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 escalating global pursuit of environmentally benign energy alternatives has spurred intensive investigations into sustainable hydrogen generation technologies. Although hydrogen energy can be produced via multiple approaches the integration of nanotechnology materials in its generation results in its production improvements and efficiency of the production methods. Nanotechnology with its astonishing ability to control materials at the atomic and molecular scale has emerged as a vital technology for improving the efficiency and affordability of hydrogen production from renewable energy sources. This technology provides a unique platform for creating materials with specific properties for energy conversion and storage. Nanotechnology is accelerating the transition to a hydrogen economy by boosting hydrogen production efficiency and storage. Its applications span from enhancing water-splitting catalysts to developing advanced membranes and photocatalysts. These nanomaterial-based innovations are crucial for producing clean hydrogen and its effective storage. Nevertheless nanotechnology highlights the significant role of nanomaterials in overcoming the kinetic challenges associated with hydrogen evolution reactions which can be attained through several features like increased surface area enhanced catalytic activity and improved charge transfer. Therefore this study explores the latest advancements in nanomaterials and their catalytic impact on hydrogen generation particularly in photocatalysis electrocatalysis and photoelectrochemical systems. The study has examined the nanomaterials’ production characterization and performance their integration into renewable energy systems and their potential for widespread commercial use.

Fuel-cell flying vehicles suffer from limited endurance while ammonia decomposed onboard to supply hydrogen offers a carbon-free high-density solution to extend flight missions. However the system’s performance is governed by a multi-scale coupling between propulsion and control systems. To this end this paper introduces a novel optimization paradigm termed physics-informed gradient-enhanced multi-objective optimization (PIGEMO) to simultaneously optimize the ammonia decomposition unit (ADU) catalyst composition powertrain sizing and flight control parameters. The PI-GEMO framework leverages a physics-informed neural network (PINN) as a differentiable surrogate model which is trained not only on sparse simulation data but also on the governing differential equations of the system. This enables the use of analytical gradient information extracted from the trained PINN via automatic differentiation to intelligently guide the evolutionary search process. A comprehensive case study on a flying vehicle demonstrates that the PIGEMO framework not only discovers a superior set of Pareto-optimal solutions compared to traditional methods but also critically ensures the physical plausibility of the results.

This study presents a techno-economic framework for assessing the potential of utilizing hybrid renewable energy sources (wind and solar) to produce green hydrogen with a specific focus on Australia. The model’s objective is to equip decision-makers in the green hydrogen industry with a reliable methodology to assess the availability of renewable resources for cost-effective hydrogen production. To enhance the credibility of the analysis the model integrates 10 min on-ground solar and wind data uses a high-resolution power dispatch simulation and considers electrolyzer operational thresholds. This study concentrates on five locations in Australia and employs high-frequency resource data to quantify wind and solar availability. A precise simulation of power dispatch for a large off-grid plant has been developed to analyze the PV/wind ratio element capacities and cost variables. The results indicate that the locations where wind turbines can produce cost-effective hydrogen are limited due to the high capital investment which renders wind farms uneconomical for hydrogen production. Our findings show that only one location—Edithburgh South Australia—under a 50% solar–50% wind scenario achieves a hydrogen production cost of 10.3 ¢USD/Nm3 which is lower than the 100% solar scenario. In the other four locations the 100% solar scenario proves to be the most cost-effective for green hydrogen production. This study suggests that precise and comprehensive resource assessment is crucial for developing hydrogen production plants that generate low-cost green hydrogen.

By integrating Renewable Energy Sources (RES) and storage devices Hybrid Energy Systems (HESs) represent a promising solution for decarbonizing isolated and remote communities. Proper sizing and management of systems comprising a variety of components requires however more advanced methods than conventional energy systems. This study proposes a novel Mixed Integer Linear Programming (MILP) framework for the simultaneous design of a grid-connected HES supported by renewable generators. Unlike the standard design approach based on parametric dispatch strategies this framework simultaneously optimizes the energy management of each system configuration under analysis. The novel approach is applied to size a combination of Li-Ion batteries an alkaline electrolyzer H2 tanks and a PEM fuel cell to maximize the NPV of a system including a wind turbine and a photovoltaic field. Managing thousands of variables at the same time the framework simultaneously optimizes how all components are used to fulfill the load and balance the input/export of power within a limited electrical network. Results show that the combination of BESS and H2 can provide for both the need for short- and long-term energy storage and that the MILP optimization can effectively allocate the energy flows and produce 558 k€ of revenues per year 15.5% of the initial investment cost of 3.6 M€. The investment cost of the system is recovered in six years and presents an NPV of 5.51 M€ after 20 years. Results from the proposed method are also compared to common approaches based on rule-based parametric dispatch strategies demonstrating the superiority of MILP for the design and management of complex HESs.

Activated carbon as a hydrogen storage material possesses advantages such as low cost high safety lightweight and good cycling performance. Zhundong coal characterized by low calorific value high volatility and elevated reaction activity stands out as an exceptional raw material for the production of activated carbon. This study employed Zhundong coal for the synthesis of hydrogen storage activated carbon exploring the impact of acid treatment and varied activation conditions on Zhundong coal. The specific surface area of sample ZD-HK3-AC is 1980 m2 /g and the gravimetric hydrogen storage density reaches 0.91 wt% under the condition of 80bar at room temperature. The adsorption–desorption isotherms nearly overlapped demonstrating excellent cycling performance and high mechanical strength. At the same time the relationship between the pore structure parameters of activated carbon and hydrogen storage density was explored revealing the mechanism of activated carbon adsorption and hydrogen storage. These findings hold significant guiding implications for the preparation and research of hydrogen storage materials utilizing activated carbon.

This study presents the development of a robust numerical model for simulating underground hydrogen storage (UHS) in salt caverns with a particular focus on the interactions between original gas-methane (CH4) and injected gas represented by hydrogen (H2). Using the Schlumberger Eclipse 300 compositional reservoir simulator the cavern was modelled as a highly permeable porous medium to accurately represent gas flow dynamics. Two principal mixing mechanisms were investigated: physical dispersion modelled by numerical dispersion and molecular diffusion. Multiple cavern configurations and a range of dispersion–diffusion coefficients were assessed. The results indicate that physical dispersion is the primary factor affecting hydrogen purity during storage cycles while molecular diffusion becomes more significant during long-term gas storage. Gas mixing was shown to directly impact the calorific value and quality of withdrawn hydrogen. This work demonstrates the effectiveness of commercial reservoir simulators for UHS analysis and proposes a methodological framework for evaluating hydrogen purity in salt cavern storage operations.

Switch-point heating systems are essential for railway reliability and safety in winter but present logistical and economic challenges in remote regions. This study presents a novel application of a hydrogen-enabled microgrid as an off-grid energy solution for powering a switch-point heating system at a rural Austrian railway station offering an alternative to conventional grid-based electricity with a specific focus on enhancing the share of renewable energy sources. The proposed system integrates photovoltaics (PV) optional wind energy and hydrogen storage to address the seasonal mismatch between a high energy supply in the summer and peak winter demand. Three energy supply scenarios are analysed and compared based on local conditions technical simplicity and economic viability. Energy flow modelling based on site-specific climate and operational data is used to determine hydrogen production rates storage capacity requirements and system sizing. A comprehensive cost analysis of all major subsystems is conducted to assess economic viability. The study demonstrates that hydrogen is a highly effective solution for seasonal energy storage with a PV-only configuration emerging as the most suitable option under current site conditions. Thus it offers a replicable framework for decarbonising critical stationary railway infrastructure.

Solid oxide electrolysers (SOEs) can decarbonise H2 supply when powered by renewable electricity but remain constrained by high electrical demand and integration penalties. Our objective is to minimise the electrical (Pel) and thermal (Qth) energy demand per mole of H2 by jointly tuning cell temperature steam fraction steam utilisation pressure and current density. Compared with prior single-variable or thermo-neutral-constrained studies we develop and validate a steady-state process-level optimisation framework that couples an Aspen Plus SOE model with electrochemical post-processing and heat caused by ohmic resistance recovery. A Box–Behnken design explores five key operating parameters to capture synergies and trade-offs between Qth and Pel energy inputs. Single-objective optimisation yields Pel = 170.1 kJ mol⁻¹ H2 a 41.4% reduction versus literature baselines. Multi-objective optimisation using an equal-weighted composite desirability function aggregating thermal and electrical demands further reduces Pel by 21.2% while balancing thermal input 4–8% lower than single-objective baselines at moderate temperature (~781 °C) and pressure (~17.5 bar). Findings demonstrate a clear process intensification advantage over previous studies by simultaneously leveraging operating parameter synergies and heat-integration. However results are bounded by steady-state perfectly mixed isothermal assumptions. The identified operating windows are mechanistically grounded targets that warrant stack-scale and plantlevel validation.

Air travel demand is rising rapidly and the aviation sector is relying on technology to decouple environmental impacts from its growth. Using Sweden as a case study we assessed the absolute environmental sustainability of medium-distance air travel in 2050 positioning the aviation sector's environmental impacts in relation to the planetary limits. We employed a novel framework that integrates prospective life cycle assessment and absolute environmental sustainability assessment methodologies. Our findings suggest that projected medium-distance air travel powered by e-kerosene or liquid hydrogen could have life cycle environmental impacts that overshoot global climate change and biodiversity loss thresholds by several orders of magnitude. Based on our case results for Sweden for aviation to develop within the planetary limits we recommend cross-sector collaboration to address environmental impacts from fossil-free energy supplies and the establishment of integrated targets that incorporate broader environmental issues. Given the unlikelihood of decoupling growth from environmental impacts policymakers and the aviation sector should consider concurrently supporting technological development and implementing measures to manage air travel demand.

Europe’s transition toward a low-carbon energy system relies on the deployment of hydrogen produced with minimized carbon emissions; however regulatory requirements increase system costs and create financial barriers. This study investigates the financial implications of enforcing European Commission rules for renewable hydrogen production from 2024 to 2048. Using a scenario-based modeling approach that draws on European power system investments in renewable energy the results show that immediate compliance leads to an additional cost of approximately eighty billion euros over twenty-four years corresponding to a 3.6 percent increase in total system costs. To address this investment gap the study employs a segmentation analysis of support mechanisms based on existing policies and market practices identifying seven categories that range from investment incentives and production subsidies to infrastructure and financial instruments. Among these hydrogen offtake support and infrastructure funding are identified as the most effective measures for reducing risk and enabling private investment. These findings provide strategic insights for policymakers seeking to align their regulatory ambitions with financially viable pathways for integrating renewable energy.

The integration of electric vehicles (EVs) and fuel-cell electric vehicles (FCEVs) requires accessible and profitable facilities for fast charging. To promote fast-charging stations (FCSs) a systematic analysis that encompasses both planning and operation is required including the incorporation of multi-energy resources and uncertainty. This paper presents an optimization framework that addresses a joint strategy for the configuration and operation of an EV/FCEV fast-charging station (FCS) integrated with distributed energy resources (DERs) and hydrogen systems. The framework incorporates uncertainties related to solar photovoltaic (PV) generation and demand for EVs/FCEVs. The proposed joint strategy comprises a four-phase decision-making framework. Phase 1 involves modeling EV/FECE demand while Phase 2 focuses on determining an optimal long-term infrastructure configuration. Subsequently in Phase 3 the operator optimizes daily power scheduling to maximize profit. A real-time uncertainty update is then executed in Phase 4 upon the realization of uncertainty. The proposed optimization framework formulated as mixed-integer quadratic programming (MIQP) considers configuration investment operational maintenance and penalty costs for excessive grid power usage. A heuristic algorithm is proposed to solve this problem. It yields good results with significantly less computational complexity. A case study shows that under the most adverse conditions the proposed joint strategy increases the FCS owner’s profit by 3.32% compared with the deterministic benchmark.

The global transition to a low-carbon energy system requires innovative solutions that integrate renewable energy production with storage and utilization technologies. The growth in energy demand combined with the intermittency of these sources highlights the need for advanced management models capable of ensuring system stability and efficiency. This paper presents the development of an optimized energy management system integrating renewable sources with a focus on green hydrogen production via electrolysis storage and use through a fuel cell. The system aims to promote energy autonomy and support the transition to a low-carbon economy by reducing dependence on the conventional electricity grid. The proposed model enables flexible hourly energy flow optimization considering solar availability local consumption hydrogen storage capacity and grid interactions. Formulated as a Mixed-Integer Linear Programming (MILP) model it supports strategic decision-making regarding hydrogen production storage and utilization as well as energy trading with the grid. Simulations using production and consumption profiles assessed the effects of hydrogen storage capacity and electricity price variations. Results confirm the effectiveness of the model in optimizing system performance under different operational scenarios.

High-renewables grids are planned in min but judged in milliseconds; credible studies must therefore resolve both horizons within a single model. Current adequacy tools bypass fast frequency dynamics while detailed simulators lack multi-hour optimization leaving investors without a unified basis for sizing storage shifting demand or upgrading transfers. We present a two-layer Hierarchical Model Predictive Control framework that links 15-min scheduling with 1-s corrective action and apply it to Germany’s four TSO zones under a stringent zero-exchange stress test derived from the NEP 2045 baseline. Batteries vehicleto-grid pumped hydro and power-to-gas technologies are captured through aggregators; a decentralized optimizer pre-positions them while a fast layer refines setpoints as forecasts drift; all are subject to inter-zonal transfer limits. Year-long simulations hold frequency within ±2 mHz for 99.9% of hours and below ±10 mHz during the worst multi-day renewable lull. Batteries absorb sub-second transients electrolyzers smooth surpluses and hydrogen turbines bridge week-long deficits—none of which violate transfer constraints. Because the algebraic core is modular analysts can insert new asset classes or policy rules with minimal code change enabling policy-relevant scenario studies from storage mandates to capacity-upgrade plans. The work elevates predictive control from plantscale demonstrations to system-level planning practice. It unifies adequacy sizing and dynamic-performance evaluation in a single optimization loop delivering an open scalable blueprint for high-renewables assessments. The framework is readily portable to other interconnected grids supporting analyses of storage obligations hydrogen roll-outs and islanding strategies.

Hydrogen embrittlement (HE) can degrade the mechanical integrity of steel pipes increasing failure risks in naval fuel systems. This study assesses HE effects on ASTM A131 and A36 steels through tensile testing and numerical modeling. Tests conducted with varying exposure times to hydrogen revealed that A131 outperformed A36 in terms of mechanical strength. However both materials experienced property degradation after six hours. After nine hours a transient increase in strength occurred due to temporary microstructural hardening though the overall trend remained a decline. The maximum reductions in ultimate tensile strength and toughness were 19% and 47% for A131 and 39% and 61% for A36 respectively. Additionally microstructural analysis revealed the presence of inclusions intergranular decohesion and micro-crack in specimens exposed for longer periods. Finally a combined GTN-PLNIH numerical model was implemented demonstrating its effectiveness in predicting the mechanical behavior of structures exposed to hydrogen.

Insular regions face unique energy management challenges due to physical isolation. Graciosa (Azores) has high renewable energy sources (RES) potential theoretically enabling a 100% green system. However RES intermittency combined with the lack of energy storage solutions reduces renewable penetration and raises curtailment. This article studies the technical and economic feasibility of producing green hydrogen from curtailment energy in Graciosa through two distinct case studies. Case Study 1 targets maximum renewable penetration with green hydrogen serving as chemical storage converted back to electricity via fuel cells during RES shortages. Case Study 2 focuses on maximum profitability where produced gases are sold to monetize curtailment without additional electricity production. Levelized Cost of Hydrogen (LCOH) values of €3.06/kgH2 and €2.68/kgH2 respectively and Internal Rate of Return (IRR) values of 3.7% and 17.1% were obtained for Case Studies 1 and 2 with payback periods of 15.2 and 6.1 years. Hence only Case Study 2 is economically viable but it does not allow increasing the renewable share in the energy mix. Sensitivity analysis for Case Study 1 shows that overall efficiency and CAPEX are the main factors affecting viability highlighting the need for technological advances and economies of scale as well as the importance of public funding to promote projects like this.

Against the dual backdrop of intensifying carbon emission constraints and the large-scale integration of renewable energy integrated electricity–hydrogen energy systems (EH-ESs) have emerged as a crucial technological pathway for decarbonising energy systems owing to their multi-energy complementarity and cross-scale regulation capabilities. This paper proposes an operational optimisation and carbon reduction capability assessment framework for EH-ESs focusing on revealing their operational response mechanisms and emission reduction potential under multi-disturbance conditions. A comprehensive model encompassing an electrolyser (EL) a fuel cell (FC) hydrogen storage tanks and battery energy storage was constructed. Three optimisation objectives—cost minimisation carbon emission minimisation and energy loss minimisation—were introduced to systematically characterise the trade-offs between economic viability environmental performance and energy efficiency. Case study validation demonstrates the proposed model’s strong adaptability and robustness across varying output and load conditions. EL and FC efficiencies and costs emerge as critical bottlenecks influencing system carbon emissions and overall expenditure. Further analysis reveals that direct hydrogen utilisation outperforms the ‘electricity–hydrogen–electricity’ cycle in carbon reduction providing data support and methodological foundations for low-carbon optimisation and widespread adoption of electricity–hydrogen systems.

A numerical sensitivity analysis of a hydrogen pore storage system is carried out on a reservoir-scale geological model of the Ketzin site (Germany) to analyze the influence of uncertainty in geological parameters and fluid properties on storage performance. Therefore the following physical geological parameters and fluid properties were investigated: Porosity and permeability of the reservoir rock the brine salinity relative permeability and capillary pressure and mechanical dispersion. The range of the applied parameters is based on experimental and field data of the chosen location obtained during the former CO2 storage projects at the Ketzin site from 2008 to 2013. Using the open-source reservoir software MUFITS for the numerical simulations strong differences between the results can be observed. The results were evaluated based on measures to quantify performance such as the ratio of produced hydrogen mass to produced cushion gas (nitrogen) productivity index and sustainability index. The strongest impact on the performance parameters was observed with variations in the capillary pressure and the relative permeability curves followed by the absolute permeabilities while the least impact was seen with changes in the porosity and salinity of the brine. This work is not only crucial as a pre-feasibility study for the Ketzin storage site for hydrogen storage but also as a basis for decision-making for other potential storage sites in sedimentary basins.

Climate change is fuelled by the continued growth of global carbon emissions with the widespread use of fossil fuels being the main driver. To achieve a decarbonisation transition of the energy mix the development of clean and renewable fuels has become crucial. Ammonia is seen as an important option for decarbonisation in the transport and energy sectors due to its zero-carbon emission potential and renewable energy compatibility. However the high energy consumption and carbon emissions of the conventional Haber– Bosch method limit its sustainability. A green ammonia synthesis system was designed using ECLIPSE and Excel simulations in the study. Results show that at a recirculation ratio of 70% the system’s annual total energy consumption is 426.22 GWh with annual ammonia production reaching 8342.78 t. The optimal system configuration comprises seven 12 MW offshore wind turbines integrated with a 460 MWh lithium battery and 240 t of hydrogen storage capacity. At this configuration the LCOE is approximately £5956.58/t. It shows that incorporating renewable energy can significantly reduce greenhouse gas emissions but further optimisation of energy storage configurations and reaction conditions is needed to lower costs. This research provides a reference for the industrial application of green ammonia in the transportation sector.

To meet decarbonization targets demand for low-emission hydrogen is increasing. A considerable share of supply will come from latecomer countries. We study how latecomer countries and firms participate in the emerging global low-emission hydrogen economy and how industrial policies can help maximize societal benefits. This requires a specific conceptualization of industrial policy: First the latecomer condition calls for specific policy mixes as latecomers typically cannot build on established innovation systems and network externalities and rather need to combine FDI attraction with measures strengthening absorptive capacity and ensuring knowledge transfer from FDI to domestic firms; second low-emission hydrogen is a policy-induced alternative that requires creating entirely new firm ecosystems while competing with lower-cost emission-intensive incumbent technologies. Hence industrial policies need to account for enhanced coordination failure and internalization of environmental costs. We analyze the published national hydrogen strategies of 20 latecomer economies and derive a novel typology differentiating four hydrogen-specific industrial development pathways. For each pathway we assess entry barriers and risks identify the policies suggested in the country strategies and discuss how likely those are to be successful. The novel pathway typology and comparison of associated policy mixes may help policymakers maximize the gains of hydrogen investments.

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.