Publications
Review on Onshore and Offshore Large-scale Seasonal Hydrogen Storage for Electricity Generation: Focusing on Improving Compression, Storage, and Roundtrip Efficiency
Jun 2024
Publication
This article presents a comprehensive review of the current landscape and prospects of large-scale hydrogen storage technologies with a focus on both onshore and offshore applications and flexibility. Highlighting the evolving technological advancements it explores storage and compression techniques identifying potential research directions and avenues for innovation. Underwater hydrogen storage and hybrid metal hydride com pressed gas tanks have been identified for offshore buffer storage as well as exploration of using metal hydride slurries to transport hydrogen to/from offshore wind farms coupled with low pressure high flexibility elec trolyser banks. Additionally it explores the role of metal hydride hydrogen compressors and the integration of oxyfuel processes to enhance roundtrip efficiency. With insights into cost-effectiveness environmental and technology considerations and geographical factors this review offers insights for policymakers researchers and industry stakeholders aiming to advance the deployment of large-scale hydrogen storage systems in the transition towards sustainable energy.
A Review on the Cost Analysis of Hydrogen Gas Storage Tanks for Fuel Cell Vehicles
Jul 2023
Publication
The most practical way of storing hydrogen gas for fuel cell vehicles is to use a composite overwrapped pressure vessel. Depending on the driving distance range and power requirement of the vehicles there can be various operational pressure and volume capacity of the tanks ranging from passenger vehicles to heavy-duty trucks. The current commercial hydrogen storage method for vehicles involves storing compressed hydrogen gas in high-pressure tanks at pressures of 700 bar for passenger vehicles and 350 bar to 700 bar for heavy-duty trucks. In particular hydrogen is stored in rapidly refillable onboard tanks meeting the driving range needs of heavy-duty applications such as regional and line-haul trucking. One of the most important factors for fuel cell vehicles to be successful is their cost-effectiveness. So in this review the cost analysis including the process analysis raw materials and manufacturing processes is reviewed. It aims to contribute to the optimization of both the cost and performance of compressed hydrogen storage tanks for various applications.
A Review of Green Hydrogen Production Based on Solar Energy; Techniques and Methods
Feb 2023
Publication
The study examines the methods for producing hydrogen using solar energy as a catalyst. The two commonly recognised categories of processes are direct and indirect. Due to the indirect processes low efficiency excessive heat dissipation and dearth of readily available heat-resistant materials they are ranked lower than the direct procedures despite the direct procedures superior thermal performance. Electrolysis bio photosynthesis and thermoelectric photodegradation are a few examples of indirect approaches. It appears that indirect approaches have certain advantages. The heterogeneous photocatalytic process minimises the quantity of emissions released into the environment; thermochemical reactions stand out for having low energy requirements due to the high temperatures generated; and electrolysis is efficient while having very little pollution created. Electrolysis has the highest exergy and energy efficiency when compared to other methods of creating hydrogen according to the evaluation.
A Comparative Total Cost of Ownership Analysis of Heavy Duty On-road and Off-road Vehicles Powered by Hydrogen, Electricity, and Diesel
Dec 2022
Publication
This study investigated the cost competitiveness using total cost of ownership (TCO) analysis of hydrogen fuel cell electric vehicles (FCEVs) in heavy duty on and off-road fleet applications as a key enabler in the decarbonisation of the transport sector and compares results to battery electric vehicles (BEVs) and diesel internal combustion engine vehicles (ICEVs). Assessments were carried out for a present day (2021) scenario and a sensitivity analysis assesses the impact of changing input parameters on FCEV TCO. This identified conditions under which FCEVs become competitive. A future outlook is also carried out examining the impact of time-sensitive parameters on TCO when net zero targets are to be reached in the UK and EU. Several FCEVs are cost competitive with ICEVs in 2021 but not BEVs under base case conditions. However FCEVs do have potential to become competitive with BEVs under specific conditions favouring hydrogen including the application of purchase grants and a reduced hydrogen price. By 2050 a number of FCEVs running on several hydrogen scenarios show a TCO lower than ICEVs and BEVs using rapid chargers but for the majority of vehicles considered BEVs remain the lowest in cost unless specific FCEV incentives are implemented. This paper has identified key factors hindering the deployment of hydrogen and conducted comprehensive TCO analysis in heavy duty on and off-road fleet applications. The output has direct contribution to the decarbonisation of the transport sector.
Sustainable Hydrogen Generation and Storage - A Review
Aug 2023
Publication
In 21st century the energy demand has grown incredibly due to globalization human population explosion and growing megacities. This energy demand is being mostly fulfilled by fossil-based sources which are non-renewable and a major cause of global warming. Energy from these fossil-based sources is cheaper however challenges exist in terms of climate change. This makes renewable energy sources more promising and viable for the future. Hydrogen is a promising renewable energy carrier for fulfilling the increasing energy demand due to its high energy density non-toxic and environment friendly characteristics. It is a non-toxic energy carrier as combustion of hydrogen produces water as the byproduct whereas other conventional fuels produce harmful gases and carcinogens. Because of its lighter weight hydrogen leaks are also easily dispersed in the atmosphere. Hydrogen is one of the most abundant elements on Earth yet it is not readily available in nature like other fossil fuels. Hence it is a secondary energy source and hydrogen needs to be produced from water or biomass-based feedstock for it to be considered renewable and sustainable. This paper reviews the renewable hydrogen generation pathways such as water splitting thermochemical conversion of biomass and biological conversion technologies. Purification and storage technologies of hydrogen is also discussed. The paper also discusses the hydrogen economy and future prospects from an Indian context. Hydrogen purification is necessary because of high purity requirements in particular applications like space fuel cells etc. Various applications of hydrogen are also addressed and a cost comparison of various hydrogen generation technologies is also analyzed. In conclusion this study can assist researchers in getting a better grasp of various renewable hydrogen generation pathways it's purification and storage technologies along with applications of hydrogen in understanding the hydrogen economy and its future prospect.
Comparative Techno-Environmental Assessment of Green Hydrogen Production via Steam Methane Reforming and Chemical Looping Reforming of Biomethane
Aug 2025
Publication
Green hydrogen derived from renewable resources is increasingly recognized as a basis for future low-carbon energy systems. This study presents a comprehensive techno-environmental comparison of two thermochemical conversion pathways utilizing biomethane: steam methane reforming (SMR) and chemical looping reforming (CLR). Through integrated process simulations compositional analyses energy modeling and cost evaluation we examine the comparative advantages of each route in terms of hydrogen yield carbon separation efficiency process energy intensity and economic performance. The results demonstrate that CLR achieves a significantly higher hydrogen concentration in the raw syngas stream (62.44%) than SMR (43.14%) with reduced levels of residual methane and carbon monoxide. The energy requirements for hydrogen production are lower in the CLR system averaging 1.2 MJ/kg compared to 3.2 MJ/kg for SMR. Furthermore CLR offers a lower hydrogen production cost (USD 4.3/kg) compared to SMR (USD 6.4/kg) primarily due to improved thermal integration and the absence of solvent-based CO2 capture. These insights highlight the potential of CLR as a next-generation reforming strategy for producing green hydrogen. To advance its technology readiness it is proposed to develop a pilot-scale CLR facility to validate system performance under operational conditions and support the pathway to commercial implementation.
Review and Prospects of Key Technologies for Integrated Systems in Hydrogen Production from Offshore Superconducting Wind Power
Dec 2024
Publication
Hydrogen production from renewable energy sources is a crucial pathway to achieving the carbon peak target and realizing the vision of carbon neutrality. The hydrogen production from offshore superconducting wind power (HPOSWP) integrated systems as an innovative technology in the renewable energy hydrogen production field holds significant market potential and promising development prospects. This integrated technology based on research into high-temperature superconducting generator (HTSG) characteristics and electrolytic water hydrogen production (EWHP) technology converts offshore wind energy (OWE) into hydrogen energy locally through electrolysis with hydrogen storage being shipped and controlled liquid hydrogen (LH2) circulation ensuring a stable low-temperature environment for the HTSGs’ refrigeration system. However due to the significant instability and intermittency of offshore wind power (OWP) this HPOSWP system can greatly affect the dynamic adaptability of the EWHP system resulting in impure hydrogen production and compromising the safety of the LH2 cooling system and reduce the fitness of the integrated system for wind electricity–hydrogen heat multi-field coupling. This paper provides a comprehensive overview of the fundamental structure and characteristics of this integrated technology and further identifies the key challenges in its application including the dynamic adaptability of electrolytic water hydrogen production technology as well as the need for large-capacity long-duration storage solutions. Additionally this paper explores the future technological direction of this integrated system highlighting the need to overcome the limitations of electrical energy adaptation within the system improve product purity and achieve large-scale applications.
Hydrogen Production by Wastewater Alkaline Electro-Oxidation
Aug 2024
Publication
The current work presents the electro-oxidation of olive mill and biodiesel wastewaters in an alkaline medium with the aim of hydrogen production and simultaneous reduction in the organic pollution content. The process is performed at laboratory scale in an own-design single cavity electrolyzer with graphite electrodes and no membrane. The system and the procedures to generate hydrogen under ambient conditions are described. The gas flow generated is analyzed through gas chromatography. The wastewater balance in the liquid electrolyte shows a reduction in the chemical oxygen demand (COD) pointing to a decrease in the organic content. The experimental results confirm the production of hydrogen with different purity levels and the simultaneous reduction in organic contaminants. This wastewater treatment appears as a feasible process to obtain hydrogen at ambient conditions powered with renewable energy sources resulting in a more competitive hydrogen cost.
Estimating the Replacement Potential of Norwegian High-speed Passenger Vessels with Zero-emission Solutions
Sep 2021
Publication
High-speed passenger vessels have high greenhouse gas emissions per passenger kilometre trav elled and require optimizations to provide a role in a low carbon society. This article works to wards this goal as a study of the potential for replacing high-speed passenger vessels with compressed hydrogen or battery electric zero emission solutions. To do this a model was developed based on automatic identification system data to calculate energy use for the existing Norwegian fleet in 2018. Using modelled energy consumption and assuming a maximum battery weight or compressed hydrogen volume each vessel can carry the most likely candidates for replacement were identified. Results showed that 51 out of 73 vessels are most suitable for hydrogen propulsion with 12 also suitable for battery electric propulsion. However timetable and route changes are required for more vessels to be suitable. Route optimisation studies are therefore required along with further detailed feasibility studies of the identified candidates and infrastructure requirements.
Decarbonising International Shipping - A Life Cycle Perspective on Alternative Fuel Options
Nov 2023
Publication
This study aimed to compare hydrogen ammonia methanol and waste-derived biofuels as shipping fuels using life cycle assessment to establish what potential they have to contribute to the shipping industry’s 100% greenhouse gas emission reduction target. A novel approach was taken where the greenhouse gas emissions associated with one year of global shipping fleet operations was used as a common unit for comparison therefore allowing the potential life cycle greenhouse gas emission reduction from each fuel option to be compared relative to Paris Agreement compliant targets for international shipping. The analysis uses life cycle assessment from resource extraction to use within ships with all GHGs evaluated for a 100-year time horizon (GWP100). Green hydrogen waste-derived biodiesel and bio-methanol are found to have the best decarbonisation po tential with potential emission reductions of 74–81% 87% and 85–94% compared to heavy fuel oil; however some barriers to shipping’s decarbonisation progress are identified. None of the alternative fuels considered are currently produced at a large enough scale to meet shipping’s current energy demand and uptake of alternative fuel vessels is too slow considering the scale of the challenge at hand. The decarbonisation potential from alternative fuels alone is also found to be insufficient as no fuel option can offer the 100% emission reduction required by the sector by 2050. The study also uncovers several sensitives within the life cycles of the fuel options analysed that have received limited attention in previous life cycle investigations into alternative shipping fuels. First the choice of allocation method can potentially double the life cycle greenhouse gas emissions of e-methanol due to the carbon ac counting challenges of using waste carbon dioxide streams during fuel production. This leads to concerns related to the true impact of using carbon dioxide captured from fossil-fuelled processes to produce a combustible product due to the resultant high downstream emissions. Second nitrous oxide emissions from ammonia combustion are found to be highly sensitive due to high greenhouse gas potency potentially offsetting any greenhouse reduction potential compared to heavy fuel oil. Further uncertainties are highlighted due to limited available data on the rate of nitrous oxide production from ammonia engines. The study therefore highlights an urgent need for the shipping sector to consider these factors when investing in new ammonia and methanol engines; failing to do so risks jeopardizing the sector’s progress towards decarbonisation. Finally whilst alternative fuels can offer good decarbonisation potential (particularly waste derived biomethanol and bio-diesel and green hydrogen) this cannot be achieved without accelerated investment in new and retrofit vessels and new fuel supply chains: the research concludes that existing pipeline of vessel orders and fuel production facilities is insufficient. Furthermore there is a need to integrate alternative fuel uptake with other decarbonisation strategies such as slow steaming and wind propulsion.
A Bibliometric Analysis on Renewable Energy Microgrids Integrating Hydrogen Storage: Strategies for Optimal Sizing and Energy Management
Feb 2025
Publication
Hydrogen is regarded as a viable alternative energy carrier because of its superior energy density and low emissions with great potential for decarbonizing multiple sectors and improving energy sustainability by integrating into the existing energy systems and renewable energy source within the utility. This paper provides a bibliometric assessment through an extensive review of highly cited articles on hydrogen storage integrated microgrid. The study utilized the Web of Science (WoS) database to look for specific keywords related to hydrogen storage integrated microgrid and associated research. The findings reveal that optimization highly positioned and connected to many other keywords is demonstrating its importance in the research area. Notable insights highlight the dominance of simulation-based studies a significant number of publications in toptier journals and the rise of innovative research fields including the creation of sustainable electrodes and improvements in system reliability and efficiency. The evaluation of the articles that are highly cited sheds light on diverse elements such as approach and system challenges and research spaces. This analysis shows ways to improve the performance of operation energy efficiency environmental sustainability cost-effectiveness stable supply of power on-location energy generation and flexibility thereby advancing technological innovation and fostering the development of hydrogen storage-integrated microgrids.
Enhanced Combustion and Emission Characteristics of Diesel-Algae Biodiesel-Hydrogen Blends in a Single-Cylinder Diesel Engine
Mar 2025
Publication
With the escalating global energy demand the pursuit of sustainable energy sources has become increasingly urgent. Among these biofuels have gained significant attention for their potential to provide renewable and eco-friendly alternatives. Biodiesel is recognized for its diverse and cost-effective feedstock options. The study provides a novel approach to the production of biodiesel by employing the use of Dunaliella salina microalgae as a green source. The research suggests the blends provide a future solution to less toxic fuel sources achieving efficiency and minimizing emissions. This research emphasize on the production of biodiesel from Dunaliella salina microalgae a promising resource due to its high energy yield. The microalgae were cultivated in an f/2 nutrient medium enriched with carbon dioxide vitamins and trace metals. A total of 700 mL of bio-oil was extracted using ultrasonication at 50 Hz for 85 minutes. Then the bio-oil was transesterified in a single-stage sodium hydroxide-catalysed process with methanol as a solvent. The process yielded a high extraction efficiency of 94%. The produced biodiesel was characterized through advanced analytical techniques including NMR spectroscopy GC-MS and FTIR test studies confirming its suitability as a fuel. Combustion and emission analyses revealed that the direct substitution of biodiesel blends for diesel in engines significantly reduced hydrocarbon and carbon monoxide emissions although a slight increase in nitrogen oxide (NOx) emissions was noted. The combustion and emission characteristics were influenced by blend composition and calorific value. Additionally the study provides a detailed comparison of the performance of pure diesel biodiesel blends and hydrogen-enriched biodiesel in diesel engines offering valuable insights into their environmental and performance impacts. This study gives additional insights towards future work such as scalability (consisting large scale cultivation of algae for better studies) engine durability (studies on engine wear and tear) and integration with renewable energy sources (integrating renewable sources like solar and wind energies).
Low-temperature Water Electrolysis: Fundamentals, Progress, and New Strategies
May 2022
Publication
Water electrolysis is a promising technology for sustainable energy conversion and storage of intermittent and fluctuating renewable energy sources and production of high-purity hydrogen for fuel cells and various industrial applications. Low-temperature electrochemical water splitting technologies include alkaline proton exchange membrane and anion exchange membrane water electrolyses which normally consist of two coupled half reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Despite the advances over decades formidable challenges still exist and hinder the practical application of large-scale energy-efficient and economically viable water electrolysis including large energy penalty sluggish kinetics high cost of precious metal based electrocatalysts possible H2/O2 gas crossover difficulty in storage and distribution of H2. Herein we first briefly introduce the fundamentals of water electrolysis summarize the recommended standardized electrochemical characterization protocols and demonstrate the metrics and key performance indicators that are used to evaluate the performances of HER and OER electrocatalysts and electrolyser cells. Then we present six new strategies to mitigate the technical challenges in conventional water electrolysis. These emerging strategies for disruptive innovation of water electrolysis technology include overall water electrolysis based on bifunctional nonprecious electrocatalysts (or pre-catalysts) magnetic field-assisted water electrolysis decoupled water electrolysis hybrid water electrolysis acid/alkaline asymmetric electrolyte electrolysis and tandem water electrolysis. Finally the remaining challenges perspectives and future directions are discussed. This review will provide guidance and inspire more endeavours to deepen the mechanistic understanding and advance the development of water electrolysis.
Hydrogen Refueling Station: Overview of the Technological Status and Research Enhancement
Jan 2023
Publication
Hydrogen refueling stations (HRSs) are key infrastructures rapidly spreading out to support the deployment of fuel cell electric vehicles for several mobility purposes. The research interest in these energy systems is increasing focusing on different research branches: research on innovation on equipment and technology proposal and development of station layout and research aiming to provide experimental data sets for perfor mance investigation. The present manuscript aims to present an overview of the most recent literature on hydrogen stations by presenting the technological status of the system at the global level and their research enhancement on the involved components and processes. After the review of the mentioned aspects this paper will present the already existing layouts and the potential configurations of such infrastructures considering several options of the delivery routes the end-user destination and hydrogen storage thermodynamic status whether liquid or gaseous.
Recent Developments in Hydrogen Production, Storage, and Transportation: Challenges, Opportunities, and Perspectives
Jul 2024
Publication
Hydrogen (H2 ) is considered a suitable substitute for conventional energy sources because it is abundant and environmentally friendly. However the widespread adoption of H2 as an energy source poses several challenges in H2 production storage safety and transportation. Recent efforts to address these challenges have focused on improving the efficiency and cost-effectiveness of H2 production methods developing advanced storage technologies to ensure safe handling and transportation of H2 and implementing comprehensive safety protocols. Furthermore efforts are being made to integrate H2 into the existing energy infrastructure and explore new opportunities for its application in various sectors such as transportation industry and residential applications. Overall recent developments in H2 production storage safety and transportation have opened new avenues for the widespread adoption of H2 as a clean and sustainable energy source. This review highlights potential solutions to overcome the challenges associated with H2 production storage safety and transportation. Additionally it discusses opportunities to achieve a carbon-neutral society and reduce the dependence on fossil fuels.
AI-ML Techniques for Green Hydrogen: A Comprehensive Review
Feb 2025
Publication
Green hydrogen is a cleaner source to replace fossil-based fuels and is critical in the global shift toward energy production to combat climate change. This review of embedding artificial intelligence (AI) and machine learning (ML) in the value chain of green hydrogen outlines the significant potential for full transformation. These include optimizing the utilization of renewable sources of energy improving electrolysis process hydrogen storage in the salt cavern that has better condition and smarter systems in distribution side with inexpensive logistics. In this it nullifies leak risks and safeguards the safety operations with detection using AI. Consequently it positions the paper emphasizing AI-ML approaches demonstrating significant advancements in efficiency and sustainability in green hydrogen technology.
Everything About Hydrogen Podcast: Resilience
Jul 2023
Publication
The EAH team discuss Nataliya’s plan for a green Ukraine including working with the current government on the Hydrogen Road Map. We also get another example of incredible Ukrainian resilience and discuss its importance for the current and future energy system.
The podcast can be found on their website.
The podcast can be found on their website.
Solar-Powered Water Electrolysis Using Hybrid Solid Oxide Electrolyzer Cell (SOEC) for Green Hydrogen—A Review
Nov 2023
Publication
The depletion of fossil fuels in the current world has been a major concern due to their role as a primary source of energy for many countries. As non-renewable sources continue to deplete there is a need for more research and initiatives to reduce reliance on these sources and explore better alternatives such as renewable energy. Hydrogen is one of the most intriguing energy sources for producing power from fuel cells and heat engines without releasing carbon dioxide or other pollutants. The production of hydrogen via the electrolysis of water using renewable energy sources such as solar energy is one of the possible uses for solid oxide electrolysis cells (SOECs). SOECs can be classified as either oxygen-ion conducting or proton-conducting depending on the electrolyte materials used. This article aims to highlight broad and important aspects of the hybrid SOEC-based solar hydrogen-generating technology which utilizes a mixed-ion conductor capable of transporting both oxygen ions and protons simultaneously. In addition to providing useful information on the technological efficiency of hydrogen production in SOEC this review aims to make hydrogen production more efficient than any other water electrolysis system.
Evaluation and Outlook for Australian Renewable Energy Export via Circular Liquid Hydrogen Carriers
Oct 2023
Publication
To combat global temperature rise we need affordable clean and renewable energy that does not add carbon to the atmosphere. Hydrogen is a promising option because it can be used as a carbon-free energy source. However storing and transporting pure hydrogen in liquid or gaseous forms is challenging. To overcome the limitations associated with conventional compressed and liquefied hydrogen or physio-chemical adsorbents for bulk storage and transport hydrogen can be attached to other molecules known as hydrogen carriers. Circular carriers which involve the production of CO2 or nitrogen during the hydrogen recovery process include substances such as methanol ammonia or synthetic natural gas. These carriers possess higher gravimetric and volumetric hydrogen densities (i.e. 12.5 wt% and 11.88 MJ/L for methanol) than cyclic carriers (i.e. 6.1 wt% and 5.66 MJ/L for methylcyclohexane (MCH)) which produce cyclic organic chemicals during dehydrogenation. This makes circular carriers particularly appealing for the Australian energy export market. Furthermore the production-decomposition cycle of circular carriers can be made carbon-neutral if they are derived from renewable H2 sources and combined with atmospheric or biomass-based CO2 or nitrogen. The key parameters are investigated in this study focusing on circular hydrogen carriers relevant to Australia. The parameters are ranked from 0 (worst) to 10 (best) depending on the bandwidth of the parameter in this review. Methanol shows great potential as a cost-effective solution for long-distance transport of renewable energy being a liquid at standard conditions with a boiling point of 64.7 °C. Methane is also an important hydrogen carrier due to the availability of natural gas infrastructure and its role as a significant export product for Australia.
Numerical Simulation of Diffusion Characteristics and Hazards in Multi-Hole Leakage from Hydrogen-Blended Natural Gas Pipelines
Aug 2025
Publication
In this study a 3D model is developed to simulate multi-hole leakage scenarios in buried pipelines transporting hydrogen-blended natural gas (HBNG). By introducing three parameters—the First Dangerous Time (FDT) Ground Dangerous Range (GDR) and Farthest Dangerous Distance (FDD)—to characterize the diffusion hazard of the gas mixture this study further analyzes the effects of the number of leakage holes hole spacing hydrogen blending ratio (HBR) and soil porosity on the diffusion hazard of the gas mixture during leakage. Results indicate that gas leakage exhibits three distinct phases: initial independent diffusion followed by an intersecting accelerated diffusion stage and culminating in a unified-source diffusion. Hydrogen exhibits the first two phases whereas methane undergoes all three and dominates the GDR. Concentration gradients for multi-hole leakage demonstrate similarities to single-hole scenarios but multi-hole leakage presents significantly higher hazards. When the inter-hole spacing is small diffusion characteristics converge with those of single-hole leakage. Increasing HBR only affects the gas concentration distribution near the leakage hole with minimal impact on the overall ground danger evolution. Conversely variations in soil porosity substantially impact leakage-induced hazards. The outcomes of this study will support leakage monitoring and emergency management of HBNG pipelines.
A Study on the Thermal Behavior of Series and Parallel Connection Methods in the Process of Hydrogenation of Ship-Borne Hydrogen Storage Cylinder
Feb 2024
Publication
As a subdivision of the hydrogen energy application field ship-borne hydrogen fuel cell systems have certain differences from vehicle or other application scenarios in terms of their structural type safety environmental adaptability and test verification. The connection method of the ship-borne hydrogen storage cylinder (SHSC) is very important for the hydrogen fuel cell ship and the structural parameters of the SHSC are particularly important in the hydrogen refueling process. To ensure the safe and reliable operation of the hydrogen-powered ship research on the filling of the SHSC under different connection modes was carried out during refueling. In our study a thermal flow physical model of the SHSC was established to research the hydrogen refueling process of the series and parallel SHSCs. The influence of series and parallel modes of the SHSCs on the hydrogen refueling process was explored and the evolution law of the internal flow field pressure and temperature of series and parallel SHSCs under different filling parameters was analyzed by numerical simulation. Our results confirmed the superiority of the parallel modular approach in terms of thermal safety during refueling. The results can supply a technical basis for the future development of hydrogen refueling stations and ship-board hydrogenation control algorithms.
An Improved Artificial Ecosystem Optimization Algorithm for Optimal Configuration of a Hybrid PV/WT/FC Energy System
Oct 2020
Publication
This paper mainly focuses on the optimal design of a grid-dependent and off-grid hybrid renewable energy system (RES). This system consists of Photovoltaic (PV) Wind Turbine (WT) as well as Fuel Cell (FC) with hydrogen gas tank for storing the energy in the chemical form. The optimal components sizes of the proposed hybrid generating system are achieved using a novel metaheuristic optimization technique. This optimization technique called Improved Artificial Ecosystem Optimization (IAEO) is proposed for enhancing the performance of the conventional Artificial Ecosystem Optimization (AEO) algorithm. The IAEO improves the convergence trends of the original AEO gives the best minimum objective function reaches the optimal solution after a few iterations numbers as well as reduces the falling into the local optima. The proposed IAEO algorithm for solving the multiobjective optimization problem of minimizing the Cost of Energy (COE) the reliability index presented by the Loss of Power Supply Probability (LPSP) and excess energy under the constraints are considered. The hybrid system is suggested to be located in Ataka region Suez Gulf (latitude 30.0 longitude 32.5) Egypt and the whole lifetime of the suggested case study is 25 years. To ensure the accurateness stability and robustness of the proposed optimization algorithm it is examined on six different configurations representing on-grid and off-grid hybrid RES. For all the studied cases the proposed IAEO algorithm outperforms the original AEO and generates the minimum value of the fitness function in less execution time. Furthermore comprehensive statistical measurements are demonstrated to prove the effectiveness of the proposed algorithm. Also the results obtained by the conventional AEO and IAEO are compared with those obtained by several well-known optimization algorithms Particle Swarm Optimization (PSO) Salp Swarm Algorithm (SSA) and Grey Wolf Optimizer (GWO). Based on the obtained simulation results the proposed IAEO has the best performance among other algorithms and it has successfully positioned itself as a competitor to novel algorithms for tackling the most complicated engineering problems.
Exploring European Hydrogen Demand Variations under Tactical Uncertainty with Season Hydrogen Storage
Aug 2025
Publication
Achieving a net-zero energy system in Europe by 2050 will likely require large-scale deployment of hydrogen and seasonal energy storage to manage variability in renewable supply and demand. This study addresses two key objectives: (1) to develop a modeling framework that integrates seasonal storage into a stochastic multihorizon capacity expansion model explicitly capturing tactical uncertainty across timescales; and (2) to assess the impact of seasonal hydrogen storage on long-term investment decisions in European power and hydrogen infrastructure under three hydrogen demand scenarios. To this end the multi-horizon stochastic programming model EMPIRE is extended with tactical stages within each investment period enabling operational decisions to be modeled as a multi-stage stochastic program. This approach captures short-term uncertainty while preserving long-term investment foresight. Results show that seasonal hydrogen storage considerably enhances system flexibility displacing the need for up to 600 TWh/yr of dispatchable generation in Europe after 2040 and sizing down cross-border hydrogen transmission capacities by up to 12%. Storage investments increase by factors of 5–14 which increases the investments in variable renewables and improve utilization particularly solar. Scenarios with seasonal storage also show up to 6% lower total system costs and more balanced infrastructure deployment across regions. These findings underline the importance of modeling temporal uncertainty and seasonal dynamics in long-term energy system planning.
Modulating Selectivity and Stability of the Direct Seawater Electrolysis for Sustainable Green Hydrogen Production
Feb 2025
Publication
Direct seawater electrolysis (DSE) has emerged as a compelling route to sustainable hydrogen production leveraging the vast global reserves of seawater. However the inherently complex composition of seawater—laden with halide ions multivalent cations (Mg2+ Ca2+) and organic/biological impurities—presents formidable challenges in maintaining both selectivity and durability. Chief among these obstacles is mitigating chloride corrosion and suppressing chlorine evolution reaction (ClER) at the anode while also preventing the precipitation of magnesium and calcium hydroxides at the cathode. This review consolidates recent advances in material engineering and cell design strategies aimed at controlling undesired side reactions enhancing electrode stability and maximizing energy efficiency in DSE. We first outline the fundamental thermodynamic and kinetic hurdles introduced by Cl⁻ and other impurities. This discussion highlights how these factors accelerate catalyst degradation and drive suboptimal reaction pathways. We then delve into innovative approaches to improve selectivity and durability of DSE—such as engineering protective barrier layers tuning electrolyte interfaces developing corrosion-resistant materials and techniques to minimize Mg/Ca-related precipitations. Finally we explore emerging reactor configurations including asymmetric and membrane-free electrolyzers which address some barriers for DSE commercialization. Collectively these insights provide a framework for designing next-generation DSE systems which can achieve large-scale cost-effective and environmentally benign hydrogen production.
Governance of Future-making: Green Hydrogen in Namibia and South Africa
Feb 2025
Publication
The green-hydrogen sector has created considerable expectations in the Global South about export-oriented development and industrial path creation. However whether and how these expectations are really materializing requires further scrutiny. This article develops a conceptual approach that we call governance of futuremaking. Thereby we want to understand how actors try to coordinate their expectations about future economic development in different contexts and across scales over time. We conceptualize the emergence of new regional development trajectories as resulting from the use of governance instruments with an increasing bindingness which reflect the interplay between governance of and by expectations. Based on this approach we analyze and compare green-hydrogen activities in Namibia and South Africa. We find that future-making is becoming more binding in both countries but has not resulted in path creation yet.
Hydrogen Revolution: Artificial Intelligence and Machine Learning Driven Policies, Feasibility, Challenges and Opportunities: Insights from Asian Countries
Aug 2025
Publication
Green hydrogen a zero-carbon emission fuel has become a real competitor to transform the energy market thanks to improvements in the electrolysis process decreased costs and the presence of renewable energy resources. Energy industries have shown considerable progress in hydrogen production due to the incorporation of artificial intelligence (AI) knowledge through algorithms AI-based models and data programs. These techniques can greatly enhance the production storage and transportation of hydrogen fuel. The main goal of this article is to demonstrate the recent technological advancements and the influence of various AI techniques algorithms and models on the hydrogen energy sector along with this further examination of the energy policies of countries like China Japan India and South Korea. The key challenges related to these energy policies are addressed through standardized datasets AI models and optimized environmental conditions. This paper serves as a valuable resource for researchers engineers and practitioners interested in applying cutting-edge technologies to enhance hydrogen safety systems. AI-based models contribute to the overall shift towards a sustainable energy future by enhancing efficiency reducing costs and facilitating hydrogen energy commerce for Asian countries. This study accelerates the global investigation and tremendous applications of sophisticated machine-learning methodologies for producing renewable green hydrogen.
Enhancing Efficiency in Photovoltaic Hydrogen Production: A Comparative Analysis of MPPT and Electrolysis Control Strategies
Feb 2025
Publication
With the rapid growth of photovoltaic installed capacity photovoltaic hydrogen production can effectively solve the problem of electricity mismatch between new energy output and load demand. Photovoltaic electrolysis systems pose unique challenges due to their nonlinear multivariable and complex nature. This paper presents a thorough investigation into the control methodologies for such systems focusing on both Maximum Power Point Tracking (MPPT) and electrolysis cell control strategies. Beginning with a comprehensive review of MPPT techniques including classical intelligent optimization and hybrid approaches the study delves into the intricate dynamics of Proton Exchange Membrane Electrolysis Cells (PEMEL). Considering the nonlinear and time-varying characteristics of PEMEL various control strategies such as Proportional-Integral-Derivative (PID) robust Model Predictive Control (MPC) and Fault Tolerant Control (FTC) are analyzed. Evaluation metrics encompass stability accuracy computational complexity and response speed. This paper provides a comparative analysis encapsulating the strengths and limitations of each MPPT and PEM control technique.
The Recent Progresses of Electrodes and Electrolysers for Seawater Electrolysis
Jan 2024
Publication
The utilization of renewable energy for hydrogen production presents a promising pathway towards achieving carbon neutrality in energy consumption. Water electrolysis utilizing pure water has proven to be a robust technology for clean hydrogen production. Recently seawater electrolysis has emerged as an attractive alternative due to the limitations of deep-sea regions imposed by the transmission capacity of long-distance undersea cables. However seawater electrolysis faces several challenges including the slow kinetics of the oxygen evolution reaction (OER) the competing chlorine evolution reaction (CER) processes electrode degradation caused by chloride ions and the formation of precipitates on the cathode. The electrode and catalyst materials are corroded by the Cl− under long-term operations. Numerous efforts have been made to address these issues arising from impurities in the seawater. This review focuses on recent progress in developing high-performance electrodes and electrolyser designs for efficient seawater electrolysis. Its aim is to provide a systematic and insightful introduction and discussion on seawater electrolysers and electrodes with the hope of promoting the utilization of offshore renewable energy sources through seawater electrolysis.
Hydrogen-Powered Marine Vessels: A Rewarding yet Challenging Route to Decarbonization
Aug 2025
Publication
The maritime industry while indispensable to global trade is a significant contributor to greenhouse gas (GHG) emissions accounting for approximately 3% of global emissions. As international regulatory bodies particularly the International Maritime Organization (IMO) push for ambitious decarbonization targets hydrogen-based technologies have emerged as promising alternatives to conventional fossil fuels. This review critically examines the potential of hydrogen fuels—including hydrogen fuel cells (HFCs) and hydrogen internal combustion engines (H2ICEs)—for maritime applications. It provides a comprehensive analysis of hydrogen production methods storage technologies onboard propulsion systems and the associated techno-economic and regulatory challenges. A detailed life cycle assessment (LCA) compares the environmental impacts of hydrogenpowered vessels with conventional diesel engines revealing significant benefits particularly when green or blue hydrogen sources are utilized. Despite notable hurdles—such as high production and retrofitting costs storage limitations and infrastructure gaps—hydrogen holds considerable promise in aligning maritime operations with global sustainability goals. The study underscores the importance of coordinated government policies technological innovation and international collaboration to realize hydrogen’s potential in decarbonizing the marine sector.
Everything About Hydrogen Podcast: Electric or Hydrogen? It's 'AND' not 'OR'
May 2023
Publication
On this weeks episode we have Juergen Guldner General Program Manager Hydrogen Technology at BMW. The role of hydrogen in passenger vehicles has for many years been seen as a lonely pursuit for Toyota and Hyundai but the landscape is changing. With the Warrego from startup H2X the Ford H2 pick up the Grenadier/Defender F-Cell from INEOS and now the BMW IX5 it is clear that the race to net zero is far from settled!
In this episode the team dive into the what why and how of the BMW story towards one of the world’s most exciting zero emission vehicle offerings. We explore the details of the vehicle and its performance the reasons why BMW are exploring the potential for hydrogen and why now is the time they feel for hydrogen as a passenger vehicle solution to compliment BEV and finally the How or rather the plan for the testing and broader roll-out of not only the IX5 but also the infrastructure that supports it.
The podcast can be found on their website.
In this episode the team dive into the what why and how of the BMW story towards one of the world’s most exciting zero emission vehicle offerings. We explore the details of the vehicle and its performance the reasons why BMW are exploring the potential for hydrogen and why now is the time they feel for hydrogen as a passenger vehicle solution to compliment BEV and finally the How or rather the plan for the testing and broader roll-out of not only the IX5 but also the infrastructure that supports it.
The podcast can be found on their website.
Everything About Hydrogen Podcast: Getting Steel in the Ground in an IRA Driven H2 Market
May 2023
Publication
On this episode we speak with Scott Weiss Senior Vice President for Corporate Strategy and Ashleigh Cotting Senior Manager for Green Fuels Marketing with Apex Clean Energy. Apex has a history of developing utility scale renewables with more than 2GW under management and with nearly 8GW of renewables financed. Apex also partnered with Plug Power in April 2021 to develop a 345MW wind facility to support a 30 tonne per day green hydrogen production facility.
We are excited to discuss the emerging opportunities in the US hydrogen market and learn more about the challenges and learnings that the first project is providing and how that helps the team build the next generation of production facilities particularly in the Gulf Coast.
The podcast can be found on their website.
We are excited to discuss the emerging opportunities in the US hydrogen market and learn more about the challenges and learnings that the first project is providing and how that helps the team build the next generation of production facilities particularly in the Gulf Coast.
The podcast can be found on their website.
Geomechanical and Geochemical Considerations for Hydrogen Storage in Shale and Tight Reservoirs
Aug 2025
Publication
Underground hydrogen storage (UHS) in shale and tight reservoirs offers a promising solution for large-scale energy storage playing a critical role in the transition to a hydrogenbased economy. However the successful deployment of UHS in these low-permeability formations depends on a thorough understanding of the geomechanical and geochemical factors that affect storage integrity injectivity and long-term stability. This review critically examines the geomechanical aspects including stress distribution rock deformation fracture propagation and caprock integrity which govern hydrogen containment under subsurface conditions. Additionally it explores key geochemical challenges such as hydrogen-induced mineral alterations adsorption effects microbial activity and potential reactivity with formation fluids to evaluate their impact on storage feasibility. A comprehensive analysis of experimental studies numerical modeling approaches and field applications is presented to identify knowledge gaps and future research directions.
Mutli-scale Solar-to-hydrogen System Design: An Open-source Modeling Framework
Sep 2025
Publication
Hydrogen produced from renewable energy holds significant potential in providing sustainable solutions to achieve Net-Positive goals. However one technical challenge hindering its widespread adoption is the absence of open-source precise modeling tools for sizing and simulating integrated system components under realworld conditions. In this work we developed an adaptable user-friendly and open-source Python® model that simulates grid-connected battery-assisted photovoltaic-electrolyzer systems for green hydrogen production and conversion into high-value chemicals and fuels. The code is publicly available on GitHub enabling users to predict solar hydrogen system performance across various sizes and locations. The model was applied to three locations with distinct climatic patterns – Sines (Portugal) Edmonton (Canada) and Crystal Brook (Australia) – using commercial photovoltaic and electrolyzer systems and empirical data from different meteorological databases. Sines emerged as the most productive site with an annual photovoltaic energy yield 39 % higher than Edmonton and 9 % higher than Crystal Brook. When considering an electrolyzer load with 0.5 WEC/Wp PV capacity solely powered by the photovoltaic park the solar-to-hydrogen system in Sines can reach an annual green hydrogen production of 27 g/Wp PV and export 283 Wh/Wp PV of surplus electricity to the grid. Continuous 24/7 electrolyzer operation increased the annual hydrogen output to 33 g/Wp PV with a reduced Levelized Cost of Hydrogen of €6.42/kgH2. Overall this work aims to advance green hydrogen production scale-up fostering a more sustainable global economy.
Recent Updates in Direct Radiation Water-splitting Methods of Hydrogen Production
Dec 2023
Publication
The exploration of green energy is a demanding issue due to climate change and ecology. Green energy hydrogen is gaining importance in the area of alternative energy sources. Many methods are being explored for this but most of them are utilizing other sources of energy to produce hydrogen. Therefore these approaches are not economic and acceptable at the industrial level. Sunlight and nuclear radiation as free or low-cost energy sources to split water for hydrogen. These methods are gaining importance in recent times. Therefore attempts are made to explore the latest updates in direct radiation water-splitting methods of hydrogen production. This article discusses the advances made in green hydrogen production by water splitting using visible and UV radiations as these are freely available in the solar spectrum. Besides water splitting by gamma radiation (a low-cost energy source) is also reviewed. Eforts are also made to describe the water-splitting mechanism in photo- and gamma-mediated water splitting. In addition to these challenges and future perspectives have also been discussed to make this article useful for further advanced research.
A Review of Hydrogen Storage and Transportation: Progresses and Challenges
Aug 2024
Publication
This review aims to summarize the recent advancements and prevailing challenges within the realm of hydrogen storage and transportation thereby providing guidance and impetus for future research and practical applications in this domain. Through a systematic selection and analysis of the latest literature this study highlights the strengths limitations and technological progress of various hydrogen storage methods including compressed gaseous hydrogen cryogenic liquid hydrogen organic liquid hydrogen and solid material hydrogen storage as well as the feasibility efficiency and infrastructure requirements of different transportation modes such as pipeline road and seaborne transportation. The findings reveal that challenges such as low storage density high costs and inadequate infrastructure persist despite progress in high-pressure storage and cryogenic liquefaction. This review also underscores the potential of emerging technologies and innovative concepts including metal–organic frameworks nanomaterials and underground storage along with the potential synergies with renewable energy integration and hydrogen production facilities. In conclusion interdisciplinary collaboration policy support and ongoing research are essential in harnessing hydrogen’s full potential as a clean energy carrier. This review concludes that research in hydrogen storage and transportation is vital to global energy transformation and climate change mitigation.
Thermo-economic Optimization of a Hybrid Solar-wind Energy System for the Production of Clean Hydrogen and Electricity
Feb 2025
Publication
With the increasing warming of the atmosphere and the growth of energy consumption in the world new methods and highly efficient energy systems take precedence over conventional methods. This study concentrates on the proposition and techno-economical investigation of a hybrid wind-solar energy system encompassing flat plate solar collector for the purpose of clean hydrogen and electricity generation. The proposed system is a combination of flat plate solar collectors wind turbine organic Rankine cycle and proton exchange membrane electrolyser. Wind speed turbine inlet temperature incident solar irradiation and collector-related parameters including its surface area and fluid mass flow rate are selected decision variables the impacts of which on the exergy efficiency and exergy loss of the scheme are examined. The objective functions included total cost rate and total exergy efficiency. The Nelder-Mead optimization method and EES software were utilized to achieve the mentioned goals followed by a comparative case study was conducted for two cities with high potential in Iran. According to the optimization results the exergy efficiency of 13.35% was achieved while the cost rate was equal to $25.48 per hour respectively. According to the sensitivity analysis the increment in the solar collector area incident solar irradiation wind speed and turbine inlet temperature improved the system's technical performance. Furthermore the exergy loss analysis pointed out that the increment in the turbine inlet temperature not only improves the system's performance but also reduces the exergy loss. A comparison of the electricity production in Semnan and Isfahan showed that 1192613.4 and 1188897.6 of electricity were produced in the two cities in one year respectively. The city of Semnan with the production of 2762.86 kg/h of hydrogen presented better system performance compared to the city of Isfahan with 2757.004 kg/h of hydrogen.
Hydrogen from Wastewater by Photocatalytic and Photoelectrochemical Treatment
Dec 2020
Publication
In recent years the intensification of human activities has led to an increase in waste production and energy demand. The treatment of pollutants contained in wastewater coupled to energy recovery is an attractive solution to simultaneously reduce environmental pollution and provide alternative energy sources. Hydrogen represents a clean energy carrier for the transition to a decarbonized society. Hydrogen can be generated by photosynthetic water splitting where oxygen and hydrogen are produced and the process is driven by the light energy absorbed by the photocatalyst. Alternatively hydrogen may be generated from hydrogenated pollutants in water through photocatalysis and the overall reaction is thermodynamically more favourable than water splitting for hydrogen. This review is focused on recent developments in research surrounding photocatalytic and photoelectrochemical hydrogen production from pollutants that may be found in wastewater. The fundamentals of photocatalysis and photoelectrochemical cells are discussed along with materials and efficiency determination. Then the review focuses on hydrogen production linked to the oxidation of compounds found in wastewater. Some research has investigated hydrogen production from wastewater mixtures such as olive mill wastewater juice production wastewater and waste activated sludge. This is an exciting area for research in photocatalysis and semiconductor photoelectrochemistry with real potential for scale up in niche applications.
Energy and Cost Analysis of a Hydrogen Driven High Speed Passenger Ferry
Apr 2020
Publication
BACKGROUND: Norway is facing the challenge of reducing transport emissions. High speed crafts(HSC) are the means of transport with highest emissions. Currently there is little literature or experienceof using hydrogen systems for HSC.OBJECTIVE: Evaluate the economic feasibility of fuel cell (FC) powered HSC vs diesel and biodieseltoday and in a future scenario based on real world operation profile.<br/>METHOD: Historical AIS position data from the route combined with the speed-power characteristicsof a concept vessel was used to identify the energy and power demand. From the resulting data a suitableFC system was defined and an economic comparison made based on annual costs including annualizedinvestment and operational costs.<br/>RESULTS: HSC with a FC-system has an annual cost of 12.6 MNOK. It is 28% and 12% more expensivethan diesel and biodiesel alternative respectively. A sensitivity analysis with respect to 7 key design pa-rameters indicates that highest impact is made by hull energy efficiency FC system cost and hydrogen fuelcost. In a future scenario (2025–2030) with moderate technology improvements and cost developmentthe HSC with FC-systems can become competitive with diesel and cheaper than biodiesel.<br/>CONCLUSIONS: HSC with FC-systems may reach cost parity with conventional diesel in the period2025–2030.
Everything About Hydrogen Podcast: Opportunities in Africa
Sep 2023
Publication
For the second episode in this new season the team interviews Oghosa Erhahon to discuss hydrogen opportunities in Africa including the African Climate Summit in September and what to look forward to at COP28.
The podcast can be found on their website.
The podcast can be found on their website.
Optimization and Dynamic Responses of an Integrated Fuel Cell and Battery System for an 800 kW Ferry: A Case Study
Aug 2022
Publication
The recent targets by different countries to stop the sales or registrations of internal combustion engines (ICE) have led to the further development of battery and fuel cell technologies to provide power for different applications. The main aim of this study is to evaluate the possibility of using an integrated Lithium-Ion battery and proton exchange membrane fuel cell (PEMFC) as the prime mover for a case study of a 800 kW ferry with a total length of 50.8 m to transport 780 passengers for a distance of 24 km in 70 min. Accounting for five types of Lithium-Ion batteries and different numbers of PEMFCs twenty-five scenarios are suggested based on a quasi-static model. To perform the optimization the Performance Criterion of the Fuel cell–Battery integrated systems (PCFB) is introduced to include the effects of the sizes weights costs hydrogen consumption efficiency and power in addition to the number of fuel cells and the battery capacity. Results indicate that the maximum PCFB value of 10.755 (1/kg2m3 $) can be obtained once the overall size weight efficiency hydrogen consumption and cost of the system are 18 m3 11160 kg 49.25% 33.6 kg and 119.58 k$ respectively using the Lithium Titanite Oxide (LTO) Lithium-Ion battery with nine PEMFCs.
Impacts of Intermittency on Low-temperature Electrolysis Technologies: A Comprehensive Review
May 2024
Publication
By offering promising solutions to two critical issues – the integration of renewable energies into energy systems and the decarbonization of existing hydrogen applications – green hydrogen production through water electrolysis is set to play a crucial role in addressing the major challenges of the energy transition. However the successful integration of renewable energy sources relies on gaining accurate insights into the impacts that intermittent electrical supply conditions induce on electrolyzers. Despite the rising importance of addressing intermittency issues to accelerate the widespread adoption of renewable energy sources the state-of-the-art lacks research providing an in-depth understanding of these concerns. This paper endeavors to offer a comprehensive review of existing research focusing on proton exchange membrane (PEM) and alkaline electrolysis technologies operating under intermittent operation. Despite growing interest over the last ten years the review underscores the scarcity of industrial-scale databases for quantifying these impacts.
Assessing the Cost-effectiveness of Carbon Neutrality for Light-duty Vehicle Sector in China
Nov 2023
Publication
China’s progress in decarbonizing its transportation particularly vehicle electrification is notable. However the economically effective pathways are underexplored. To find out how much cost is necessary for carbon neutrality for the light-duty vehicle (LDV) sector this study examines twenty decarbonization pathways combining the New Energy and Oil Consumption Credit model and the China-Fleet model. We find that the 2060 zero-greenhouse gas (GHG) emission goal for LDVs is achievable via electrification if the battery pack cost is under CNY483/kWh by 2050. However an extra of CNY8.86 trillion internal subsidies is needed under pessimistic battery cost scenarios (CNY759/kWh in 2050) to eliminate 246 million tonnes of CO2-eq by 2050 ensuring over 80% market penetration of battery electric vehicles (BEVs) in 2050. Moreover the promotion of fuel cell electric vehicles is synergy with BEVs to mitigate the carbon abatement difficulties decreasing up to 34% of the maximum marginal abatement internal investment.
Efficiency and Consistency Enhancement for Alkaline Electrolyzers Driven by Renewable Energy Sources
May 2023
Publication
Low-cost alkaline water electrolysis from renewable energy sources (RESs) is suitable for large-scale hydrogen production. However fluctuating RESs lead to poor performance of alkaline water electrolyzers (AWEs) at low loads. Here we explore two urgent performance issues: inefficiency and inconsistency. Through detailed operation process analysis of AWEs and the established equivalent electrical model we reveal the mechanisms of inefficiency and inconsistency of low-load AWEs are related to the physical structure and electrical characteristics. Furthermore we propose a multi-mode self-optimization electrolysis converting strategy to improve the efficiency and consistency of AWEs. In particular compared to a conventional dc power supply we demonstrate using a lab-scale and large-scale commercially available AWE that the maximum efficiency can be doubled while the operation range of the electrolyzer can be extended from 30–100% to 10–100% of rated load. Our method can be easily generalized and can facilitate hydrogen production from RESs.
Entropy Production and Filling Time in Hydrogen Refueling Stations: An Economic Assessment
Aug 2024
Publication
A multi-objective optimization is performed to obtain fueling conditions in hydrogen stations leading to improved filling times and thermodynamic efficiency (entropy production) of the de facto standard of operation which is defined by the protocol SAE J2601. After finding the Pareto frontier between filling time and total entropy production it was found that SAE J2601 is suboptimal in terms of these process variables. Specifically reductions of filling time from 47 to 77% are possible in the analyzed range of ambient temperatures (from 10 to 40 °C) with higher saving potential the hotter the weather conditions. Maximum entropy production savings with respect to SAE J2601 (7% for 10 °C 1% for 40 °C) demand a longer filling time that increases with ambient temperature (264% for 10 °C 350% for 40 °C). Considering average electricity prices in California USA the operating cost of the filling process can be reduced between 8 and 28% without increasing the expected filling time.
Mechanical Testing Methods for Assessing Hydrogen Embrittlement in Pipeline Steels: A Review
Oct 2025
Publication
As the transport of gaseous hydrogen and its use as a low carbon-footprint energy vector become increasingly likely scenarios both the scientific literature and technical standards addressing the compatibility of pipeline steels with high-pressure hydrogen environments are rapidly expanding. This work presents a detailed review of the most relevant hydrogen embrittlement testing methodologies proposed in standards and the academic literature. The focus is placed on testing approaches that support design-oriented assessments rather than simple alloy qualification for hydrogen service. Particular attention is given to tensile tests (conducted on smooth and notched specimens) as well as to J-integral and fatigue tests performed following the fracture mechanics’ approach. The influences of hydrogen partial pressure and deformation rate are critically examined as these parameters are essential for ensuring meaningful comparisons across different studies.
Hydrogen UK - Supply Chain Strategic Assessment: Phase I
Mar 2025
Publication
The UK Hydrogen Supply Chain Strategic Assessment – Phase II report is developed as an appendix to the UK Hydrogen Supply Chain Strategic Assessment – Phase I report published in September 2024. Whereas the Phase I report prioritised the supply side elements of the hydrogen supply chain i.e. power industry storage electrolytic production CCUS enabled production and networks the Phase II focuses on demand side elements in the hydrogen supply chain i.e. fuel cell systems (including cars vans heavy goods vehicles & non road mobile machinery rail marine) and hydrogen refuelling systems. The Phase II adopts the same approach as carried out in Phase I by utilising analysis based on feedback from survey questionnaires interviews with key industrial stakeholders and internal research.
The paper can be found on their website.
The paper can be found on their website.
Simulation of a Solar-based Small-scale Green Hydrogen Production Unit in Iran: A Techno-economic-feasibility Analysis
Aug 2025
Publication
Based on the global efforts to reduce fossil fuel dependence and its environmental concerns green hydrogen has been considered a promising pathway towards sustainable energy transition. Iran is considered a promising location for green hydrogen production due to its considerable solar energy potential. While global interest in green hydrogen continues to grow studies that explore the techno-economic feasibility of small-scale solar-based green hydrogen systems tailored to Iran’s diverse climatic conditions are still relatively limited. This study aims to assess the technical and economic feasibility of small-scale green hydrogen production based on solar energy (photovoltaics) in six cities of Iran including Isfahan Kerman Kermanshah Shiraz Tehran and Zahedan by examining whether such systems can be financially viable despite their relatively high unit costs. The study employs TRNSYS for dynamic simulation of the hydrogen production system and RETScreen for economic analysis. The results indicate that the system has an annual energy production capacity ranging from 831.52 to 1062.22 MWh across the studied locations. The system's hydrogen production rate was between 16800 and 21114 kg/year. Based on the results the lowest levelized cost of hydrogen (LCOH) was recorded in Shiraz at $6.43/kg H₂ while Tehran experienced the highest value ($8.81/kg H₂). Among the evaluated cities Shiraz demonstrated the most favorable financial performance with an internal rate of return (IRR) of 18.5% and a payback period of 8 years. These findings can be useful for policymakers in Iran and the MENA region in investment planning related to the clean energy transition.
The European Hydrogen Market Landscape - November 2024
Nov 2024
Publication
This report aims to summarise the status of the European hydrogen market landscape. It is based on the information available at the European Hydrogen Observatory (EHO) initiative the leading source of data on hydrogen in Europe exploring the basic concepts latest trends and role of hydrogen in the energy transition. The data presented in this report is based on research conducted until the end of September 2024. This report contains information on current hydrogen production and trade distribution and storage end-use cost and technology manufacturing as of the end of 2023 except if stated otherwise in Europe. A substantial portion of the data gathering was carried out within the framework of Hydrogen Europe's efforts for the European Hydrogen Observatory. Downloadable spreadsheets of the data can be accessed on the website: https://observatory.clean-hydrogen.europa.eu/. The production and trade section provides insights into hydrogen production capacity and production output by technology in Europe and into international hydrogen trade (export and import) to and between European countries. The section referring to distribution and storage presents the location and main attributes of operational dedicated hydrogen pipelines and storage facilities as well as publicly accessible and operational hydrogen refuelling stations in Europe. The end-use section provides information on annual hydrogen consumption per end-use in Europe the deployment of hydrogen fuel cell electric vehicles in Europe the current and future hydrogen Valleys in Europe and the leading scenarios for future hydrogen demand in Europe in 2030 2040 and 2050 by sector. The cost chapter offers a comprehensive examination of the levelised cost of hydrogen production by technology and country. This chapter also gives estimations of renewable hydrogen break-even prices for different end-use applications in addition to electrolyser cost components by technology. Finally a chapter on technologies manufacturing explores data on the European electrolyser manufacturing capacity and sales and the fuel cell market.
Synergistic Effects of Air Pollution and Carbon Reduction Policies in China’s Iron and Steel Industry
Oct 2025
Publication
As an energy-intensive sector China’s iron and steel industry is crucial for achieving “Dual Carbon” goals. This study fills the research gap in systematically comparing the synergistic effects of multiple policies by evaluating five key measures (2020–2023) in ultra-low-emission retrofits and clean energy alternatives. Using public macro-data at the national level this study quantified cumulative reductions in air pollutants (SO2 NOx PM VOCs) and CO2. A synergistic control effect coordinate system and a normalized synergistic emission reduction equivalent (APeq) model were employed. The results reveal significant differences: Sintering machine desulfurization and denitrification (SDD) showed the highest APeq but increased CO2 emissions in 2023. Dust removal equipment upgrades (DRE) and unorganized emission control (UEC) demonstrated stable co-reduction effects. While electric furnace short-process steelmaking (ES) and hydrogen metallurgy (HM) showed limited current benefits they represent crucial deep decarbonization pathways. The framework provides multi-dimensional policy insights beyond simple ranking suggesting balancing short-term pollution control with long-term transition by prioritizing clean alternatives.
Renewable Energy Storage in a Poly-Generative System Fuel Cell/Electrolyzer, Supporting Green Mobility in a Residential Building
Oct 2025
Publication
The European Commission through the REPowerEU plan and the “Fit for 55” package aims to reduce fossil fuel dependence and greenhouse gas emissions by promoting electric and fuel cell hybrid electric vehicles (EV-FCHEVs). The transition to this mobility model requires energy systems that are able to provide both electricity and hydrogen while reducing the reliance of residential buildings on the national grid. This study analyses a poly-generative (PG) system composed of a Solid Oxide Fuel Cell (SOFC) fed by biomethane a Photovoltaic (PV) system and a Proton Exchange Membrane Electrolyser (PEME) with electric vehicles used as dynamic storage units. The assessment is based on simulation tools developed for the main components and applied to four representative seasonal days in Rende (Italy) considering different daily travel ranges of a 30-vehicle fleet. Results show that the PG system provides about 27 kW of electricity 14.6 kW of heat and 3.11 kg of hydrogen in winter spring and autumn and about 26 kW 14 kW and 3.11 kg in summer; it fully covers the building’s electrical demand in summer and hot water demand in all seasons. The integration of EV batteries reduces grid dependence improves renewable self-consumption and allows for the continuous and efficient operation of both the SOFC and PEME demonstrating the potential of the proposed system to support the green transition.
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