Publications

Proton exchange membrane (PEM) based electrochemical systems have the capability to operate in fuel cell (PEMFC) and water electrolyser (PEMWE) modes enabling efficient hydrogen energy utilisation and green hydrogen production. In addition to the essential cell stacks the system of PEMFC or PEMWE consists of four sub-systems for managing gas supply power thermal and water respectively. Due to the system’s complexity even a small fluctuation in a certain sub-system can result in an unexpected response leading to a reduced performance and stability. To improve the system’s robustness and responsiveness considerable efforts have been dedicated to developing advanced control strategies. This paper comprehensively reviews various control strategies proposed in literature revealing that traditional control methods are widely employed in PEMFC and PEMWE due to their simplicity yet they suffer from limitations in accuracy. Conversely advanced control methods offer high accuracy but are hindered by poor dynamic performance. This paper highlights the recent advancements in control strategies incorporating machine learning algorithms. Additionally the paper provides a perspective on the future development of control strategies suggesting that hybrid control methods should be used for future research to leverage the strength of both sides. Notably it emphasises the role of artificial intelligence (AI) in advancing control strategies demonstrating its significant potential in facilitating the transition from automation to autonomy.

Innovative green vehicle concepts have become increasingly prevailing in consumer purchasing habits as technology evolves. The global transition towards sustainable transportation indicates an increase in new-generation vehicles including both fuel-cell electric vehicles (FCEVs) and plug-in electric vehicles (PEVs) that will take on roads in the future. This change requires new-generation stations to support electrification. This study introduced a prominent multi-energy system concept with a hydrogen refueling station. The proposed multi-energy system (MES) consists of green hydrogen production a hydrogen refueling station for FCEVs hydrogen injection into natural gas (NG) and a charging station for PEVs. An on-site renewable system projected at the station and a polymer electrolyte membrane electrolyzer (PEM) to produce hydrogen for two significant consumers support MES. In addition the MES offers the ability to conduct two-way trade with the grid if renewable energy systems are insufficient. This study develops a comprehensive multi-energy system with an economically optimized energy management model using a mixed-integer linear programming (MILP) approach. The determinative datasets of vehicles are generated in a Python environment using Gauss distribution. The fleet of FCEVs and PEVs are currently available on the market. The study includes fleets of the most common models from well-known brands. The results indicate that profits increase when the storage capacity of the hydrogen tank is higher and natural gas injections are limitless. Optimization results for all cases tend to choose higher-priced natural gas injections over hydrogen refueling because of the difference in costs of refueling and injection expenses. The analyses reveal the highest hydrogen sales to the natural gas (NG) grid by consuming 2214.31 kg generating a revenue of $6966 and in contrast the lowest hydrogen sales to the natural gas grid at 1045.38 kg resulting in a revenue of $3286. Regarding electricity the highest sales represent revenue of $7701 and $2375 for distribution system consumption and electric vehicles (EV) respectively. Conversely Cases 1 and 2 have achieved sales to EV of $2286 and $2349 respectively but do not have any sales to distribution system consumption regarding the constraints. Overall the optimization results show that the solution is optimal for a multi-energy system operator to achieve higher profits and that all end-user parties are satisfied.

Due to the climate crisis and the restriction measures taken in the last decade electric buses are gaining popularity in the transport sector. However one of the most significant disadvantages of this type of vehicle is its low autonomy. Many electric buses with proton-exchange membrane fuel cells (PEMFC) systems have been developed to solve this problem in recent years. These have an advantage over battery-electric buses because the autonomy depends on the capacity of the hydrogen tanks. As with batteries thermal management is crucial for fuel cells to achieve good performance and prolong service life. For this reason it is necessary to investigate different strategies or configurations of a fuel cell electric bus’s integral thermal management system (ITMS). In the present work a novel global model of a fuel cell electric bus (FCEB) has been developed which includes the thermal models of the essential components. This model was used to evaluate different strategies in the FCEB integrated thermal management system simulating driving cycles of the public transport system of Valencia Spain under winter weather conditions. The first strategy was to use the heat generated by the fuel cell to heat the vehicle’s cabin achieving savings of up to 7%. The second strategy was to use the waste heat from the fuel cells to preheat the batteries. It was found that under conditions where a high-power demand is placed on the fuel cell it is advisable to use the residual heat to preheat the battery resulting in an energy saving of 4%. Finally a hybrid solution was proposed in which the residual heat from fuel cells is used to heat both the cabin and the battery resulting in an energy saving of 10%.

The use of energy in the built environment contributes to over one-third of the world’s carbon emissions. To reduce that effect two primary solutions can be adopted i.e. (i) renovation of old buildings and (ii) increasing the renewable energy penetration. This review paper focuses on the latter. Renewable energy sources typically have an intermittent nature. In other words it is not guaranteed that these sources can be harnessed on demand. Thus complement solutions should be considered to use renewable energy sources efficiently. Hydrogen is recognized as a potential solution. It can be used to store excess energy or be directly exploited to generate thermal energy. Throughout this review various research papers focusing on hydrogen-based heating systems were reviewed analyzed and classified from different perspectives. Subsequently articles related to machine learning models optimization algorithms and smart control systems along with their applications in building energy management were reviewed to outline their potential contributions to reducing energy use lowering carbon emissions and improving thermal comfort for occupants. Furthermore research gaps in the use of these smart strategies in residential hydrogen heating systems were thoroughly identified and discussed. The presented findings indicate that the semi-decentralized hydrogen-based heating systems hold significant potential. First these systems can control the thermal demand of neighboring homes through local substations; second they can reduce reliance on power and gas grids. Furthermore the model predictive control and reinforcement learning approaches outperform other control systems ensuring energy comfort and cost-effective energy bills for residential buildings.

Green hydrogen has become a central topic in discussions about the global energy transition seen as a promising solution for decarbonizing economies and meeting climate goals. As part of the process of decarbonization green hydrogen can replace fossil fuels currently in use helping to reduce emissions in sectors vital to the global economy such as industry and transport as well as in the power and heat sectors. Whilst there is significant potential for green hydrogen there are also challenges. The upfront costs for infrastructure and technology are high and the availability and accessibility of the renewables needed for production varies by region. Green hydrogen production and storage technologies are continuously evolving and being promoted as the demand for hydrogen in many applications grows. Considering this this paper presents the main methods for its production and storage as well as its economic impact. Hence the trend of governments and international organizations is to invest in research and development to make this technology more accessible and efficient given the carbon reduction targets.

Achieving the required decarbonisation targets by the shipping industry requires a transition to technologies with zero or near-zero greenhouse gas (GHG) emissions. One promising shipping fuel with zero emission of exhaust gases (including CO2) is green hydrogen. This type of fuel recognised as a 100% clean solution is being investigated for feasible use on a service offshore vessel (SOV) working for offshore wind farms. This study aims to examine whether hydrogen may be used on an SOV in terms of the technical and economic challenges associated with the design process and other factors. In the analyses a reference has been made to the current International Maritime Organization (IMO) guidelines and regulations. In this study it was assumed that hydrogen would be directly combusted in a reciprocating internal combustion engine. This engine type was reviewed. In further research hydrogen fuel cell propulsion systems will also be considered. The hydrogen demand was calculated for the assumed data of the SOV and then the volume and number of highpressure tanks were estimated. The analyses revealed that the SOV cannot undertake 14-day missions using hydrogen fuel stored in cylinders on board. These cylinders occupy 66% of the ship’s current volume and their weight including the modular system accounts for 62% of its deadweight. The costs are over 100% higher compared to MDO and LNG fuels and 30% higher than methanol. The actual autonomy of the SOV with hydrogen fuel is 3 days.

To achieve sustainable development the transition from a fossil-based economy to a circular economy is essential. The use of renewable energy sources to make the overall carbon foot print more favorable is an important pre-requisite. In this context it is crucial to valorize all renewable resources through an optimized local integration. One opportunity arises through the synergy between bioresources and green hydrogen. Through techno-economic assessments this work analyzes four local case studies that integrate bio-based processes with green hydrogen produced via electrolysis using renewable energy sources. An analysis of the use of webGIS tools (i.e. Atlas of Biorefineries of IEA Bioenergy) to identify existing biorefineries that require hydrogen in relation to territories with a potential availability of green hydrogen has never been conducted before. This paper provides an evaluation of the production costs of the target products as a function of the local green hydrogen supply costs. The results revealed that the impact of green hydrogen costs could vary widely ranging from 1% to 95% of the total production costs depending on the bio-based target product evaluated. Additionally hydrogen demand in the target area could require an installed variable renewable energy capacity of 20 MW and 500 MW. On the whole the local integration of biorefineries and green hydrogen could represent an optimal opportunity to make hydrogenated bio-based products 100% renewable.

This study presents a method for predicting nozzle surface temperature and the timing of frost formation during hydrogen refueling using machine learning. A continuous refueling system was implemented based on a simulation model that was developed and validated in previous research. Data were collected under various boundary conditions and eight regression models were trained and evaluated for their predictive performance. Hyperparameter optimization was performed using random search to enhance model performance. The final models were validated by applying boundary conditions not used during model development and comparing the predicted values with simulation results. The comparison revealed that the maximum error rate occurred after the second refueling with a value of approximately 4.79%. Currently nitrogen and heating air are used for defrosting and frost reduction which can be costly. The developed machine learning models are expected to enable prediction of both frost formation and defrosting timings potentially allowing for more cost-effective management of defrosting and frost reduction strategies.

An integrated renewable system that utilizes solid waste-based biogas is important steps towards the sustainable energy solutions to rural off-grid communities in Bangladesh. In this study a hybrid energy system consisting of photovoltaic modules wind turbines biogas generators fuel cells and electrolyzer-hydrogen tank-based energy storage is optimized using non-dominated sorting genetic algorithm (NSGA-II). The hybrid system is optimized based on the cost of energy and human health damage as objective functions and a fuzzy decision-making technique is employed to determine the optimal solution to the multi-objective approach. Additionally several economic ecological and social indicators are also investigated while meeting a certain load reliability. An energy management strategy has been developed in the MATALB environment to satisfy the community load and the battery-driven electric vehicle load. Results from this comprehensive analysis suggest that the optimal configuration of PV/WT/FC/BG has an energy cost of 0.1634 $/kWh and an ecosystem damage of 0.00098 species.year. The human health damage and the human development index of the optimized system are 0.1732 DALYs and 0.696 DALYs respectively. Additionally the proposed system has a lifecycle emission of 123730 kg CO2-eq/year carbon emission penalties of $1856/year a job creation potential of 30 jobs/MW over the 25 years of project lifetime. The hybrid system oversees solid waste management solutions and provides the community with sustainable energy and vehicle recharge.

This paper provides an in-depth analysis of alternative fuels including liquefied natural gas (LNG) hydrogen ammonia and biofuels assessing their feasibility based on operational requirements availability safety concerns and the infrastructure needed for large-scale adoption. Moreover it examines hybrid and fully electric propulsion systems considering advancements in battery technology and the integration of renewable energy sources such as wind and solar power to further reduce SOV emissions. Key findings from this research indicate that LNG serves as a viable short- to medium-term solution for reducing GHG emissions in the SOV sector due to its relatively lower carbon content compared to MDO and HFO. This paper finally insists that while LNG presents an immediate opportunity for emission reduction in the SOV sector a combination of hydrogen ammonia and hybrid propulsion systems will be necessary to meet long-term decarbonisation goals. The findings underscore the importance of coordinated industry efforts technological innovation and supportive regulatory frameworks to overcome the technical economic and infrastructural challenges associated with decarbonising the maritime industry.

This study investigates the feasibility of utilizing surplus hydropower from Ecuador’s major hydroelectric plants to produce green hydrogen a clean energy source that can be used to meet a large percentage of energy needs. Given Ecuador’s significant hydropower infrastructure this approach leverages untapped energy resources for hydrogen production with potential impacts on decarbonization strategies. A Pareto analysis identified five key hydroelectric plants that contribute the most to the national surplus. Using historical data from 2019 to 2023 a stochastic model was applied to estimate future surplus availability through 2030. The findings indicate that although Ecuador’s surplus hydropower peaked in 2021 the general trend shows a decline suggesting an urgent need to capitalize on these resources efficiently. The results indicate a projected annual surplus of hydroelectric energy in Ecuador ranging from 7475 to 3445 GWh over the next five years which could be utilized for green hydrogen production. Ecuador thus has promising potential to become a green hydrogen producer enhancing both regional energy security and carbon reduction goals. The reduction in energy availability for hydrogen production is attributed to the increasing energy demand and variable climatic conditions.

The weather-dependent nature of renewable energy production has led to periodic overproduction making hydrogen production a practical solution for storing excess energy. In addition to conventional storage methods such as physical tanks or chemical bonding using the existing natural gas network as a storage medium has also proven to be effective. Households can play a role in this process as well. The purpose of these experiments is to evaluate the parameters of a household heating device currently in use but not initially designed for hydrogen operation. The appliance used in the tests has a closed combustion chamber with a natural draft induced by a density difference which is a common type. The tests were conducted at nominal load with a mix of 0–40 V/V% hydrogen and natural gas; no flashbacks or other issues occurred. As the hydrogen ratio increased from 0 to 40 V/V% the input heat decreased from 3.9 kW to 3.4 kW. The NOx concentration in the flue gas dropped from 26.2 ppm to 14.2 ppm and the CO2 content decreased from 4.5 V/V% to 3.4 V/V%. However the CO con centration slightly increased from 40.0 ppm to 44.1 ppm. Despite these changes efficiency remained stable fluctuating between 86.9% and 87.0%. The internal flame cone height was 3.27 mm when using natural gas but reduced sharply to just 0.38 mm when using 62 V/V% hydrogen. In addition to the fact that the article examines a group of devices that has been rarely investigated but is also widely distributed it also provides valuable experience for other experiments since the experiments were carried out with a higher hydrogen ratio compared to previous works.

Water electrolysis is a promising technology for sustainable energy conversion and storage of intermittent and fluctuating renewable energy sources and production of high-purity hydrogen for fuel cells and various industrial applications. Low-temperature electrochemical water splitting technologies include alkaline proton exchange membrane and anion exchange membrane water electrolyses which normally consist of two coupled half reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Despite the advances over decades formidable challenges still exist and hinder the practical application of large-scale energy-efficient and economically viable water electrolysis including large energy penalty sluggish kinetics high cost of precious metal based electrocatalysts possible H2/O2 gas crossover difficulty in storage and distribution of H2. Herein we first briefly introduce the fundamentals of water electrolysis summarize the recommended standardized electrochemical characterization protocols and demonstrate the metrics and key performance indicators that are used to evaluate the performances of HER and OER electrocatalysts and electrolyser cells. Then we present six new strategies to mitigate the technical challenges in conventional water electrolysis. These emerging strategies for disruptive innovation of water electrolysis technology include overall water electrolysis based on bifunctional nonprecious electrocatalysts (or pre-catalysts) magnetic field-assisted water electrolysis decoupled water electrolysis hybrid water electrolysis acid/alkaline asymmetric electrolyte electrolysis and tandem water electrolysis. Finally the remaining challenges perspectives and future directions are discussed. This review will provide guidance and inspire more endeavours to deepen the mechanistic understanding and advance the development of water electrolysis.

Hydrogen safety is a general concern because of the high reactivity compared to hydrocarbon-based fuels. The strength of knowledge in risk assessments related to the physical phenomena and the ability of models to predict the consequence of accidental releases is a key aspect for the safe implementation of new technologies. Nuclear safety considers the possibility of accidental leakages of hydrogen gas and subsequent explosion events in risk analysis. In many configurations the considered gaseous streams involve a large fraction of nitrogen gas mixed with hydrogen. This work presents the results of a large scale explosion experimental campaign for hydrogen-nitrogen-air mixtures. The experiments were performed in a 50 m3 vessel at Gexcon’s test site in Bergen Norway. The nitrogen fraction the equivalence ratio and the congestion level were investigated. The experiments are simulated in the FLACS-CFD software to inform about the current level of conservatism of the predictions for engineering application purposes. The study shows the reduced overpressure with nitrogen added to hydrogen mixtures and supports the use of FLACS-CFD-based risk analysis for hydrogen-nitrogen scenarios.

In response to the global climate change and the need for green and low-carbon development hydrogen energy has been recognized as a clean energy source that can achieve carbon neutrality unlike fossil fuels. As a country with a shortage of energy resources the development of hydrogen energy is of significant importance for China to adjust its energy structure and accelerate the new era of energy transformation. Based on the development of China’s hydrogen energy industry this paper elaborates on the current status and development trends of key technologies in the entire industrial chain of hydrogen energy in various stages including production storage transportation and application and identifies the problems and challenges of hydrogen energy development. The paper focuses on the analysis of hydrogen storage and transportation application scenarios and clarifies the selection of hydrogen storage and transportation technologies in different scenarios. To achieve healthy devel opment of China’s hydrogen energy industry it is necessary to strengthen top-level design make strategic planning encourage large-scale state-owned energy enterprises to play a leading role promote the development of the entire industry chain increase technological research and development efforts prevent the risk of core technology constraints and vigorously promote the application of hydrogen energy to realize the construction of a hydrogen energy society.

Unlocking the potential of offshore renewables for green hydrogen (GH2) production can be a game-changer empowering economies with their visionary clean energy policies amplifying energy security and promoting economic growth. However their novelty entails uncertainty and risk necessitating a robust framework for facility deployment and infrastructure planning. To optimize offshore GH2 infrastructure placement this work proposes a novel and robust GIS-based multi-criteria decision-making (MCDM) framework. Encompassing thirtytwo techno-socio-economic-safety factors and ocean environmental impact analysis this methodology facilitates informed decision-making for sustainable and safe GH2 development. Utilizing the synergies between offshore wind and solar resources this study investigates the potential of hybrid ocean technologies to enhance space utilization and optimize efficiency. To illustrate the practical application of the proposed framework a case study examining a GH2 system in Australia's marine region and its potential nexus with nearby offshore industries has been conducted. The performed life cycle assessment (LCA) explored various configurations of GH2 production storage and transportation technologies. A Bayesian objective weight integrating technique has been introduced and contrasted statistically with the hybrid CRITIC Entropy MEREC and MARCOS-based MCDM approaches. Various locations are ranked based on the net present value of life cycle cost GH2 production capacity risk availability and environment sustainability factors illustrating their compatibility. A sensitivity analysis is conducted to confirm that a Bayesian approach improves the decision-making outcomes through identifying optimal criteria weights and alternative ranks more effectively. Empowering strategic GH2 decisions globally the proposed approach optimizes system performances cost sustainability and safety excelling in harsh environments.

Hydrogen is an abundant element and a flexible energy carrier offering substantial potential as an environmentally friendly energy source to tackle global energy issues. When used as a fuel hydrogen generates only water vapor upon combustion or in fuel cells presenting a means to reduce carbon emissions in various sectors including transportation industry and power generation. Nevertheless conventional hydrogen production methods often depend on fossil fuels leading to carbon emissions unless integrated with carbon capture and storage solutions. Conversely green hydrogen is generated through electrolysis powered by renewable energy sources like solar and wind energy. This production method guarantees zero carbon emissions throughout the hydrogen’s lifecycle positioning it as a critical component of global sustainable energy transitions. In Africa where there are extensive renewable energy resources such as solar and wind power green hydrogen is emerging as a viable solution to sustainably address the increasing energy demands. This research explores the influence of policy frameworks technological innovations and market forces in promoting green hydrogen adoption across Africa. Despite growing investments and favorable policies challenges such as high production costs and inadequate infrastructure significantly hinder widespread adoption. To overcome these challenges and speed up the shift towards a sustainable hydrogen economy in Africa strategic investments and collaborative efforts are essential. By harnessing its renewable energy potential and establishing strong policy frameworks Africa can not only fulfill its energy requirements but also support global initiatives to mitigate climate change and achieve sustainable development objectives.

This paper presents the results of increasing the hydrogen concentration in natural gas distributed within the territory of the Slovak Republic. The range of hydrogen concentrations in the mathematical model is considered to be from 0 to 100 vol.% for the resulting combustion products temperature and heating value and for the scientific assessment of the environmental and economic implications. From a technical perspective it is feasible to consider enriching natural gas with hydrogen up to a level of 20% within the Slovak Republic. CO2 emissions are estimated to be reduced by 3.76 tons for every 1 TJ of energy at an operational cost of EUR 10000 at current hydrogen prices.

In the transition to sustainable public transportation with zero-emission buses hydrogen fuel cell electric buses have emerged as a promising alternative to traditional diesel buses. However assessing their economic viability is crucial for widespread adoption. This study carries out a comprehensive examination encompassing both sensitivity and probabilistic analyses to assess the total cost of ownership (TCO) for the bus fleet and its corresponding infrastructure. It considers various hydrogen supply options encompassing on-site electrolysis on-site steam methane reforming and off-site hydrogen procurement with both gaseous and liquid delivery methods. The analysis covers critical cost elements encompassing bus acquisition costs infrastructure capital expenses and operational and maintenance costs for both buses and infrastructure. This paper conducted two distinct case studies: one involving a current small bus fleet of five buses and another focusing on a larger fleet set to launch in 2028. For the current small fleet the off-site gray hydrogen purchase with a gaseous delivery option is the most cost-effective among hydrogen alternatives but it still incurs a 26.97% higher TCO compared to diesel buses. However in the case of the expanded 2028 fleet the steam methane-reforming method without carbon capture emerges as the most likely option to attain the lowest TCO with a high probability of 99.5%. Additionally carbon emission costs were incorporated in response to the growing emphasis on environmental sustainability. The findings indicate that although diesel buses currently represent the most economical option in terms of TCO for the existing small fleet steam methane reforming with carbon capture presents a 69.2% likelihood of being the most cost-effective solution suggesting it is a strong candidate for cost efficiency for the expanded 2028 fleet. Notably substantial investments are required to increase renewable energy integration in the power grid and to enhance electrolyzer efficiency. These improvements are essential to make the electrolyzer a more competitive alternative to steam methane reforming. Overall the findings in this paper underscore the substantial impact of the hydrogen supply chain and carbon emission costs on the TCO of zero-emission buses.

Hydrogen-fueled engines require large values of the excess air ratio in order to achieve high thermal efficiency. A low value of this coefficient promotes knocking combustion. This paper analyzes the conditions for the occurrence of knocking combustion in an engine with a turbulent jet ignition (TJI) system with a passive pre-chamber. A single-cylinder engine equipped with a TJI system was running with an air-to-fuel equivalence ratio λ in the range of 1.25–2.00 and the center of combustion (CoC) was regulated in the range of 2–14 deg aTDC (top dead center). Such process conditions made it possible to fully analyze the ascension of knock combustion until its disappearance with the increase in lambda and CoC. Measures of knock in the form of maximum amplitude pressure oscillation (MAPO) and integral modulus of pressure oscillation (IMPO) were used. The absolute values of these indices were pointed out which can provide the basis for the definition of knock combustion. Based on our own work the MAPO index > 1 bar was defined determining the occurrence of knocking (without indicating its quality). In addition taking into account MAPO it was concluded that IMPO > 0.13 bar·deg is the quantity responsible for knocking combustion.

Importing substantial amount of green hydrogen from countries like South Africa which have abundant solar and wind potentials to replace fossil fuels has attracted interest in developed regions. This study analyses South African strategies for improving and decarbonizing the power sector while also producing hydrogen for export. These strategies include the Integrated Resource Plan the Transmission Development Plan Just Energy Transition and Hydrogen Society Roadmap for grid connected hydrogen production in 2030. Results based on an hourly resolution optimisation in Plexos indicate that annual grid-connected hydrogen production of 500 kt can lead to a 20–25% increase in the cost of electricity in scenarios with lower renewable energy penetration due to South African emission constraints by 2030. While the price of electricity is still in acceptable range and the price of hydrogen can be competitive on the international market (2–3 USD/kgH2 for production) the emission factor of this hydrogen is higher than the one of grey hydrogen ranging from 13 to 24 kgCO2/kgh2. When attempting to reach emission factors based on EU directives the three policy roadmaps become unfeasible and free capacity expansion results in significant sixteen-fold increase of wind and seven-fold increase in solar installations compared to 2023 levels by 2030 in South Africa.

In recent years production and supply of hydrogen has gained significant attention within the German energy transition. This is due to increasingly urgent pressures to mitigate climate change and geopolitical imperatives to substitute natural gas. Hydrogen is seen as an important cross-sectoral energy carrier serving multiple functions including heat production for industry and households fuel for transportation and energy storage for stabilization of electricity supply. In the context of various funding mechanisms on several administrative levels regional value chains for green hydrogen supply are emerging. To date however few studies analyzing regional hydrogen systems exist. Due to its high projected demand of energy sources for heating industrial processes and mobility Germany appears to be a very relevant research area in this emerging field. Situated within the concept of the multi-level perspective this article examines the way how regional “niches” of green hydrogen evolve and how they are organized. The study takes an evolutionary perspective in analyzing processes of embedding green hydrogen infrastructures in regional energy regimes which entered “re-configuration”-pathways. It argues that the congruence of available resources for renewable electricity established networks of institutional entrepreneurs and access to higher level funding are conditions which put incumbent regime-actors in favorable positions to implement green hydrogen niches. Conversely the embedding of green hydrogen infrastructures in regional energy systems is a case in point of how the attributes of niches in particular technological domains can be used to explain the transition pathway entered by a surrounding energy regime.

Aiming to solve the problems of insufficient dynamic responses the large loss of energy storage life of a single power cell and the large fluctuation in DC (direct current) bus voltage in fuel cell vessels this study takes a certain type of fuel cell ferry as the research object and proposes an improved equivalent minimum hydrogen consumption energy management strategy based on fuzzy logic control. First a hybrid power system including a fuel cell a lithium–iron–phosphate battery and a supercapacitor is proposed with the simulation of the power system of the modified mother ship. Second a power system simulation model and a double-closed-loop PI (proportion integration) control model are established in MATLAB/Simulink to design the equivalent hydrogen consumption model and fuzzy logic control strategy. The simulation results show that under the premise of meeting the load requirements the control strategy designed in this paper improves the Li-ion battery’s power the Li-ion battery’s SOC (state of charge) the bus voltage stability and the equivalent hydrogen consumption significantly compared with those before optimization which improves the stability and economy of the power system and has certain practical engineering value.

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.

Hydrogen has great growth potential due to its green carbon-neutral nature but public acceptance is low due to negative perceptions of the dangers associated with hydrogen energy. Safety concerns particularly related to its flammability and explosiveness are an obstacle to hydrogen energy policy. In South Korea recent hydrogen-related explosions have exacerbated these concerns undermining public confidence. This study developed public relations (PR) strategies to manage risk perception and promote hydrogen energy acceptance by analyzing the opinions of government officials and experts using SWOT factors the TOWS matrix and the analytic hierarchy process. The findings highlight the importance of addressing weaknesses and threats in PR efforts. Key weaknesses include Korea’s technological lag and the low localization of core hydrogen technologies both of which hinder competitiveness and negatively impact public perception of hydrogen energy. Notable threats include deteriorating energy dependency and expanding global carbon regulations. This information can be used to influence attitudes and foster public acceptance of hydrogen energy policies. Emphasizing weaknesses and threats may result in more effective PR strategies even if they do not directly address the primary concerns of scientific experts. The persuasive insights identified in this study can support future policy communication and PR strategies.