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In the contemporary global discourse on environmental and developmental issues, the dual challenges of sustainable green energy and water supply stand paramount. These elements are vitally intertwined with the socio-economic vitality of the world. Notably, regions plagued by freshwater scarcity are increasingly turning to desalination which consists of a reliable and unconventional water source. The intersection of renewable energy with desalination and water purification processes presents a compelling synergy. This approach is particularly pertinent in areas where freshwater shortages coexist with abundant solar energy availability. Additionally, these technologies boast the advantage of low operational and maintenance costs. This paper delves into the design, optimization and financial analysis of a novel, standalone hybrid energy system, integrating photovoltaic and fuel cell technologies, for an agriculture farm situated in Kairouan, Tunisia. Unlike conventional systems, this model foregoes battery storage in favour of hydrogen storage, generated through water electrolysis powered by solar energy. This system harnesses solar energy for direct electrical power generation and hydrogen gas production. A segment of the generated electricity is allocated to electrolysis for green hydrogen production. In times of solar unavailability, the stored hydrogen is reconverted to electricity via a fuel cell. An intriguing aspect of this system is the utilization of saline well water, which, due to its high salt content, necessitates purification through desalination to prevent damage to the electrolysis unit and to render it suitable for agricultural irrigation. [Display omitted] • The production of green hydrogen, water and electricity for agriculture farm in Tunisia is analyzed. • The Levelized cost of green hydrogen produced in the PV farm is 2.25 €/kg. • A PV hydrogen Farm station with a capacity of 140 kW produces 1991 kg of green hydrogen and 235 MW h of electricity yearly. [ABSTRACT FROM AUTHOR]

The present study examines the potential for hydrogen production using the hybrid energy system at the Shagaya renewable power plant. Techno-economic and optimization analyses are used to identify the optimum configurations that reduce costs while increasing the renewable fraction and lowering greenhouse gas emissions. Three configurations were considered, exploring on- and off-grid combinations of photovoltaic solar (PV), wind turbine (WT), fuel cells and batteries. Integrating PV solar with wind power connected to the power grid was found to achieve the lowest levelized cost of energy of 0. 539 $ / kWh and a hydrogen production cost of 6. 85 $ / kg. However, for the stand-alone system where battery storage banks or fuel cells are used, the cost of hydrogen increases to more than 8. 0 $ / kg due to the larger capital cost of the system. The optimized system achieves annual green hydrogen production of 111 877 kg along with an annual carbon dioxide emission reduction of 14 819 kg. A sensitivity analysis proves that COE is more sensitive to PV price than wind turbines and electrolyzers. LCOE falls by 32.3% to 0.365 kWh when the PV unit price drops to 50%. The LCOE falls by 4% to 0.517 kWh when WT costs decrease by 50%. [Display omitted] • PV and wind integration connected to the power grid achieves low LCOE ($0.539/kWh) and hydrogen cost ($6.85/kg). • Battery and fuel cell systems increase hydrogen cost to more than $8.0/kg due to high capital expenses. • Optimized system produces 111,877 kg of green hydrogen annually, reducing CO 2 emissions by 14,819 kg. • LCOE is highly sensitive to PV cost. A 50% PV price drop reduces LCOE by 32.3% to $0.365/kWh. [ABSTRACT FROM AUTHOR]

Hydrogen embrittlement is a widely known phenomenon in high-strength and storage materials. Hydrogen embrittlement is responsible for subcritical crack growth in material, fracture initiation, subsequent loss in mechanical properties, and catastrophic failure. Hydrogen is induced in the material during an electrochemical reaction between the hydrogen, storage materials, and high-pressure gaseous hydrogen environment. Various mechanisms which are responsible for crack development, growth, and fracture have been deliberated and reported. However, the fundamental mechanism of hydrogen embrittlement remains unclear. Several techniques such as linearly increasing stress test techniques (LIST), constant extension rate test (CERT) and slow strain rate testing (SSRT), thermal desorption spectroscopy (TDS), permeation testing (PT), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been utilized to determine the amount of hydrogen diffused and available in the hydrogen storage material. The review intends to categorize and provide a clear understanding of the degradation mechanism that occurs during hydrogen embrittlement. The improvement in mitigating the hydrogen embrittlement degradation as a function of modifying the structure and surfaces of the material is established. Prospects for addressing hydrogen embrittlement degradation through further experimental and numerical research are suggested. Lastly, this paper through recommendation endeavors to prevent hydrogen storage tank degradation and reduces high costs associated with the replacement of the component in renewable energy applications. • Hydrogen storage tank is critical in renewable energy. • Hydrogen tank performance can be enhanced by appropriate material selection. • Microstructural modification reduces the hydrogen embrittlement. • Embrittlement degradation mechanism affects hydrogen tank storage. [ABSTRACT FROM AUTHOR]

Clean energy resources will be used more for sustainability improvement and durable development. Efficient technologies of energy production, storage, and usage results in reduction of gas emissions and improvement of the world economy. Despite 30% of electricity being produced from wind energy, the connection of wind farms to medium and large-scale grid power systems is still leading to instability and intermittency problems. Therefore, the conversion of electrical energy generated from wind parks into green hydrogen consists of an exciting solution for advancing the development of green hydrogen production, and the clean transportation sector. This paper presents a techno-economic optimization of hydrogen production for refueling fuel cell vehicles, using wind energy resources. The paper analyses three configurations, standalone Wind-Park Hydrogen Refueling Station (WP-HRS) with backup batteries, WP-HRS with backup fuel cells, and grid-connected WP-HRS. The analysis of different configurations is based on the wind potential at the site, costs of different equipment, and hydrogen load. Therefore, the study aims to find the optimized capacity of wind turbines, electrolyzers, power converters, and storage tanks. The optimization results show that the WP-HRS connected to the grid has the lowest Present Worth Cost (PWC) of 6,500,000 €. Moreover, the Levelized Hydrogen Cost (LHC) of this solution was found to be 6.24 €/kg. This renewable energy system produces 80,000 kg of green hydrogen yearly. • Wind to green hydrogen represents an interesting solution for greenhouse gas reduction. • Three configurations of wind-park stations designed for green hydrogen production are analyzed. • Grid-connected wind park consists of an optimal solution for the wind park hydrogen station. • The Levelized cost of hydrogen production using a 5 MW grid-connected wind park is 6.24 €/kg. [ABSTRACT FROM AUTHOR]

Green hydrogen reduces carbon dioxide emission, advances the dependency on fossil fuels and improves the economy of the energy sector, especially in developing countries. Hydrogen is required for the green transportation sector and many other industrial applications. However, the high cost of green hydrogen production reduces the fast development of renewable energy projects based on hydrogen production. So, sizing by optimization is required to determine the optimum solutions for green hydrogen production. In this context, this paper aims to analyze three methods that can be developed and implemented for the production of green hydrogen for refueling stations using photovoltaic (PV) systems. Techno-economic models are adopted to calculate the Levelized Hydrogen Cost (LHC) for the PV grid-connected system, stand-alone PV system with batteries, and stand-alone PV system with fuel cells. The photovoltaic systems based green hydrogen refueling stations are optimized using Homer software. The optimization results of the Net Profit Cost (NPC), and the LHC permit the comparison of the three cases and the selection of the optimal solution. The analysis has shown that a 3 MWp grid-connected PV system represents a promising green hydrogen production at an LHC of 5.5 €/kg. The system produces 58 615 kg of green hydrogen per year reducing carbon dioxide emission by 8209 kg per year. The LHC in the stand-alone PV system with batteries, and stand-alone PV system with fuel cells are 5.74 €/kg and 7.38 €/kg, respectively. • Levelized costs of hydrogen produced in photovoltaic refueling stations are analyzed. • Grid-connected photovoltaic system is an optimal solution providing green hydrogen. • Surplus of electricity produced in hydrogen stations is sold back to the power grid. • A 3 MWp photovoltaic system produces 58 615 kg of hydrogen at a levelized cost of 5.5 €/kg. [ABSTRACT FROM AUTHOR]

This paper sheds the light on the future of green hydrogen in Tunisia. So, a detailed economic assessment and evaluation of the Levelized Hydrogen Cost (LHC) and the Net Profit (NP) of a Photovoltaic (PV) Hydrogen Refueling Station (HRS) are presented and discussed. Tunisia is characterized by its high PV potential which makes the production of electricity from solar energy an effective alternative source. However, due to the regulations and issues related to the connection of medium PV scale to the power grid, the energy produced from renewable sources (RS) is still less than 3% of the total produced electricity. On the other hand, the price of hydrocarbon fuels is still increasing. The gap between production and total demand in hydrocarbons has created a deficit in the primary energy balance. Therefore, the production of hydrogen from solar energy for refueling Fuel Cell Vehicles (FCV)s consists of a promising solution to boost the development of the country, reduce hydrocarbon fuels consumption, and protect the environment. The sizing of a small PV-HRS to produce 150 kg of hydrogen per day shows the necessity to install PV systems with a total Direct Current (DC) capacity of 1.89 MWp. The Initial Cost (IC) analysis shows that while the PV system cost represents 48.5% of the total IC, the IC of electrolysers represents 41%. The storage system cost is approximately equal to 3.2% of the total IC. The LHC is equal to 3.32€/kg with a total IC of 2.34 million €. • An economic assessment and evaluation of PV-HRS producing 150 kg of hydrogen in Tunis are presented. • The LHC for the hydrogen produced at PV-HRS is estimated at 3.32€/kg. • The 150 kg PV-HRS has a breakdown of 8 years for a selling price of 8€ per kg of Hydrogen. • The IC and the LHC depend mainly on the prices of the PV panels, electrolyzers, and storage tanks. • Green hydrogen is a promising solution for future transport systems in Tunisia. [ABSTRACT FROM AUTHOR]

Hydrogen energy will play a credible role to reduce gas emissions in the transportation sector, the storage of energy, and other industrial applications. Moreover, the hydrogen produced from renewable energy sources allows to minimize greenhouse gas and increase the net profit of energy projects. This paper discusses the feasibility of the conversion of solar energy into hydrogen in a Photovoltaic Hydrogen Station (PVHS) in the south of Oman. Then, the sizing of different equipment and hydrogen production estimation in a 5 MWp PVHS is presented. The analysis of the investment cost (IC), the Net Profit (NP), and the Levelized Hydrogen Energy Cost (LHEC) are discussed to investigate the benefit of the project. The energy generated from the PV system and the produced hydrogen is calculated through an analytical model. The PVHS consists of 5 MWp PV panels connected to electrolyzers through maximum power point-controlled converters. The electrolyzers convert the electrical energy and the water into hydrogen. The hydrogen compressed and stored in special tanks can be used later in many industrial applications. The system produces about 90 910 kg of hydrogen per year with an IC of 5 301 760 €. The calculated LHEC is equal to 6.2 €/kg at an interest rate of 2%. The analysis has shown promising green hydrogen production projects in Oman. • The production of hydrogen using photovoltaic energy in Oman is analysed. • PV system consists of a promising process for green hydrogen production in Oman. • A 5 MWp photovoltaic power station produces around 90 910 kg of hydrogen per year. • The Levelized hydrogen cost produced in 5MWp PV station is 6.2 €/kg. • The breakeven point of the 5 MWp PV hydrogen station is 8 years for a hydrogen selling price of 10 € per kg. [ABSTRACT FROM AUTHOR]

Water electrolysis can produce hydrogen by using a photovoltaic array as an electrical source to power the electrolyzer. Combining multiple energy sources has the potential to increase hydrogen production while also meeting other electrical needs. As Oman is planning to develop green hydrogen production, this study is proposed to help the private and governmental sectors to invest in the green hydrogen industry. In this study, the unique geographical location of Salalah and the meteorological data collected were utilized in the hybrid energy arrangement to generate electricity and produce a significant amount of hydrogen in Salalah using HOMER (Hybrid optimization model for electric renewables). The findings showed that the wind turbine (WT), photovoltaic (PV), fuel cell (FC), and hydrogen tank (HT) hybrid energy system is economically viable when compared to its counterparts in other systems and was chosen to meet Salalah in Oman's electrical and hydrogen production needs. The PV-WT-FC-HT hybrid energy system is clearly the best option for the proposed hydrogen project in Salalah because it has the lowest Levelized Cost of Hydrogen (LCOH), 1.15 ($/kg), and Cost of Energy (COE), 19.0 ($/kWh). [ABSTRACT FROM AUTHOR]

Continuous monitoring and proper diagnosis of production systems are daily concerns that involve many manufacturers. In this context, this paper proposes a feasible and effective diagnostic methodology. It is based on a recurrent dynamic neural model application, in industrial anomaly detection, with a high identification rate. The general context of this approach is summarized in the improvement of the detection and control mechanisms using intelligent systems. These tools can collaborate objectively in industrial processes diagnosis, then in anomalies detection and classification to intervene correctly. The final purpose of this paper consists in guaranteeing the operational safety for processes, ensuring their reliability and affirming the production continuity. [ABSTRACT FROM AUTHOR]

Salalah is known for its Al-Khareef unique weather that is marked by influx of tourists into the community resulting in high electrical load demand during the Al-Khareef season. This paper investigates the viability of two hybridised energy systems for application in Salalah community. The result demonstrated that the Photovoltaic, Wind and Battery combination is more cost effective in terms of energy consumption, initial cost and renewal price, in comparison to the other hybrid energy system. The Homer Pro software, return on investment and internal rate of return analysis showed that the Photovoltaic/Wind/Battery scheme commands higher economic and environmental viability, presenting the Photovoltaic, Wind and Battery scheme as a better option to meet the power demand for Salalah city. [ABSTRACT FROM AUTHOR]

Engineering programs offered by higher education institutions around the world are providing high level of scientific and technical knowledge to students. However, many programs are still adopting the teacher-centered learning method, where the teacher is the main source of knowledge and the students' role is mostly passive. In this case, students are not given autonomy to control their own learning. Moreover, in many programs' students don't have the opportunity to experiment and explore the material in their own way. This type of learning is less effective than self-directed learning. Indeed, in addition to knowledge, the job market requires soft and professional skills to satisfy the needs of the different stakeholders, developed market, and diversified environment. The skills of communication, leadership, team work, research, and life-long learning are becoming a necessity for engineers in a fast growing industrial and economic environment. This paper analyses the effects of controlled self-learning approaches on the improvement of cognitive and soft skills of students. In this context, different self-learning activities are analyzed to identify the advantages and drawbacks of each method. The analysis shows that the controlled self-learning through team work, group discussion and flipped class are best self-learning practices to enhance soft skills. Moreover, the controlled self-learning is highly recommended for the improvement of the students' outcomes, especially the called cognitive skills. • Self-learning methods are analyzed. • Effects of self-learning on the improvement of soft and cognitive skills are discussed. • Self-learning is an effective method to enhance soft and cognitive skills. [ABSTRACT FROM AUTHOR]

The escalating trend of using hydro and solar resources to generate electricity and providing green hydrogen for the transportation sector is considered as a most optimal pathway to reducing the greenhouse gas emission. As a contribution, this study focuses on optimizing the production of green hydrogen in a combined hydroelectric-photovoltaic power station located in southern Oman. The study employed a simulated model to perform techno-economic analysis and optimize the components of the hybrid power station. The model aims to optimize the components of hydroelectric photovoltaic hybrid power station connected to the power grid. The fundamental parameters to perform this analysis are the average stream flow and solar radiation. This study is depicting the production of hydrogen from a power grid as well as its utilization in conversion to green hydrogen. The economic analysis of the project depends mainly on the cost of hydro turbines, power converters, PV panels, electrolyzers and hydrogen tanks. After the overall analysis, the researchers have concluded that the net profit is playing an imperative role in optimizing the levelized cost of green hydrogen to be €2.25/kg. This analysis is providing the opportunity to the researchers to do techno-economic analysis of the hydrogen production and to utilize the produced hydrogen to facilitate green transportation thereby reducing the greenhouse gas emission. • Optimization of green hydrogen production in a combined hydroelectric-photovoltaic grid connected system. • Techno-economic analysis is performed through Homer-Pro. • Results proved that the NPC depends mainly on the cost of hydro turbines, power converters, PV panels, and electrolyzer. • The Levelized cost of green hydrogen is optimized to be 2.25 €/kg. [ABSTRACT FROM AUTHOR]

This paper presents and discusses the longitudinal and transversal end effects which affects the propulsive force of linear motors. Generally, the modeling of linear machine considers the forces distortion due to the specific geometry of linear actuators. The insertion of permanent magnets on the stator allows improving the propulsive force produced by switched reluctance linear motors. Also, the inserted permanent magnets in the hybrid structure allow reducing considerably the ends effects observed in linear motors. The analysis was conducted using 2D and 3D finite elements method. The permanent magnet reinforces the flux produced by the winding and reorients it which allows modifying the impact of end effects. Presented simulations and discussions show the importance of this study to characterize the end effects in two different linear motors. [ABSTRACT FROM AUTHOR]

Alkaline water electrolysis was experimentally performed using a low-cost homemade alkaline electrolyzer to produce hydrogen. The effect of electrode material on hydrogen production and efficiency was investigated. The results showed that although the increase in temperature increases the voltage, and current, the electrode material has a significant effect on hydrogen production. From the study, it was found that the stainless steel 316L Smaller electrode is a better choice for hydrogen production compared to the carbon steel electrode. • Photovoltaic solar cell converts solar energy to electrical energy. • Temperature influences current and voltage. • Hydrogen can be produced through water splitting electrolysis. • Material properties affect the hydrogen production and efficiency. [ABSTRACT FROM AUTHOR]

Hydrogen is one of the energy carriers that can be produced using different techniques. Combining multiple energy sources can enhance hydrogen production and meet other electrical demands. The hybrid arrangement allows the produced hydrogen to be stored and used when the electrical energy sources are not adequate. In this study, utilizing the meteorological data was investigated using HOMER (Hybrid Optimization of Multiple Energy Resources) software for the optimal solution. The results demonstrated that the "best-optimized system has 270 kW of photovoltaic (PV), 1 unit of 300 kW of wind turbine (WT), 500 kW of electrolyzer, 100 kg/L of the hydrogen tank, 70 units of 1 kWh lithium-ion battery, and 472 kW of the converter. The selected hybrid energy system has the lowest Levelized cost of energy (LCOE), Levelized cost of hydrogen (LCOH), and net present cost (NPC) of $/kg 0.6208, $/kg 9.34, and $ 484,360.00 respectively which judged the system to be the best choice for the proposed hydrogen project in AI-Kharj. This investigation will help stakeholders and policymakers optimize hybrid energy systems that economically meet the hydrogen production and refueling station demands of the AI-Kharj community. • Study of electrical energy generation for hydrogen production using renewable energy sources was performed. • Renewable energy sources are available in AI-Kharj as a result of the geographical location of the city. • HOMER software enhances the optimization and selection of the best hybrid energy system. • The selected hybrid energy system to meet the energy needs of the AI-Kharj has the lowest NPC, LCOE, and LCOH. [ABSTRACT FROM AUTHOR]

This paper presents a simple strategy for controlling an interleaved boost converter that is used to reduce the current fluctuations in proton exchange membrane fuel cells, with high impact on the fuel cell lifetime. To keep the output voltage at the desired reference value under the strong fluctuations of the fuel flow rate, fuel supply pressure, and temperature, a neural network controller is developed and implemented using Matlab-Simulink (R2012b, MathWorks limited, London, UK). The advantage of this controller resides in its simplicity, where limited number of tests are carried out using Matlab-Simulink to construct it. To investigate the robustness of the proposed converter and the neural network controller, strong variations of the fuel flow rate, fuel supply pressure, temperature and air supply pressure are applied to both the fuel cell and the neural network controller of the converter. The simulation results show the effectiveness and the robustness of the both the proposed controller and converter to control the load voltage and minimize the current and voltage ripples. As a result of that, fuel cell current oscillations are considerably reduced on the one hand, while on the other hand, the load voltage is stabilized during transient variations of the fuel cell inputs. [ABSTRACT FROM AUTHOR]

Proton Exchange Membrane Fuel Cells (PEMFCs) have the perspective to intensely decrease global emission through environmentally-friendly potential. This review paper summarizes the degradation of platinum catalyst layer that has become a significant issue in the improvement of PEMFCs. The review intends to categorise and provide a clear understanding between disintegration and agglomerate that occurs during platinum degradation. In each process, different degradation mechanisms and their migration processes are presented. The improvement in platinum degradation as a function of increasing the performance of PEMFC is established. Prospects for addressing platinum degradation through the exploration of further experimental and numerical research are recommended. Lastly, this paper through recommendation attempts to prevent platinum degradation and reduces high costs associated with the replacement of catalysts in the PEMFCs. • Platinum is used as a catalyst in the proton exchange membrane fuel cell. • Degradation of platinum has been a great barrier in the fuel cell achieving an optimal performance. • Platinum degradation follows different disintegration and agglomerate mechanisms. • Several methods have been used to understand the platinum degradation process. • Improvement in the performance of platinum can be achieved through material selection. [ABSTRACT FROM AUTHOR]

One of the main goals of the designers of the power systems is the reduction of extra systems costs. The main part of these costs is related to energy loss, and the methods for loss reduction significantly lead to a cost reduction. The voltage regulators (VRs) can be used along the distribution feeders and the improvement of the network voltage profile results in the loss reduction of the system. However, the important problem is the installation location of this equipment to have the most profitability with the lowest cost. In this paper, the optimal placement of the VRs along the distribution systems is performed using intersect mutation differential evolution algorithm. The method aims to reduce loss and the primary investment and maintenance of the VRs. To this aim, the studies are performed on two scenarios for two standard distribution systems with 33 and 69 buses. A genetic algorithm (GA) is also utilized for the VRs placement to validate the results. The results show that the VRs reduce the loss to about 15% of the maximum system load. Moreover, the improved differential evolution algorithm performs better than the GA and makes the objective function in the minimum value. [ABSTRACT FROM AUTHOR]