiple linear regression analyses revealed that moisture and ash contents had strong negative effects on calorific value, while density and charcoal yield positively influenced fuel quality. The results of regression analysis for calorific value versus volatile matter, ash content, moisture content, density, charcoal yield, species had R2 (Model Fit) of 0.8959, meaning 89.59% of the variation in calorific value is explained by the predictors. These findings support the hypothesis that fuelwood properties vary significantly by species and offer practical guidance for selecting efficient, clean-burning wood types. The results contribute to improved biomass energy use and support informed decisions for sustainable fuelwood utilization in sub-Saharan Africa.
This article examined how Kenya’s transition to renewable energy can be made more just, focusing on the roles of policy incentives, institutional capacity, and equity-oriented provisions. The study aimed to assess whether financial and regulatory incentives, local institutional strength, and community benefit measures influenced renewable capacity adoption, employment creation, and public acceptance across counties. A concurrent mixed methods design was employed, combining a cross-sectional survey of 162 stakeholders from Busia, Kilifi, Turkana, Garissa, and Nakuru counties with twelve semi-structured interviews involving county energy officers, project managers, and community leaders. Quantitative data were analyzed using simple linear regression, while qualitative data were coded thematically in NVivo. The findings showed that counties offering stronger policy incentives achieved higher renewable energy capacity per capita, though these gains were contingent on effective institutional support. Institutional capacity strongly correlated with employment in the renewable energy sector, highlighting the importance of skilled personnel, dedicated energy offices, and coordinated governance. Equity-oriented provisions, such as local hiring and benefit-sharing programs, significantly increased public acceptance, but only when implementation was credible and transparent. The study concludes that a just energy transition requires the integration of policy support, institutional competence, and visible equity measures. It recommends aligning incentives with local capacity, embedding fairness in project design, and engaging communities early to ensure that renewable energy growth is both technically successful and socially inclusive.
In this study, the solar irradiance of four different localities in the Far North province of Cameroon was assessed with a view to selecting a site for a large-scale photovoltaic array. The global radiation extrapolation method is used to evaluate the solar potential in the four localities. To verify the reliability of the chosen method, the coefficient of determination is calculated to estimate the difference between the real-time experimental method and the theoretical method based on the statistical test. So, the Root Mean Square Error, the Mean Absolute Relative Error and the Coefficient of determination are calculated, in order to make a conjecture on the performance of the proposed method. The localities of Muidere, Bougaye, Youaye and Hoyo were chosen on the basis of the availability of sunlight in these areas. The results obtained also demonstrate the feasibility of implementing the system, taking into account the real data extracted from the site.
When compression ignition engines operate with biodiesel, emissions of carbon monoxide (CO), particulate matter, and hydrocarbons are significantly reduced, whereas emissions of nitric oxides (NOx) increase substantially. Steam injection was used in this study to reduce NOx emissions and for its effects on the chemical equilibrium of combustion products. Variations in the thermodynamic properties of the combustion products at chemical equilibrium, as well as changes in the temperature of the adiabatic flame and the combustion products at chemical equilibrium, were studied during combustion of both conventional diesel fuel and biodiesel, with and without 5% steam injection. These variations were analyzed at different pressures, equivalence ratios, and temperatures of the unburned mixture. The results showed that when the flame temperature exceeded 1800 K, a decrease of 103 K in the maximum flame temperature due to steam injection reduced thermal nitric oxide (NO) production by 73%. The results also indicated that while NO emissions and adiabatic temperature decrease significantly, specific heat values increase as the steam injection rate was raised. At chemical equilibrium, combustion products contain only the most stable species in substantial quantities below 1300 K. The emission of CO and NOx by lean combustion systems indicates that chemical equilibrium is not maintained when the combustion products are cooled.
The use of low-temperature solar thermal energy is of vital importance to households both in temperate zones for heating and in Sahelian zones for domestic hot water. This study focuses on the thermal analysis and simulation of an uncovered flat plate collector with parallel tubes using water as the heat transfer fluid. It is based on the analysis of the thermal performance and the careful selection of each component of the system, namely the coating, the absorber, and the insulator, to obtain optimal operation of the solar collector. The equations are presented in such a way that they can be easily solved by programming in the structured language MATLAB. The Newton-Raphson method was used to determine the temperature of the absorber wall after obtaining a nonlinear equation. Unlike stainless steel and Aluminum, the copper absorber does not store enough energy in itself, but transmits most of the energy flow to the heat transfer fluid, resulting in outlet temperatures of 82.62°C from a 2m tube, making copper the most suitable material for an absorber. TINOX and black chrome are better quality coatings, with a tube outlet temperature of 82.9°C, while that of the selective black plate is 80.12°C. The study also involved a comparative analysis of the thermal system with four types of insulation at the tube outlet. The water temperature ranged from 81.56°C to 82.32°C with insulation, meanwhile it was 73.37°C without insulation. As the fluid inlet temperature approaches ambient temperature, collector efficiency increases until it attains a maximum value of 62%.
In Sub-Saharan Africa, electricity access is severely limited in rural areas, despite the abundance of sunlight. This poses a significant challenge to rural electrification initiatives, which are crucial for sustainable development. In light of this, the government of Cameroon has initiated the deployment of several solar power plants in rural regions. However, there is sometimes an imbalance between energy supply and demand, depending on the power plant's installed capacity and the size of the population. A life-cycle study is therefore being carried out in rural areas of Cameroon's Far North region with solar power plants. The study involves analyzing the balance between electricity supply and four modes of electricity consumption. These modes depend on the percentage of households that subscribe to a subscription: 100%, 50%, or 30%. The final scenario considers the International Energy Agency's (IEA) projections, wherein each Cameroonian is expected to consume 280 kWh/person/year. The findings suggest that the solar power plants installed are oversized for low-voltage domestic use, even in scenarios where 100% of households subscribe. It is only possible to achieve a balance between supply and demand from the 23rd year of operation in densely populated localities, and only if all households subscribe. If all households hold a combined domestic and non-domestic subscription, it is anticipated that demand will exceed supply between the first and seventh years of operation. The validity of this forecast is contingent upon two key variables: installed capacity and population density. Should 50% of households subscribe, it is estimated that solar power plants will encounter difficulties within the 8 to 13-year timeframe. Consequently, solar power plants will be capable of supplying less than 30% of households until the conclusion of the project.
