Publications

In this study the annual electricity consumption of nine real houses from different cities in Türkiye was recorded on a monthly basis. The feasibility of meeting the electrical energy needs of houses with hydrogen and supplying the energy required for hydrogen production using solar panels is examined. The annual electricity consumption of the houses was normalized based on house size. The solar panel area for hydrogen production needed for these houses was defined. Additionally it was calculated that the average volumetric amount of hydrogen produced per hour during peak sun hours in the investigated cities was 1 m3/h. This approach reduced the solar panel area for hydrogen production by a factor of 1.7.

As the consequences of global warming become more severe it is more crucial than ever to capitalize on all locally accessible potential renewable energy sources and produce sufficient useable energy outputs to meet community demands while causing the least damage to the ecosystem. Therefore this paper focuses on a unique parabolic trough collector solar systempowered electro-biomembrane unit that combines a heat and power system with fresh water electricity and hydrogen (H2) production. The proposed integrated system contains the following subsystems: a combining parabolic trough collector solar system an organic Rankine cycle a steam Rankine cycle a multi-stage flash desalination system and an electro-biomembrane H2 and freshwater production system. A thorough analysis and parametric research are performed on the multigeneration system to determine how important characteristics affect system performance and evaluate the energy and exergy efficiency and exergy destruction levels for particular system elements. The study results show that solar irradiation is the most critical parameter for improving system performance. The highest freshwater production of 1303333.3 L/day is observed at the solar irradiation of 935768 kWh/day. Furthermore the combined output of three electricity production technologies exceeds 2000000 kWh/day highlighting the ability of the system to harness solar thermal energy effectively. The findings indicate that using solar power and biomass as renewable energy sources the proposed integrated system provided 328.56 kg of biohydrogen per day. Overall the energy and exergy efficiencies of the integrated system are obtained at 34.3 and 29.5 % respectively.

Hydrogen production via water splitting is a crucial strategy for addressing the global energy crisis and promoting sustainable energy solutions. This review systematically examines water-splitting mechanisms with a focus on photocatalytic and electrochemical methods. It provides in-depth discussions on charge transfer reaction kinetics and key processes such as the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Various electrode synthesis techniques including hydrothermal methods chemical vapor deposition (CVD) pulsed laser deposition (PLD) and radio frequency sputtering (RF) are reviewed for their advantages and limitations. The role of carbon-based materials such as graphene biochar and graphitic carbon nitride (g-C3N4) in photocatalytic and photoelectrochemical (PEC) water splitting is also highlighted. Their exceptional conductivity tunable band structures and surface functionalities contribute to efficient charge separation and enhanced light absorption. Further advancements in heterojunctions doped systems and hybrid composites are explored for their ability to improve photocatalytic and PEC performance by minimizing charge recombination optimizing electronic structures and increasing active sites for hydrogen and oxygen evolution reactions. Key challenges including material stability cost scalability and solar spectrum utilization are critically analyzed along with emerging strategies such as novel synthesis approaches and sustainable material development. By integrating water splitting mechanisms electrode synthesis techniques and advancements in carbon-based materials this review provides a comprehensive perspective on sustainable hydrogen production bridging previously isolated research domains.

This article discusses the planning sizing and placement of a vehicle refueling station supplied by renewable energy systems including photovoltaic wind biomass units and an integrated battery system within a smart distribution network. The proposed station comprises facilities for hydrogen fueling and electric vehicle charging stations structured as a bi-level optimization approach. The upper-level model focuses on the planning phase of the refueling station. Its objective is to minimize annual costs associated with construction maintenance and operation. Key constraints involve operational planning for renewable sources battery systems and vehicle refueling stations while accounting for reactive power management. In contrast the lower-level formulation deals with the eco-scheduling of smart distribution grid. Its goal is to minimize the sum of annual energy losses and operation costs within the grid governed by linearized optimal power flow model. To account for uncertainties in demand energy prices renewable generation output and refueling station performance a stochastic optimization framework is employed. The solution is derived using Benders decomposition algorithm to achieve optimal results. The primary innovation highlighted in this paper includes integrating renewable resources and battery systems to power the refueling station leveraging reactive power control for improved station performance and addressing both operational and economic objectives in the distribution system. Numerical results underscore the advantages of this strategy. Constructing a refueling station without battery and renewable units leads to significant drawbacks an increase in network operation cost by 144.6% and grid energy loss by 167.6%. Voltage levels drop below 0.9 per-unit and distribution lines experience severe loading of up to 34.7%. In contrast the proposed plan enhances network economics by 51.3%-74.5% and operational conditions by 17.7%-148.1% effectively showcasing the benefits of incorporating sustainable technologies and advanced planning methods into refueling station development.

Decreasing prices of renewable energy sources (RES) like wind and solar in recent years have led to numerous studies on the optimal design of RES for hydrogen production in an off-grid system. RES are intermittent and vary from year to year. Yet most of the studies still consider only a random single weather year for system design often ignoring the impact of input weather data on system design and its performance. This study evaluates for a gaseous hydrogen system the impact of input weather data on optimal system design system reliability and system costs. Random single-year averaged and multiple years of weather data from 1994 to 2021 are considered. Further multiple years of weather data are considered using a novel method of near-optimal solutions and a maximum of near-optimal solutions. The results show that using the maximum of near-optimal solutions method improves system reliability by as much as 96 % when used in other weather years. The system costs are reduced to 0.1 €/kgH2 in other weather years at the expense of an oversized system design. Meanwhile a wind-to-hydrogen system (WHS) designed using randomly selected single-year weather data results in a significantly undersized system with lower reliability (3.5 %) and higher cost variability (up to 4.7 €/kgH2) in other weather years. On the other hand averaging the weather data smoothens the weather fluctuations and always results in a WHS design with lower reliability and higher cost variability than a WHS designed using multi-year weather data values. The results reveal that the size of input weather dataset significantly impacts the system design and its performance. The maximum of near-optimal solutions method proposed in this study provided significantly lower computational time with improved system performance (reliability and cost variability) in comparison to solving the WHS using multiple years of weather data outright.

This paper presents a comprehensive SWOT (strengths weaknesses opportunities and threats) analysis of utilizing hydrogen as a renewable fuel of non-biological origin (RFNBO) in Poland’s energy transition. Given Poland’s reliance on fossil fuels its deep decarbonization poses socio-economic and infrastructural challenges. This study examines the strengths weaknesses opportunities and threats associated with integrating hydrogen as an RFNBO fuel into Poland’s energy mix focusing on economic regulatory technological and social factors. The strengths identified include potential energy independence from fossil fuels increased investment and hydrogen’s applicability in hard-to-abate sectors. Weaknesses involve a low share of renewable hydrogen in the energy mix and the need for infrastructure development. Opportunities arise from European Union policies technological advancements and global trends favoring renewable hydrogen adoption. Threats encompass high production costs regulatory uncertainties and competition from other energy carriers. The analysis concludes that while hydrogen as an RFNBO fuel offers potential for decarbonizing Poland’s energy mix realizing this potential requires large-scale investments a supportive regulatory framework and technological innovation.

Transitioning from fossil fuels to renewable energies is imperative for Germany to reduce CO2 emissions and achieve greenhouse gas neutrality by 2045. Green hydrogen holds great potential to contribute to this energy transition by enabling the storage of surplus renewable energy. However Germany's green hydrogen production industry is still in its infancy with only a few green hydrogen plants existing. Studies examining the public's acceptance of green hydrogen production are scarce in this context. Still high societal acceptance can contribute to the future expansion of green hydrogen production in Germany in terms of speed and volume. Therefore our study aims to identify significant factors influencing the German population's acceptance of green hydrogen production within various acceptance groups with differing preferences for future green hydrogen production systems. We conducted an online survey (n=1203) in Germany in 2022/2023 incorporating a choice experiment. Through subsequent latent class analysis four acceptance groups with distinct preferences regarding local green hydrogen production were identified: Unconvinced citizens Security-conscious citizens Regional electricity consumers and Financial beneficiaries. A discriminant analysis identified 9 out of 11 factors as significant for distinguishing between these acceptance groups regarding their preferences for local green hydrogen production: trust in plant safety trust in project managers risk/benefit perception environmental self-identity negative attitude towards renewable energies positive attitude towards renewable energies emotions age and gender. However no significant effects were observed for experience with green hydrogen and distance to the place of residence. Based on our results it is recommended that required renewable energy for green hydrogen production should be produced as close to the green hydrogen plants as possible. It must be ensured and communicated to the public that the (planned) green hydrogen plants meet high safety standards and pose a very low risk of fire or explosion. The neighbouring population should also benefit through annual heating cost savings and financial participation. Implementing these measures can increase acceptance of local green hydrogen production facilitating the transition towards a more sustainable energy future in Germany and beyond.

A composite hydrogen storage vessel (CHSV) is one key component of the hydrogen fuel cell vehicle which always suffers random vibration during transportation resulting in fatigue failure and a reduction in service life. In this paper firstly the free and constrained modes of CHSV are experimentally studied and numerically simulated. Subsequently the random vibration simulation of CHSV is carried out to predict the stress distribution while Steinberg’s method and Dirlik’s method are used to predict the fatigue life of CHSV based on the results of stress distribution. In the end the optimization of ply parameters of the composite winding layer was conducted to improve the stress distribution and fatigue life of CHSV. The results show that the vibration pattern and frequency of the free and constrained modes of CHSV obtained from the experiment tests and the numerical predictions show a good agreement. The maximum difference in the value of the vibration frequency of the free and constrained modes of CHSV from the FEA and experiment tests are respectively 8.9% and 8.0% verifying the accuracy of the finite element model of CHSV. There is no obvious difference between the fatigue life of the winding layer and the inner liner calculated by Steinberg’s method and Dirlik’s method indicating the accuracy of FEA of fatigue life in the software Fe-safe. Without the optimization the maximum stresses of the winding layer and the inner liner are found to be near the head section by 469.4 MPa and 173.0 MPa respectively and the numbers of life cycles of the winding layer and the inner liner obtained based on the Dirlik’s method are around 1.66 × 106 and 3.06 × 106 respectively. Through the optimization of ply parameters of the composite winding layer the maximum stresses of the winding layer and the inner liner are reduced by 66% and 85% respectively while the numbers of life cycles of the winding layer and the inner liner both are increased to 1 × 107 (high cycle fatigue life standard). The results of the study provide theoretical guidance for the design and optimization of CHSV under random vibration.

Geological storage is an integral element of the green energy transition. Geological formations such as aquifers depleted reservoirs and hard rock caverns are used mainly for the storage of hydrocarbons carbon dioxide and increasingly hydrogen. However potential adverse effects such as ground movements leakage seismic activity and environmental pollution are observed. Existing research focuses on monitoring subsurface elements of the storage while on the surface it is limited to ground movement observations. The review was carried out based on 191 research contributions related to geological storage. It emphasizes the importance of monitoring underground gas storage (UGS) sites and their surroundings to ensure sustainable and safe operation. It details surface monitoring methods distinguishing geodetic surveys and remote sensing techniques. Remote sensing including active methods such as InSAR and LiDAR and passive methods of multispectral and hyperspectral imaging provide valuable spatiotemporal information on UGS sites on a large scale. The review covers modelling and prediction methods used to analyze the environmental impacts of UGS with data-driven models employing geostatistical tools and machine learning algorithms. The limited number of contributions treating geological storage sites holistically opens perspectives for the development of complex approaches capable of monitoring and modelling its environmental impacts.

The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen if produced efficiently can play a pivotal role in decarbonizing the global energy systems. Therefore this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA) with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria including capital cost feedstock cost O&M cost hydrogen production and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally slack-based DEA computed the efficiency of alternatives. Among the 11 three alternatives (wind electrolysis PV electrolysis and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.

The net zero emissions policy represents a crucial component of the global initiative to address climate change. The European Union has set a target of achieving net zero greenhouse gas emissions by 2050. This study assesses Poland’s feasibility of achieving net zero emissions. Currently Poland relies on fossil fuels for approximately 71% of its electricity generation with electricity accounting for only approximately 16% of the country’s total final energy consumption. Accordingly the transition to net zero carbon emissions will necessitate significant modifications to the energy system particularly in the industrial transport and heating sectors. As this is a long-term process this article demonstrates how the development of renewable energy sources will progressively necessitate the utilisation of electrolysers in line with the ongoing industrial transformation. A new framework for the energy system up to 2060 is presented with transition phases in 2030 2040 and 2050. This study demonstrates that it is feasible to attain a sustainable zero-emission and stable energy system despite reliance on uncontrolled and weather-dependent energy sources. Preparing the electricity grid to transmit almost three times the current amount represents a significant challenge. The resulting simulation capacities comprising 64 GW of onshore wind 33 GW of offshore wind 136 GW of photovoltaic 10 GW of nuclear and 22 GW of electrolysers enable a positive net energy balance to be achieved under the weather conditions observed between 2015 and 2023. To guarantee system stability electrolysers must operate within a centralised framework functioning as centrally controlled dispatchable load units.

In order to determine thermally safe driving parameters of ignition coils for hydrogen internal combustion engines (ICE) a reliable estimation of internal power losses is essential. These losses include resistive winding losses magnetic core losses due to hysteresis and eddy currents dielectric losses in the insulation and electronic switching losses. Direct experimental assessment is difficult because the components are inaccessible while conventional computer-aided engineering (CAE) approaches face challenges such as the need for accurate input data the need for detailed 3D models long computation times and uncertainties in loss prediction for complex structures. To address these limitations we propose an artificial intelligence (AI)-based framework for estimating internal losses from external temperature measurements. The method relies on an artificial neural network (ANN) trained to capture the relationship between external coil temperatures and internal power losses. The trained model is then employed within an optimization process to identify losses corresponding to experimental temperature values. Validation is performed by introducing the identified power losses into a CAE thermal model to compare predicted and experimental temperatures. The results show excellent agreement with errors below 3% across the −30 ◦C to 125 ◦C range. This demonstrates that the proposed hybrid ANN–CAE approach achieves high accuracy while reducing experimental effort and computational demand. Furthermore the methodology allows for a straightforward determination of the coil safe operating area (SOA). Starting from estimates derived from fitted linear trends the SOA limits can be efficiently refined through iterative verification with the CAE model. Overall the ANN–CAE framework provides a robust and practical tool to accelerate thermal analysis and support coil development for hydrogen ICE applications.

This article provides an overview of the requirements for a grid-oriented integration of hydrogen energy storage (HES) and components into the power grid. Considering the general definition of HES and the possible components this paper presents future hydrogen demand electrolysis performance and storage capacity. These parameters were determined through various overall system studies aiming for climate neutrality by the year 2045. In Germany the targeted expansion of renewable energy generation capacity necessitates grid expansion to transport electricity from north to south and due to existing grid congestions. Therefore electrolysis systems could be used to improve the integration of renewable energy systems by reducing energy curtailment and providing grid services when needed. Currently however there are hardly any incentives for a grid-friendly allocation and operation of electrolysis or power-to-gas plants. Two possible locations for hydrogen plants from two current research projects HyCavMobil (Hydrogen Cavern for Mobility) and H2-ReNoWe (Hydrogen Region of north-western Lower Saxony) are presented as practical examples. Using power grid models the integration of electrolysis systems at these locations in the current high and extra-high voltage grid is examined. The presented results of load flow calculations assess power line utilization and sensitivity for different case scenarios. Firstly the results show that power lines in these locations will not be overloaded which would mean an uncritical operation of the power grid. While the overall grid stability remains unaffected in this case selecting suitable locations is vital to prevent negative effects on the local grid.

Hydrogen is a promising candidate for addressing environmental challenges in aviation yet its use in structural validation tests for Wing Structure-Integrated highpressure Hydrogen Tanks (SWITHs) remains underexplored. To the best of the authors’ knowledge this study represents the first attempt to assess the feasibility of conducting such tests with hydrogen at aircraft scales. It first introduces hydrogen’s general properties followed by a detailed exploration of the potential hazards associated with its use substantiated by experimental and simulation results. Key factors triggering risks such as ignition and detonation are identified and methods to mitigate these risks are presented. While the findings affirm that hydrogen can be used safely in aviation if responsibly managed they caution against immediate large-scale experimental testing of SWITHs due to current knowledge and technology limitations. To address this a roadmap with two long-term objectives is outlined as follows: first enabling structural validation tests at scales equivalent to large aircraft for certification; second advancing simulation techniques to complement and eventually reduce reliance on costly experiments while ensuring sufficient accuracy for SWITH certification. This roadmap begins with smaller-scale experimental and numerical studies as an initial step.

The adoption of hydrogen fuel cell vehicles (HFCVs) is essential for achieving sustainable low-carbon transportation but many barriers hinder this transition. Therefore this study aims to identify categorize and prioritize these barriers in the context of the Gulf-Europe corridor also known as the Iraq Development Road Project (DRP). To achieve this we adopt a two-stage methodological framework that integrates the Fuzzy Analytical Hierarchy Process (Fuzzy AHP) to quantify the relative importance of thirty secondary barriers and Interpretive Structural Modeling (ISM) to explore the interdependencies among the top ten. The Fuzzy AHP results highlight technological economic and infrastructure-related barriers as the most critical primary barriers. The ISM analysis further reveals that three barriers lack of hydrogen production hubs limited hydrogen transport options and hydrogen storage and transportation are independent. Six barriers fuel cell efficiency and durability hydrogen production and distribution costs vehicle range and refueling time infrastructure investment refueling station compatibility issues and hydrogen purity requirements are classified as linkage barriers. One barrier high initial vehicle cost is found to be dependent. To accelerate HFCVs adoption we recommend strengthening hydrogen infrastructure fostering technological innovation reducing costs through targeted incentives and enhancing policy coordination among stakeholders and policymakers. This study contributes to literature by offering a comprehensive understanding of the adoption barriers and providing actionable insights to support the development of more effective strategies. Notably it uniquely addresses social logistical and technological barriers alongside geographic barriers that have been largely overlooked in previous studies.

Oceanic energy such as offshore wind energy and various marine energy sources holds signifi cant potential for generating green hydrogen through water electrolysis. Offshore-generated hydrogen has the potential to be transported through standard pipelines and stored in diverse forms. This aids in mitigating the variability of renewable energy sources in power generation and consequently holds the capacity to reshape the framework of electrical systems. This research provides a comprehensive review of the existing state of investigation and technological advancement in the domain of offshore wind energy and other marine energy sources for generating green hydrogen. The primary focus is on technical economic and environmental is sues. The technology’s optimal features have been pinpointed to achieve the utmost capacity for hydrogen production providing insights for potential enhancements that can propel research and development efforts forward. The objective of this study is to furnish valuable information to energy companies by pre senting multiple avenues for technological progress. Concurrently it strives to expand its tech nical and economic outlook within the clean fuel energy sector. This analysis delivers insights into the best operating conditions for an offshore wind farm the most suitable electrolyzer for marine environments and the most economical storage medium. The green hydrogen production process from marine systems has been found to be feasible and to possess a reduced ecological footprint compared to grey hydrogen production.

This study investigates the performance of an online hydrogen quality analyzer (HQA) integrated with gas chromatography with a pulsed discharge helium ionization detector (GC-PDHID) and a dew point transmitter (DPT) for real-time monitoring at a hydrogen production plant (HPP). The HQA measures impurities such as O2 N2 H2O CO CO2 and CH4. Over two months of monitoring O2 and H2O concentrations consistently exceeded ISO 14687 thresholds even without calibration or maintenance events suggesting potential leaks or inefficiencies in the hydrogen production process. The study highlights the importance of real-time monitoring in ensuring hydrogen fuel quality and improving the efficiency of hydrogen production and distribution. While the HQA does not detect all impurities specified in ISO 14687 focusing on key indicators mitigates the limitations of offline methods. The findings emphasize the need to update ISO standards to include guidance for online monitoring technologies to meet evolving purity requirements.

The current research critically evaluates the technical economic and environmental performance of a Power-toLiquid (PtL) system for the production of sustainable aviation fuel (SAF). This SAF production system comprises a direct air capture (DAC) unit an off-shore wind farm an alkaline electrolyser and a refinery plant (reverse water gas shift coupled with a Fischer-Tropsch reactor). The calculated carbon conversion efficiency hydrogen conversion efficiency and Power-to-liquids efficiency are 88 % 39.16 % and 25.6 % respectively. The heat integration between the refinery and the DAC unit enhances the system’s energy performance while water integration between the DAC and refinery units and the electrolyser reduces the demand for fresh water. The economic assessment estimates a minimum jet fuel selling price (MJSP) of 5.16 £/kg. The process is OPEX intensive due to the electricity requirements while the CAPEX is dominated by the DAC unit. A Well-to-Wake (WtWa) life cycle assessment (LCA) shows that the global warming potential (GWP) equals 21.43 gCO2eq/ MJSAF and is highly dependent on the upstream emissions of the off-shore wind electricity. Within a 95 % confidence interval a stochastic Monte Carlo LCA reveals that the GWP of the SAF falls below the UK aviation mandate treshold of 50 % emissions reduction compared to fossil jet fuel. Moreover the resulting WtWa water footprint is 0.480 l/MJSAF with the refinery’s cooling water requirements and the electricity’s water footprint to pose as the main contributors. The study concludes with estimating the required monetary value of SAF certificates for different scenarios under the UK SAF mandate guidelines.

Numerical simulations reveal the combustion dynamics of hydrogen-blended natural gas (H-BNG) in semi-open spaces. In the typical semi-open space scenario increasing the hydrogen blending ratio from 0% to 60% elevates peak internal pressure by 107% (259.3 kPa → 526.0 kPa) while reducing pressure rise time by 56.5% (95.8 ms → 41.7 ms). A vent size paradox emerges: 0.5 m openings generate 574.6 kPa internal overpressure whereas 2 m openings produce 36.7 kPa external overpressure. Flame propagation exhibits stabilized velocity decay (836 m/s → 154 m/s 81.6% reduction) at hydrogen concentrations ≥30% within 2–8 m distances. In street-front restaurant scenarios 80% H-BNG leaks reach alarm concentration (0.8 m height) within 120 s with sensor response times ranging from 21.6 s (proximal) to 40.2 s (distal). Forced ventilation reduces hazard duration by 8.6% (151 s → 138 s) while door status shows negligible impact on deflagration consequences (412 kPa closed vs. 409 kPa open) maintaining consistent 20.5 m hazard radius at 20 kPa overpressure threshold. These findings provide crucial theoretical insights and practical guidance for the prevention and management of H-BNG leakage and explosion incidents.

This study evaluates the techno-economic feasibility of solar-based green hydrogen potential for off-grid and utility-scale systems in Niger. The geospatial approach is first employed to identify the area available for green hydrogen production based on environmental and socio-technical constraints. Second we evaluate the potential of green hydrogen production using a geographic information system (GIS) tool followed by an economic analysis of the levelized cost of hydrogen (LCOH) for alkaline and proton exchange membrane (PEM) water electrolyzers using fresh and desalinated water. The results show that the electricity generation potential is 311617 TWh/year and 353166 TWh/year for off-grid and utility-scale systems. The hydrogen potential using PEM (alkaline) water electrolyzers is calculated to be 5932 Mt/year and 6723 Mt/year (5694 Mt/year and 6454 Mt/year) for off-grid and utility-scale systems respectively. The LCOH production potential decreases for PEM and alkaline water electrolyzers by 2030 ranging between 4.72–5.99 EUR/kgH2 and 5.05–6.37 EUR/kgH2 for off-grid and 4.09–5.21 EUR/kgH2 and 4.22–5.4 EUR/kgH2 for utility-scale systems.

The study focuses on the deployment of renewable and low-carbon gases in the Baltic Energy Market Interconnection Plan (BEMIP) region focusing on the 8 BEMIP Member States (Denmark Estonia Finland Germany Latvia Lithuania Poland and Sweden). The report 1) assesses the economic and technical potential supply as well as demand for renewable and low-carbon gases in the BEMIP region; 2) maps current supply infrastructure and demand policies and measures; 3) documents existing technical safety and economic barriers for the development of infrastructure for the integration of biomethane and hydrogen; 4) identifies the hydrogen and methane infrastructure needs to facilitate the integration of renewable and low-carbon gases in the region; and 5) provides recommendations to address identified challenges.

With the rising demand for renewable hydrogen as an alternative sustainable fuel efficient transport strategies have become essential particularly for regional and small-scale applications. While most previous studies focus on the long-distance transport of hydrogen little attention has been given to the application in regions that are remote from major transmission infrastructure. This study evaluates the techno-economic performance of hydrogen road transport using multiple-element hydrogen gas containers and compares it with multimodal transport using rail. The comparison is performed for the southeastern region of the Czech Republic. The comprehensive techno-economic assessment incorporates detailed technical evaluations precise fuel and energy consumption calculations and realworld infrastructure planning to enhance accuracy. Results showed that multimodal transport of hydrogen can significantly reduce the cost for distances exceeding 90 km. The cost is calculated based on annual vehicle utilization assuming the remaining utilization will be allocated to other tasks throughout the year. However the cost-effectiveness of rail transportation is influenced by track capacity limits and possible delays. Additionally this study highlights the crucial role of regional logistics hubs in optimizing transport modes further reducing costs and improving efficiency

Located in the Arabian Gulf Kuwait is a renewable-abundant country ideal for producing hydrogen via solar energy (green hydrogen). With a global transition away from fossil fuels underway due to their adverse environmental impacts hydrogen is gaining significant traction as a promising clean energy alternative for the transport sector. Despite this there are still various challenges associated with implementing a hydrogen supply chain particularly with regard to the conflicting objectives of minimising cost environmental impact and risk. This study determines the feasibility of implementing a green hydrogen supply chain in Kuwait based on a multiobjective design to determine which combination of production (electrolysis type) storage method and transportation method is the most optimal for Kuwait. Three objective functions were considered in this study: the hydrogen supply chain cost environmental impact and safety/risk. A mathematical formulation based on mixed integer linear programming (MILP) was used involving a multi-criteria approach where the three considered objectives must be optimised simultaneously i.e. cost global warming potential and safety/risk. The multiobjective optimisation approach via the weighted sum method was applied in this study and solved via GAMS. To account for the ranking of multi-objective criteria a hybrid AHP-TOPSIS approach was used. Results showed that medium and high demand scenarios better reflect the comparative advantages of each considered method in terms of their multi-objective trade-offs. In particular it was found that higher hydrogen demand amplifies the impact of higher efficiency and operational savings within several production storage and transportation methods and that despite higher initial capital investments these costs are at some point offset by superior operational efficiency as hydrogen production volumes increase. Conversely using highly efficient electrolysers or transportation methods at low demand was found to limit their performance.

A comprehensive literature review highlights how the nature of active metals support materials promoters and synthesis methods influences catalytic performance with particular attention to ruthenium-based catalysts as the current benchmark. Kinetic models are presented to describe the reaction pathway and predict catalyst behavior. Various reactor configurations including fixed-bed membrane catalytic membrane perovskitebased and microreactors are evaluated in terms of their suitability for ammonia decomposition. While ruthenium remains the benchmark catalyst alternative transition metals such as iron nickel and cobalt have also been investigated although they typically require higher operating temperatures (≥500 °C) to achieve comparable conversion levels. At the industrial scale catalyst development must balance performance with cost. Inexpensive and scalable materials (e.g. MgO Al2O3 CaO K Na) and simple preparation techniques (e.g. wet impregnation incipient wetness) may offer lower performance than more advanced systems but are often favored for practical implementation. From a reactor engineering standpoint membrane reactors emerge as the most promising technology for combining catalytic reaction and product separation in a single unit operation. This review provides a critical overview of current advances in ammonia decomposition for hydrogen production offering insights into both catalytic materials and reactor design strategies for sustainable energy applications.

Hydrogen-fueled internal combustion engines present a promising pathway for reducing carbon emissions in urban transportation by allowing for the reuse of existing vehicle platforms while eliminating carbon dioxide emissions from the exhaust. However operating these engines with lean air–fuel mixtures—necessary to reduce nitrogen oxide emissions and improve thermal efficiency—leads to significant reductions in power output due to the low energy content of hydrogen per unit volume and slower flame propagation. This study investigates whether integrating a mild hybrid electric system operating at 48 volts can mitigate the performance losses associated with lean hydrogen combustion in a small passenger vehicle. A complete simulation was carried out using a validated one-dimensional engine model and a full zero-dimensional vehicle model. A Design of Experiments approach was employed to vary the electric motor size (from 1 to 15 kW) and battery capacity (0.5 to 5 kWh) while maintaining a fixed system voltage optimizing both the component sizing and control strategy. Results showed that the best lean hydrogen hybrid configuration achieved reductions of 18.6% in energy consumption in the New European Driving Cycle and 5.5% in the Worldwide Harmonized Light Vehicles Test Cycle putting its performance on par with the gasoline hybrid benchmark. On average the lean H2 hybrid consumed 41.2 kWh/100 km nearly matching the 41.0 kWh/100 km of the gasoline P0 configuration. Engine usage analysis demonstrated that the mild hybrid system kept the hydrogen engine operating predominantly within its high-efficiency region. These findings confirm that lean hydrogen combustion when supported by appropriately scaled mild hybridization is a viable near-zero-emission solution for urban mobility— delivering competitive efficiency while avoiding tailpipe CO2 and significantly reducing NOx emissions all with reduced reliance on large battery packs.

This study presents a holistic technoeconomic analysis of solar photovoltaic-based green hydrogen production facilities assessing hydrogen output potential and cost structures under various facility configurations. Four system cases are defined based on the inclusion of new photovoltaic (PV) panels and hydrogen storage (HS) subsystems considering Southern Ontario solar data and a 30-year operational lifespan. Through a system level modeling we incorporate the initial costs of sub-systems (PV panels power conditioning devices electrolyser battery pack and hydrogen storage) operating and maintenance expenses and replacement costs to determine the levelized cost of hydrogen (LCOH). The results of this study indicate that including hydrogen storage significantly impacts optimal electrolyser sizing creating a production bottleneck around 400 kW for a 1 MWp PV system (yielding approximately 590 tons H2 over a period of 30 years) whereas systems without storage achieve higher yields (about 1080 tons of H2) with larger electrolysers (approximately 620 kW). The lifetime cost analysis reveals that operating and maintenance cost constitutes the dominant expenditure (68–76 %). Including hydrogen storage increases the minimum LCOH and sharply penalizes electrolyser oversizing relative to storage capacity. For a 1 MWp base system minimum LCOH ranged from approximately $3.50/kg (existing PV no HS) to $6/kg (existing PV with HS) $11–12/kg (new PV no HS) and $22–25/kg (new PV with HS). Leveraging existing PV infrastructure drastically reduces LCOH. Furthermore significant economies of scale are observed with increasing PV facility capacity potentially lowering LCOH below $2/kg at the 100 MWp scale. The study therefore underscores that there is a critical interplay between system configuration component sizing operating and maintenance management and facility scale in determining the economic viability of solar hydrogen production.

This review thoroughly examines the potential of water ultrasonication (US) for producing hydrogen. First it discusses ultrasonication reactor designs and techniques for measuring ultrasonication power and optimizing energy. Then it explores the results of hydrogen production via ultrasonication experiments focusing on the impact of processing factors such as ultrasonication frequency acoustic intensity dissolved gases pH temperature and static pressure on the process. Additionally it examines advanced ultrasonication techniques such as US/photolysis US/catalysis and US/photocatalysis emphasizing how these techniques could increase hydrogen production. Lastly to progress the efficacy and scalability of hydrogen generation through ultrasonication the review identifies existing challenges proposes solutions and suggests areas for future research.

Rapid socio-economic development has made energy application and environmental issues increasingly prominent. Hydrogen energy clean eco-friendly and highly synergistic with renewable energy has become a global research focus. This study using the EnergyPLAN model that includes the electricity transportation and industrial sectors takes Jinan City as the research object and explores how hydrogen penetration changes affect the decarbonization path of the urban integrated energy system under four scenarios. It evaluates the four hydrogen scenarios with the entropy weight method and technique placing them in an order of preference according to their similarity to the ideal solution considering comprehensive indicators like cost carbon emissions and sustainability. Results show the China Hydrogen Alliance potential scenario has better CO2 emission reduction potential and unit emission reduction cost reducing them by 7.98% and 29.39% respectively. In a comprehensive evaluation it ranks first with a score of 0.5961 meaning it is closest to the ideal scenario when cost environmental and sustainability indicators are comprehensively considered. The Climate Response Pioneer scenario follows with 0.4039 indicating that higher hydrogen penetration in terminal energy is not necessarily the most ideal solution. Instead appropriate hydrogen penetration scenarios should be selected based on the actual situation of different energy systems.

As hydrogen products emerge as a promising energy alternative in multiple sectors low carbon hydrogen supply chains require concerted efforts among a diverse array of stakeholders. Within an evolving energy transition landscape stakeholders’ competition and cooperation play a critical role in expediting the deployment of the hydrogen economy. In this review different strategies referred to as Hydrogen Competition Cooperation and Coopetition (H2CCC) dynamics are analyzed from the lenses of game theory. The study employs hybrid literature review methodology integrating both bibliometric and structured review approaches. The study reveals that competition and cooperation represent a contrasting but interconnected dynamics that drive the energy transition. Coopetition models are less common. Furthermore it is observed that Integrated Energy Systems are mainly used in cooperative and coopetitive approaches while H2 technologies and Hydrogen Supply Chains are more explored in competitive approaches. Industrial and mobility sectors are present in H2CCC dynamics with technological players more present than institutional entities. Maps definitions gaps and perspectives are developed. These insights may be valuable for policymakers industry stakeholders modelers and researchers. There remains a need for further empirical H2CCC case studies and applications of pure coopetitive games.

Hydrogen-based greenhouse gas (GHG) mitigation strategies can have multi-sector benefits and are considered necessary to reach net-zero emissions by 2050. Assessments of hydrogen scale-up have not included long-term implications for water resources. This work aims to fill this knowledge gap through a long-term integrated assessment of the water consumption GHG emissions and costs of conventional and low-carbon hydrogen scenarios to the year 2050. A framework was developed and 120 long-term scenarios were assessed for the large-scale deployment of low-carbon hydrogen in a hydrogen-intensive economy. This study considered 15 different natural gas- and electrolysis-based hydrogen production technologies. A case study for Alberta a western Canadian province and a fossil fuel-intensive region was carried out. The results obtained project a cumulative mitigation of 9 to 162 million tonnes of carbon emissions between 2026 and 2050 through the implementation of low-carbon hydrogen production scenarios compared to the business-as-usual scenario. However cumulative water consumption increases considerably with the large-scale deployment of low-carbon hydrogen reaching 8 to 3815 million cubic meters. The adoption of green hydrogen technologies increases water consumption significantly. Depending on the jurisdiction of analysis and its water bodies this increase may or may not be a long-term issue. Low-carbon hydrogen scenarios start becoming cost-effective as the carbon price rises to $170/tCO2e. The developed integrated framework can be used globally to assess long-term hydrogen implementation with appropriate adjustments in data.

Hydrogen is gaining interest as a clean energy source from both governments and fossil fuel companies. For hydrogen projects to succeed securing public acceptability is crucial with trust in the implementing actors playing a central role. Drawing from reputation management and attribution theory we experimentally evaluated whether people’s perceptions of energy companies wanting to start producing hydrogen for sustainability reasons differ based on two features of hydrogen production. Specifically we examined the influence of (1) the type of hydrogen (blue versus green) and (2) the energy company’s history in energy production (fossil fuels versus renewables) on perceptions about the companies’ reputation management efforts —that is the belief that companies adopt hydrogen primarily to improve their public image— as well as on levels of trust both overall and specifically in terms of integrity and competence. We further explored whether perceived reputation management explains the effects on trust and whether these factors also shape public acceptability of hydrogen production itself. Results indicated that people perceived the company with a history of working with fossil fuels as trying to improve its reputation more than one associated with renewables and trusted it less. Furthermore perceived reputation management explained the lower (general and integrity-based) trust people had in companies with a past in fossil fuels. For public acceptability of hydrogen the company’s history was not relevant with green hydrogen being more acceptable than blue regardless of which company produced it. We discuss these findings in relation to the literature on public perceptions of hydrogen.

The future is bright for hydrogen as a clean mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production storage and conversion and highlights recent commercialization efforts to realize its potential. Also the paper presents selected notable patents issued within the last few years. There is no shortage of inventions and innovations in hydrogen technologies in both academia and industry. While metal hydrides and functionalized carbon-based materials have improved tremendously as hydrogen storage materials over the years storing gaseous hydrogen in underground salt caverns has also become feasible in many commercial projects. Production of “blue hydrogen” is rising as a method of producing hydrogen in large quantities economically. Although electric/battery powered vehicles are dominating the green transport today innovative hydrogen fuel cell technologies are knocking at the door because of their lower refueling time compared to EV charging time. However the highest impact of hydrogen technologies in trans portation might be seen in the aviation industry. Hydrogen is expected to play a key role and provides hope in transforming aviation into a zero-carbon emission transportation over the next few decades.

Green hydrogen is a promising energy vector for replacing fossil fuels in hard-to-abate sectors but its cost hinders widespread deployment. This research develops an exact MILP model to optimize the design of integrated green energy projects minimizing the total annual cost between different power configurations. The model is applied to a case study in regional Victoria Australia which supports a fleet of nine fuel cell electric buses requiring 1160 kg of hydrogen per week. The optimal system includes a 453 kW electrolyzer 212 kg of storage in compressed hydrogen vessels 704 kW of solar PV and 635 kW of wind power firmed with grid electricity. The LCOH is 14.8 A$/kg which is higher than other estimates in the literature for Australia. This is arguably due to the idle capacities resulting from intermittent hydrogen demand. Producing additional hydrogen with surplus or low-priced electricity could reduce LCOH to 12.4 A$/kg. Sensitivity analyzes confirm the robustness of the system to variations in key parameter costs resource availability and estimated energy supply and demand.

Hydrogen internal combustion engines (ICEs) have gained significant attention as a promising solution for achieving zero-carbon emissions in the transportation sector. This study investigates the conversion of a 2 L Diesel ICE into a lean hydrogen-powered ICE focusing on key challenges such as hydrogen mixing pre-ignition combustion flame development and NOx emissions. The novelty of this research lies in the specific modifications made to optimize engine performance and reduce emissions while utilizing the existing Diesel engine infrastructure. The study identifies several important design changes for the successful conversion of a Diesel engine to hydrogen including the following: Intake port design: transitioning from a swirl to a tumble design to enhance hydrogen mixing; Injection and spark plug configuration: using a lateral injection system combined with a central spark plug to improve combustion; Piston design: employing a lenticular piston shape with adaptable depth to enhance mixing; Mitigating Coanda effect: preventing hydrogen issues at the spark plug using deflectors or caps; and Head design: maintaining a flat head design for efficient mixing while ensuring adequate cooling to avoid pre-ignition. These findings highlight the importance of specific modifications for converting Diesel engines to hydrogen providing a solid foundation for further research in hydrogen-powered ICEs which could contribute to carbon emission reduction and a more sustainable energy transition.

Hydrogen has attracted widespread attention due to its zero emissions and high energy density and hydrogen-fueled power systems are gradually emerging. This paper combines the advantages of the high conversion efficiency of fuel cells and strong engine power to propose a hydrogen hybrid energy system architecture based on a mixture of fuel cells and engines in order to improve the conversion efficiency of the energy system and reduce its fuel consumption rate. Firstly according to the topology of the hydrogen hybrid energy system and the circuit model of its core components a state-space model of the hydrogen hybrid energy system is established using the Kirchhoff node current principle laying the foundation for the control and management of hydrogen hybrid energy systems. Then based on the state-space model of the hydrogen hybrid system and Pontryagin’s minimum principle a hydrogen hybrid system management strategy based on adaptive equivalent fuel consumption minimum strategy (A-ECMS) is proposed. Finally a hydrogen hybrid power system model is established using the AVL Cruise simulation platform and a control strategy is developed using matlab 2021b/Simulink to analyze the output power and fuel economy of the hybrid energy system. The results show that compared with the equivalent fuel consumption minimum strategy (ECMS) the overall fuel economy of A-ECMS could improve by 10%. Meanwhile the fuel consumption of the hydrogen hybrid energy system is less than half of that of traditional engines.

The present work aims to develop a uniquely designed experimental test rig for hydrogen (H2) production from hydrogen sulfide (H2S) and perform performance tests. The experimental activity focuses on the FeCl3 hybrid process for H2S cracking followed by H2S absorption sulfur purification and electrolysis for efficient H2 production. Hydrogen production is studied using KOH and FeCl3 electrolytes under varying temperatures between 20-80 ◦C. An electrochemical impedance spectroscopy (EIS) is employed to characterize the electrochemical cell under potentiostatic (0.5-2.0 V) and galvanostatic (0-0.5 mA) modes to analyze the system’s electrochemical response. The study results showed that hydrogen production increased by over 426 % from 20 ◦C to 80 ◦C. EIS analysis under potentiostatic mode showed Nyquist semicircle diameter reduced as the applied voltage increased from 0.5 V to 1.5 V and phase angle shifted from -5.59◦ to -1.27◦ confirming enhanced conductivity. Under galvanostatic mode the impedance dropped from ~25 Ω to ~21 Ω as current increased demonstrating improved kinetics for efficient H2 production.

Effective water management is crucial for the optimal performance and durability of proton exchange membrane fuel cells (PEMFCs) in automotive applications. Conventional techniques like electrochemical impedance spectroscopy (EIS) face challenges in accurately measuring high-frequency resistance (HFR) impedance during dynamic vehicle operations. This study proposes a novel stack water management stability control and vehicle energy control method to address these limitations. Simulation and experimental results demonstrate improved system and powertrain efficiency extended stack lifespan and optimized hydrogen consumption. These findings contribute to advancing robust water management strategies supporting the transition toward sustainable zero-emission fuel cell vehicles.

As the need to reduce Greenhouse Gas (GHG) emissions and dependence on fossil fuels grows new vehicle concepts are emerging as sustainable solutions for urban mobility. Beyond evaluating tailpipe emissions indirect emissions associated with energy and hydrogen production as vehicle manufacturing must be accounted offering a holistic Lifecycle Assessment (LCA) perspective. This study compares Battery Electric Vehicles (BEVs) Fuel Cell Vehicles (FCVs) Hydrogen Internal Combustion Engine Vehicles (H2ICEVs) and hybrid H2ICEVs analyzing energy efficiency and GHG emissions in urban environment across the European Union. Future scenarios (2030 2050) are examined as well with evolving energy mixes and manufacturing impacts. Findings show BEVs as the most efficient configuration with the lowest GHG emissions in 2024 while FCVs become the best option in future scenarios due to greener hydrogen production and improved manufacturing. This study emphasizes the need for tailored strategies to achieve sustainable urban mobility providing insights for policymakers and stakeholders.

The escalating climate crisis and unsustainable waste management practices necessitate integrated approaches that simultaneously address energy security and environmental degradation. Hydrogen with its high energy density and zero-carbon combustion is a key vector for decarbonization; however conventional production methods are fossildependent and carbon-intensive. This systematic review explores biowaste-to-hydrogen (WtH) technologies as dual-purpose solutions converting organic waste to clean hydrogen while reducing greenhouse gas emissions and landfill reliance. A comprehensive analysis of different conversion pathways including thermochemical (gasification pyrolysis hydrothermal and partial oxidation (POX)) biochemical (dark fermentation photofermentation and sequential fermentation) and electrochemical methods (MECs) is presented assessing their hydrogen yields feedstock compatibilities environmental impacts and technological readiness. Systematic literature review methods were employed using databases such as Scopus and Web of Science with strict inclusion criteria focused on recent peerreviewed studies. This review highlights hydrothermal gasification and dark fermentation as particularly promising for wet biowaste streams like food waste. Comparative environmental analyses reveal that bio-based hydrogen pathways offer significantly lower greenhouse gas emissions energy use and pollutant outputs than conventional methods. Future research directions emphasize process integration catalyst development and lifecycle assessment. The findings aim to inform technology selection policymaking and strategic investment in circular low-carbon hydrogen production.

High-temperature electrolysis offers a solution for industry decarbonisation by high-efficiency hydrogen production. This study presents a system based on Solid Oxide Electrolysis Cells (SOEC) fed by photovoltaic and waste heat recovery for hydrogen blending with natural gas in industrial burners. The aim of this work is to assess techno-economic feasibility of the proposed configuration investigating hydrogen blending limits Levelized Cost of Hydrogen (LCOH) and decarbonisation cost. LCOH values below 6 €/kgH2 cannot be achieved at current SOEC costs. The system can be applied without significant burner modifications since maximum hydrogen volumetric fractions are less than 20 %. Higher efficiency and emission reduction potential in comparison to alkaline electrolysers can be achieved but they are offset by higher LCOH and carbon abatement costs. Forthcoming reduction in SOEC costs can improve the cost-effectiveness and high natural gas prices experienced during the energy crisis make the decarbonisation cost competitive with the emission trading system.

Japan and other industrialized countries rely on the import of green hydrogen (H2 ) as they lack the resources to meet their own demand. In contrast countries such as Australia have the potential to produce hydrogen and its derivatives using wind and solar energy. Solar energy can be harnessed to produce electricity using photovoltaic systems or to generate thermal energy by concentrating solar irradiation. Thus thermal and electrical energy can be used in a solid oxide electrolysis process for low-cost hydrogen production. The operation of a solid oxide electrolysis cell (SOEC) stack integrated with solar energy is experimentally investigated and further analyzed using a validated simulation model. Furthermore a techno-economic assessment is conducted to estimate the hydrogen production costs including the expenses associated with liquefaction and transportation from Australia to Japan. High conversion efficiencies and low-cost SOECs are projected to result in production costs below 4 USD/kg.

Against the backdrop of ever‑increasing energy demand and growing awareness of en‑ vironmental protection the research and optimization of hydrogen‑related multi‑energy systems have become a key and hot issue due to their zero‑carbon and clean characteristics. In the scheduling of such multi‑energy systems a typical problem is how to describe and deal with the uncertainties of multiple types of energy. Scenario‑based methods and ro‑ bust optimization methods are the two most widely used methods. The first one combines probability to describe uncertainties with typical scenarios and the second one essentially selects the worst scenario in the uncertainty set to characterize uncertainties. The selection of these scenarios is essentially a trade‑off between the economy and robustness of the so‑ lution. In this paper to achieve a better balance between economy and robustness while avoiding the complex min‑max structure in robust optimization we leverage artificial in‑ telligence (AI) technology to generate enough scenarios from which economic scenarios and feasible scenarios are screened out. While applying a simple single‑layer framework of scenario‑based methods it also achieves both economy and robustness. Specifically first a Transformer architecture is used to predict uncertainty realizations. Then a Gener‑ ative Adversarial Network (GAN) is employed to generate enough uncertainty scenarios satisfying the actual operation. Finally based on the forecast data the economic scenar‑ ios and feasible scenarios are sequentially screened out from the large number of gener‑ ated scenarios and a balance between economy and robustness is maintained. On this ba‑ sis a multi‑energy collaborative optimization method is proposed for a hydrogen‑based multi‑energy microgrid with consideration of the coupling relationships between energy sources. The effectiveness of this method has been fully verified through numerical exper‑ iments. Data show that on the premise of ensuring scheduling feasibility the economic cost of the proposed method is 0.67% higher than that of the method considering only eco‑ nomic scenarios. It not only has a certain degree of robustness but also possesses good economic performance.

Urban transportation systems particularly public buses contribute significantly to global pollution creating an urgent need for sustainable solutions. Alternative fuel buses and other disruptive technological advancements in this field are essential to resolve these problems. The absence of studies on the life cycle assessment (LCA) of hydrogen-fueled buses along with comparative analyses of alternative-fueled buses makes this research particularly timely. This study develops a comprehensive LCA framework to measure the economic and environmental impact of using different technologies (i.e. hydrogen-fueled electric and diesel buses). Different fuel production methods were examined considering operational factors such as energy consumption across various routes. This study contributes to enhancing the LCA methodology for public bus operations by using machine learning algorithms to cluster routes and identify optimal demonstration routes for analysis. The results highlight the impact of fuel production methods for hydrogen-fueled buses in the significant pollutant reductions (e.g. CO2 and NO ) despite their high life cycle costs. The proposed framework is validated with real data from Halifax Canada and expanded to assess public bus networks in cities with varying routes topology and population levels. The paper’s analyses consider future technological advances to lower costs aligning them with electric buses over time. This study helps policymakers choose the best public bus alternatives to improve the economic environmental and social sustainability of urban transportation.

A tool for parametric finite element modeling and analysis of LH2 tanks for aviation is developed. Passively insulated cryogenic composite sandwich pressure vessels are investigated as they conjugate simplicity effectiveness and lightweight design for aeronautical applications. Several parametric analyses are performed with the aim of gaining both general and case-specific understanding of how particular design choices may impact the tank mechanical and thermal performance. Differently from most of previous studies multiple design choices including tank walls thicknesses constraints for airframe integration strategies as well as the presence position and integration of refuelling cutouts and anti-sloshing bulkheads are considered. The thermo-mechanical analyses are performed considering first a simple reference configuration with the aim of evaluating possible directions for performance enhancement. Results indicate how different design features affect the gravimetric and thermal efficiency of the tank without compromising structural integrity if the walls thicknesses are suitably sized. The effects of different constraints and geometric discontinuities which reflect specific fuselage integration choices must be carefully assessed as they reduce safety margins. Ultimately a vessel model including features necessary for safe operation is presented as it serves as a baseline for further optimization.

Hydrogen is a promising energy carrier in the future which can help improve air quality and enhance energy security. Hydrogen production mainly relies on fossil fuels (natural gas and coal). Hydrogen production from fossil fuels can result in the significant emissions of carbon dioxide aggravating the global greenhouse effect. At the same time fossil fuels are non-renewable and the use of fossil fuels to produce hydrogen further exacerbates the crisis of fossil fuel shortages. Fortunately water as a carbon-free and hydrogen-rich renewable resource offers one of the best solutions to replace hydrogen production from fossil fuels through its decomposition. Furthermore hydrogen production by decomposition of water is vital for the realization of the sustainable development. In this paper we review the current mainstream technologies (electrolysis pyrolysis and photolysis) for hydrogen production by decomposing water. The principles processes advantages and disadvantages and the latest progresses of these technologies are also discussed. At last this paper provides a summary and outlook on water decomposition for hydrogen production and thinks that the yield energy efficiency and cost of hydrogen production from water decomposition are largely dependent on the development of new materials and the improvement of existing materials. Moreover utilizing renewable energy to decompose water for hydrogen production offers the possibility of achieving the hydrogen economy.

This study explores hydrogen’s potential as a sustainable energy source for Brunei given the nation’s reliance on fossil fuels and associated environmental concerns. Specifically it evaluates two hydrogen production technologies; steam methane reforming (SMR) and alkaline water electrolysis (AWE) through a techno-economic framework that assesses life cycle cost (LCC) efficiency scalability and environmental impact. SMR the most widely used technique is cost-effective but carbon-intensive producing considerable carbon dioxide emissions unless combined with carbon capture to yield “blue hydrogen”. On the other hand AWE particularly when powered by renewable energy offers a cleaner alternative despite challenges in efficiency and cost. The assessment revealed that AWE has a significantly higher LCC than SMR making AWE the more economically viable hydrogen production method in the long term. A sensitivity analysis was also conducted to determine the main cost factors affecting the LCC providing insights into the long term viability of each technology from an operational and financial standpoint. AWE’s economic viability is mostly driven by the high electricity and feedstock costs while SMR relies heavily on feedstock costs. However Environmental Impact Analysis (EIA) indicates that AWE produces significantly higher carbon dioxide emissions than SMR which emits approximately 9100 metric tons of carbon dioxide annually. Nevertheless findings suggest that AWE remains the more sustainable option due to its higher LCC costs and compatibility with renewable energy especially in regions with access to low-cost renewable electricity

An experimental study was devised to assess the technical environmental and economic impact of incorporating hydrogen into natural gas. The experimental tests were conducted on a GUNT ET 792 demonstration unit characterized by operating on a gas cycle in a twin-shaft configuration. The equipment was adapted to accommodate natural gas and mixtures of natural gas with hydrogen in volumetric fractions of 5% 10% and 20%. The tests carried out ensured the viability of using these mixtures from a safety perspective. On the other hand it was possible to evaluate the main differences in the use of these fuel gases in terms of the temperatures and pressures that characterize the main points of the gas cycle fuel injection pressures air/fuel ratios excess air power output overall cycle efficiencies NOX and CO2 emissions and operational cost.

As global energy demand increases and reliance on fossil fuels becomes unsustainable hydrogen presents a promising clean energy alternative due to its high energy density and potential for significant CO2 emission reductions. However current hydrogen production methods largely depend on fossil fuels contributing to considerable CO2 emissions and underscoring the need to transition to renewable energy sources and improved production technologies. Life Cycle Analysis (LCA) is essential for evaluating and optimizing hydrogen production by assessing environmental impacts such as Global Warming Potential (GWP) energy consumption toxicity and water usage. The key findings indicate that energy sources and feedstocks heavily influence the environmental impacts of hydrogen production. Hydrogen production from renewable energy sources particularly wind solar and hydropower demonstrates significantly lower environmental impacts than grid electricity and fossil fuel-based methods. Conversely hydrogen production from grid electricity primarily derived from fossil fuels shows a high GWP. Furthermore challenges related to data accuracy economic analysis integration and measuring mixed gases are discussed. Future research should focus on improving data accuracy assessing the impact of technological advancements and exploring new hydrogen production methods. Harmonizing assessment methodologies across different production pathways and standardizing functional units such as “1 kg of hydrogen produced “ are critical for enabling transparent and consistent sustainability evaluations. Techniques such as stochastic modelling and Monte Carlo simulations can improve uncertainty management and enhance the reliability of LCA results.

Against the backdrop of high investment costs in distributed energy storage systems this paper proposes a bi-level energy management model based on shared multi-type energy storage to enhance system economics and resource utilization efficiency. First an electricity–heat–hydrogen coupled shared storage architecture is developed incorporating hydrogen-blended gas turbines gas boilers and hydrogen loads to achieve deep coupling between the power grid and natural gas network. Then a bi-level game model is formulated with the upper-level objective of minimizing the storage operator’s cost and the lower-level objective of minimizing the cost of the integrated energy microgrid (IEM) aggregator. A cooperative game mechanism is introduced within the microgrids to support peer-to-peer energy trading. Nash bargaining theory is applied to determine benefit allocation and dynamic pricing strategies among microgrids. The model is solved using a genetic algorithm (GA) and the alternating direction method of multipliers (ADMM). Simulation results validate the proposed strategy’s effectiveness and feasibility in reducing system costs improving overall benefits and achieving fair benefit allocation.

Supplying the growing energy demand of emerging economies by utilizing available biogenic streams will be a key challenge in the coming years. Hydrogen is a promising alternative energy carrier to support the transition of the energy sector and other industries. In recent years the use of biomass as a renewable energy source for bio-based hydrogen production has gained significant attention due to its potential to reduce environmental impact. Among the various thermochemical processes biomass pyrolysis can be used to produce hydrogen though the current use of this process is limited. Reforming the volatile fraction of biomass pyrolysis products has been only marginally explored differently from gasification; the reforming of pyrogasses can then be seen as a viable method to enhance hydrogen yield. This review explores the key factors influencing hydrogen yield including operating conditions and the role of catalysts. It is noteworthy that most of the studies evaluated in this review are in the laboratory and pilot scales and the focus of this study is on the slow pyrolysis process in the first stage. Findings indicate that hydrogen production can be significantly improved with the proper choice of catalysts with metal-based and nonmetal-based catalysts among the most effective. The outcomes of this review highlight the key effect of increasing the reforming temperature and steam-to-biomass ratio to enhance hydrogen production.