Publications

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Application of low-emission hydrogen production methods in the decarbonization process remains a highly relevant topic particularly in the context of sustainable hydrogen value chains. This study evaluates hydrogen applications beyond industry focusing on its role as an energy carrier and applying multi-criteria decision analysis (MCDA) to assess economics environmental impact efficiency and technological readiness. The analysis confirmed that hydrogen use for heating was the most competitive non-industrial application (ranking first in 66%) with favorable efficiency and costs. Power generation placed among the top two alternatives in 75% of cases. Transport end-use was less suitable due to compression requirements raising emissions to 272–371 g CO2/kg H2 and levelizing the cost of hydrogen (LCOH) to 13–17 EUR/kg. When H2 transport was included new pipelines and compressed H2 clearly outperformed other methods for short- and long-distances adding only 3.2–3.9% to overall LCOH. Sensitivity analysis confirmed that electricity price variations had a stronger influence on LCOH than capital expenditures. Comparing electrolysis technologies yielded that proton-exchange membrane and solid oxide reduced costs by 12–20% and CO2 emissions by 15–25% compared to alkaline. The study highlights heating end-use and compressed hydrogen and pipeline transport proving MCDA to be useful for selecting scalable pathways.

To address the global climate crisis maritime logistics are undergoing a transition away from fossil-based energy sources. The transition is envisaged to be both green (involving renewables) and digital (involving various kinds of digitalization). Much of the hope rests on the new hydrogen economy involving the build-up of infrastructure for hydrogen-derived alternative fuels such as methanol and ammonia. Indeed the new hydrogen economy is often portrayed as set to revolutionize maritime transport. The hope behind the hype reflects a belief in the performativity of hypes: some technological phenomenon will eventually materialise in innovation and business practices. In this paper we critically analyse the current hydrogen hype in the field of Finnish maritime logistics as a paradigmatic case of performative techno-optimism. Based on causal network analysis and thematic analysis of expert interviews and workshop data we argue that the phenomenon of performative techno-optimism is more nuanced than hitherto presented in the related literature. We showcase a variety of stances along a spectrum ranging from radical optimism to radical pessimism. Furthermore our causal network analysis indicates that the current green and digital transition of maritime transport is caught in a systemic catch-22: transitioning to alternative fuels in maritime logistics faces a lock-in of between overly cautious demand for alternative fuels leading to overly cautious investment in supply which only secures the modest demand. Finally our thematic analysis of techno-optimist stances suggests the following two major ways out of the systemic dilemma: large-scale technological innovations and global regulatory solutions.

Green hydrogen is an important technology in the energy transition with potential to decarbonize industrial processes increase renewable energy use and reduce reliance on fossil fuels yet it currently accounts for less than 1% of global hydrogen demand. One promising approach to expand production is the direct coupling of photovoltaic–electrolyzer systems. In this study overall and sub-system efficiencies were analyzed for different system setups coupling points and operating conditions such as temperature and irradiance. The highest overall system efficiencies were found to be more than 18%. The effect of varying irradiances on the coupled efficiency was not more than 5.7%. Different system designs optimized for different irradiances led to effects such as an increase in current density at the electrolyzer and thus an increase in the overvoltage which resulted in an overall efficiency loss of more than 3%. A key finding was that aligning the PV maximum power point with the electrolyzer polarization curve enables consistently high system efficiencies across the investigated irradiances. The findings were validated with two real life systems reproducing the coupling efficiencies of the model with 12%–14% including loss factors and approximately 18% for a direct coupled system respectively

Protonic solid oxide electrolysis cells are pivotal for environmentally sustainable hydrogen production via water splitting but suffer from efficiency losses due to partial hole conductivity. Here we introduce a device architecture based on a hydride-ion (H− )/proton (H+ ) bipolar electrolyte which exploits electrochemical rectification at a heteroionic interface to overcome this limitation. The perovskite-type BaZr0.5In0.5O2.75 electrolyte undergoes an in situ transformation under electrolysis conditions forming an H+ -conducting hydrate layer adjacent to the anode and an H− -conducting oxyhydride layer near the cathode governed by competitive thermodynamic equilibria of hydration and hydrogenation. This bipolar configuration enables high Faradaic currents through the superior H− ion conductivity of the oxyhydride phase stabilized by cathodic potentials while facilitating continuous H+ /H− interconversion at the interface. Furthermore electrochemical hydrogenation generates an electron-depleted interfacial layer that effectively suppresses hole conduction. Consequently the cells achieve efficiencies of ∼95% at 1.0 A cm− 2 surpassing conventional H+ unipolar designs.

Hydrogen Valley represents localised ecosystems that enable the integrated production storage distribution and utilisation of hydrogen to support the decarbonisation of the energy system. However planning such integrated systems necessitates a detailed evaluation of their interconnections with variable renewable generation sector coupling and system flexibility. The novelty of this work lies in addressing a critical gap in system-level modelling for Hydrogen Valleys by introducing an optimization-based framework to determine their optimal configuration. This study focuses on the scenario-based multiobjective design of local hydrogen energy systems considering renewable integration infrastructure deployment and sector coupling. We developed and simulated three scenarios based on varying hydrogen pathways and penetration levels using the EnergyPLAN model implemented through a custom MATLAB Toolbox. Several decision variables such as renewable energy capacity electrolyser size and hydrogen storage were optimised to minimise CO₂ emissions total annual system cost and critical excess electricity production simultaneously. The findings show that Hydrogen Valley deployment can reduce CO₂ emissions by up to 30 % triple renewable penetration in the primary energy supply and lower the levelized cost of hydrogen from 7.6 €/kg to 5.6 €/kg despite a moderate increase in the total cost of the system. The approach highlights the potential of sector coupling and Power-to-X technologies in enhancing system flexibility and supporting green hydrogen integration. The outcome of our research offers valuable insights for policymakers and planners seeking to align local hydrogen strategies with broader decarbonisation targets and regulatory frameworks.

Hydrogen is a potential source of imminent clean energy in the future with its transportation playing a crucial role in allowing large-scale deployment. The challenge lies in selecting an effective sustainable and scalable transportation alternative. This study develops a multi-criteria decision-making (MCDM) framework based on the intuitionistic fuzzy analytic hierarchy process (IF-AHP) to evaluate land-based hydrogen transportation alternatives across Canada. The framework includes uncertainty and decision-maker hesitation through the application of triangular intuitionistic fuzzy numbers (TIFNs). Seven factors their subsequent thirty-three subfactors and three alternatives to hydrogen transportation were identified through a literature review. Pairwise comparison was aggregated among factors subfactors and alternatives from three decision makers using an intuitionistic fuzzy weighted average and priority weights were computed using entropy-based weight. The results show that safety and economic efficiency emerged as the most influential factors in the evaluation of hydrogen transportation alternatives followed by environmental impact security and social impact and public health in ascending order. Among the alternatives tube truck transport obtained the highest overall weight (0.3551) followed by pipelines (0.3272) and rail lines (0.3251). The findings suggest that the tube ruck is currently the most feasible transport option for land-based hydrogen distribution that aims to provide a transition of Canada’s energy mix.

Hydrogen is poised to play a pivotal role in achieving net-zero targets and advancing green economies. However a range of complex operational challenges hinders its planning production delivery and adoption. At the same time numerous drivers within the hydrogen value chain present significant opportunities. This paper investigates the intricate relationships between these drivers and barriers associated with hydrogen supply chain (HSC). Utilising expert judgment in combination Grey-DEMATEL technique we propose a framework to assess the interplay of HSC drivers and barriers. Gaining insight into these relationships not only improves access to hydrogen but also foster innovation in its development as a low-carbon resource. The use of prominence scores and net influence rankings for each driver and barrier in the framework provides a comprehensive understanding of their relative significance and impact. Our findings demonstrate that by identifying and accurately mapping these attributes clear cause-and-effect relationships can be established contributing to a more nuanced understanding of the HSC. These insights have broad implications across operational policy scholarly and social domains. For instance this framework can aid stakeholders in recognizing the range of opportunities available by addressing key barriers to hydrogen adoption.

The inherent randomness and intermittency of offshore renewable energy sources such as wind and solar power pose significant challenges to the stable and secure operation of the power grid. These fluctuations directly affect the performance of grid-connected systems particularly in terms of harmonic distortion and load response. This paper addresses these challenges by proposing a novel harmonic control strategy and load response optimization approach. An integrated three-winding transformer filter is designed to mitigate high-frequency harmonics and a control strategy based on converter-side current feedback is implemented to enhance system stability. Furthermore a hybrid PI-VPI control scheme combined with feedback filtering is employed to improve the system’s transient recovery capability under fluctuating load and generation conditions. Experimental results demonstrate that the proposed control algorithm based on a transformer-oriented model effectively suppresses low-order harmonic currents. In addition the system exhibits strong anti-interference performance during sudden voltage and power variations providing a reliable foundation for the modulation and optimization of offshore wind–solar coupled hydrogen production power supply systems.

Renewable hydrogen offers compelling climate mitigation prospects with Norway possessing the opportunity to become a main global producer given its unique combination of wind energy potential available infrastructure and political motivation. However comprehensive environmental impact assessments of hydrogen from offshore wind are lacking and hydrogen leakage rates remain uncertain. A life-cycle assessment of hydrogen production from offshore wind farms in Norway is presented where different combinations of turbines (floating or bottomfixed) storage options (tank or salt cavern) and distribution methods (trucks or pipelines) are considered. Climate change impacts are assessed across the supply chain using global warming potential 100 (GWP100) and 20 (GWP20) and include hydrogen leakage contributions. The results range from 1.56 ± 0.14–2.28 ± 0.14 kg CO2-eq/kg H2 for GWP100 and 2.96 ± 0.76 and 3.75 ± 0.76 kg CO2-eq/kg H2 for GWP20 and are on average 55 % and 45 % lower than those of blue hydrogen respectively. At a default rate of 5 % hydrogen leakage contributes 50–63 % of the total impact for GWP20 and 25–37 % for GWP100. If higher-end leakage rates from literature are considered the impacts increase to 3.46 kg CO2-eq/kg H2 for GWP100 which is still lower than that of blue hydrogen. The scenario combining bottom-fixed turbines salt cavern storage and pipeline distribution presents the lowest environmental impacts. However while bottom-fixed turbines generally offer lower impacts floating turbines pose lesser risk to marine biodiversity. Overall infrastructure represents the main driver of environmental impacts. Mitigation in this area will improve potential benefits.

With the increasing maturity of renewable energy technologies and the pressing need to address climate change urban power systems are striving to integrate a higher proportion of low-carbon renewable energy sources. However the inherent variability and intermittency of wind and solar power pose significant challenges to the stability and reliability of urban power grids. Existing research has primarily focused on short-term energy storage solutions or small-scale integrated energy systems which are insufficient to address the long-term large-scale energy storage needs of urban areas with high renewable energy penetration. This paper proposes a mid-to-long-term capacity expansion model for hydrogen energy storage in urban-scale power systems using Shanghai as a case study. The model employs mixed-integer linear programming (MILP) to optimize the generation portfolios from the present to 2060 under two scenarios: with and without hydrogen storage. The results demonstrate that by 2060 the installed capacity of hydrogen electrolyzers could reach 21.5 GW and the installed capacity of hydrogen power generators could reach 27.5 GW accounting for 30% of the total installed capacity excluding their own. Compared to the base scenario the electricity–hydrogen collaborative energy supply system increases renewable penetration by 11.6% and utilization by 12.9% while reducing the levelized cost of urban comprehensive electricity (LCOUCE) by 2.514 cents/kWh. These findings highlight the technical feasibility and economic advantages of deploying long-term hydrogen storage in urban grids providing a scalable solution to enhance the stability and efficiency of high-renewable urban power systems.

Many countries of the Global South struggle to achieve inclusive growth paths despite investment in the exploitation of rich resources. Resource-based industrialization literature stresses the potential for achieving broader development effects via the development of production linkages with local enterprises. The focus lies on market-driven outsourcing dynamics that foster linkage development such as efficiency location-specific knowledge and technology and scale complexity. However little is known about the opportunity space for both policy making and local firms to create these linkages. To address this issue we incorporate the concept of change agency stemming from the path development literature into the discussion on production linkages to show how both (local) firm agency and system-level agency can achieve linkage creation for inclusive path transplantation. We illustrate the framework by scrutinizing the potential inclusion of solar energy companies in Namibia’s emerging green hydrogen economy. The study finds that while the potential for renewable energy companies in Namibia to participate in the value chain is limited an integrated bundle of measures relying on firm- and system-level agency could address peripheral contextual factors overcome entry barriers and leverage further potential for linkage creation in the solar energy sector: mobilizing the local workforce fostering inter-firm cooperation leveraging local advantages creating knowledge institutions enhancing the regulatory framework upgrading infrastructure and enforcing local content regulations.

Hydrogen shaft injection into blast furnaces (BFs) has a large potential to eliminate carbon dioxide emissions yet the temporal evolution of thermal and chemical states following shaft-injected hydrogen utilisation has not been reported in the open literature. In this research a recently developed transient-state multifluid BF model is applied to elucidate the temporal evolution of in-furnace phenomena. Besides a domain-average method is adopted to analyse the extensive simulation data to determine the time required to attain the next steady-like state. The results show that the evolution of thermal and chemical conditions varies across different regions with distinct characteristics near the furnace wall. The shifts in iron oxide reduction behaviour are completed within 10 to 20 h after the new operation and the transition time points to the next steady-like states of thermal and chemical conditions are different. As the hydrogen flow rate increases the average transition time decreases. However 2 to 4 days are required for the studied BF to reach a new steady-like state in the considered scenarios. The model offers a cost-effective approach to investigating the transient smelting characteristics of an ironmaking BF with hydrogen injection.

Underground hydrogen storage (UHS) in depleted oil and gas fields is pivotal for balancing large-scale renewable-energy systems yet the wettability of reservoir rocks in contact with hydrogen after decades of Enhanced Oil Recovery (EOR) operations remains poorly quantified. This work experimentally investigates how two common EOR legacies cationic surfactant (city-trimethyl-ammonium bromide CTAB) and supercritical carbon dioxide (SC–CO2) flooding alter rock–water–Hydrogen (H2) wettability in carbonate formations. Contact angles were measured on dolomite and limestone rock slabs at 30–75 ◦C and 3.4–17.2 MPa using a high-pressure captive-bubble cell. Crude-oil aging shifted clean dolomite from strongly water-wet (θ ~ 28–29◦) to intermediate-wet (θ ≈ 84◦). Subsequent immersion in dilute CTAB solutions (0.5–2 wt %) fully reversed this effect restoring or surpassing the original water-wetness (θ ≈ 21–28◦). Limestone samples exposed to SC-CO2 at 60–80 ◦C became more hydrophilic (θ ≈ 18–30◦) relative to untreated controls; moderate carbonate dissolution (≤6 × 103 ppm Ca2+) produced the most significant improvement in water-wetness whereas severe dissolution yielded diminishing returns. These findings show that many mature reservoirs are already water-wet (post-CO2) or can be easily re-wetted (via residual CTAB). Across all scenarios sample wettability showed little sensitivity to pressure but higher temperature consistently promoted stronger water-wetness. Future work should include dynamic core-flooding experiments with realistic reservoir.

In the context of the evolving energy landscape the need to harness renewable energy sources (RESs) has become increasingly imperative. Within this framework hydrogen emerges as a promising energy storage vector offering a viable solution to the flexibility challenges caused by the inherent variability of RESs. This work investigates the feasibility of integrating a hydrogen-based energy storage system within an energy community in Barcelona using surplus electricity from photovoltaic (PV) panels. A power-to-power configuration is modelled through a comprehensive methodology that determines optimal component sizing based on high-resolution real-world data. This analysis explores how different operational strategies influence the system’s cost-effectiveness. The methodology is thus intended to assist in the early-stage decision-making process offering a flexible approach that can be adapted to various market conditions and operational scenarios. The results show that under the current conditions the combination of PV generation energy storage and low-cost grid electricity purchases yield the most favourable outcomes. However in a long-term perspective considering projected cost reductions for hydrogen technologies strategies including energy sales back to the grid become more profitable. This case study offers a practical example of balancing engineering and economic considerations providing replicable insights for designing hydrogen storage systems in similar energy communities.

This study evaluated the economic feasibility of producing hydrogen from natural gas via thermal degradation in a plasma reactor. Plasma pyrolysis where natural gas passes through the space between electrodes and serves as the working medium enables high hydrogen yields without emitting carbon monoxide or carbon dioxide. Instead the primary products are hydrogen and solid carbon. Unlike conventional methods this approach requires no catalysts addressing a major technological limitation. A thermodynamic equilibrium model based on Gibbs free energy minimization was used to analyze the process over a temperature range of 500–2500 K. The results indicate an optimal temperature of approximately 1500 K which achieved a 99.5% methane conversion by mass. Considering the capital and operating costs and profit margins the hydrogen production cost was estimated at 3.49 EUR/kg. The sensitivity analysis revealed that the price of solid carbon had the most significant impact which potentially raised the hydrogen cost to 4.53 EUR/kg or reduced it to 1.70 EUR/kg.

The aim of this study is to review and identify H2 storage suitability in geological reservoirs of the Republic of Lithuania. Notably Lithuania can store clean H2 effectively and competitively because of its wealth of resources and well-established infrastructure. The storage viability in Lithuanian geological contexts is highlighted in this study. In addition when it comes to injectivity and storage capacity salt caverns and saline aquifers present less of a challenge than other kinds of storage medium. Lithuania possesses sizable subterranean reservoirs (Cambrian rocks) that can be utilized to store H2. For preliminary assessment the cyclic H2 injection and production simulation is performed. A 10-year simulation of hydrogen injection and recovery in the Syderiai saline aquifer demonstrated the feasibility of UHS though efficiency was reduced by nearly 50% when using a single well for both injection and production. The study suggests using separate wells to improve efficiency. However to guarantee economic injectivity and containment security a detailed assessment of the geological structures is required specifically at the pore scale level. The volumetric approach estimated a combined storage capacity of approximately 898.5 Gg H2 (~11 TWh) for the Syderiai and Vaskai saline aquifers significantly exceeding previous estimates. The findings underscore the importance of detailed geological data and further research on hydrogen-specific factors to optimize UHS in Lithuania. Addressing technical geological and environmental challenges through multidisciplinary research is essential for advancing UHS implementation and supporting Lithuania’s transition to a sustainable energy system. UHS makes it possible to maximize the use of clean energy reduce greenhouse gas emissions and build a more sustainable and resilient energy system. Hence intensive research and advancements are needed to optimize H2 energy for broader applications in Lithuania.

Importing renewable energy to Europe may offer many potential benefits including reduced energy costs lower pressure on infrastructure development and less land use within Europe. However open questions remain: on the achievable cost reductions how much should be imported whether the energy vector should be electricity hydrogen or derivatives like ammonia or steel and their impact on Europe’s infrastructure needs. This study integrates a global energy supply chain model with a European energy system model to explore net-zero emission scenarios with varying import volumes costs and vectors. We find system cost reductions of 1-10% within import cost variations of ± 20% with diminishing returns for larger import volumes and a preference for methanol steel and hydrogen imports. Keeping some domestic power-to-X production is beneficial for integrating variable renewables leveraging local carbon sources and power-to-X waste heat. Our findings highlight the need for coordinating import strategies with infrastructure policy and reveal maneuvering space for incorporating non-cost decision factors.

Developing new injection systems and combustion chambers for hydrogen is a central topic for the new generation of engines. In this effort simulations take a central role but methods developed for conventional hydrocarbons (methane kerosene) must be revisited for hydrogen. Validation then becomes an essential part and clean well documented experiments are needed to guaranty that computational fluid dynamics solvers are as predictive and accurate as expected. In this framework the HYLON case is a swirled hydrogen/air burner used by multiple groups worldwide to validate simulation methods for hydrogen combustion in configurations close to gas turbine burners with experimental data available through the TNF web site. The present study compares recent Raman spectroscopy and Particle Image Velocimetry measurements and Large Eddy Simulations (LES). The LES results are evaluated against a dataset comprising mean and RMS measurements of H2 N2 O2 H2O molar fractions temperature and velocity fields offering new insights into flame stabilization mechanisms. The simulations incorporate conjugate heat transfer to predict the combustor wall temperatures and are conducted for two atmospheric-pressure operating conditions each representing distinct combustion regimes diffusion and partially premixed. Novelty and significance statement Data on confined hydrogen flames in burner similar as industrial ones are limited. This work aims to fill this gap by performing multiple and simultaneous diagnostics on the swirled hydrogen-air flame called HYLON. For the first time in such a swirled configuration mean and RMS fields of temperature main species and velocities are compared to LES allowing new insight into the potential and limits of the models as well as the physics of these flames. These experimental results will be made available on TNF as over 30 research groups worldwide have expressed interest in using them.

Currently there are many gaps in the research on the safety of hydrogen-powered trains and the hazardous points vary across different scenarios. It is necessary to conduct safety analysis for various scenarios in order to develop effective accident response strategies. Considering the implementation of hydrogen power in the rail transport sector this paper reviews the development status of hydrogen-powered trains and the hydrogen leak hazard chain. Based on the literature and industry data a thorough analysis is conducted on the challenges faced by hydrogen-powered trains in the scenario of electrified railways tunnels train stations hydrogen refueling stations and garages. Existing railway facilities are not ready to deal with accidental hydrogen leakage and the promotion of hydrogen-powered trains needs to be cautious.

The research focuses on enhancing hydrogen production using a blend of municipal solid waste (MSW) with Biomass and mixed plastic waste (MPW) under the Bioenergy with Carbon Capture Utilisation and Storage (BECCUS) concept. The key challenges include optimising the feedstock blends and gasification process parameters to maximise hydrogen yield and carbon dioxide capture. This study introduces a novel approach that employs sorption-enhanced gasification and a high-temperature regenerator reactor. Using this method syngas streams with high hydrogen contents of up to 93 mol% and 66 mol% were produced respectively. Thermodynamic simulations with Aspen Plus® validated the integrated system for achieving high-purity hydrogen (99.99 mol%) and effective carbon dioxide isolation. The system produced 70.33 molH2 /kgfeed when using steam as a gasifying agent while 37.95 molH2 /kgfeed was produced under air gasification conditions. Case I employed a mixture of MSW and wood residue at a ratio of 1:1.25 with steam and calcium oxide added at 2:1 and 0.92:1 respectively resulting in 68.80 molH2 /kgfeed and a CO2 capture efficiency of 92 %. Case II utilised MSW and MPW at a 1:1 ratio with steam and calcium oxide at 2:1 and 0.4:1 respectively producing 100.17 molH2 /kgfeed and achieving a 90.09 % CO2 capture efficiency. The optimised parameters significantly improve hydrogen yield and carbon capture offering valuable insights for BECCUS applications.

The integration of renewable resources with advanced storage technologies is critical for sustainable energy systems. In this paper a planning framework for an energy hub incorporating hydrogen and renewable energy systems is developed with the objective of minimizing operational costs while participating in flexible ramping product (FRP) markets. The energy hub is designed to utilize a hybrid storage system comprising multi-type battery energy storage (BESS) accounting for diverse chemistries and degradation behaviors and hydrogen storage (HS) to meet concurrent electric and hydrogen demands. To address uncertainties in renewable generation and market prices a stochastic optimization model is developed to determine the optimal investment capacities while optimizing operational decisions under uncertainty using scenario-based stochastic programming. Financial risks associated with price and renewable variability are mitigated through the Conditional Value-at-Risk (CVaR) metric. Case studies demonstrate that hybrid storage systems including both BESS and HS can reduce total costs by 23.62% compared to single-storage configurations that rely solely on BESS. Based on the results BESS participates more in providing flexible ramp-up services while HS plays a major role in providing flexible ramp-down services. The results emphasize the critical role of co-optimized hydrogen and multi-type BESS in enhancing grid flexibility and economic viability.

The aviation industry is responsible for approximately 2–3% of worldwide CO2 emissions and is increasingly subjected to demands for the attainment of net-zero emissions targets by the year 2050. Traditional fossil jet fuels which exhibit lifecycle emissions of approximately 89 kg CO2-eq/GJ play a substantial role in exacerbating climate change contributing to local air pollution and fostering energy insecurity. In contrast Sustainable Aviation Fuels (SAFs) derived from renewable feedstocks including biomass municipal solid waste algae or through CO2- and H2-based power-to-liquid (PtL) represent a pivotal solution for the immediate future. SAFs generally accomplish lifecycle greenhouse gas (GHG) reductions of 50–80% (≈20–30 kg CO2-eq/GJ) possess reduced sulfur and aromatic content and markedly diminish particulate emissions thus alleviating both climatic and health-related repercussions. In addition to their environmental advantages SAFs promote energy diversification lessen reliance on unstable fossil fuel markets and invigorate regional economies with projections indicating the creation of up to one million green jobs by 2030. This comprehensive review synthesizes current knowledge on SAF sustainability advantages compared to conventional aviation fuels identifying critical barriers to large-scale deployment and proposing integrated solutions that combine technological innovation supportive policy frameworks and international collaboration to accelerate the aviation industry’s sustainable transformation.

The use of hydrogen as an energy carrier represents a promising alternative for mitigating climate change. However its practical application requires achieving a high degree of purity throughout the production process. In this study the influence of the type of catalytic support on H2 production via steam glycerol reforming was evaluated with the objective of obtaining syngas with the highest possible H2 concentration. Three types of support were analyzed: two natural materials (zeolite and dolomite) and one metal oxide alumina. Alumina and dolomite were coated with Ni at different loadings while zeolite was only evaluated without Ni. Reforming experiments were carried out at a constant temperature of 850 ◦C with continuous monitoring of H2 CO2 CO and CH4 concentrations. The results showed that zeolite yielded the lowest H2 concentration (51%) mainly due to amorphization at high temperatures and the limited effectiveness of physical adsorption processes. In contrast alumina and dolomite achieved H2 purities of around 70% which increased with Ni loading. The improvement was particularly significant in dolomite owing to its higher porosity and the recarbonation processes of CaO enabling H2 purities of up to 90%.

Reducing CO2 emissions in general aviation is a critical challenge where battery electric and fuel cell technologies face limitations in energy density cost and robustness. As a result hydrogen (H2) dual-fuel combustion is a promising alternative but its practical implementation is constrained by abnormal combustion phenomena such as knocking and pre-ignition which limit the achievable H2 energy share. In response to these challenges this paper focuses on strategies to mitigate these irregular combustion phenomena while effectively increasing the H2 energy share. Experimental evaluations were conducted on an engine test bench using a one-cylinder dual-fuel H2 kerosene (Jet A-1) engine utilizing two strategies including water injection (WI) and rising the air–fuel ratio (AFR) by increasing the boost pressure. Additionally crucial combustion characteristics and emissions are examined and discussed in detail contributing to a comprehensive understanding of the outcomes. The results indicate that these strategies notably increase the maximal possible hydrogen energy share with potential benefits for emissions reduction and efficiency improvement. Finally through the use of 0D/1D simulations this paper offers critical thermodynamic and efficiency loss analyses of the strategies enhancing the understanding of their overall impact.

Hydrogen is considered a key alternative to fossil fuels in the broader context of ecological transition. Repurposing natural gas pipelines for hydrogen transport is one of the challenges of this approach. However hydrogen can diffuse into metallic lattices leading to hydrogen embrittlement (HE). For this reason typically ductile materials can experience unexpected brittle fractures and it is therefore necessary to assess the HE propensity of the current pipeline network to ensure its fitness for hydrogen transport. This study examines the relationship between the microstructure of the circumferential weld joint in X52 pipeline steel and hydrogen concentration introduced electrolytically. Base material heat affected zone and fused zone were subjected to 1800 3600 7200 and 14400 s of continuous charging with a current density J = − 10 mA/cm2 in an acid solution. Results showed that the fusion zone absorbed the most hydrogen across all charging times while the base material absorbed more hydrogen than the heat-affected zone due to the presence of non-metallic inclusions. Fracture toughness was assessed using single edge notch tension specimens (SENT) in air and electrolytic hydrogen. Results indicate that the base material is particularly vulnerable to hydrogen environments exhibiting the greatest reduction in toughness when exposed to hydrogen compared to air.