Publications
Integrated Energy Storage and Transmission Solutions: Evaluating hydrogen, Ammonia, and Compressed Air for Offshore Wind Power Delivery
Mar 2025
Publication
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.
Synergies Between Green Hydrogen and Renewable Energy in South Africa
Aug 2025
Publication
South Africa has excellent conditions for renewable energy generation making it well placed to produce green hydrogen for both domestic use and export. In building a green hydrogen economy around export markets it will face competition from countries with equivalent or better resources and/or that are located closer to export markets (e.g. in North Africa and the Middle East) or have lower capital costs (developed markets like Australia and Canada). South Africa however has an extensive energy system with unserved electricity demand. The ability to trade electricity with the national grid (feeding into the grid during times of peak dedicated renewable energy supply and extracting from the grid during times of low dedicated renewable energy availability) could reduce the cost of producing green hydrogen by as much as 10–25 %. This paper explores the opportunity for South African green hydrogen producers presented by the electricity supply crisis that has been ongoing since 2007. It highlights the potential for a mutually reinforcing growth cycle between renewable energy and green hydrogen to be established which will contribute not only to the mitigation of greenhouse gas emissions but to the local economy and broader society.
Progress on Research and Application of Energy and Power Systems for Inland Waterway Vessels: A Case Study of the Yangtze River in China
Aug 2025
Publication
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.
Hydrogen Mole Fraction Distributions Inferred from Inverse-LIF Measurements on High-pressure Hydrogen Injections
Oct 2025
Publication
The mixing of fuel and ambient in a compression-igniting combustion engine is a critical process affecting ignition delay burn duration and cycle efficiency. This study aims to visualize and quantify hydrogen mole fraction distributions resulting from high-pressure (10 MPa) hydrogen injections into an inert pressurized (1 MPa) nitrogen ambient at room temperature. Using inverse planar laser-induced fluorescence in which the ambient rather than the jet is seeded with a fluorescent tracer two different injectors (nozzle hole sizes of 0.55 and 0.65 mm) and two different tracers (toluene and acetone) are compared. It is concluded that a non-intensified CCD camera for fluorescence detection is superior to the use of an intensified one due to the linear behavior on contrast. The two injectors produce similar jets in terms of jet penetration and angle. Jet penetration derived from inverse-LIF measurements agree with Schlieren data on nominally the same jets but the hydrogen mole fractions are generally 2.5-5 percent lower than those obtained by planar Rayleigh scattering. Quasi-steadiness and self-similarity were found for ensemble-averaged mole fraction distributions of both injectors which aligns with theory and highlights the importance of using RANS simulations or time-averaged experiments for future comparisons.
Multi-Fuel SOFC System Modeling for Ship Propulsion: Comparative Performance Analysis and Feasibility Assessment of Ammonia, Methanol and Hydrogen as Marine Fuels
Oct 2025
Publication
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
Quantifying Natural Hydrogen Generation Rates and Volumetric Potential in Onshore Serpentinization
Mar 2025
Publication
This study explores the generation of natural hydrogen through the serpentinization of onshore ultramafic rocks highlighting its potential as a clean energy resource. By investigating critical factors such as mineral composition temperature and pressure the research develops an empirical model using multiple regression analysis to predict hydrogen generation rates under varying geological conditions. A novel five-stage volumetric calculation methodology is introduced to estimate hydrogen production from ultramafic rock bodies. The application of this framework to the Giles Complex an ultramafic-mafic intrusion in Australia suggests a hydrogen generation potential of approximately 2.24 × 1013 kg of hydrogen through partial serpentinization. This estimate is based on the assumed mineral composition depth and temperature conditions within the intrusion which influence the extent of serpentinization reactions. The findings demonstrate the significant potential of ultramafic complexes for natural hydrogen production and provide a foundation for advancing natural hydrogen exploration refining predictive models and supporting sustainable energy development.
The Link Between Microstructural Heterogeneity and Hydrogen Redistribution
Jul 2025
Publication
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.
Modeling and Simulation of Coupled Biochemical and Two-phase Compositional Flow in Underground Hydrogen Storage
Aug 2025
Publication
Integrating microbial activity into underground hydrogen storage models is crucial for simulating longterm reservoir behavior. In this work we present a coupled framework that incorporates bio-geochemical reactions and compositional flow models within the Matlab Reservoir Simulation Toolbox (MRST). Microbial growth and decay are modeled using a double Monod formulation with populations influenced by hydrogen and carbon dioxide availability. First a refined Equation of State (EoS) is employed to accurately capture hydrogen dissolution thereby improving phase behavior and modeling of microbial activity. The model is then discretized using a cell-centered finite-volume method with implicit Euler time discretization. A fully coupled fully implicit strategy is considered. Our implementation builds upon MRST’s compositional module by incorporating the Søreide–Whitson EoS microbial reaction kinetics and specific effects such as bio-clogging and molecular diffusion. Through a series of 1D 2D and 3D simulations we analyze the effects of microbialinduced bio-geochemical transformations on underground hydrogen storage in porous media.These results highlight that accounting for bio-geochemical effects can substantially impact hydrogen loss purity and overall storage performance.
Comprehensive Review of Emerging Trends in Thermal Energy Storage Mechanisms, Materials and Applications
Aug 2025
Publication
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.
Feasibility of Using Rainwater for Hydrogen Production via Electrolysis: Experimental Evaluation and Ionic Analysis
Oct 2025
Publication
This study evaluates the feasibility of employing rainwater as an alternative feedstock for hydrogen production via electrolysis. While conventional systems typically rely on high-purity water—such as deionized or distilled variants—these can be cost-prohibitive and environmentally intensive. Rainwater being naturally available and minimally treated presents a potential sustainable alternative. In this work a series of comparative experiments was conducted using a proton exchange membrane electrolyzer system operating with both deionized water and rainwater collected from different Austrian locations. The chemical composition of rainwater samples was assessed through inductively coupled plasma ion chromatography and visual rapid tests to identify impurities and ionic profiles. The electrolyzer’s performance was evaluated under equivalent operating conditions. Results indicate that rainwater in some cases yielded comparable or marginally superior efficiency compared to deionized water attributed to its inherent ionic content. The study also examines the operational risks linked to trace contaminants and explores possible strategies for their mitigation.
Hydrogen-Based Solutions for Enhancing Frequency Stability in Renewable Energy-Integrated Power Systems
Mar 2025
Publication
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.
Market Readiness Analysis: Expected Uptake of Alternative Fuel Heavy-duty Vehicles until 2030 and their Corresponding Infrastructure Needs
Jun 2025
Publication
This report assesses the market readiness of zero-emission heavy-duty vehicles and the required infrastructure to meet the 45% emission reduction targets set by the revised CO2 standards by 2030. Achieving these goals requires the widespread adoption of zero-emission vehicles and a robust recharging and hydrogen refuelling infrastructure Three main aspects are investigated: the market readiness of the vehicles considering both the demand and supply side the corresponding infrastructure requirements and the barriers. Building on the inputs of the stakeholders a ‘study scenario’ is developed. This scenario shows a concrete picture of what the zero-emission heavy-duty vehicle fleet and its infrastructure requirement could look like by 2030. There are however key barriers that need to be overcome such as high total cost of ownership limited electricity grid capacity lengthy permitting processes and uncertainty in hydrogen availability and pricing. Stakeholders also emphasize the importance of policy drivers such as emissions trading systems and tolling and tax reforms to stimulate demand. In conclusion achieving the 2030 targets demands a coordinated approach involving manufacturers operators and policymakers to address infrastructure gaps market barriers and policy incentives ensuring the transition to a zero-emission HDV fleet.
Design and Analysis of Small‑Scale Hydrogen Valleys Success Factors: A Stratified Network‑Based Hybrid Fuzzy Approach
Sep 2025
Publication
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.
A Fuzzy Multi-Criteria Framework for Sustainability Assessment of Wind–Hydrogen Energy Projects: Method and Case Application
Oct 2025
Publication
This study develops a comprehensive framework for assessing the sustainability performance of wind power systems integrated with hydrogen storage (WPCHS). Unlike previous works that mainly emphasized economic or environmental indicators our approach incorporates a balanced set of economic environmental and social criteria supported by expert evaluation. To address the uncertainty in human judgment we introduce an interval-valued fuzzy TOPSIS model that provides a more realistic representation of expert assessments. A case study in Manjil Iran demonstrates the application of the model highlighting that project A4 outperforms other alternatives. The findings show that both economic factors (e.g. levelized cost of energy) and social aspects (e.g. poverty alleviation) strongly influence project rankings. Compared with earlier studies in Europe and the Middle East this work contributes by extending the evaluation scope beyond financial and environmental metrics to include social sustainability thereby enhancing decision-making relevance for policymakers and investors.
Capacity Configuration and Benefit Assessment of Deep-Sea Wind–Hydrogen System Considering Dynamic Hydrogen Price
Sep 2025
Publication
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.
Sustainable Aviation Fuels: A Review of Current Techno Economic Viability and Life Cycle Impacts
Oct 2025
Publication
Australia has set a new climate target of reducing emissions by 62–70% below 2005 levels by 2035 with sustainable aviation fuel (SAF) central to achieving this goal. This review critically examines techno-economic analysis (TEA) and life cycle assessment (LCA) of Powerto-Liquid (PtL) electrofuels (e-fuels) which synthesize atmospheric CO2 and renewable hydrogen (H2) via Fischer-Tropsch (FT) synthesis. Present PtL pathways require ~0.8 kg of H2 and 3.1 kg of CO2 per kg SAF with ~75% kerosene yield. While third-generation feedstocks could cut greenhouse gas emissions by up to 93% (as low as 8 gCO2e/MJ) real world reductions have been limited (~1.5%) due to variability in technology rollout and feedstock variability. Integrated TEA–LCA studies demonstrate up to 20% energy efficiency improvements and 40% cost reductions but economic viability demands costs below $3/kg. In Australia abundant solar resources vast transport networks and supportive policy frameworks present both opportunities and challenges. This review provides the first comprehensive assessment of PtL-FT SAF for Australian conditions highlighting that large-scale development will require technological advancement feedstock development infrastructure investment and coordinated policy support.
Risk Assessment of Offshore Wind–Solar–Current Energy Coupling Hydrogen Production Project Based on Hybrid Weighting Method and Aggregation Operator
Oct 2025
Publication
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.
A Comparative Study of Alternative Polymer Binders for the Hydrogen Evolution Reaction
Aug 2025
Publication
Given the economic industrial and environmental value of green dihydrogen (H2) optimization of water electrolysis as a means of producing H2 is essential. Binders are a crucial component of electrocatalysts yet they remain largely underdeveloped with a significant lack of standardization in the field. Therefore targeted research into the development of alternative binder systems is essential for advancing performance and consistency. Binders essentially act as the key to regulating the electrode (support)–catalyst–electrolyte interfacial junctions and contribute to the overall reactivity of the electrocatalyst assembly. Therefore alternative binders were explored with a focus on cost efficiency and environmental compatibility striving to achieve desirable activity and stability. Herein the alkaline hydrogen evolution reaction (HER) was investigated and the sluggish water dissociation step was targeted. Controlled hydrophilic poly(vinyl alcohol)-based hydrogel binders were designed for this application. Three hydrogel binders were evaluated without incorporated electrocatalysts namely PVA145 PVA145-blend-bPEI1.8 and PVA145-blend-PPy. Interestingly the study revealed that the hydrophilicity of the binders exhibited an enhancing effect on the observed activity resulting in improved performance compared to the commercial binder Nafion™. Notably the PVA145 system stands out with an overpotential of 224 mV at−10 mA·cm−2 (geometric) in 1.0 M KOH compared to the 238 mV exhibited by Nafion™. Inclusion of Pt as active material in PVA145 as binder exhibited a synergistic increase in performance achieving a mass activity of 1.174 A.cm−2.mg−1 Pt in comparison to Nafion™’s 0.344 A.cm−2.mg−1 Pt measured at−150 mV vs RHE. Our research aimed to contribute to the development of cost-effective and efficient binder systems stressing the necessity to challenge the dominance of the commercially available binders.
AI-driven Advances in Composite Materials for Hydrogen Storage Vessels: A Review
Sep 2025
Publication
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.
Biohydrogen Production from Industrial Waste: The Role of Pretreatment Methods
Oct 2025
Publication
This study aimed to investigate the effectiveness of dark fermentation in biohydrogen production from agro-industrial wastes including apple pomace brewer’s grains molasses and potato powder subjected to different pretreatment methods. The experiments were conducted at a laboratory scale using 1000 cm3 anaerobic reactors at a temperature of 35 ◦C and anaerobic sludge as the inoculum. The highest yield of hydrogen was obtained from pre-treated apple pomace (101 cm3/g VS). Molasses a less complex substrate compared to the other raw materials produced 25% more hydrogen yield following pretreatment. Methanogens are sensitive to high temperatures and low-pH conditions. Nevertheless methane constituted 1–6% of the total biogas under these conditions. The key factor was appropriate treatment of the inoculum to limit competition from methanogens. Increasing the inoculum dose from 150 cm3/dm3 to 250 cm3/dm3 had no further effect on biogas production. The physicochemical parameters and VFA data confirmed the stability and usefulness of activated sludge as a source of microbial cultures for H2 production via dark fermentation.
No more items...