Applications & Pathways

Cruise ship decarbonisation was studied on a Mediterranean cruise profile. The analysis focused on ship energy flows fuel consumption carbon emissions ship CII and EEDI. A combination of technologies for reducing ship fuel consumption was simulated before introducing hydrogen fueled machinery for the ship. The studied technologies included ultrasound antifouling shore power battery hybrid machinery waste heat recovery and air lubrication. Their application on the selected operational profile led to combined fuel savings of 187%. When the same technologies were combined to a hydrogen machinery the ship total energy consumption compared to baseline was reduced by 25%. The cause of this was the synergies in the ship energy system such as ship auxiliary powers heat consumption and machinery efficiency. The proposed methodology of ship energy analysis is important step in starting to evaluate new fuels for ships and in preliminary technology screening prior to integrating them in the ship design.

The world is experiencing the effects of climate change at an increasing rate including rising average global temperature caused primarily by greenhouse gas (GHG) emissions. Energy-intensive industries (EIIs) are major contributors to greenhouse gas emissions. The pulp and paper industry (PPI) is among the top five most energyintensive industries and it accounts for approximately 6 % of global industrial energy use and 2 % of direct industrial CO2 emissions. Therefore it is important to decarbonize this industrial sector to achieve the climate policy goal of achieving net-zero emissions as per the Paris Agreement. This paper presents a comprehensive review of the decarbonization options also known as decarbonization pathways for the pulp and paper industrial sector. These pathways are selected from available literature and they mainly include energy efficiency measures (EEMs) paper recycling switching to carbon-neutral fuels such as biomass and hydrogen electrification of heat supply and carbon capture & storage (CCS) among other emerging technologies. After identifying each decarbonization pathway is discussed in detail with its drivers and barriers to implementation. The Analytical Hierarchy Process AHP a multi-criteria decision-making MCDM technique is carried out to rank the decarbonization pathways on five distinct criteria: cost emission reduction potential technological readiness level (TRL) implementation time and scalability. The ranking is carried out in four distinct criteria weight regimes to present clear choices on different criterion weights. This review paper aims to add to the existing literature to provide clear indications in choosing the pathways toward the decarbonization effort in the pulp & paper industry under various strategic priorities.

The main motivation for this paper was the lack of studies and comparative analyses on the new generation of alternative fuels in the marine sector such as methane methanol ammonia and hydrogen. Firstly a review of international legislation and the status of these new fuels was carried out highlighting the current situation and the different existing alternatives for reducing greenhouse gas (GHG) emissions. In addition the status and evolution of the current order book for ships since the beginning of this decade were used for this analysis. Secondly each fuel and its impact on the geometry and operation of the engine were evaluated in a theoretical engine called MW-1. Lastly an economic analysis of the current situation of each fuel and its availability in the sector was carried out in order to select using the indicated methodology the most viable fuel at present to replace traditional fuels with a view to the decarbonization set for 2050.

The burgeoning adoption of photovoltaic and wind energy has limitations of volatility and intermittency which hinder their application. Electro-hydrogen coupling energy storage systems emerge as a promising solution to address this issue. This technology combines renewable energy power generation with hydrogen production through water electrolysis and hydrogen fuel cell power generation effectively enabling the consumption and peak load management of renewable energy sources. This paper presents a power system with a 10 kW photovoltaic system and lithium battery energy storage system designed for hydrogen-electric coupled energy storage validated through the physical experiments. The results demonstrate the system's effectiveness in mitigating the impact of randomness and volatility in photovoltaic power generation. Moreover the energy management system can adjust bus power based on load demand. Testing the system in the absence of photovoltaic power generation reveals its capability to supply energy to the load for three hours with a minimum operating load power of 3 kW even under weather conditions unsuitable for photovoltaic power generation. These findings showed the potential of electro-hydrogen coupling energy storage systems in addressing the challenges associated with renewable energy integration paving the way for a reliable and sustainable energy supply.

Buildings are major energy consumers accounting for a significant portion of global energy consumption. Integrating hydrogen systems electrolyzers accumulation and fuel cells is proposed as a clean and efficient energy alternative to mitigate this impact and move toward a more sustainable future. This paper presents a systematic procedure for incorporating these technologies into buildings considering building engineers and stakeholders. First an in-depth analysis of buildings’ main energy consumption parameters is conducted identifying areas of energy need with the most significant optimization potential. Next a detailed review of the various opportunities for hydrogen applications in buildings is conducted evaluating their advantages and limitations. Performing a scientific review to find and understand the requirements of building engineers and the stakeholders has given notions of integration that emphasize the needs. As a result of the review process and identifying the needs to integrate hydrogen into buildings a flowchart is proposed to facilitate decision-making regarding integrating hydrogen systems into buildings. This flowchart is accompanied by a matrix of variables that considers the defined requirements allowing for combining the most suitable solution for each case. The results of this research contribute to advancing the adoption of hydrogen technologies in buildings thus promoting the transition to a more sustainable and resilient energy model.

This research presents a hierarchically synchronized Multi-Energy System (MES) designed for regional communities incorporating a network of small-scale Integrated Energy Microgrids (IEMs) to augment efficiency and collective advantages. The MES framework innovatively integrates energy complementarity pairing algorithms with efficient iterative optimization processes significantly curtailing operational expenditures for constituent microgrids and bolstering both community-wide benefits and individual microgrid autonomy. The MES encompasses electricity hydrogen and heat resources while leveraging controllable assets such as battery storage systems fuel cell combined heat and power units and electric vehicles. A comparative study of six IEMs demonstrates an operational cost reduction of up to 26.72% and a computation time decrease of approximately 97.13% compared to traditional methods like ADMM and IDAM. Moreover the system preserves data privacy by limiting data exchange to aggregated energy information thus minimizing direct communication between IEMs and the MES. This synergy of multi-energy complementarity iterative optimization and privacy-aware coordination underscores the potential of the proposed approach for scalable community-centered energy systems.

Electric arc furnace slag is a major by-product of steelmaking yet its industrial utilization remains limited due to its complex chemical and mineralogical composition. This study presents a hydrogen-based approach to recover metallic components from EAF slag for potential reuse in steelmaking. Laboratory experiments were conducted by melting 50 g of industrial slag samples at 1600 ◦C and injecting hydrogen gas through a ceramic tube into the liquid slag. After cooling both the slag and the metallic phases were analyzed for their chemical and phase compositions. Additionally the reduction process was modeled using a combination of approaches including the thermochemical software FactSage 8.1 models for density surface tension and viscosity as well as a diffusion model. The injection of hydrogen resulted in the reduction of up to 40% of the iron oxide content in the liquid slag. In addition the fraction of reacted hydrogen gas was calculated.

The turbocharging of hydrogen fuel cell systems (FCSs) has recently become a prominent research area aiming to improve FCS efficiency to help decarbonise the energy and transport sectors. This work compares the performance of an electrically assisted variable-geometry turbocharger (VGT) with a fixed-geometry turbocharger (FGT) by optimising both the sizing of the components and their operating points ensuring both designs are compared at their respective peak performance. A MATLAB-Simulink reducedorder model is used first to identify the most efficient components that match the fuel cell air path requirements. Maps representing the compressor and turbines are then evaluated in a 1D flow model to optimise cathode pressure and stoichiometry operating targets for net system efficiency using an accelerated genetic algorithm (A-GA). Good agreement was observed between the two models’ trends with a less than 10.5% difference between their normalised e-motor power across all operating points. Under optimised conditions the VGT showed a less than 0.25% increase in fuel cell system efficiency compared to the use of an FGT. However a sensitivity study demonstrates significantly lower sensitivity when operating at non-ideal flows and pressures for the VGT when compared to the FGT suggesting that VGTs may provide a higher level of tolerance under variable environmental conditions such as ambient temperature humidity and transient loading. Overall it is concluded that the efficiency benefits of VGT are marginal and therefore not necessarily significant enough to justify the additional cost and complexity that they introduce.

Liquid hydrogen (LH2) is a promising energy carrier to decrease the climate impact of aviation. However the inevitable formation of hydrogen boil-off gas (BOG) is a main drawback of LH2. As the venting of BOG reduces the overall efficiency and implies a safety risk at the airport means for capturing and re-using should be implemented. Metal hydrides (MHs) offer promising approaches for BOG recovery as they can directly absorb the BOG at ambient pressures and temperatures. Hence this study elaborates a design concept for such an MH-based BOG recovery system at hydrogen-ready airports. The conceptual design involves the following process steps: identify the requirements establish a functional structure determine working principles and combine the working principles to generate a promising solution.

Hydrogen is increasingly recognized as an element in the effort to decarbonize the energy sector. Within the development of large-scale supply chain the storage phase emerges as a significant challenge. This study reviews Life Cycle Assessment (LCA) literature focused exclusively on hydrogen as an energy vector aiming to identify areas for improvement highlight effective solutions and point out research gaps. The goal is to provide a comprehensive overview of hydrogen storage technologies from an environmental perspective. A systematic search was conducted in the SCOPUS database using a specific set of keywords resulting in the identification of 30 relevant studies. These works explore hydrogen storage across different scales and applications which were classified into five categories based on the type of storage application most of them related to stationary use. The majority of the selected studies focus on storing hydrogen in compressed gas tanks. Notably 33 % of the analyzed articles assess only greenhouse gas (GHG) emissions and 10 % evaluate only two environmental impact categories including GHGs. This reflects a limited understanding of broader environmental impacts with a predominant focus on CO₂eq emissions. When comparing different case studies storage methods associated with the lowest emissions include metal hydrides and underground hydrogen storage. Another important observation is the trend of decreasing CO₂eq emissions as the storage system scale increases. Future studies should adopt more comprehensive approaches by analyzing a wider range of hydrogen storage technologies and considering multiple environmental impact categories in LCA. Moreover it is crucial to integrate environmental economic and social dimensions of sustainability as multidimensional assessments are essential to support well-informed balanced decisions that align with the sustainable development of hydrogen storage systems.

Hydrogen injection (HI) is an emerging decarbonisation technology for ironmaking blast furnaces (BFs) yet its impact on the in-furnace phenomenon in the raceway of an industry BF remains unclear. In this study an industrialscale Reactive Computational Fluid Dynamic Discrete Element Method coupling model (rCFD-DEM) is developed to study the impacts of HI on the raceway dynamics and coke combustion inside an industrial-scale BF. To overcome the limit in previous CFD-DEM works this work considers the impact of top loading on the in-raceway reacting flow for the first time. The comparisons show that the raceway size is sensitive to the top loading ratio suggesting that the top loading should be considered in future raceway modelling. Then the quantitative effect of the HI rate is numerically evaluated. It is indicated that when the HI rate increases from zero to 8 kg/tHM the raceway height and depth increase by 95% and 81% respectively under the investigated conditions. The underlying mechanism is explored: the increase in HI rate leads to an increase in inter-phase drag force and interparticle collision and in the convection and radiation heat transfer rates by 33 and 32 times respectively. This study provides a cost-effective tool to understand and optimise HI in industrial-scale BFs for a lower carbon footprint empowering the steel industry with crucial insights.

Novel hydrogen-based aircraft concepts pose significant challenges for the system development process. This paper proposes a generic adaptable and multidisciplinary framework for integrated model-based systems engineering (MBSE) and model-based safety assessment (MBSA) for the conceptual design of complex systems. The framework employs a multi-granularity modelcentric approach whereby the architectural specification is utilized for design as well as query purposes as part of a qualitative and quantitative graphbased preliminary safety assessment. For the qualitative assessment design and safety rules based on existing standards and best practices are formalized in the model and applied to a graph-based architecture representation. Consequently the remaining architectures are quantitatively assessed using automated fault trees. This safety-integrated approach is applied to the conceptual design of a liquid hydrogen fuel system architecture as a novel uncertain and complex system with many unknown system interrelations. This paper illustrates the potential of a combined MBSE-MBSA framework to streamline complex early-stage system design and demonstrates that all qualitatively down-selected hydrogen system architecture variants also satisfy quantitative assessment. Furthermore it is shown that the design space of novel systems is also constrained by safety and certification requirements significantly reducing the number of actual feasible solutions.

This paper addresses public acceptance of a proposed sub-regional hydrogen– electric aviation service reporting initial empirical evidence from the UK HEART project. The objective was to assess public acceptance of a wide range of service features including hydrogen power electric motors and pilot assistance automation in the context of an ongoing realisable commercial plan. Both qualitative and quantitative data collection instruments were leveraged including focus groups and stakeholder interviews as well as the questionnaire-based Scottish National survey coupled with the advanced discretechoice modelling of the data. The results from each method are presented compared and contrasted focusing on the strength reliability and validity of the data to generate insights into public acceptance. The findings suggest that public concerns were tempered by an incomplete understanding of the technology but were interpretable in terms of key service elements. Respondents’ concerns and opinions centred around hydrogen as a fuel singlepilot automation safety and security disability and inclusion environmental impact and the perceived usefulness of novel service features such as terminal design automation and sustainability. The latter findings were interpreted under a joint framework of technology acceptance theory and the diffusion of innovation. From this we drew key insights which were presented alongside a discussion of the results.

This study introduces an effective analysis framework for exploring the complex interrelation between the renewable energy factor (REF) and the economic dimensions of a PV-driven microgrid featuring a dual-level storage system that incorporates both hydrogen and electrical energy storage. By establishing a coupled model that integrates dynamic simulations with a statistical multi-objective optimization algorithm the research aims to achieve optimal component sizing—a critical step in assessing the hybrid system across various REF levels—while effectively reducing the levelized cost of electricity (LCOE). Using the analysis outcomes of a case study a comprehensive techno-economic assessment facilitates a nuanced evaluation of the interplay between the REF system economics across various equipment cost quartiles and grid tariffs addressing the feasibility of the proposed solution for a sustainable energy transition. The results highlight how grid tariffs and REF jointly influence LCOE values across cost quartiles impacting hybrid system design and decision-making. An exponential correlation is observed between life cycle cost (LCC) and REF with the increase in annual operating costs being marginal compared to the initial cost rise. For the net-zero energy case the LCOE ranges from 0.0380 to 0.1873 $/kWh while at REF = 0.6 it spans from 0.0461 to 0.1334 $/kWh reflecting a 71 % larger difference (range). A sensitivity analysis indicates that each 5 % increase in REF leads to an average 20.7 % rise in payback period (PBP) for a given grid tariff.

To enable hydrogen-powered aircraft operations liquid hydrogen infrastructure has to be planned well in advance. This study analyses the transition pathway of liquid hydrogen supply infrastructure from the initial development phase to market penetration optimizing the design and dispatch of the system. The findings reveal that the single-year approach used in previous studies significantly underestimates the costs associated with supply infrastructure. During the transition phase substantial investments are required in specific years leading to high supply costs particularly in the early years. Off-take agreements could be used to achieve a more balanced cost distribution. For the considered location of a generic airport on-site liquid hydrogen supply costs range between 3.83 and 5.03 USD/kgH2 assuming a long-term supply agreement. At a less favourable airport supply costs are 29% higher compared to a favourable location. However costs could be reduced by up to 12% if hydrogen is imported via vessels or the European Hydrogen Backbone. The primary factors influencing supply costs are the availability of renewable energy resources and the distances to the nearest port as well as hydrogen production hubs. Therefore the optimal supply chain must be assessed individually for each airport. Overall this study provides insights and a methodology that can support the development of future liquid hydrogen infrastructure roadmaps for hydrogen-powered aviation.

The long term and large-scale energy storage operations require quick response time and round-trip efficiency which is not feasible with conventional battery systems. To address this issue while endorsing high energy density long term storage and grid adaptability the hydrogen energy storage (HES) is preferred. This proposed work makes a comprehensive review on HES while synthesizing recent research on energy storage technologies and integration into renewable energy (RE) applications. The proposed research also identifies critical challenges related to system optimization energy management strategies and economic viability while featuring emerging technologies like artificial intelligence (AI) and machine learning (ML) for energy management. The proposed survey also discusses key advancements in battery technologies (lithium-ion Ni-Cd Ni/MH and flow batteries) which are examined alongside innovations in HES methods. The proposed survey utilizes an extensive list of publications to date in the open literature to canvass and portray various developments in this area.

China has emerged as a global leader in promoting new energy vehicles; however the impact of these efforts on the commercial vehicle sector remains limited. Hydrogen fuel cell vehicles are crucial for improving the environmental performance of commercial vehicles in China. This study evaluates the effectiveness of China’s Hydrogen fuel cell vehicle policies. Firstly an evaluation index system for hydrogen fuel cell vehicle policies is established quantifying the policy through two key metrics: policy comprehensiveness and policy synergy. Subsequently city-level data from 84 municipalities (2018-2022) are analyzed to assess policy impacts on hydrogen fuel cell vehicles adoption. The results show that both policy comprehensiveness and synergy significantly drive hydrogen fuel cell vehicle sales growth. Early sales figures also strongly influence current trends. Therefore promoting growth in hydrogen fuel cell vehicle sales can further enhance policy efforts while also accounting for the cumulative effects of initial promotional activities.

This study evaluates the potential of hydrogen as a clean additive to conventional diesel fuel. Experiments were carried out on a single-cylinder air-cooled diesel engine under half- and full-load conditions across engine speeds ranging from 1000 to 3000 rpm. Hydrogen produced on site via a proton exchange membrane electrolyser was supplied to the engine at a constant flow rate of 0.5 L/min. Compared to pure diesel the hydrogen–diesel blend reduced specific fuel consumption by 10% and increased brake thermal efficiency by 10% at full load. Emissions of carbon monoxide and carbon dioxide decreased by 13% and 17% respectively at half load. Additionally nitrogen oxide emissions dropped by 17%. These results highlight the potential of hydrogen to improve combustion efficiency while significantly mitigating emissions offering a viable transitional solution for cleaner power generation using existing diesel infrastructure.

The article presents the results of an experimental study on the influence of hydrogen as gaseous fuel on the combustion process parameters of a single-cylinder diesel engine operating in dual-fuel mode. The study is conducted at an average engine speed of n = 2000 min⁻ 1 four engine load levels and two different diesel fuel injection timing angles. Indicator diagrams are recorded for each operating mode at varying hydrogen mass fractions in the total fuel supplied to the engine. The data from the indicator diagrams are processed using a developed software that enables the determination of combustion process parameters. The analysis of the experimental results focuses on changes in cylinder temperature the coefficients of total and active heat release the rate of heat release the duration of the combustion process phases and other parameters as a function of the hydrogen mass fraction in the total fuel mixture.

Hydrogen as fuel in civil aviation gas turbines is promising due to its no-carbon content and higher net specific energy. For an entry-level market and cost-saving strategy it is advisable to consider reusing existing engine components whenever possible and retrofitting existing engines with hydrogen. Feasible strategies of retrofitting state-of-theart Jet A-1 fuelled turbofan engines with hydrogen while applying minimum changes to hardware are considered in the present study. The findings demonstrate that hydrogen retrofitted engines can deliver advantages in terms of core temperature levels and efficiency. However the engine operability assessment showed that retrofitting with minimum changes leads to a ~5% increase in the HP spool rotational speed for the same thrust at take-off which poses an issue in terms of certification for the HP spool rotational speed overspeed margin.

Even if the aviation sector only accounts for 2% of global energy-related CO2 emissions and is the most challenging sector to decarbonize. As aviation demand grows and the need for sustainable jet fuels becomes urgent green hydrogen could substitute conventional fossil fuels thereby enabling carbon-free flights. This study investigates a techno-economic analysis of onsite versus off-site green hydrogen supply chains. A case study at the Toulouse-Blagnac airport (Europe’s first station for the production and distribution of renewable hydrogen) in France is developed to meet commercial aviation's hydrogen fuel demand between 2025 and 2050. Demand of hydrogen is projected based on the trend of jet fuel consumption. First the cost of solar-based renewable electricity is estimated at the two green hydrogen production sites using levelized cost of electricity production. Second levelized cost of hydrogen (LCOH) is evaluated for three value chain scenarios: one on-site (Toulouse airport) and two off-site (Marseille) for gaseous and cryogenic transportation of liquid hydrogen (LH2). A relative cost advantage is shown for the off-site case with cryogenic truck transportation at LCOH of €9.43/kg.LH2. This study also reveals the importance of electricity price investment costs operation costs economies of scale and transportation distance in different scenarios.

In the pursuit of establishing a sustainable fuel cell (FC) energy system this review highlights the necessity of examining the operational principles technical details environmental consequences and economic concerns collectively. By adopting an integrated approach the review research into various fuel cells types extending their applications beyond transportation and evaluating their potential for seamless integration into sustainable practices. A detailed analysis of the technical aspects including FC membranes performance and applications is presented. The environmental impact of hydrogen generation through fuel cell/electrolyzer is quantitatively assessed emphasizing a comparative emission footprint against traditional hydrogen generation methods. Economic considerations of fuel cell technology adoption are explored through an extensive examination of market growth and forecasts and investments into the FC systems. Some flagship commercial projects of FC technology are also discussed along with their future prospective. The article concludes with a thorough analysis of challenges associated with FC adoption encompassing membrane research performance hurdles infrastructure development and application-specific challenges. This all-round review serves as an indispensable tool for academicians and policymakers providing a directed and comprehensive FC perspective.

In the context of “dual carbon” in order to promote the consumption of renewable energy and improve energy utilization efficiency a low-carbon economic dispatch model of an integrated energy system containing carbon capture power plants and multiple utilization of hydrogen energy is proposed. First introduce liquid storage tanks to transform traditional carbon capture power plants and at the same time build a multi-functional hydrogen utilization structure including two-stage power-to-gas hydrogen fuel cells hydrogen storage tanks and hydrogen-doped cogeneration to fully exploit hydrogen. It can utilize the potential of collaborative operation with carbon capture power plants; on this basis consider the transferability and substitutability characteristics of electric heating gas load and construct an electric heating gas comprehensive demand response model; secondly consider the mutual recognition relationship between carbon quotas and green certificates Propose a green certificate-carbon trading mechanism; finally establish an integrated energy system with the optimization goal of minimizing the sum of energy purchase cost demand response compensation cost wind curtailment cost carbon storage cost carbon purchase cost carbon trading cost and green certificate trading compensation. Optimize scheduling model. The results show that the proposed model can effectively reduce the total system cost and carbon emissions improve clean energy consumption and energy utilization and has significant economical and low-carbon properties.

Hydrogen-fueled Internal Combustion Engines (H2-ICEs) are typically operated with lean mixtures to minimize NOx emissions and reduce the risk of abnormal combustion events. Due to hydrogen’s low Lewis number premixed hydrogen-air flames in lean conditions exhibit strong thermodiffusive instabilities which make the numerical simulation of the combustion process particularly challenging. Indeed the intensity of these instabilities is significantly influenced by thermodynamic parameters – such as mixture temperature pressure and dilution rate – resulting in substantial variations in combustion behaviour across different operating conditions. Therefore they have to be properly considered not only to ensure model robustness but also to improve model accuracy over a wider range of operations. In this study the combustion process in a Direct Injection H2-ICE was analyzed using 3D-CFD simulations relying on a flamelet-based combustion model. Two sets of lookup flame speed maps were defined: laminar flame speed (SL) maps derived from standard 1D-CFD simulations in homogeneous reactor and freely propagating flame speed (SM) maps which account for the effects of thermodiffusive instabilities. The model that uses SL maps required the recalibration of some combustion model parameters when changing the dilution rate to ensure consistency with experimental data. Instead the model relying on SM maps featured a noticeable accuracy across different air-to-fuel ratios without the need for recalibration any combustion model parameter highlighting the key role of thermodiffusive flame instabilities on the combustion process. Based on these findings the impact of such instabilities was evaluated throughout the entire combustion process from both global and local perspectives. The relevance of thermodiffusive instabilities was observed to increase with the air-to-fuel ratio thereby enhancing combustion speed in leaner mixtures. Additionally the implementation of thermodiffusive instabilities was found to affect also preferred direction of flame propagation as stronger instabilities were identified in the leanest and low-temperature portions of the flame front. Novelty and significance This study addresses a critical knowledge gap regarding the role of thermodiffusive flame instabilities in accurately replicating the combustion process of a direct-injection internal combustion engine within a RANS simulation framework. Indeed while these instabilities have been shown to significantly enhance the mixture consumption rate in quiescent environments at low to moderate pressures and temperatures particularly in lean mixtures their impact on the burn rate under engine-like conditions has not yet been systematically investigated to the best of the authors’ knowledge. This work provides a comprehensive analysis of the significance of these instabilities in the combustion process of a direct-injection hydrogen internal combustion engine. The analysis is conducted from both a global perspective assessing their overall influence on the combustion process and a local perspective examining how they alter flame front characteristics when incorporated into the model.

Research into the off-grid hybrid energy system to provide reliable electricity to a remote community has extensively been done. However simultaneous meeting electric freshwater and gas demands from the off-grid hybrid energy sources are very scarce in literature. Power- to-X (PtX) is gaining attention in recent days in the energy transition scenarios to generate green hydrogen the primary product of the process as an energy carrier which is deemed to replace conventional fuels to reach absolute carbon neutrality. In this study renew able–based hybrid energy is developed to simultaneously meet the electricity freshwater and gas (cooking gas via methanation process) demands for a remote Island in Bangladesh. In this process an energy management strategy has been developed to use the excess energy to generate both freshwater and the hydrogen where hydrogen is then converted to natural gas via methanation process. The PV wind turbine diesel generator battery and fuel cell have been optimized using non-dominating sorting algorithm-II (NSGA-II) to offer reliable cost-effective solutions of electricity freshwater and cooking gas for the end users. Results reported that the PV/ WT/DG/Batt configuration has been found the most economic configuration with the lowest COE (0.1724 $/kWh) which is 9 % lower than PV/WT/Batt configuration which has the second lowest COE. The cost of water (COW) and cost of gas (COG) of the PV/WT/DG/Batt system are also the lowest among all the four configurations and have been found 1.185 $/m3 and 3.978 $/m3 respectively.

This research designs a conceptual system where both solar and biomass energy subsystems are uniquely integrated to turn wastewater into useful outputs such as hydrogen fresh water and heat to achieve sustainable communities where renewable energy is utilized with the wastewater treated effectively. The system integrates several subsystems including a reheat Rankine cycle an organic Rankine cycle a multi-stage flash desalination system and a biohydrogen production unit employing a microbial electrolysis process. In order to study a potential application of this conceptually developed system the city of Oshawa in Ontario Canada is identified with its wastewater treatment facility which is designed to produce clean biohydrogen that is liquefied and stored for distribution to refueling stations for hydrogen-based transportation. In this regard thermodynamic analysis and assessment studies are conducted using the Engineering Equation Solver and demonstrating that the system achieves the overall energetic and exergetic efficiencies of 34.94% and 32.84% respectively. Furthermore the system produces freshwater at a rate of 5.36 kg/s and biohydrogen at 0.03 kg/s contributing to environmental sustainability and efficient resource utilization in addition to the heat recovered and used in the community as a useful output. This research highlights the potential of the system to significantly reduce greenhouse gas emissions while promoting sustainable energy and transportation developments in Oshawa and similar regions.

In recent years numerous hydrogen-powered rail vehicles have been developed and their deployment within public transport is steadily increasing. To avoid disadvantages compared to diesel vehicles refueling times of 15 min are stated in the industry as target independent of climate zones or vehicle configurations. As refueling time varies with these parameters this work presents the corresponding refueling times and defines optimization potentials. A simulation model was set up and parametrized with a reference vehicle and hydrogen refueling station from the FCH2RAIL project. Measurement data from this station and vehicle were analyzed and compared to simulation results for model validation. The results show that at high ambient temperature pre-cooling reduces refueling time by 71 % and type 4 tanks increase refueling time by 20 % compared to type 3. Overall optimized tank design and thermal management reduce the refueling time for rail vehicles from over 2 h to 15 min.

The UK has set an ambitious target of delivering clean power by 2030. Low carbon dispatchable power generation using hydrogen will play a key role in a clean power system by providing flexibility and other services for system operability and also by providing supply adequacy during extended periods of low renewable output decarbonising the role currently performed by an aging portfolio of unabated natural gas power generation. While some 100% hydrogen to power (H2P) commercial projects are already being deployed globally using multi megawatt fuel cells alongside blending hydrogen into existing gas turbines and new hydrogen ready turbines industrial scale 100% H2P projects face additional challenges of deploying new technology into a nascent system one which requires significant volumes of hydrogen storage with long lead times. To achieve the 2030 clean power system ambition and lay the foundations for a clean resilient and secure power system beyond 2030 it is critical that the new government takes resolute actions now to support H2P at scale. A clear strategic plan should be developed within the first 12 months of the new administration with clarity being given on policy business models and deployment rates for hydrogen to power (H2P) and its enabling infrastructure. This report produced by Hydrogen UK’s Power Generation Working Group explores the role that H2P will play in the decarbonised power system of the future the barriers to deployment and recommendations for overcoming them.

This paper can be found on their website.

This study investigates the effects of secondary jet-guided combustion on the combustion and emissions of a hydrogen direct-injection engine through numerical simulations. The results show that secondary jet-guided combustion which involves injecting and igniting the hydrogen jet at the end of the compression stroke significantly shortens the delay period improves combustion stability and brings the combustion center closer to the top dead center (TDC) achieving a maximum indicative thermal efficiency (ITE) of 46.55% (λ = 2.4). However this strategy results in higher NOx emissions due to high-temperature combustion. In contrast single and double injections lead to worsened combustion and reduced thermal efficiency under lean-burn conditions but with relatively lower NOx emissions. This study demonstrates that secondary jet-guided combustion can effectively enhance hydrogen engine performance by optimizing mixture stratification and flame propagation providing theoretical support for clean and efficient combustion.

Hydrogen fuel presents a promising pathway for achieving long-term decarbonization in the maritime sector. However its use in diesel engines introduces challenges due to high reactivity leading to increased NOx emissions and combustion instability. The aim of this study is to identify settings so that the investigated engine operates with 60% hydrogen energy fraction at high load through CFD modelling. The model is utilized to simulate a four-stroke 10.5 MW marine engine at 90% load incorporating 60% hydrogen injection by energy at the engine intake port. The CFD model is verified using experimental data from diesel operation of the marine engine and hydrogen operation of a light-duty engine. The engine performance was determined and detailed emissions analysis was conducted including NO NO2 HO2 and OH. The findings indicate a substantial rise in NOx emissions as opposed to diesel operation due to elevated combustion temperatures and increased residence time at elevated temperature of the mixture in-cylinder. The presence of HO2 and OH highlights critical zones of combustion which contribute to operational stability. The novelty of this study is supported by the examination of the high hydrogen energy fraction the advanced emissions analysis and the insights into the emissions–performance trade-offs in hydrogen-fueled dual-fuel marine engines. The results offer guidance for the development of sustainable hydrogen-based marine propulsion systems.

Solid oxide fuel cells (SOFCs) have garnered significant attention as a promising technology for clean and efficient power generation due to their ability to utilise renewable fuels such as hydrogen and ammonia. As carbon-free energy carriers hydrogen and ammonia are expected to play a pivotal role in achieving net-zero emissions. However a critical research question remains: how does the electrochemical performance of SOFCs compare when fuelled by hydrogen vs. ammonia and what are the implications for their practical application in power generation? This mini-review paper is premised on the hypothesis that while hydrogen-fuelled SOFCs currently demonstrate superior stability and performance at low and high temperatures ammonia-fuelled SOFCs offer unique advantages such as higher electrical efficiencies and improved fuel utilisation. These benefits make ammonia a viable alternative fuel source for SOFCs particularly at elevated temperatures. To address this the mini-review paper provides a comprehensive comparative analysis of the electrochemical performance of SOFCs under direct hydrogen and ammonia fuels focusing on key parameters such as open-circuit voltage (OCV) power density electrochemical impedance spectroscopy fuel utilisation stability and electrical efficiency. Recent advances in electrode materials electrolytes fabrication techniques and cell structures are also highlighted. Through an extensive literature survey it is found that hydrogen-fuelled SOFCs exhibit higher stability and are less affected by temperature cycling. In contrast ammonia-fuelled SOFCs achieve higher OCVs (by 7%) and power densities (1880 mW/cm2 vs. 1330 mW/cm2 for hydrogen) at 650 °C along with 6% higher electrical efficiency. Despite these advantages ammonia-fuelled SOFCs face challenges such as NOx emissions nitride formation environmental impact and OCV stabilisation which are discussed alongside potential solutions. This mini review aims to provide insights into the future direction of SOFC research emphasising the need for further exploration of ammonia as a sustainable fuel alternative.

The potential of utilizing the rejected heat of a fuel cell system to improve the aircraft propulsive efficiency is discussed for various flight conditions. The thermodynamic background of the process and the connection of power consumption in the fan of the ducted propulsor and fuel cell heat are given and a link between these two components is presented. A concept that goes beyond the known ram heat exchanger is discussed which outlines the potential benefits of integrating a fan upstream of the heat exchanger. The influence of the fan pressure ratio flight speed and altitude as well as the temperature level of the available fuel cell heat on the propulsive efficiency is presented. A correlation between the fan pressure ratio flight speed and exchangeable fuel cell heat is established providing a simplified computational approach for evaluating feasible operating conditions within this process. This paper identifies the challenges of heat exchanger integration at International Standard Atmosphere sea level conditions and its benefits for cruise flight conditions. The results show that for a flight Mach number of 0.8 and a fan pressure ratio of 1.5 at a cruising altitude of 11000 m the propulsion efficiency increases by approximately 8 percentage points compared to a ducted propulsor without heat utilization. Under sealevel conditions the concept does not offer any performance advantages over a ducted propulsor. Instead it exhibits either comparable or reduced propulsive efficiency.

We report on the first stage of an energy systems integration project to develop hybrid renewable energy generation and storage of hydrogen for subsequent use via research-based low regret system testbeds. This study details the design and construction of a flexible plug-and-play hybrid renewable power and hydrogen system testbed with up to 50 kW capacity aimed at addressing and benchmarking the operational parameters of the system as well as key components when commissioned. The system testbed configuration includes three different solar technologies three different battery technologies two different electrolyser technologies hydrogen storage and a fuel cell for regenerative renewable power. Design constraints include the current limit of an AC microgrid regulations for grid-connected inverters power connection inefficiencies and regulated hazardous area approval. We identify and show the resolution of systems integration challenges encountered during construction that may benefit planning for the emerging pilot or testbed configurations at other sites. These testbed systems offer the opportunity for informed decisions on economic viability for commercial-scale industry applications.

The challenge of achieving net-zero CO2 emissions will require a significant scaling up of the production of several raw materials that are critical for decarbonizing the global economy. In contrast metal extraction processes utilize carbon as a reducing agent which is oxidized to CO2 resulting in considerable emissions and having a negative impact on climate change. In order to abate their emissions extractive industries will have to go through a profound transformation including switching to alternative climateneutral energy and feedstock sources. This paper presents the authors’ perspectives for consideration in relation to the H2 potential for direct reduction of oxide and sulfide ores. For each case scenario the reduction of CO2 emissions is analyzed and a breakthrough route for H2S decomposition is presented which is a by-product of the direct reduction of sulfide ores with H2. Electrified indirect-fired metallurgical kiln advantages are also presented a solution that can substitute fossil fuel-based heating technologies which is one of the main backbones of industrial processes currently applied to the extractive industries.

Hydrogen energy is essential in the transition to sustainable transportation planning providing a clean and efficient alternative to traditional fossil fuels. As a versatile energy carrier hydrogen facilitates the decarbonization of diverse transportation modes including passenger vehicles heavy-duty trucks trains and maritime vessels. To justify and clarify the role of hydrogen energy in sustainable transportation planning this study conducts a comprehensive techno-economic and environmental assessment of hydrogen production in the USA Europe and China. Utilizing the Shlaer–Mellor method for policy modeling the analysis highlights regional differences and offers actionable insights to inform strategic decisions and policy frameworks for advancing hydrogen adoption. Hydrogen production potential was assessed from solar and biomass resources with results showing that solar-based hydrogen production is significantly more efficient producing 704 tons/yr/km2 compared to 5.7 tons/yr/km2 from biomass. A Monte Carlo simulation was conducted to project emissions and market share for hydrogen and gasoline vehicles from 2024 to 2050. The results indicate that hydrogen vehicles could achieve near-zero emissions and capture approximately 30% of the market by 2050 while gasoline vehicles will decline to a 60% market share with higher emissions. Furthermore hydrogen production using solar energy in the USA yields a per capita output of 330513 kg/yr compared to 6079 kg/yr from biomass. The study concludes that hydrogen particularly from renewable sources holds significant potential for reducing greenhouse gas emissions with policy frameworks in the USA Europe and China focused on addressing energy dependence air pollution and technological development in the transportation sector.

At present the decarbonization of the public transport sector plays a key role in international and regional policies. Among the various energy vectors being considered for future clean bus fleets green hydrogen and electricity are gaining significant attention thanks to their minimal carbon footprint. However a comprehensive Life Cycle Assessment (LCA) is essential to compare the most viable solutions for public mobility accounting for variations in weather conditions geographic locations and time horizons. Therefore the present work compares the life cycle environmental impact of different powertrain configurations for urban buses. In particular a series hybrid architecture featuring two possible hydrogenfueled Auxiliary Power Units (APUs) is considered: an H2-Internal Combustion Engine (ICE) and a Fuel Cell (FC). Furthermore a Battery Electric Vehicle (BEV) is considered for the same application. The global warming potential of these powertrains is assessed in comparison to both conventional and hybrid diesel over a typical urban mission profile and in a wide range of external ambient conditions. Given that cabin and battery conditioning significantly influence energy consumption their impact varies considerably between powertrain options. A sensitivity analysis of the BEV battery size is conducted considering the effect of battery preconditioning strategies as well. Furthermore to evaluate the potential of hydrogen and electricity in achieving cleaner public mobility throughout Europe this study examines the effect of different grid carbon intensities on overall emissions based also on a seasonal variability and future projections. Finally the present study demonstrates the strong dependence of the carbon footprint of various technologies on both current and future scenarios identifying a range of boundary conditions suitable for each analysed powertrain option.

The power to weight ratio of power plants is an important consideration especially in the design of Unmanned Aircraft System (UAS). In this paper a UAS with an MTOW of 35.3 kg equipped with a fuel cell as a prime power supply to provide electrical power to the propulsion system is considered. A pressure vessel design that can estimate and determine the total size and weight of the combined power plant of a fuel cell stack with hydrogen and air/oxygen vessels and the propulsion system of the UAS for highaltitude operation is proposed. Two scenarios are adopted to determine the size and weight of the pressure vessels required to supply oxygen to the fuel cell stack. Different types of stainless-steel materials are used in the design of the pressure vessel in order to find an appropriate material that provides low size and weight advantages. Also the design of a hydrogen pressure vessel and mass estimation are also considered. The estimated sizes and weights of the hydrogen and oxygen vessels of the power plant and propulsion system in this research offer a maximum of four hours of flying time for the UAS mission; this is based on a Horizon (H-1000) Proton Exchange Membrane (PEM) stack.

The share of renewable electricity generation has been growing steadily over the past few years. However not all sectors can be fully electrified to reach decarbonization goals. The maritime industry which plays a critical role in international trade is such a sector. Therefore there is a need for a global strategic approach towards the production transportation and use of synfuels enabling the maritime energy transition to benefit from economies of scale. There are potential locations around the world for renewable generation such as hydropower in Norway wind turbines in the North Sea and photovoltaics in the Sahara where synfuels can be produced and utilized within the country as well as exported to demand hubs. Given that a country's domestic production may not fully meet its demand a scenario-based analysis is essential to determine the feasibility of supply chains pillaring on the demand and supply for the respective sector of utilization. Our work demonstrates this methodology for the import of hydrogen and derived ammonia and methanol to Germany from Norway Namibia and Algeria in 2030 and 2050 utilizing the pipeline- and ship-based transport scenarios. Thereby the overall supply chain efficiency for maritime applications is analyzed based on the individual supply chain energy consumption from production to bunkering of the fuel to a vessel. The analysis showed that the efficiency of import varies from 44.6% to 53.9% between the analyzed countries. Furthermore a sensitivity analysis for green and blue hydrogen production pathways is presented along with the influence of qualitative factors like port infrastructure geopolitics etc. As an example through these analyses recommendations for supply from Norway Algeria and Namibia at the Port of Wilhelmshaven within a supply chain are examined.

The current research critically evaluates the technical economic and environmental performance of a Power-toLiquid (PtL) system for the production of sustainable aviation fuel (SAF). This SAF production system comprises a direct air capture (DAC) unit an off-shore wind farm an alkaline electrolyser and a refinery plant (reverse water gas shift coupled with a Fischer-Tropsch reactor). The calculated carbon conversion efficiency hydrogen conversion efficiency and Power-to-liquids efficiency are 88 % 39.16 % and 25.6 % respectively. The heat integration between the refinery and the DAC unit enhances the system’s energy performance while water integration between the DAC and refinery units and the electrolyser reduces the demand for fresh water. The economic assessment estimates a minimum jet fuel selling price (MJSP) of 5.16 £/kg. The process is OPEX intensive due to the electricity requirements while the CAPEX is dominated by the DAC unit. A Well-to-Wake (WtWa) life cycle assessment (LCA) shows that the global warming potential (GWP) equals 21.43 gCO2eq/ MJSAF and is highly dependent on the upstream emissions of the off-shore wind electricity. Within a 95 % confidence interval a stochastic Monte Carlo LCA reveals that the GWP of the SAF falls below the UK aviation mandate treshold of 50 % emissions reduction compared to fossil jet fuel. Moreover the resulting WtWa water footprint is 0.480 l/MJSAF with the refinery’s cooling water requirements and the electricity’s water footprint to pose as the main contributors. The study concludes with estimating the required monetary value of SAF certificates for different scenarios under the UK SAF mandate guidelines.

This study evaluates the techno-economic feasibility of solar-based green hydrogen potential for off-grid and utility-scale systems in Niger. The geospatial approach is first employed to identify the area available for green hydrogen production based on environmental and socio-technical constraints. Second we evaluate the potential of green hydrogen production using a geographic information system (GIS) tool followed by an economic analysis of the levelized cost of hydrogen (LCOH) for alkaline and proton exchange membrane (PEM) water electrolyzers using fresh and desalinated water. The results show that the electricity generation potential is 311617 TWh/year and 353166 TWh/year for off-grid and utility-scale systems. The hydrogen potential using PEM (alkaline) water electrolyzers is calculated to be 5932 Mt/year and 6723 Mt/year (5694 Mt/year and 6454 Mt/year) for off-grid and utility-scale systems respectively. The LCOH production potential decreases for PEM and alkaline water electrolyzers by 2030 ranging between 4.72–5.99 EUR/kgH2 and 5.05–6.37 EUR/kgH2 for off-grid and 4.09–5.21 EUR/kgH2 and 4.22–5.4 EUR/kgH2 for utility-scale systems.

This study presents a techno-economic analysis of hydrogen transportation via liquid organic hydrogen carriers by road comparing this option with compressed hydrogen (350 bar) and liquefied hydrogen. The analysis includes the simulation of hydrogenation and dehydrogenation reactors for the dibenzyltoluene/perhydro-dibenzyltoluene system using ASPEN Plus along with a cost assessment of compression liquefaction and trucking. A sensitivity analysis is also carried out evaluating hydrogen transport at varying daily demand levels (1 2 and 4 t/d) and transport distances (50 150 and 300 km) with varying electricity prices and capital expenditures for hydrogenation and dehydrogenation units. Results indicate that compressed hydrogen is the most cost-effective solution for short distances up to 150 km with a levelized cost of transported hydrogen ranging from 1.10 to 1.61 EUR/kg. However LOHC technology becomes more competitive at longer distances with LCOTH values between 1.49 and 1.90 EUR/kg at 300 km across all demand levels. Liquefied hydrogen remains the least competitive option reaching costs up to 5.35 EUR/kg although it requires fewer annual trips due to higher trailer capacity. Notably at 150 km LOHC transport becomes more cost-effective than compressed hydrogen when electricity prices exceed 0.22 EUR/kWh or when the capital costs for hydrogenation and dehydrogenation units are minimized. From an environmental perspective switching from compressed to liquid hydrogen carriers significantly reduces CO2 emissions—by 56% for LOHCs and 78% for liquid hydrogen—highlighting the potential of these technologies to support the decarbonization of hydrogen logistics.

Rapid socio-economic development has made energy application and environmental issues increasingly prominent. Hydrogen energy clean eco-friendly and highly synergistic with renewable energy has become a global research focus. This study using the EnergyPLAN model that includes the electricity transportation and industrial sectors takes Jinan City as the research object and explores how hydrogen penetration changes affect the decarbonization path of the urban integrated energy system under four scenarios. It evaluates the four hydrogen scenarios with the entropy weight method and technique placing them in an order of preference according to their similarity to the ideal solution considering comprehensive indicators like cost carbon emissions and sustainability. Results show the China Hydrogen Alliance potential scenario has better CO2 emission reduction potential and unit emission reduction cost reducing them by 7.98% and 29.39% respectively. In a comprehensive evaluation it ranks first with a score of 0.5961 meaning it is closest to the ideal scenario when cost environmental and sustainability indicators are comprehensively considered. The Climate Response Pioneer scenario follows with 0.4039 indicating that higher hydrogen penetration in terminal energy is not necessarily the most ideal solution. Instead appropriate hydrogen penetration scenarios should be selected based on the actual situation of different energy systems.

In 2021 the global electricity and heat sector recorded the highest increase in carbon dioxide (CO2) emissions in comparison with the previous year highlighting the ongoing challenges in reducing emissions within the sector. Therefore combined heat and power (CHP) plants running on renewable fuels can play an important role in the energy transition by decarbonising a process increasing the efficiency and capacity factor. Since 2003 Luxembourgish CHP plants have been transitioning from natural gas to biomass mainly wood pellets. However even though wood pellets are a renewable alternative the market volatility in 2022 highlighted the vulnerability of a system reliant solely on one type of fuel. This study assesses the feasibility of using hydrogen to decarbonise a cogeneration plant powered by a natural gas-fuelled internal combustion engine. Although the technology to use hydrogen as a fuel for such systems already exists a technical and economic analysis of implementing a hydrogen-ready plant is still lacking. Our results show that from a technical perspective retrofitting an existing power plant to operate with hydrogen is feasible either by adapting or replacing the engine to accommodate hydrogen blends from 0 up to 100%. The costs of making the CHP plant hydrogen-ready vary depending on the scenario ranging from a 20% increase for retrofitting to a 60% increase for engine replacement in the best-case scenarios. However these values remain highly variable due to uncertainties associated with the ongoing technology development. From an economic standpoint as of 2024 running the plant on hydrogen remains more expensive due to significant initial investments and higher fuel costs. Nevertheless projections indicate that rising climate concerns CO2 taxes geopolitical factors and the development of the hydrogen framework in the region—through projects such as MosaHYc and HY4Link— could accelerate the competitiveness of hydrogen making it a more viable alternative to fossil-based solutions in the near future.

Hydrogen has attracted widespread attention due to its zero emissions and high energy density and hydrogen-fueled power systems are gradually emerging. This paper combines the advantages of the high conversion efficiency of fuel cells and strong engine power to propose a hydrogen hybrid energy system architecture based on a mixture of fuel cells and engines in order to improve the conversion efficiency of the energy system and reduce its fuel consumption rate. Firstly according to the topology of the hydrogen hybrid energy system and the circuit model of its core components a state-space model of the hydrogen hybrid energy system is established using the Kirchhoff node current principle laying the foundation for the control and management of hydrogen hybrid energy systems. Then based on the state-space model of the hydrogen hybrid system and Pontryagin’s minimum principle a hydrogen hybrid system management strategy based on adaptive equivalent fuel consumption minimum strategy (A-ECMS) is proposed. Finally a hydrogen hybrid power system model is established using the AVL Cruise simulation platform and a control strategy is developed using matlab 2021b/Simulink to analyze the output power and fuel economy of the hybrid energy system. The results show that compared with the equivalent fuel consumption minimum strategy (ECMS) the overall fuel economy of A-ECMS could improve by 10%. Meanwhile the fuel consumption of the hydrogen hybrid energy system is less than half of that of traditional engines.

As the need to reduce Greenhouse Gas (GHG) emissions and dependence on fossil fuels grows new vehicle concepts are emerging as sustainable solutions for urban mobility. Beyond evaluating tailpipe emissions indirect emissions associated with energy and hydrogen production as vehicle manufacturing must be accounted offering a holistic Lifecycle Assessment (LCA) perspective. This study compares Battery Electric Vehicles (BEVs) Fuel Cell Vehicles (FCVs) Hydrogen Internal Combustion Engine Vehicles (H2ICEVs) and hybrid H2ICEVs analyzing energy efficiency and GHG emissions in urban environment across the European Union. Future scenarios (2030 2050) are examined as well with evolving energy mixes and manufacturing impacts. Findings show BEVs as the most efficient configuration with the lowest GHG emissions in 2024 while FCVs become the best option in future scenarios due to greener hydrogen production and improved manufacturing. This study emphasizes the need for tailored strategies to achieve sustainable urban mobility providing insights for policymakers and stakeholders.

Against the backdrop of ever‑increasing energy demand and growing awareness of en‑ vironmental protection the research and optimization of hydrogen‑related multi‑energy systems have become a key and hot issue due to their zero‑carbon and clean characteristics. In the scheduling of such multi‑energy systems a typical problem is how to describe and deal with the uncertainties of multiple types of energy. Scenario‑based methods and ro‑ bust optimization methods are the two most widely used methods. The first one combines probability to describe uncertainties with typical scenarios and the second one essentially selects the worst scenario in the uncertainty set to characterize uncertainties. The selection of these scenarios is essentially a trade‑off between the economy and robustness of the so‑ lution. In this paper to achieve a better balance between economy and robustness while avoiding the complex min‑max structure in robust optimization we leverage artificial in‑ telligence (AI) technology to generate enough scenarios from which economic scenarios and feasible scenarios are screened out. While applying a simple single‑layer framework of scenario‑based methods it also achieves both economy and robustness. Specifically first a Transformer architecture is used to predict uncertainty realizations. Then a Gener‑ ative Adversarial Network (GAN) is employed to generate enough uncertainty scenarios satisfying the actual operation. Finally based on the forecast data the economic scenar‑ ios and feasible scenarios are sequentially screened out from the large number of gener‑ ated scenarios and a balance between economy and robustness is maintained. On this ba‑ sis a multi‑energy collaborative optimization method is proposed for a hydrogen‑based multi‑energy microgrid with consideration of the coupling relationships between energy sources. The effectiveness of this method has been fully verified through numerical exper‑ iments. Data show that on the premise of ensuring scheduling feasibility the economic cost of the proposed method is 0.67% higher than that of the method considering only eco‑ nomic scenarios. It not only has a certain degree of robustness but also possesses good economic performance.

This paper addresses the challenge of renewable energy curtailment which stems from the inherent uncertainty and volatility of wind and photovoltaic (PV) generation by developing a robust model predictive control (RMPC)-based scheduling strategy for an integrated wind–PV–hydrogen storage multi-energy flow system. By building a “wind– PV–hydrogen storage–fuel cell” collaborative system the time and space complementarity of wind and PV is used to stabilize fluctuations and the electrolyzer–hydrogen production– gas storage tank–fuel cell chain is used to absorb surplus power. A multi-time scale state-space model (SSM) including power balance equation equipment constraints and opportunity constraints is established. The RMPC scheduling framework is designed taking the wind–PV joint probability scene generated by Copula and improved K-means and SSM state variables as inputs and the improved genetic algorithm is used to solve the min–max robust optimization problem to achieve closed-loop control. Validation using real-world data from Xinjiang demonstrates a 57.83% reduction in grid power fluctuations under extreme conditions and a 58.41% decrease in renewable curtailment rates markedly enhancing the local system’s capacity to utilize wind and solar energy.

Aiming at resolving the problem of stable and efficient operation of integrated green hydrogen production storage and supply hydrogen refueling stations at different time scales this paper proposes a multi-time-scale hierarchical energy management strategy for integrated green hydrogen production storage and supply hydrogen refueling station (HFS). The proposed energy management strategy is divided into two layers. The upper layer uses the hourly time scale to optimize the operating power of HFS equipment with the goal of minimizing the typical daily operating cost and proposes a parameter adaptive particle swarm optimization (PSA-PSO) solution algorithm that introduces Gaussian disturbance and adaptively adjusts the learning factor inertia weight and disturbance step size of the algorithm. Compared with traditional optimization algorithms it can effectively improve the ability to search for the optimal solution. The lower layer uses the minute-level time scale to suppress the randomness of renewable energy power generation and hydrogen load consumption in the operation of HFS. A solution algorithm based on stochastic model predictive control (SMPC) is proposed. The Latin hypercube sampling (LHS) and simultaneous backward reduction methods are used to generate and reduce scenarios to obtain a set of high-probability random variable scenarios and bring them into the MPC to suppress the disturbance of random variables on the system operation. Finally real operation data of a HFS in southern China are used for example analysis. The results show that the proposed energy management strategy has a good control effect in different typical scenarios.

Against the backdrop of high investment costs in distributed energy storage systems this paper proposes a bi-level energy management model based on shared multi-type energy storage to enhance system economics and resource utilization efficiency. First an electricity–heat–hydrogen coupled shared storage architecture is developed incorporating hydrogen-blended gas turbines gas boilers and hydrogen loads to achieve deep coupling between the power grid and natural gas network. Then a bi-level game model is formulated with the upper-level objective of minimizing the storage operator’s cost and the lower-level objective of minimizing the cost of the integrated energy microgrid (IEM) aggregator. A cooperative game mechanism is introduced within the microgrids to support peer-to-peer energy trading. Nash bargaining theory is applied to determine benefit allocation and dynamic pricing strategies among microgrids. The model is solved using a genetic algorithm (GA) and the alternating direction method of multipliers (ADMM). Simulation results validate the proposed strategy’s effectiveness and feasibility in reducing system costs improving overall benefits and achieving fair benefit allocation.

Renewing a vision for European aviation: Europe today leads the world in civil aviation and air traffic management (ATM). This success should not be taken for granted particularly as the sector undergoes decarbonisation and digitalisation in today’s challenging geopolitical context. Significant value is at stake and capturing this value – for the sake of Europe’s competitiveness sustainability and sovereignty – is contingent on substantial investment in aviation research and innovation (R&I) and support to market uptake of new technologies to avoid the “valley of death” between technological development and product entry-into-service. Aviation is a major socio-economic contributor to Europe: The aviation industry is a vital component of Europe’s economy contri buting significantly to jobs gross domestic product (GDP) and trade. Overall the European aviation sector supports 15 million jobs and contributes EUR 1.1 trillion to European economic activity. The aviation sector is also critical to the EU single market European integration and global connectivity. It drives innovation and enhances Europe’s global influence and security through its combined focus on sustainability and competitiveness. The importance of aviation in achieving these fundamental goals for Europe is underscored by the findings of the Draghi report.