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READ RESPONSES FROM In 'Moving Beyond the Hype on Hydrogen' (Issues, Summer 2024), Valerie J. Karplus and M. Granger Morgan provide an excellent assessment of hydrogen's advantages and significant barriers [...]

Polymer membrane electrolyzers are a useful tool for producing hydrogen, which is a renewable energy source. Unmanned aerial vehicle (UAV) fuel cells can be powered by the hydrogen and oxygen produced by the electrolyzer. The primary losses of polymer membrane electrolyzers must therefore be identified in order to maximize their performance. A renewable-based multi-energy system considers power, cooling, heating, and hydrogen energy as utility systems for integrated sport buildings. In this study, we investigate the effect of radiation intensity, current density, and other performance factors on the rate of hydrogen production in water electrolysis using a polymer membrane electrolyzer in combination with a solar concentrator. The findings showed that a rise in hydrogen generation led to an increase in current density, which increased the electrolyzer's voltage and decreased its energy and exergy efficiencies. The voltage was also increased, and the electrolyzer's efficiency was enhanced by a rise in temperature, a decrease in pressure, and a reduction in the thickness of the nafion membrane. Additionally, with a 145% increase in radiation intensity, hydrogen production increased by 110% while the electrolyzer's energy and exergy efficiencies decreased by 13.8% as a result of the electrolyzer's high input electric current to hydrogen output ratio. [ABSTRACT FROM AUTHOR]

This paper establishes a framework of boundary conditions for implementing hydrogen energy systems in ships, identifying what is feasible within maritime constraints. To support a comprehensive understanding of hydrogen systems onboard vessels, an extensive technical review of hydrogen storage and power systems is provided, covering the entire power value chain. Key aspects include equipment arrangement, integration of fuel cell powertrain, and presentation of the complete storage system, in compliance with regulations. Engineering considerations, such as material selection and insulation, equipment specifications (e.g., pressure relief valves and hydrogen purity), and system configurations are analysed. Key findings reveal that fuel cells must achieve operational lifespans exceeding 46,000 h to be viable for maritime applications. Additionally, reliance solely on volumetric energy density underestimates storage needs, necessitating provisions for cofferdams, ullage space, tank heels, and hydrogen conditioning areas. Regulatory gaps are identified, including inadequate safety provisions and inappropriate material guidelines. • Engineering overview of ships powered by hydrogen. • Framework for models of storage system requirements. • Lifespan requirements of fuel cells for shipping. • Identification of regulation inconsistencies. [ABSTRACT FROM AUTHOR]

The study proposes an alternative speed control algorithm for a permanent magnet synchronous motor to the classical PID controller, called direct discontinuous sliding mode control, based on relay controllers. Due to the demonstrated advantages, this method is supposed to be used to control the speed of an electric vehicle using hydrogen fuel cells. A mathematical description of the sliding mode method is presented, which gives an understanding of the processes occurring in the system during transient modes. Using mathematical modeling in MATLAB/Simulink, a comparison was made of the dynamic characteristics of the speed transient process for a system with classical PID controllers and a system with sliding mode control. The sliding mode system showed better control time and response to load changes. Thus, it is concluded that the use of the sliding mode method is preferable in problems of controlling the speed of an electric vehicle using hydrogen fuel cells. Graphic abstraction (Provided to the authors of the article for publication by Fermaltech Montenegro Limited and the author A.L. Gusev, the drawing was made using the Designer program. On the DALL E 3 platform.). [Display omitted] [ABSTRACT FROM AUTHOR]

With the development of hydrogen energy, there has been increasing attention toward fuel cells and water electrolysis. Among them, the zero-gap membrane electrode assembly (MEA) serves as an important triple-phase reaction site that determines the performance and efficiency of the reaction system. The development of efficient and durable MEAs plays a crucial role in the development of hydrogen energy. Consequently, a great deal of effort has been devoted to developing ordered MEAs that can effectively increase catalyst utilization, maximize triple-phase boundaries, enhance mass transfer and improve stability. The research progress of ordered MEAs in recent advances is highlighted, involving hydrogen fuel cells and low temperature water electrolysis technology. Firstly, the fundamental scientific understanding and structural characteristics of MEAs based on one-dimensional nanostructures such as nanowires, nanotubes and nanofibers are summarized. Then, the classification, preparation and development of ordered MEAs based on three-dimensional structures are summarized. Finally, this review presents current challenges and proposes future research on ordered MEAs and offers potential solutions to overcome these obstacles. [ABSTRACT FROM AUTHOR]

Hydrogen energy is based on the widespread use of renewable and non-renewable environmentally friendly energy sources. Almost all devices for converting natural energy flow into a target energy flow use machines equipped with gears. Gear is a mechanism whose operating principle is to transmit power by rotation. The mechanism has become widespread in various areas of production due to its relatively simple and reliable design, ease of maintenance and low energy consumption during operation. It should be noted that synchronous machines with permanent magnets play an important role in connecting renewable energy generators to the network. The results of the work also play an important role in the design of electric cars on hydrogen fuel cells. Energy generation, especially from renewable sources, requires reliable and durable technological solutions. The paper presents the cogging torque minimization method based on numerical calculation. The considered method assumes that the amplitude of the permeance harmonic is a periodic function of the slot opening, and it will be equal to zero if the opening value is a multiple of or equal to the period of the permeance harmonic. The numerical methods are applied for accuracy enchantment under magnetic field calculation. The air gap permeance function is calculated considering the actual pattern of field distribution in the area of the gap and slot opening, the edge effects, and steel saturation. The two-dimensional finite element model corresponding to the cross-section of a cylindrical machine and the Maxwell stress tensor method is used for cogging torque calculation. The paper provides a quantitative comparison of the relative slot opening values under analytical and finite element method calculation. The developed permanent magnet machine prototype is presented. The harmonic composition of cogging torque is obtained for machine prototype, and the fundamental harmonic is determined. Thus, the fundamental harmonic of the cogging torque can be eliminated by means of optimal slot opening width. The experimental and analytical results confirmed the cogging torque could be reduced by 2–8 times. (Provided to the authors of the article for publication by Fermaltech Montenegro Limited and the author A.L. Gusev, the drawing was made using the Designer program. On the DALL E 3 platform.). [Display omitted] [ABSTRACT FROM AUTHOR]

As the global demand for clean energy continues to rise, hydrogen, as a promising clean energy carrier, is increasingly becoming the focus of international attention. This paper aims to present a comprehensive overview of hydrogen preparation strategies, recent advances in storage and transportation technologies, and the extensive application of hydrogen in many fields. First, we explored the current mainstream hydrogen preparation paths, including but not limited to hydroelectrolysis (decomposition of water molecules using renewable energy power); gas steam reforming (traditional but efficient hydrogen production methods requiring carbon emission management); biomass gasification and coal gasification (based on innovative utilisation of renewable and fossil resources); and hydrolysis hydrogen production (advanced cutting-edge technology directly using solar energy). Each method shows its unique advantages and potential application scenarios. Subsequently, we have focused on hydrogen storage technology, a key area that is undergoing rapid technological innovation and widespread application. Hydrogen storage technology, with its energy storage and release characteristics without carbon dioxide emissions, is regarded as an important bridge to promote the transformation of energy structure and achieve the sustainable development goals. This paper not only expounds the basic principle of hydrogen storage technology and historical evolution, also analyzed in detail in the compressed hydrogen, liquid hydrogen and solid hydrogen storage form of concrete application examples, at the same time, the selection of hydrogen storage materials, cost efficiency, safety performance and deeply analyzes the core challenges, and the future development trend and potential solutions. In terms of hydrogen transport, this paper will introduce three common transport modes: gas transport, liquid transport and hydrogen carrier transport. Further, we turned to the diversified utilisation technology of hydrogen, focusing on the breakthroughs of fuel cell technology in energy conversion efficiency, Hydrogen combustionand, thow hydrogen energy can help to achieve low-carbon travel in the transportation field. The integration and application of these technologies not only broaden the use of hydrogen energy, but also lay a solid foundation for them to occupy a core position in the clean energy system. To sum up, through a detailed review, this paper draws a panorama of hydrogen production, storage, transportation and use, revealing the key role and huge potential of hydrogen energy in the clean energy transition. We look forward to that this paper will provide valuable reference and inspiration for researchers, engineers and policy makers, jointly promote the continuous progress and wide application of hydrogen technology, and contribute to the construction of a green and low-carbon future. [Display omitted] • Multiple hydrogen production techs, both traditional & renewable. • Efficient H 2 storage materials, including metal hydrides, carbon-based, MOFs. • H 2 transport: gas, liquid, pipeline. Pipeline best for long-distance. • H 2 applications: transport, fuel, power. Wide prospects, future energy key. [ABSTRACT FROM AUTHOR]

Energy hubs are efficient energy systems in which multiple energy carriers are converted, conditioned and stored to supply multiple forms of energy demands such as electricity, gas and heat. On the other hand, the penetration of fuel cell vehicles in transportation sector is increasing. The role of hydrogen refuelling stations is to inject hydrogen into fuel cell vehicles. A hydrogen refuelling station may absorb its required electricity from an energy hub. The operational planning of the microgrids with hydrogen refuelling station-integrated energy hubs has not been addressed before; therefore, the main goal of this research is to develop a hierarchical stochastic framework for operational planning of isolated microgrids with hydrogen refuelling station-integrated energy hubs, considering the uncertainties. In a hierarchical framework, the players are not obliged to submit their models to a central agent, so the privacy of players is preserved; moreover, it is computationally inexpensive. Mixed-integer linear programming models are used for hydrogen refuelling stations and energy hubs, while a mixed-integer quadratic programming model is used for modeling microgrid. CPLEX and GUROBI solvers are respectively used for solving the developed models. SCENRED module is used for scenario reduction. The studied microgrid is a renewable-rich 69-bus radial network. The findings approve the efficiency of the proposed methodology. The impact of batteries and wind generators on the operation of energy hubs has been evaluated. • A model for integration of hydrogen stations in energy hubs and microgrid. • Stochastic method for dealing with uncertainties of demands, PV, wind and prices. • The impact of renewable power generation on profit of hubs is investigated. [ABSTRACT FROM AUTHOR]

In the mining industry, the work system relies on equipment that consumes large amounts of energy. In mining operations, diesel equipment is widely used due to its flexibility, load capacity and adaptability to various terrain conditions. However, it has high diesel consumption and high greenhouse gas emissions, mainly carbon monoxide. Using hydrogen as a fuel not only offers the opportunity to decarbonize transportation and the mining industry, but also significantly reduces local air pollution. The list of possible objects for using the proposed hydrogen technology includes: diesel power plants, high-voltage diesel distillation stations, mining excavators, drilling rigs, diesel-powered loading and hauling vehicles and others. The use of hydrogen as a fuel to drive engines of power plants and transport facilities in the mining industry requires the development of equipment to control the leakage of hydrogen from storage elements and fuel supply to the engines. The solution to the problem of monitoring hydrogen leaks from fuel tanks of mining vehicles and power equipment that ensures the operation of mining enterprises using Raman lidar is considered. It is shown that at a laser radiation wavelength of 532 nm it is possible to obtain the minimum time for measuring the hydrogen concentration in the air with a Raman lidar at a given sensing distance. It was found that lidar sensing from geostationary orbit at a laser radiation wavelength of 532 nm also provides the minimum measurement time for a given concentration of the hydrogen molecules under study. [ABSTRACT FROM AUTHOR]

The maritime transportation sector is a large and growing contributor of greenhouse gas and other emissions. Therefore, stringent measures have been taken by the International Maritime Organization to mitigate the environmental impact of the international shipping. These lead to the adoption of new technical solutions, involving clean fuels, such as hydrogen, and high efficiency propulsion technologies, that is, fuel cells. In this framework, this paper proposes a methodological approach aimed at supporting the retrofit design process of a car-passenger ferry, operating in the Greece's western maritime zone, whose conventional powertrain is replaced with a fuel cell hybrid system. To this aim, first the energy/power requirements and the expected hydrogen consumption of the vessel are determined basing on a typical operational profile, retrieved from data provided by the shipping company. Three hybrid powertrain configurations are then proposed, where fuel cell and batteries are balanced out according to different design criteria. Hence, a new vessel layout is defined for each of the considered options, by taking into account on-board weight and space constraints to allocate the components of the new hydrogen-based propulsion systems. Finally, the developed vessel configurations are simulated in a virtual towing tank environment, in order to assess their hydrodynamic response and compare them with the original one, thus providing crucial insights for the design process of new hydrogen-fueled vessel solutions. Findings from this study reveal that the hydrogen-based configurations of the vessel are all characterized by a slight reduction of the payload, mainly due to the space required to allocate the hydrogen storage system; instead, the hydrodynamic behavior of the H 2 powered vessels is found to be similar to the one of the original Diesel configuration; also, from a hydrodynamic point of view, the results show that mid load operating conditions get relevance for the design process of the hybrid vessels. • Design of three hybrid fuel cell/battery powertrains for a RoPax ferry is performed. • New layouts for the H2 vessel by rearranging on-board technical spaces are designed. • Numerical analysis of H2 vessel hydrodynamics in calm water conditions is performed. • For all analysed powertrains, the vessel is affected by a slight payload reduction. • No significant changes in the hydrodynamic response of the vessel are found. [ABSTRACT FROM AUTHOR]

Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen. The solar-hydrogen spacecraft power supply system is based on the principle of partial conversion of excess energy generated on board into gaseous and cryogenic hydrogen. The efficiency of converting sunlight into hydrogen is 14%. Solar-hydrogen energy systems are also called rechargeable hydrogen cells. They consist of solar panels that generate electricity, water tanks and a membrane that separates hydrogen and oxygen. The power supply system implements three modes in its operation. Mode A - the planned amount of electrical energy generated by solar cells is consumed to meet the needs of the spacecraft in the normal mode. Mode B - from the excess electricity in excess of the energy consumption on board, the solar panels generate electricity, with the help of which water is electrolyzed. The resulting hydrogen is stored in special tanks and can be used during the peak period of energy consumption. Mode C - part of the hydrogen can be liquefied by the onboard cryogenerator and it can be used to generate electricity in fuel cells in super-peak power consumption situations: accidents, repairs, experiments that require a lot of energy. The efficiency of converting sunlight into cryogenic hydrogen is 5%. The article considers a new version of the median signal selection element, which provides the possibility of practically unlimited scaling of the number of input signals without loss of performance, as well as the ability to monitor malfunctions or failures in the operation of the selection element itself. The experiments have shown that the implementation of a selection element for 7 inputs takes no more than 432 logical cells on the Altera Cyclone IV EP4CE115F29C7 FPGA, which is much less than the amount occupied by the analogs discussed in the article. In this case, the delay in calculating the median signal does not exceed one FPGA cycle. [ABSTRACT FROM AUTHOR]

Hydrogen fuel cell vehicles (HFCVs) are a promising technology for reducing vehicle emissions and improving energy efficiency. Due to the ongoing evolution of this technology, there is limited comprehensive research and documentation regarding the energy modeling of HFCVs. To address this gap, the paper develops a simple HFCV energy consumption model using new fuel cell efficiency estimation methods. Our HFCV energy model leverages real-time vehicle speed, acceleration, and roadway grade data to determine instantaneous power exertion for the computation of hydrogen fuel consumption, battery energy usage, and overall energy consumption. The results suggest that the model's forecasts align well with real-world data, demonstrating average error rates of 0.0% and −0.1% for fuel cell energy and total energy consumption across all four cycles. However, it is observed that the error rate for the UDDS drive cycle can be as high as 13.1%. Moreover, the study confirms the reliability of the proposed model through validation with independent data. The findings indicate that the model precisely predicts energy consumption, with an error rate of 6.7% for fuel cell estimation and 0.2% for total energy estimation compared to empirical data. Furthermore, the model is compared to FASTSim, which was developed by the National Renewable Energy Laboratory (NREL), and the difference between the two models is found to be around 2.5%. Additionally, instantaneous battery state of charge (SOC) predictions from the model closely match observed instantaneous SOC measurements, highlighting the model's effectiveness in estimating real-time changes in the battery SOC. The study investigates the energy impact of various intersection controls to assess the applicability of the proposed energy model. The proposed HFCV energy model offers a practical, versatile alternative, leveraging simplicity without compromising accuracy. Its simplified structure reduces computational requirements, making it ideal for real-time applications, smartphone apps, in-vehicle systems, and transportation simulation tools, while maintaining accuracy and addressing limitations of more complex models. [ABSTRACT FROM AUTHOR]

The global transport sector, a significant contributor to energy consumption and greenhouse gas (GHG) emissions, requires innovative solutions to meet sustainability goals. Artificial intelligence (AI) has emerged as a transformative technology, offering opportunities to enhance energy efficiency and reduce GHG emissions in transport systems. This study provides a comprehensive review of AI's role in optimizing vehicle energy management, traffic flow, and alternative fuel technologies, such as hydrogen fuel cells and biofuels. It explores AI's potential to drive advancements in electric and autonomous vehicles, shared mobility, and smart transportation systems. The economic analysis demonstrates the viability of AI-enhanced transport, considering Total Cost of Ownership (TCO) and cost-benefit outcomes. However, challenges such as data quality, computational demands, system integration, and ethical concerns must be addressed to fully harness AI's potential. The study also highlights the policy implications of AI adoption, underscoring the need for supportive regulatory frameworks and energy policies that promote innovation while ensuring safety and fairness. [ABSTRACT FROM AUTHOR]

The South Korean government has an ambitious policy to roll out hydrogen-powered vehicles across the country with 2000 hydrogen refueling stations (HRSs) infrastructure by 2050. However, the country currently lacks sufficient HRS infrastructure. In this context, this study proposes and investigates the technoeconomic feasibility and performance assessment of an optimal hybrid renewable energy system integrated with a vanadium redox flow battery for on-site hydrogen production. The system is designed to refuel a fleet of 20 fuel cell electric vehicles at seven South Korean locations with distinct climates. Based on the typical daily hydrogen and electric load profile of the HRS, the capital expenditure, net present cost, operation expenditure, levelized cost of hydrogen and levelized cost of energy were estimated to be, $5.95 - $13.2 M, $8.93 - $19.4 M, 82,670–202,184 $/yr, 8.77–19.1 $/kg and 2.1–4.58 $kWh, respectively. [Display omitted] • Modeled non-conventional resources powered hydrogen refueling stations (HRS). • Obtained optimal HRS components in seven locations in South Korea for refueling hydrogen powered vehicles fleet. • The detailed economic parameters and energy profile of HRS were analyzed. • Carbon footprint was also determined for considered HRS. [ABSTRACT FROM AUTHOR]

This article discusses advances in the design of hydrogen fuel engines; the main characteristics of the hybrid engine are studied; prospects for further research are outlined; development and improvement of engine designs, research of processes in engines running on natural gas and hydrogen. Transport is one of the key elements of modern civilization. Its condition and development prospects largely depend on the ability to supply transport power plants with fuel. The depletion of liquid hydrocarbon fuel reserves and problems of environmental pollution may present humanity with a choice - either to reduce transport transportation or to find new ways to supply energy to transport. OBJECTIVE: To review the electrochemical technologies used for the production of hydrogen at gas stations and the operation of hybrid electric vehicle engines using fuel cell batteries. Conduct a comparative analysis of the production and use of energy by electrochemical and traditional methods in vehicles. METHODS are based on analysis of literature data and mathematical calculations. For a passenger electric vehicle, the amount of electricity that can be obtained in a fuel cell by processing 1 kg of hydrogen was calculated. It has been shown that the specific fuel consumption for a hydrogen electric vehicle averages 1 kg of hydrogen per 100 km. Hydrogen has the potential to be the sustainable fuel of the future, reducing global dependence on fossil fuel resources and reducing carbon emissions from the transportation industry. [ABSTRACT FROM AUTHOR]

The transformation from a fossil fuel economy to a low-carbon economy has reshaped the way energy is transmitted. As most renewable energy is obtained in the form of electricity, using green electricity to produce hydrogen is considered a promising energy carrier. However, most studies have not considered the transportation mode of hydrogen. In order to encourage the utilization of renewable energy and hydrogen, this paper proposes a comprehensive energy system optimization operation strategy considering multi-mode hydrogen transport. Firstly, to address the shortcomings in the optimization operation of existing systems regarding hydrogen transport, modeling is conducted for multi-mode hydrogen transportation through hydrogen tube trailers and pipelines. This model reflects the impact of multi-mode hydrogen delivery channels on hydrogen utilization, which helps promote the consumption of new energy in electrolysis cells to meet application demands. Based on this, the constraints of electrolyzers, combined heat and power units, hydrogen fuel cells, and energy storage systems in integrated energy systems (IESs) are further considered. With the objective of minimizing the daily operational cost of the comprehensive energy system, an optimization model for the operation considering multi-mode hydrogen transport is constructed. Lastly, based on simulation examples, the impact of multi-mode hydrogen transportation on the operational cost of the system is analyzed in detail. The results indicate that the proposed optimization strategy can reduce the operational cost of the comprehensive energy system. Hydrogen tube trailers and pipelines will have a significant impact on operational costs. Properly allocating the quantity of hydrogen tube trailers and pipelines is beneficial for reducing the operational costs of the system. Reasonable arrangement of hydrogen transportation channels is conducive to further promoting the green and economic operation of the system. [ABSTRACT FROM AUTHOR]

The transformation from combustion-based to renewable energy technologies is of paramount importance due to the rapid depletion of fossil fuels and the dramatic increase in atmospheric CO2 levels resulting from growing global energy demands. To achieve the Paris Agreement's long-term goal of carbon neutrality by 2050, the full implementation of clean and sustainable energy sources is essential. Consequently, there is an urgent demand for zero or low-carbon fuels with high energy density that can produce electricity and heat, power vehicles, and support global trade. This review presents the global motivation to reduce carbon dioxide by utilizing hydrogen technology, which is key to meeting future energy demands. It discusses the basic properties of hydrogen and its application in both prototype and large-scale efficient technologies. Hydrogen is a clean fuel and a versatile energy carrier; when used in fuel cells or combustion devices, the final product is water vapor. Hydrogen gas production methods are reviewed across renewable and non-renewable sources, with reaction processes categorized as green, blue, grey, black, pink, and turquoise, depending on the reaction pathway and CO2 emissions management. This review covers the applications of hydrogen technology in petroleum refining, chemical and metrological production, hydrogen fuel cell electric vehicles (HFCEVs), backup power generation, and its use in transportation, space, and aeronautics. It assesses physical and material-based hydrogen storage methods, evaluating their feasibility, performance, and safety, and comparing HFCEVs with battery and gasoline vehicles from environmental and economic perspectives. Finally, the prospects and challenges associated with hydrogen production, handling, storage, transportation, and safety are also discussed. [ABSTRACT FROM AUTHOR]

The testing of relay protection devices is an extremely important task on which the stable and safe operation of the power systems depends. One of the most complex and responsible kinds of protection in networks with rotating generation, which includes hydrogen fuel generation, is protection against loss-of-synchronism. Integration of heterogeneous generating electrical devices based on renewable energy sources and based on a hydrogen fuel cell is associated with the need for reliable relay protection. It disconnects tie-lines between the systems in out-of-step conditions. And it is a challenging task to simulate input signals corresponding to the exact settings of the out-of-step protection to make sure it operates correctly. This is because one has to simulate exact parameters of impedance locus (its radius, coordinates of the center in the impedance plane, spin direction, speed, etc.) while available tools embedded in testing devices often don't support such parameters directly. To deal with the problem, the authors present the approach to simulate instantaneous values of line currents and phase-to-ground voltages during the out-of-step operation. These electrical signals form the locus of the impedance vector with the desired parameters to test the operation of the out-of-step protection devices. The software based on the proposed algorithm also provides a graphical representation of the simulation results. All the proposed solutions proved to reduce the time required for commissioning of out-of-step protection and thereby increase tests quality and speed. (provided to the authors on 29.08.2024 for printing in IJHE from the archive of Fermaltech Montenegro Limited, made by A.L. Gusev using Designer. On the DALL E 3 platform.). [Display omitted] [ABSTRACT FROM AUTHOR]

Anion exchange membrane fuel cells (AEMFCs) are advantageous for reducing or even eliminating the dependency on platinum resources, as the alkaline environment allows the use of non‐precious metal catalysts for oxygen reduction reaction at the cathode. However, the intrinsic activity of hydrogen oxidation reaction (HOR) catalysts in alkaline environments is 2 to 4 orders of magnitude lower than in acidic environments, which becomes the major challenge for AEMFCs. This review examines the current developments in the intrinsic activity of alkaline HOR catalysts and systematically summarizes the hydrogen activation mechanism with a focus on potential influencing factors and enhancement strategies. Furthermore, it offers insights into the prospects for developing more efficient alkaline HOR catalysts. [ABSTRACT FROM AUTHOR]

Efficient catalysis of ammonia borane (AB) holds potential for realizing controlled energy release from hydrogen fuel and addressing cost challenges faced by hydrogen storage. Here, we report that amorphous domains on metallic Fe crystal structures (R-Fe2O3 Foam) can achieve AB catalytic performances and stability (turnover frequency (TOF) of 113.6 min−1, about 771 L H2 in 900 h, and 43.27 mL/(min·cm2) for 10×10 cm2 of Foam) that outperform reported benchmarks (most <14 L H2 in 45 h) by at least 20 times. These notable increases are enabled by the stable Fe crystal structure, while defects and unsaturated atoms in the amorphous domains form Fe-B intermediates that significantly lower the dissociation barriers of H2O and AB. Given that the catalyst lifetime is a key determinant for the practical use in fuel cells, our R-Fe2O3 Foam also provides decent H2 supply (180 mL H2/min, AB water solution of 7.5 wt% H2) in a driven commercial car fuel cell at stable power outputs (7.8 V and 1.6 A for at least 5 h). When considered with its facile synthesis method, these materials are potentially very promising for realizing durable high-performance AB catalysts and viable chemical storage in hydrogen powered vehicles. Hydrogen storage and release are critical issues for commercial use. Here, authors report a Fe Foam with amorphous domains for the hydrolysis of ammonia borane with ultra-long lifetime over 900 h, realizing the on-board H2 supply of a model car. [ABSTRACT FROM AUTHOR]

To meet the greenhouse gas reduction targets and address the uncertainty introduced by the surging penetration of stochastic renewable energy sources, energy storage systems are being deployed in microgrids. Relying solely on short-term uncertainty forecasts can result in substantial costs when making dispatch decisions for a storage system over an entire day. To mitigate this challenge, an adaptive robust optimization approach tailored for a hybrid hydrogen battery energy storage system (HBESS) operating within a microgrid is proposed, with a focus on efficient state-of-charge (SoC) planning to minimize microgrid expenses. The SoC ranges of the battery energy storage (BES) are determined in the dayahead stage. Concurrently, the power generated by fuel cells and consumed by electrolysis device are optimized. This is followed by the intraday stage, where BES dispatch decisions are made within a predetermined SoC range to accommodate the uncertainties realized. To address this uncertainty and solve the adaptive optimization problem with integer recourse variables in the intraday stage, we proposed an outer-inner column-and-constraint generation algorithm (outer-inner-CCG). Numerical analyses underscored the high effectiveness and efficiency of the proposed adaptive robust operation model in making decisions for HBESS dispatch. [ABSTRACT FROM AUTHOR]

Zero-carbon parks have broad prospects in carbon neutralization. As an energy hub, hydrogen energy storage plays an important role in zero-carbon parks. However, the nonlinear characteristics of hydrogen energy storage systems (HESSs) have a significant impact on the system economy. Therefore, considering the variable working condition characteristics of HESSs, a hybrid operation method is proposed for HESS, to support the efficient and economic operation of zero-carbon parks, By analyzing the operating principle of a zero-carbon park with HESS, the system structure framework and variable condition linearization model of the equipment in HESS are established. Moreover, considering the energy output characteristics of hydrogen energy storage equipment under variable working conditions, a multimodule hybrid operation strategy is proposed for electrolytic and fuel cells, effectively meeting the thermoelectric load demand of zerocarbon parks in different scenarios. Finally, the economy of the proposed hybrid operation strategy was verified in typical scenarios, using a zero-carbon park embedded with a HESS. [ABSTRACT FROM AUTHOR]

The performance of a PEM fuel cell that uses hydrogen as the fuel and pure oxygen as the oxidant strongly depends on water management, which has been primarily studied in a single-channel domain. Therefore, there is a need to examine water distribution throughout the entire fuel cell domain, including both the anode and cathode sides. Liquid water can cause flooding in the gas diffusion layer, catalyst layer, and channels, reducing the active surface area of the catalyst and, consequently, the reaction rate. Phase transfer between liquid water and water vapor influences the buildup of liquid water in these domains. In the present work, a three-dimensional, non-isothermal, two-phase numerical model incorporating both the cathode and anode domains has been developed to study water distribution. This model includes water phase transition in the gas diffusion layer, catalyst layer, and channels. The mixed flow distributor is used to analyze water formation and distribution throughout the domain. The study shows that using pure oxygen at the inlet increases the ohmic region in the polarization curve and decreases concentration losses, which could be important for applications such as spacecraft. Additionally, the effects of liquid water accumulation in the porous layers on reactant transport and cell performance are investigated. [ABSTRACT FROM AUTHOR]

The significance of hydrogen energy has grown considerably due to climate change and the depletion of fossil fuels. PEM fuel cells are the key hydrogen technologies. Commercial membranes based on perfluorosulfonic acid (PFSA) with a polymer structure containing fluorine are currently available. However, it has been determined that certain perfluorosulfonic acids (PFSAs) are hazardous, persistent, and bioaccumulative. Advancements in hydrogen technology rely on effective, inexpensive, and perfluorocarbon‐free membranes, specifically proton exchange membranes (PEMs). In this research, a PFSA‐free polyacrylonitrile‐co‐methyl acrylate (PAN‐MA) membrane doped with phosphoric acid is prepared using the electrospinning method and then characterized by SEM, FE‐SEM, XRD, FTIR, TGA, DMA, and EIS. The DMA analysis reveals that the storage modulus of the doped membrane increases from 0.98 to 5.66 MPa at 80 °C. The nanofiber composite membrane, with a thickness of 181 µm, exhibits the highest proton conductivity of 0.306 S m−1 at 20 °C, 1.76 times higher than that of the Nafion 212 membrane. The Nafion 212 membrane has an ionic conductivity of 0.173 S m−1 under the same conditions. These results indicate that the prepared nanofiber membranes are promising materials for evaluating fuel cell applications. [ABSTRACT FROM AUTHOR]

This study conducts a comprehensive literature review, analyzing academic articles, government documents, and reports from international organizations to discern trends in hydrogen fuel deployment for heavy transportation in New Zealand (NZ). It specifically assesses the current state-of-the-art technology, economic policies, and the impact of hydrogen fuel and fuel cell vehicles on decarbonization efforts and economic growth, acknowledging the influence of consumer preferences, diesel prices, and technological advancements on market demand. While recognizing the cost-competitiveness challenges these vehicles face, the research highlights the necessity of significant investments in infrastructure development. Methodologically, the study integrates economies of scale and technological learning rates to evaluate hydrogen fuel investment returns. Furthermore, this paper employs the Castalia-MBIE model for scenario analysis, revealing two key insights. First, it underscores the criticality of maintaining a favorable equilibrium between domestic and international production costs alongside hydrogen fuel consumption to bolster NZ's competitiveness on the global stage. Second, it highlights the pronounced vulnerability of fuel cell electric vehicles to supply-side influences as compared to demand-related variables. These insights contribute scientifically to understanding the economic dynamics of hydrogen fuel adoption and its implications for NZ's transport sector. [ABSTRACT FROM AUTHOR]

Under the guidance of energy-saving and emission reduction goals, a low-carbon economic operation method for integrated energy systems (IES) has been proposed. This strategy aims to enhance energy utilization efficiency, bolster equipment operational flexibility, and significantly cut down on carbon emissions from the IES. Firstly, a thorough exploration of the two-stage operational framework of Power-to-Gas (P2G) technology is conducted. Electrolyzers, methane reactors, and hydrogen fuel cells (HFCs) are introduced as replacements for traditional P2G equipment, with the objective of harnessing the multiple benefits of hydrogen energy. Secondly, a cogeneration and HFC operational strategy with adjustable heat-to-electricity ratio is introduced to further enhance the IES's low-carbon and economic performance. Finally, a step-by-step carbon trading mechanism is introduced to effectively steer the IES towards carbon emission control. [ABSTRACT FROM AUTHOR]

The serious problem of carbon monoxide (CO) poisoning on the surface of Pt-based catalysts has long constrained the commercialization of proton exchange membrane fuel cells (PEMFCs). Regeneration of Pt sites by maintaining CO scavenging ability through precise construction of the surface and interface structure of the catalyst is the key to obtaining high-performance CO-resistant catalysts. Here, we used molybdenum carbide (MoCx) as the support for Pt and introduced Ru single atoms (SA-Ru) at the Pt-MoCx interface to jointly decrease the CO adsorption strength on Pt. More importantly, the MoCx and SA-Ru are immune to CO poisoning, which continuously assists in the oxidation of adsorbed CO by generating oxygen species from water dissociation. These two effects combine to confer this anode catalyst (SA-Ru@Pt/MoCx) remarkable CO tolerance and the ability to operate stably in fuel cell with high CO concentration (power output 85.5 mW cm−2@20,000 ppm CO + H2 – O2), making it possible to directly use the cheap reformed hydrogen as the fuel for PEMFCs. Here, authors report a Pt-based catalyst resistant to high concentration CO poisoning for fuel cell applications, making it possible to use reformed hydrogen directly as fuel for fuel cells. [ABSTRACT FROM AUTHOR]

Enhancing high-performance proton exchange membrane fuel cell (PEMFC) technology is crucial for the widespread adoption of hydrogen energy, a leading renewable resource. In this research, we introduce an innovative and cost-effective data-driven approach using the BP-AdaBoost algorithm to accurately predict the power output of hydrogen fuel cell stacks. The algorithm's effectiveness was validated with experimental data obtained from an advanced fuel cell testing platform, where the predicted power outputs closely matched the actual results. Our findings demonstrate that the BP-AdaBoost algorithm achieved lower RMSE and MAE, along with higher R2, compared to other models, such as Partial Least Squares Regression (PLS), Support Vector Machine (SVM), and back propagation (BP) neural networks, when predicting power output for electric stacks of the same type. However, the algorithm's performance decreased when applied to electric stacks with varying material compositions, highlighting the need for more sophisticated models to handle such diversity. These results underscore the potential of the BP-AdaBoost algorithm to improve PEMFC efficiency while also emphasizing the necessity for further research to develop models capable of accurately predicting power output across different types of PEMFC stacks. [ABSTRACT FROM AUTHOR]

Global shipping contributes (2.8%) to greenhouse gas emissions and needs to find future fuels which will allow the International Maritime organisation's 2050 net zero targets to be met. There is much uncertainty as to which fuels should be used between hydrogen, ammonia or methanol as future costs are uncertain. We propose and evaluate a Wind-to-Wake ratio that provides an objective measure based on the amount of renewable energy required to propel a ship. Time domain voyage energy demand profiles are used to simulate the fuel used and emissions for a cruise ship, a research survey vessel, a container ship and a large multi-fuel Liquefied Natural Gas carrier. Alternative ship power systems are investigated using various carbon-based fuels, ammonia and hydrogen either using conventional engines or fuel cells. For all voyage and fuel scenarios the combination of hydrogen and fuel cells uses 30% less renewable energy than ammonia and 26% less than methanol. Hydrogen only emits steam whereas the other fuel scenarios still emit significant amounts of greenhouse gasses. [Display omitted] • Wind to wake ratio provides an objective measure for comparing future fuels • Time-domain energy demand allows for 4 vessel types and 12 power systems. • Quantitative comparison of methanol, ammonia and hydrogen as future marine fuels. • Hydrogen through fuel cells requires the least amount of renewable energy investment. • Methanol and ammonia combustion scenarios yield a carbon footprint and other air emissions. [ABSTRACT FROM AUTHOR]

In this work, a novel cold startup strategy is presented for a large-scale metal hydride–fuel cell system. Due to the thermal requirement of the system, when the initial temperature of metal hydride and ambient air is low, the system cannot be started because the hydrogen pressure in the metal hydrides storage system is lower than the minimal pressure required by the fuel cell. The cold startup is achieved by maintaining a part of metal hydride storage at a target temperature and using coolant control to transfer heat to the remaining cold metal hydride storage upon operation of the fuel cells. The strategy is studied numerically and a novel Quasi-2-Dimensional approach is developed to describe heat transfer within metal hydrides and validated. By the proper selection of the value of the control variable, both fast startup and immediate uninterrupted fuel cell power supply are achieved. The effect of initial conditions on the startup process is studied and the strategy consumed 30 % less energy than the alternative without control. The proposed strategy is suitable and efficient for the cold startup of large-scale metal hydride-fuel cell systems. • A novel cold startup strategy is proposed for a large scale metal hydride hydrogen storage unit coupled with a fuel cell. • A Quasi 2-D heat and mass transfer model for the metal hydrides storage system is presented and validated. • A successful fast cold startup along with maximum fuel cell power output is achieved using the current strategy. • Energy savings of 30% are achieved for current strategy when compared with an alternative without control. [ABSTRACT FROM AUTHOR]

Hydrogen energy, as a zero-carbon emission type of energy, is playing a significant role in the development of future electricity power systems. Coordinated operation of hydrogen and electricity will change the direction and shape of energy utilization in the power grid. To address the evolving power system and promote sustainable hydrogen energy development, this paper initially examines hydrogen preparation and storage techniques, summarizes current research and development challenges, and introduces several key technologies for hydrogen energy application in power systems. These include hydrogen electrification technology, hydrogen-based medium- and long-term energy storage, and hydrogen auxiliary services. This paper also analyzes several typical modes of hydrogen–electricity coupling. Finally, the future development direction of hydrogen energy in power systems is discussed, focusing on key issues such as cost, storage, and optimization. [ABSTRACT FROM AUTHOR]

Proton‐exchange membrane fuel cells (PEMFCs) and water electrolysis (PEMWE) are rapidly developing hydrogen energy conversion devices. Catalyst layers and membranes have been studied extensively and reviewed. However, few studies have compared gas diffusion layers (GDLs) in PEMWE and PEMFC. This review compares the differences and similarities between the GDLs of PEMWE and PEMFC in terms of their material and mass transport characteristics. First, the GDL materials are selected based on their working conditions. Carbon materials are prone to rapid corrosion because of the high anode potential of PEMWEs. Consequently, metal materials have emerged as the primary choice for GDLs. Second, the mutual counter‐reactions of the two devices result in differences in mass transport limitations. In particular, water flooding and the effects of bubbles are major drawbacks of PEMFCs and PEMWE, respectively; well‐designed structures can solve these problems. Imaging techniques and simulations can provide a better understanding of the effects of materials and structures on mass transfer. Finally, it is anticipated that this review will assist research on GDLs of PEMWE and PEMFC. [ABSTRACT FROM AUTHOR]

The location and quantity of hydrogen refueling stations (HRSs) play a crucial role in the development and promotion of hydrogen fuel cell vehicles (HFCVs). This study proposes a multi-period urban HRSs site selection and capacity planning with many-objective optimization framework for hydrogen supply chain (HSC). Firstly, the city's multi-period hydrogen requirement is predicted based on a generalized Bass diffusion model. Using publicly available data, including gas station network data, geographic information system (GIS) data, population data, and regional economic data, a spatially aggregated demand model is established to allocate hydrogen requirement at candidate sites in the city of the geographic grid model with a 1 km resolution. On this basis, four interrelated objective functions (total investment cost, hydrogen requirement coverage, risk coefficient, and environmental factors) are developed. The third-generation non-dominated sorting genetic algorithm (NSGA-III) and the technique for order preference by similarity to an ideal solution (TOPSIS) are employed to achieve multi-period urban HRSs site selection and capacity planning with many-objective optimization for HSC. By comparing the results of single-objective optimization focusing on minimum cost and maximum hydrogen requirement coverage, it is observed that many-objective optimization achieves a better balance among the four conflicting objectives. After comprehensive analysis, the distribution of HRSs exhibits a clustered structure, influenced by the population and economic structure of the city. In the initial stages of HFCV development, most stations serve the peripheral areas around the city center; while n the later stages of the optimization period, a few high-capacity HRSs begin to concentrate in the city center. • In this study, two main contributions are achieved: • First, based on the generalized Bass diffusion model and low-resolution GIS data, population data, and regional economic data, the urban hydrogen demand is predicted for multiple periods. • Second, a novel multi-period urban hydrogen fueling station and HSC many-objective optimization framework is proposed. This provides a brand-new solution for the site selection and sizing of urban HRSs and the many-objective optimization of HSCs. [ABSTRACT FROM AUTHOR]

In recent years, research and application of hydrogen fuel emergency power supply vehicle technologies have been steadily advancing. However, due to the highly flammable and explosive nature of hydrogen gas, the safety risk of hydrogen leakage has been taken seriously. Addressing the current inadequacies in the understanding of hydrogen leakage risks, unclear sources of risk, incomplete coverage of risk scenarios, and insufficiencies in risk assessment methods associated with hydrogen fuel emergency power supply vehicles, this study firstly establishes a multi-scenario and multi-factor coupled hydrogen leakage risk event database and an accident risk system. This effort focuses on the diversity of application scenarios, types of hydrogen leakage hazards and complexity of interfering factors. Subsequently, by refining existing risk assessment methods, a more balanced subjective-objective evaluation and more granular risk ratings approach, termed AET-RM, is proposed, which ensures finer risk grading. Finally, through this method, the types of hydrogen leakage hazards and their harm boundaries are clarified, achieving a systematic and precise graded quantitative assessment of risk sources, probabilities, and consequences. The study results indicate that the established event database contains no risk events rated as I (acceptable) or V (unacceptable). There are 37 events classified as low risk (rating II), accounting for 17.54% of the total. Medium-risk events (rating III) comprise 142 incidents, making up 67.30%, while high-risk events (rating IV) include 32 cases, representing 15.17%. The highest risk score, determined by the AET-RM method, pertains to a risk event in the power generation scenario, Contingencies: metal corrosion within the battery. • Summarized hydrogen leakage risk events and established a risk event repository. • Established a multi-scenario hydrogen leakage risk system. • Proposed a reasonable and sophisticated risk assessment method. • Analysis and evaluation of risk events for hydrogen fuel emergency power supply vehicles. [ABSTRACT FROM AUTHOR]

As a new type of energy, hydrogen-enriched methane mixed fuel has a high risk of deflagration in the application process. In order to better understand the deflagration and inhibition characteristics of hydrogen-enriched methane fuel, the effect of potassium salt modified dry water material (DW) on the deflagration characteristics of hydrogen-enriched methane fuel was studied by 20 L spherical explosive apparatus, combined with pyrolysis characteristics and kinetic model. The results show that when the addition of different modifier concentrations, it can be divided into three types: small curvature, medium curvature and large curvature according to the change of pressure rising rate. With the increase of the proportion of potassium salt modifiers, the number of areas with small curvature is gradually increasing, the number of large curvature is gradually decreasing, and the number of medium curvature is almost unchanged. When the proportion of potassium salt modifier is 15% and ϕ ≤ 0.7, all enter the area below the medium curvature. When the addition of different modifiers, 15%KCl-DW has the best inhibition effect on P max and (dP/dt) max , while CH 3 COOK-DW and K 2 CO 3 -DW have better inhibition effect on Δ t 2 and Δ t 2. In general, when the hydrogen addition ratio is less than 70%, the addition of inhibitors can significantly reduce the explosion intensity. In terms of inhibition mechanism, we established the decomposition model of potassium salt modified dry water and found that potassium salt modified dry water will produce a large amount of gaseous K and KOH in the explosion system. And gaseous K and KOH will catalyze each other and combine with H and OH to form stable H 2 O, which significantly reduces the mass fraction of H and OH radicals in the chain reaction. The results of this paper provide a theoretical basis for the safe use of hydrogen-enriched methane fuel and the research and development of explosion emergency prevention and control technology. • The explosion suppression of potassium salt modified dry water on H 2 /CH 4 was studied. • The hierarchical inhibition model of H 2 /CH 4 explosion by dry water was defined. • Particle swarm optimization is adopted to optimize the decomposition parameters of DW. • Suppression mechanism of potassium salt modified dry water was analyzed. [ABSTRACT FROM AUTHOR]

The pollutant emissions of diesel-powered heavy-duty trucks (HDTs) seriously damage the air quality. The promotion of hydrogen fuel cell HDTs through purchase subsidy policy to reduce emissions has become an important approach to control air pollution. This study focuses on the impact of hydrogen fuel cell HDT purchase subsidies on air quality in the context of China, covering the panel data of 31 Chinese cities from 2014 to 2021 and applying a two-way fixed effects model to analyze the contribution of purchase subsidies and hydrogen refueling station construction subsidies to air quality. Results show that (1) the increase in purchase subsidies could improve the air quality by around 6.1% and there is a lag effect. (2) Purchase subsidies make a larger contribution to air quality compared with construction subsidies. (3) Purchase subsidies can improve air quality by reducing carbon emissions in transport industry. In sight of these results, policy makers should emphasize the implementation of purchase subsidies and hydrogen refueling station construction subsidies and stimulate manufacturers to improve the performance of hydrogen fuel cell so as to contribute more to the environment. [ABSTRACT FROM AUTHOR]

To achieve zero carbon emissions, increasing the scale of renewable energy implementation is imperative. Hydrogen is considered the prospective solution for sustainable energy due to its dual nature as a carbon-neutral fuel and an efficient storage medium for renewable energy sources. So, in this work, a standalone new hybrid energy system powered by solar energy for yearly power and freshwater production for building demand in New Borg El-Arab, Egypt. The system comprises photovoltaic (PV) panels, a water electrolyzer, multi-effect mechanical vapor compression desalination (MED-MVC), and fuel cells with hydrogen storage. A complete mathematical system model is built and solved by MATLAB/Simulink to study the daily, monthly, and yearly performance and sizing of the different system components based on the location climate conditions. The results indicate that PV panels of an area of 1824 m2, in conjunction with an electrolyzer, 863 fuel cells, and a storage tank capacity of 3013.4 m3can satisfy the annual building requirements of 255.17 MWh electricity, 766.5 m3 hot water and 876 m3 cold water. The maximum hydrogen storage lies between September and October, with maximum consumption between February and March. The average annual efficiency of PV, electrolyzer, fuel cell, electrolyzer output, fuel cell output, and overall hybrid system is 20.7%, 68.2%, 34.6%, 13.4%, 4.4%, and 16.5%, respectively, and the performance ratio (PR) of MED-MVC is 2.61. The system proves its capability to supply the building with electrical and water requirements with a levelized cost of energy (LCOE) equal to 0.712 $/kWh. Additionally, This system shows the potential to include other activities in remote areas or islands besides its contribution to achieving SDGs 6, 7, and 13. • A Standalone solar system with hydrogen storage for power and water building demand is studied. • The system proved its capability to meet the building's electrical and water demands with LCOE of 0.712 $/kWh. • The average annual PV, electrolyzer, and fuel cell efficiency are 20.7%, 68.2%, and 34.6%, respectively. • The performance ratio of MED-MVC is 2.61, and overall system efficiency is 16.5%. [ABSTRACT FROM AUTHOR]

There are a large number of applications in which hydrogen internal combustion engines represent a sensible alternative to battery electric propulsion systems and to fuel cell electric propulsion systems. The main advantages of combustion engines are their high degree of robustness and low manufacturing costs. No critical raw materials are required for production and there are highly developed production plants worldwide. A CO 2 -free operation is possible when using hydrogen as a fuel. The formation of nitrogen oxides during hydrogen combustion in the engine can be effectively mitigated by a lean-burn combustion process. However, achieving low NO x raw emissions conflicts with achieving high power yields. In this work, a series industrial diesel engine was converted for hydrogen operation and comprehensive engine tests were carried out. Various measures to improve the trade-off between NO x emissions and performance were investigated and evaluated. The rated power output and the maximum torque of the series diesel engine could be exceeded while maintaining an indicated specific NO x emission of 1 g/kWh along the entire full load curve. In the low-end-torque range, however, the gap to the full load curve of the series diesel engine could not be fully closed with the hardware used. • Converted hydrogen engine exceeds the rated power output and the maximum torque of the series diesel engine. • Indicated specific NO x raw emissions at full load in the entire speed range are less than 1 g/kWh. • Indicated thermal efficiency map is similar to that of the series diesel engine. • Minimum modifications to the series diesel engine hardware. [ABSTRACT FROM AUTHOR]

Molecular hydrogen is a promising energy carrier and the best potential alternative for environment-damaging fossil fuels. Hydrogen as a secondary clean energy can lead to the development of fuel cell technology. Hydrogen transportation is highly costly due to its low volumetric energy density at ambient temperature and pressure. However, reactive hydrogen can be electrochemically generated in the solid state and occurs either as a surface-adsorbed or lattice-settled species. Herein, the mesoporous structures of LiMn 2 O 4 and NiMn 2 O 4 were prepared by using Aleo Vera extract as a complexing agent. The samples were characterized by various techniques to determine their crystal structures, surface morphology, and porosity. Electrochemical hydrogen storage abilities and the specific capacitance values of as-prepared mixed metal manganese oxides were measured in the 2 M KOH electrolyte solution. The results showed that LiMn 2 O 4 and NiMn 2 O 4 nanoparticles have an excellent specific capacitance of 783 and 552 Fg-1, respectively. The maximum discharge capacities of LiMn 2 O 4 and NiMn 2 O 4 nanoparticles were obtained to be 3605 and 1501 mAh/g after 11 cycles, respectively. The higher and excellent discharge capacity of LiMn 2 O 4 can partially be ascribed to its higher porosity. [Display omitted] • LiMn 2 O 4 and NiMn 2 O 4 nanoparticles were produced using a green method. • The crystalline texture, morphology, and porosity support hydrogen storage abilities. • The discharge capacity of the LiMn 2 O 4 and NiMn 2 O 4 nanoparticles were obtained 3605 and 1501 mAhg−1, respectively. • Promising materials for electrochemical hydrogen storage. [ABSTRACT FROM AUTHOR]

Significant resources and diligent research have been dedicated to the investigation and enhancement of energy storage devices utilising hydrogen, lithium, or sodium. Efforts of this nature strive to offer sustainable energy storage solutions that are both dependable and environmentally friendly. This report presents a review a thorough an examination of the aforementioned technologies, with a particular emphasis on cost-effectiveness and State of Charge (SoC) administration. Furthermore, it comprehensively assesses their specific advantages and downsides. Sodium-based systems, such as sodium-sulfur batteries, exhibit remarkable stability and efficiency in sustaining desired charge levels, starting from the control of SoC. Lithium-based alternatives, such as Lithium-ion batteries (LIBs) have gained extensive usage adopted in several industries because to their enhanced energy density and improved SoC accuracy. The complexity associated with SoC is a challenge for hydrogen-based systems, including hydrogen fuel cells, due to their dependence on gas storage and conversion techniques. The assessment places significant emphasis on cost analysis, which evaluates the economic feasibility of each storage method. Sodium-based systems, known for their well-established technology and ample availability of raw materials, frequently present a financially viable option, especially for large-scale grid implementations. The pricing of lithium-based systems, particularly in the domains of portable devices and electric cars, is competitive because to their quick improvements and decreasing costs. Hydrogen-based systems, despite their initial expensive capital expenditure, exhibit potential through continuous advancements and the expansion of production capacity. [ABSTRACT FROM AUTHOR]

This study focuses on overview and general economic viability evaluation of four types of portable electric generators: diesel and petrol internal combustion engines, batteries/accumulators and inverter systems (especially lithium polymer and lithium-ion battery systems), hydrogen fuel cell systems and combination (hybrid) of the latter. It does not include the rarely used, inefficient forms of energy conversion, such as steam turbines, as well as energy generators that are difficult to adjust with consumption and supply variations (variable forms of RES like wind and solar energy). The main targets of the study are battery/inverter systems, hydrogen fuel cell systems, and hybrid battery/inverter and hydrogen fuel cell systems, with hydrogen fuel cell systems being the thematic core. [ABSTRACT FROM AUTHOR]

Fuel cell vehicles are considered as the direct alternative to fuel vehicles due to their similar driving range and refueling time. The United Nations World Forum for Harmonization of Vehicle Regulations (UN/WP29) released the Global Technical Regulation on Hydrogen and Fuel Cell Vehicles (GTR13) in July 2013, which was the first international regulation in the field of fuel cell vehicles. There exist some differences between GTR13 and the existing safety technical specifications and standards in China. This paper studied the safety requirements of the GTR13 compressed hydrogen storage system, analyzed the current hydrogen storage safety standards for fuel cell vehicles in China, and integrated the advantages of GTR13 to propose relevant suggestions for future revision of hydrogen storage standards for fuel cell vehicle in China. [ABSTRACT FROM AUTHOR]