Publications

This paper introduces a novel dual-purpose transmission system that integrates power transmission and energy storage using hydrogen ammonia and compressed air—an area largely unexplored in the literature. Unlike conventional cable transmission which requires separate storage infrastructure the proposed approach leverages the transmission medium itself as an energy storage solution enhancing system efficiency and reducing costs. By incorporating a defined storage allocation factor this study examines the delivery of offshore-generated power to onshore locations calculating the necessary media flow rates and evaluating the required transportation infrastructure including tunnels and pipelines. A comparative cost-effectiveness analysis is conducted to determine optimal conditions under which storage-integrated transmission outperforms conventional cable transmission. Various transmission powers storage fractions pressures and distances are analysed to assess feasibility and economic viability. The findings indicate that for a 75 % storage allocation factor compressed air can transmit up to 450 MW over 300 km more cost-effectively than cables while hydrogen enables 230 MW transmission beyond 310 km. Ammonia proves to be the most efficient facilitating the transmission of over 2000 MW across distances exceeding 140 km at a lower cost than cables all without requiring onshore storage. Moreover for a 500-km transmission line compressed air hydrogen and ammonia can store the equivalent of 62 58 and 152 h of wind farm output respectively significantly reducing the need for additional onshore storage. This study fills a critical research gap by optimizing offshore wind power delivery through an innovative cost-effective and scalable transmission and storage approach.

This study focuses on the power systems of inland waterway vessels in Chinese Yangtze River systematically outlining the low-carbon technology pathways for different power system types. A comparative analysis is conducted on the technical feasibility emission reduction potential and economic viability of LNG methanol ammonia pure electric and hybrid power systems revealing the bottlenecks hindering the large-scale application of each system. Key findings indicate that: (1) LNG and methanol fuels offer significant short-term emission reductions in internal combustion engine power systems yet face constraints from methane slip and insufficient green methanol production capacity respectively; (2) ammonia enables zero-carbon operations but requires breakthroughs in combustion stability and synergistic control of NOX; (3) electric vessels show high decarbonization potential but battery energy density limits their range while PEMFC lifespan constraints and SOFC thermal management deficiencies impede commercialization; (4) hybrid/range-extended power systems with superior energy efficiency and lower retrofitting costs serve as transitional solutions for existing vessels though challenged by inadequate energy management strategies and multi-equipment communication protocol interoperability. A phased transition pathway is proposed: LNG/methanol engines and hybrid systems dominate during 2025–2030; ammonia-powered systems and solid-state batteries scale during 2030–2035; post-2035 operations achieve zero-carbon shipping via green hydrogen/ammonia.

To reduce fossil fuel dependency in shipping adopting alternative fuels and innovative propulsion systems is essential. Solid Oxide Fuel Cells (SOFC) powered by hydrogen carriers represent a promising solution. This study investigates a multi-fuel SOFC system for ocean-going vessels capable of operating with ammonia methanol or hydrogen thus enhancing bunkering flexibility. A thermodynamic model is developed to simulate the performance of a 3 kW small-scale system subsequently scaling up to a 10 MW configuration to meet the power demand of a container ship used as the case study. Results show that methanol is the most efficient fueling option reaching a system efficiency of 58% while ammonia and hydrogen reach slightly lower values of about 55% and 51% respectively due to higher auxiliary power consumption. To assess technical feasibility two installation scenarios are considered for accommodating multiple fuel tanks. The first scenario seeks the optimal fuel share equivalent to the diesel tank’s chemical energy (17.6 GWh) minimizing mass increase. The second scenario optimizes the fuel share within the available tank volume (1646 m3 ) again minimizing mass penalties. In both cases feasibility results have highlighted that changes are needed in terms of cargo reduction equal to 20.3% or alternatively in terms of lower autonomy with an increase in refueling stops. These issues can be mitigated by the benefits of increased bunkering flexibility

Green hydrogen is likely to play a major role in decarbonising the aviation industry. It is crucial to understand the effects of microstructure on hydrogen redistribution which may be implicated in the embrittlement of candidate fuel system metals. We have developed a multiscale finite element modelling framework that integrates micromechanical and hydrogen transport models such that the dominant microstructural effects can be efficiently accounted for at millimetre length scales. Our results show that microstructure has a significant effect on hydrogen localisation in elastically anisotropic materials which exhibit an interesting interplay between microstructure and millimetre-scale hydrogen redistribution at various loading rates. Considering 316L stainless steel and nickel a direct comparison of model predictions against experimental hydrogen embrittlement data reveals that the reported sensitivity to loading rate may be strongly linked with rate-dependent grain scale diffusion. These findings highlight the need to incorporate microstructural characteristics in hydrogen embrittlement models.

Thermal energy storage (TES) technologies are emerging as key enablers of sustainable energy systems by providing flexibility and efficiency in managing thermal resources across diverse applications. This review comprehensively examines the latest advancements in TES mechanisms materials and structural designs including sensible heat latent heat and thermochemical storage systems. Recent innovations in nano-enhanced phase change materials (PCMs) hybrid TES configurations and intelligent system integration are highlighted. The role of advanced computational methods such as digital twins and AI-based optimization in enhancing TES performance is also explored. Applications in renewable energy systems industrial processes district heating networks and green hydrogen production are discussed along with associated challenges and future research directions. This review aims to synthesize current knowledge while identifying pathways for accelerating the development and practical deployment of next-generation TES technologies.

With the increasing adoption of renewable energy sources such as solar and wind power it is essential to achieve carbon neutrality. However several shortcomings including their intermittence pose significant challenges to the stability of the electrical grid. This study explores hydrogen-based technologies such as fuel cells and water electrolysis systems as an effective solution to improve frequency stability and address the problems of power grid reliability. Using power system analysis programs modeling and simulations performed on IEEE-25 Bus and Jeju Island systems demonstrate the potential of these technologies to mitigate reductions reduce transmission constraints and stabilize frequencies. The results show that hydrogen-based systems are important factors enabling sustainable energy transition.

Hydrogen energy one of the renewable energy sources plays a crucial role in combating climate change since its usage aims to reduce carbon emissions and enhance energy security. As the global energy trend moves toward cleaner alternatives countries start to adapt their energy strategies. In this transition hydrogen is one of the energy sources with the potential to increase long-term energy security. Developing countries face challenges such as high energy import dependency rising industrial demand and the need for infrastructure modernization making hydrogen valleys one of the viable solutions since they integrate hydrogen production storage distribution and utilization at one facility. However establishing small-scale hydrogen valleys requires a comprehensive decision-making strategy consisting of technical financial environmental social and political factors while addressing uncertainties in the system. To systematically manage the process this study proposes a Z-numberbased fuzzy cognitive mapping approach which models the interdependencies among success factors supported by Z-number Decision-Making Trial and Evaluation Laboratory for structured prioritization with a multi-expert perspective. The results indicate that Financial Factors emerged as the most critical category with Government Incentives Infrastructure Investment Cost and Land Acquisition Cost ranking as the top three sub-success factors. Availability of Skilled Workforce and Regional Energy Supply followed in importance which demonstrates the importance of social and technical dimensions in the hydrogen valley development. These findings demonstrate the critical role of policy support infrastructure readiness and workforce availability in the design process. Sensitivity analyses are also conducted to present robustness of the given decisions for the analysis of the results. Based on the results and analyses possible implications based on the policy and practical dimensions are also discussed. By integrating fuzzy logic and Z-numbers the study aims to minimize loss of information enhances the analytical background for decision-making and provides a strategic roadmap for hydrogen valley development.

Against the backdrop of the global transition towards clean energy deep-sea wind-power hydrogen production integrates offshore wind with green hydrogen technology. Addressing the technical coupling complexity and the impact of uncertain hydrogen prices this paper develops a capacity optimization model. The model incorporates floating wind turbine output the technical distinctions between alkaline (ALK) electrolyzers and proton exchange membrane (PEM) electrolyzers and the synergy with energy storage. Under three hydrogen price scenarios the results demonstrate that as the price increases from 26 CNY/kg to 30 CNY/kg the optimal ALK capacity decreases from 2.92 MW to 0.29 MW while the PEM capacity increases from 3.51 MW to 5.51 MW. Correspondingly the system’s Net Present Value (NPV) exhibits an upward trend. To address the limitations of traditional methods in handling multi-dimensional benefit correlations and information ambiguity a comprehensive benefit evaluation framework encompassing economic technical environmental and social synergies was constructed. Sensitivity analysis indicates that the comprehensive benefit level falls within a relatively high-efficiency interval. The numerical characteristics an entropy value of 3.29 and a hyper-entropy of 0.85 demonstrate compact result distribution and robust stability validating the applicability and stability of the proposed offshore wind–hydrogen benefit assessment model.

Under the dual pressures of global climate change and energy structure transition the offshore wind–solar–current energy coupling hydrogen production (OCWPHP) system has emerged as a promising integrated energy solution. However its complex multi-energy structure and harsh marine environment introduce systemic risks that are challenging to assess comprehensively using traditional methods. To address this we develop a novel risk assessment framework based on hesitant fuzzy sets (HFS) establishing a multidimensional risk criteria system covering economic technical social political and environmental aspects. A hybrid weighting method integrating AHP entropy weighting and consensus adjustment is proposed to determine expert weights while minimizing risk information loss. Two aggregation operators—AHFOWA and AHFOWG—are applied to enhance uncertainty modeling. A case study of an OCWPHP project in the East China Sea is conducted with the overall risk level assessed as “Medium.” Comparative analysis with the classical Cumulative Prospect Theory (CPT) method shows that our approach yields a risk value of 0.4764 closely aligning with the CPT result of 0.4745 thereby confirming the feasibility and credibility of the proposed framework. This study provides both theoretical support and practical guidance for early-stage risk assessment of OCWPHP projects.

This review provides a comprehensive examination of artificial intelligence methods applied to the design optimization and performance prediction of composite-based hydrogen storage vessels with a focus on composite overwrapped pressure vessels. Targeted at researchers engineers and industrial stakeholders in materials science mechanical engineering and renewable energy sectors the paper aims to bridge traditional mechanical modeling with evolving AI tools while emphasizing alignment with standardization and certification requirements to enhance safety efficiency and lifecycle integration in hydrogen infrastructure. The review begins by introducing HSV types their material compositions and key design challenges including high-pressure durability weight reduction hydrogen embrittlement leakage prevention and environmental sustainability. It then analyzes conventional approaches such as finite element analysis multiscale modeling and experimental testing which effectively address aspects like failure modes fracture strength liner damage dome thickness winding angle effects crash behavior crack propagation charging/discharging dynamics burst pressure durability reliability and fatigue life. On the other hand it has been shown that to optimize and predict the characteristics of hydrogen storage vessels it is necessary to combine the conventional methods with artificial intelligence methods as conventional methods often fall short in multi-objective optimization and rapid predictive analytics due to computational intensity and limitations in handling uncertainty or complex datasets. To overcome these gaps the paper evaluates hybrid frameworks that integrate traditional techniques with AI including machine learning deep learning artificial neural networks evolutionary algorithms and fuzzy logic. Recent studies demonstrate AI’s efficacy in failure prediction design optimization to mitigate structural risks structural health monitoring material property evaluation burst pressure forecasting crack detection composite lay-up arrangement weight minimization material distribution enhancement metal foam ratio optimization and optimal material selection. By synthesizing these advancements this work underscores AI’s potential to accelerate development reduce costs and improve HSV performance while advocating for physics-informed models robust datasets and regulatory alignment to facilitate industrial adoption.

Crude oil distillation is one of the most energy-intensive processes in petroleum refining consuming up to 20% of total refinery energy. Improving the energy efficiency of crude distillation units (CDUs) is essential for reducing costs lowering emissions and achieving sustainable refining. Current studies often examine energy savings operational flexibility or renewable energy integration separately. This review brings these aspects together focusing on heat integration advanced control systems and renewable energy options such as solar-assisted preheating and green hydrogen. Advanced column designs including dividing-wall and hybrid systems can cut energy use by 15–30% while AI-based optimization improves process stability and flexibility. Solar-assisted preheating can reduce fossil fuel demand by up to 20% and green hydrogen offers strong potential for decarbonization. Our findings highlight that integrated strategies including advanced simulation tools and machine learning significantly improve CDU performance. We recommend exploring hybrid algorithms renewable energy integration and sustainable technologies to address these challenges and achieve long-term environmental and economic benefits.

Hydrogen-based direct reduction of iron ore is a promising route to reduce CO2 emissions in steelmaking where uniform particle flow inside shaft furnaces is essential for efficient operation. In this study a full-scale three-dimensional Discrete Element Method (DEM) model of a shaft furnace was developed to investigate the effects of a diverter device on granular flow. By systematically varying the radial width and top/bottom diameters of the diverter particle descent velocity residence time compressive force distribution and collision energy dissipation were analyzed. The results demonstrate that introducing a diverter effectively suppresses funnel flow prolongs residence time and improves radial flow uniformity. Among the tested configurations the smaller central diameter diverter showed the most favorable performance achieving a faster and more uniform descent reduced compressive force concentration and lower collision energy dissipation. These findings highlight the critical role of diverter design in regulating particle dynamics and provide theoretical guidance for optimizing shaft furnace structures to enhance the efficiency of hydrogen-based direct reduction processes.

The present work focused on the comparison between HHO and hydrogen electrolyzers in design gas production and various parameters which affect the performance and efficiency of alkaline electrolyzers. The primary goal is to generate the highest possible hydrogen and HHO gas flow rates. Hydrogen and HHO were produced using 3 mm electrode of stainless steel 316L with 224 cm2 surface area. Hydroxy and hydrogen rates were affected by electrolyte content cell connection electric current operating time electrolyte temperature and voltage. Maximum HHO generation values were 1020 1076 1125 and 1175 mL min−1 n at 5 10 15 and 20 g L−1 of sodium hydroxide (NaOH) with supply currents of 15 15.3 15.6 and 16 A respectively. Once it stabilized after 30 min the temperature increased to 26 30 35 and 38 °C respectively and remained there. With currents of 18 18.45 18.7 19.2 19.5 and 19.8 A hydrogen output peak values after 60 min. stayed constant at 680 734 785 846 897 and 945 mL min-1. at 5 10 15 and 20 g L−1 NaOH catalyst concentrations. At 5 10 15 and 20 g L−1 catalyst ratios the temperatures were elevated to constant values of 28.5 32 37.9 40.5 41.4 and 43 °C respectively. With cell design [4C3A19N] electrolyte concentration of 5 g L−1 NaOH and current of 14 A maximum HHO productivity was 866 mL min−1. and 74.23% efficiency. In a cell design of [4C5A17N] with catalyst content of 10 g L−1 maximum productivity was 680 mL min−1 for hydrogen and highest production efficiency of 72.85% was attained at 18 A.

This article takes the perspective of Hydrogen Load Aggregator (HLA) to optimize the declaration strategy of peak shaving market improve the flexible regulation capability of power system and HLA economy as the research objectives and proposes an optimization strategy method for HLA to participate in peak shaving market. Firstly an improved Convolutional Neural Networks–Long Short-Term Memory (CNN-LSTM) time series prediction model is developed to address peak shaving demand uncertainty. Secondly a bidding strategy model incorporating dynamic pricing is constructed by comprehensively considering electrolyzer regulation costs market supply–demand relationships and system constraints. Thirdly a market clearing model for peak shaving markets with HLA participation is designed through analysis of capacity contribution and marginal costs among different regulation resources. Finally the capacity allocation model is designed with the goal of minimizing the total cost of peak shaving among various stakeholders within HLA and the capacity won by HLA in the peak shaving market is reasonably allocated. Simulations conducted on a Python3.12-based experimental platform demonstrate the following: the improved CNN-LSTM model exhibits strong adaptability and robustness the bidding model effectively enhances HLA market competitiveness and the clearing model reduces system operator costs by 5.64%.

The transition to a sustainable energy future hinges on the development of reliable large-scale hydrogen storage solutions to balance the intermittency of renewable energy and decarbonize hard-to-abate industries. Underground hydrogen storage (UHS) in salt caverns emerged as a technically and economically viable strategy leveraging the unique geomechanical properties of salt formations—including low permeability self-healing capabilities and chemical inertness—to ensure safe and high-purity hydrogen storage under cyclic loading conditions. This review provides a comprehensive analysis of the advantages of salt cavern hydrogen storage such as rapid injection and extraction capabilities cost-effectiveness compared to other storage methods (e.g. hydrogen storage in depleted oil and gas reservoirs aquifers and aboveground tanks) and minimal environmental impact. It also addresses critical challenges including hydrogen embrittlement microbial activity and regulatory fragmentation. Through global case studies best operational practices for risk mitigation in real-world applications are highlighted such as adaptive solution mining techniques and microbial monitoring. Focusing on China’s regional potential this study evaluates the hydrogen storage feasibility of stratified salt areas such as Jiangsu Jintan Hubei Yunying and Henan Pingdingshan. By integrating technological innovation policy coordination and cross-sector collaboration salt cavern hydrogen storage is poised to play a pivotal role in realizing a resilient hydrogen economy bridging the gap between renewable energy production and industrial decarbonization.

Due to the environmental impact of fossil fuels renewable energy such as wind and solar energy is rapidly developed. In energy systems energy storage units are important which can regulate the safe and stable operation of the power system. However different energy storage methods have different environmental and economic impacts in renewable energy systems. This paper proposed three different energy storage methods for hybrid energy systems containing different renewable energy including wind solar bioenergy and hydropower meanwhile. Based on Homer Pro software this paper compared and analyzed the economic and environmental results of different methods in the energy system through the case of a residential community in Baotou City. The result showed that (1) the use of batteries as energy storage in communities posed the lowest energy costs whose NPC was $197396 and LCOE was $0.159 consisting of 20 batteries 19.3 kW PV 6 wind turbines a 12.6 kW converter. (2) Lower fuel cell prices mean lower NPC and the increase in the Electric Load Scaled Average implied a decrease in LCOE and the increase of the NPC. (3) The use of fuel cells also had impacts on the environment such as resulting CO2 and SO2.

This study develops a photovoltaic (PV)-based hydrogen production system specifically designed for university campuses which is expected to lead in sustainability efforts. The proposed system aims to meet the electricity demand of a Hydrogen Research Center while supplying energy to an electric charging station and a hydrogen refueling station for battery-electric and fuel-cell electric vehicles operating within the campus. In this integrated system the electricity generation capacity of PV panels installed on the research center’s roof is determined and the surplus electricity after meeting the energy demand is allocated to cover the varying proportions needed for both electric charging station and hydrogen production system. The green hydrogen produced by the system is compressed to 100 350 and 700 bar with intermediate cooling stages where the heat generated at the compressor outlet is absorbed by a cooling fluid and repurposed in a condenser for domestic hot water production. A full thermodynamic analysis of this entirely renewable energy-powered system is conducted by considering a 9-hour daily operational period from 8:00 AM to 5:00 PM. The average incoming solar radiation is determined to be 484.63 W/m2 resulting in an annual electricity generation capacity of 494.86 MWh. Based on the assumptions and data considered the energy and exergy efficiencies of the proposed system are calculated as 17.71 % and 17.01 % respectively with an annual hydrogen production capacity of 3.642 tons. Various parametric studies are performed for varying solar intensity values and PV surface areas to investigate how the overall system capacities and efficiencies are affected. The results show that an integration of hydrogen production systems with solar energy offers significant advantages including mitigating intermittency issues found in standalone renewable systems reducing carbon emissions compared to fossil-based alternatives and enhancing the flexibility of energy systems.

This study presents a techno-economic and environmental optimization of hydrogen-based hybrid energy systems (HESs) for Broken Hill City Council in New South Wales Australia. Two configurations are evaluated: Configuration 1 includes solar PV battery fuel cell electrolyzer and hydrogen storage while Configuration 2 includes solar PV fuel cell electrolyzer and hydrogen storage but excludes the battery. The system is optimized using advanced metaheuristic algorithms such as Harris Hawks Algorithm (HHA) Red-Tailed Hawk Algorithm and Non-Dominated Sorting Genetic Algorithm-II while ensuring real-time supply–demand balance and system stability through a robust energy management strategy. This integrated approach simultaneously determines the optimal sizes of PV arrays battery storage (where applicable) fuel cells electrolyzers and hydrogen storage units and maintains reliable energy supply. Results show that HHA Configuration 1 achieves the lowest net present cost of $338111 a levelized cost of electricity of $0.185/kWh and a levelized cost of hydrogen of $4.60/kg. Sensitivity analysis reveals that PV module and hydrogen storage costs significantly impact system economics while improving fuel cell efficiency from 40% to 60% can reduce costs by up to 40%. Beyond cost-effectiveness life cycle analysis demonstrates annual CO2 emission reductions exceeding 500000 kg compared to an equivalent diesel generator system meeting the same load demand. Socio-economic assessments further indicate that the HES can support improvements in the Human Development Index by enhancing access to healthcare education and economic opportunities while also creating local jobs in PV installation battery maintenance and hydrogen infrastructure. These findings establish hydrogen-based HES as a scalable cost-effective and environmentally sustainable solution for energy access in remote areas.

Enhancing the economics of microgrid systems and achieving a balance between energy supply and demand are critical challenges in capacity allocation research. Existing studies often neglect the optimization of electrolyzer efficiency and multi-stack operation leading to inaccurate assessments of system benefits. This paper proposes a capacity allocation model for wind-PV-hydrogen integrated microgrid systems that incorporates hydrogen production efficiency optimization. This paper analyzes the relationship between the operating efficiency of the electrolyzer and the output power regulates power generation-load mismatches through a renewable energy optimization model and establishes a double-layer optimal configuration framework. The inner layer optimizes electrolyzer power allocation across periods to maximize operational efficiency while the outer layer determines configuration to maximize daily system revenue. Based on the data from a demonstration project in Jiangsu Province China a case study is conducted to verify that the proposed method can improve system benefits and reduce hydrogen production costs.

Fuel cell vehicles (FCVs) represent an intriguing alternative to battery electric vehicles (BEVs). While the acceptance of BEVs has been widely discussed acceptance-based recommendations for promoting adoption of FCVs remain ambiguous. This paper aims to improve our understanding by reporting results from a pioneer study based on the standardized Unified Theory of Acceptance and Use of Technology 2 (UTAUT2). The sample consists of n1 = 258 registered customers of H2mobility in Germany. For effect control another n2 = 294 participant sample was drawn from the baseline population. Data were analyzed using SmartPLS 4 and importance-performance mapping (IPMA). Results demonstrate that FCV acceptance primarily relies on Perceived Usefulness Perceived Conditions and Normative Influence while surprisingly hypotheses involving Perceived Risk and Green Attitude are rejected. Finally a discussion reveals ways to increase the level of public acceptance. Three practical strategies emerge. For future acceptance analyses the authors suggest incorporating the young concept of ‘societal readiness’.

Vietnam recognizes hydrogen as a key fuel for decarbonization under its National Hydrogen Strategy. Here we quantified the environmental and economic performance of Vietnam’s optimal hydrogen-production pathways by evaluating combinations of green and blue hydrogen under varying demand scenarios using life-cycle assessment and optimization modeling techniques. The environmental performance of hydrogen production proved highly sensitive to the electricity source with water electrolysis powered by renewable energy offering the most favorable outcomes. Although green hydrogen production reduced carbon emissions it shifted environmental burdens toward increased resource extraction. Producing 20 Mt of hydrogen by 2050 would require 741.56 TWh of electricity 178 Mt of water and USD 294 billion in investment and it would emit 50.48 Mt CO2. These findings highlight the importance of strategic hydrogen planning and resource strategy aligned with national priorities for energy transition to navigate trade-offs among technology selection emissions costs and resource consumption.

This paper presents a method for gas turbine performance calculations with alternative fuels with a particular focus on their use in aircraft engines. The effects of various alternative aviation fuels on fuel consumption CO2 emissions and contrail formation are examined in a comparative study. We use the GasTurb performance software and calculate heat release and hot section gas properties using a chemical equilibrium solver. Fuels with complex compositions are included in the calculation via surrogates of a limited number of known species that mimic the relevant properties of the real fuel. An automated method is used for the fuel surrogate formulation. We compare the results of this rigorous approach with the simplified approach of calculating the heat release using an alternative fuel’s heating value while still using the gas properties of conventional Jet A-1. The results show that the latter approach systematically overpredicts fuel consumption by up to 0.2% for aromaticsfree synthetic kerosene (e.g. “biofuels”). Overall aircraft engines running on alternative fuels tend to be more fuel efficient due to their often higher hydrogen contents and thus fuel heating values. We find reductions in fuel consumption of up to 2.8% during cruise when using aromatics-free synthetic kerosene. We further assess how alternative fuels affect contrail formation based on the Schmidt-Appleman criterion. Contrails can form 200 m lower under cruise conditions when burning aromatics-free synthetic kerosene instead of Jet A-1 with identical thrust requirements and under the same atmospheric conditions mainly due to their higher hydrogen content. In summary we present a flexible yet easy-to-use method for studying fuel effects in performance calculations that avoids small but systematic errors by rigorously calculating the heat release and hot section gas properties for each fuel.

Solar-driven water electrolysis has emerged as a prominent technology for the production of green hydrogen facilitated by advancements in both water electrolyzers and solar cells. Nevertheless the majority of integrated solar-to-hydrogen systems still struggle to exceed 20% efficiency particularly in large-scale applications. This limitation arises from suboptimal coupling methodologies and system-level inefficiencies that have rarely been analyzed. To address these challenges this study investigates the fundamental principles of solar hydrogen production and examines key energy losses in photovoltaic-electrolyzer systems. Subsequently it systematically discusses optimization strategies across three dimensions: (1) enhancing photovoltaic (PV) system output under variable irradiance (2) tailoring electrocatalysts and electrolyzer architectures for high-performance operation and (3) minimizing coupling losses through voltage-matching technologies and energy storage devices. Finally we review existing large-scale solar hydrogen infrastructure and propose strategies to overcome barriers related to cost durability and scalability. By integrating material innovation with system engineering this work offers insights to advance solar-powered electrolysis toward industrial applications.

China’s dual-carbon goals have positioned hydrogen as a central pillar of its energy transition. This review examines the recent development of China’s hydrogen supply chain with particular focus on manufacturing technologies for alkaline electrolysers high-pressure cylinders and diaphragm compressors. In 2024 China produced 36.5 million tons of hydrogen of which 77 % was grey and only 1 % derived from electrolysis. Storage and transportation account for nearly 30 % of end-use costs while reliance on imported compressors increases refuelling station expenses by approximately 40 %. We identify key bottlenecks including limited electrolyser efficiency the high cost of carbon fibres for Type III/IV cylinders and insufficient domestic capacity for highreliability compressors. To address these challenges targeted advances are proposed: membrane materials with engineered hydrophilicity advanced surface modifications and hydrophilic inhibitors; liner design incorporating grooved-liner braided layers with double-fibre configurations; and a three-layer diaphragm compressor architecture. By consolidating fragmented studies this review provides the integrated manufacturing perspective on China’s hydrogen supply chain offering both scientific insights and practical guidance for accelerating costeffective large-scale low-carbon hydrogen deployment.

Offshore hydrogen production offers a promising solution for harnessing wind energy far from shore by using hydrogen as an energy carrier instead of electrical cables. Flexibility in hydrogen production systems is crucial to maximising the conversion of intermittent wind energy into hydrogen. To improve the performance of lowpressure compressed gas buffer stores hybrid gas-hydride tanks have been identified as a viable solution increasing useable storage density from 1.2 kg m− 3 to 6.3 kg m− 3 with just a 5 vol% addition of hydride. This study evaluates the reduction in tank volume reduction in cost and enhancements in useable storage density achieved by integrating different hydrides under varying temperature conditions. Using hydrogen mass flow rate profiles a storage mass target was determined for optimisation. The results demonstrate that hybrid gas-hydride tanks can reduce tank size by around 80 % lowering costs by 24 % and achieve a 5.1-fold improvement in useable storage density.