Applications & Pathways

This study aims to elucidate the behavior of diffusible hydrogen and delayed fracture in martensitic steel with 1500 MPa strength during automotive painting process and under vehicle service conditions. A sequential process of automotive pretreatment line and vehicle service environment is simulated to evaluate the hydrogen pick up in each process. In case of the automotive painting line the absorption of hydrogen is within the common range in the process of phosphating treatment and electrodeposition. The baking process plays an effective role for desorbing the diffusible hydrogen absorbed during the automotive pre-treatment such as zinc-phosphating and electrodeposition process. In case of the corrosion environment under the automotive driving conditions hydrogen induced delayed fracture is accelerated as the exposure time increases. Further it is clarified that severe plastic deformation are the significant factors for hydrogen induced delayed fracture under with low pH value and present of chloride ion in a chemical solution parameter. In summary hydrogen is transported constantly during electrodeposition sequential line process of automobile manufacturing below the hydrogen content of 0.5 ppm which is not critical value for leading to hydrogen delayed fracture based on results of slow strain rate tensile tests. However exposure to extreme conditions under service environment of vehicle such as acidic solution and chloride chemistry solution that result in high level of hydrogen absorption severe plastic deformation in the sheared edge and constantly applied internal or external stresses can cause the hydrogen induced delayed fracture in the fully martensitic steels.

This paper investigates the challenges and solutions associated with integrating a hydrogen-generating nuclear-renewable integrated energy system (NR-IES) under a transactive energy framework. The proposed system directs excess nuclear power to hydrogen production during periods of low grid demand while utilizing renewables to maintain grid stability. Using digital real-time simulation (DRTS) in the Typhoon HIL 404 model the dynamic interactions between nuclear power plants electrolyzers and power grids are analyzed to mitigate issues such as harmonic distortion power quality degradation and low power factor caused by large non-linear loads. A three-phase power conversion system is modeled using the Typhoon HIL 404 model and includes a generator a variable load an electrolyzer and power filters. Active harmonic filters (AHFs) and hybrid active power filters (HAPFs) are implemented to address harmonic mitigation and reactive power compensation. The results reveal that the HAPF topology effectively balances cost efficiency and performance and significantly reduces active filter current requirements compared to AHF-only systems. During maximum electrolyzer operation at 4 MW the grid frequency dropped below 59.3 Hz without filtering; however the implementation of power filters successfully restored the frequency to 59.9 Hz demonstrating its effectiveness in maintaining grid stability. Future work will focus on integrating a deep reinforcement learning (DRL) framework with real-time simulation and optimizing real-time power dispatch thus enabling a scalable efficient NR-IES for sustainable energy markets.

Background: This study applied levelized cost of hydrogen (LCOH) and environmental cost accounting techniques to evaluate the feasibility of producing green hydrogen (GH2) via alkaline electrolysis for use in a bus fleet in Fortaleza Brazil. Methods: A GH2 plant with a 3 MW wind tower was considered in this financial project. A sensitivity analysis was conducted to assess the economic viability of the project considering the influence of production volume the number of electrolysis kits financing time and other kay economic indices. Revenue was derived from the sale of by-products including green hospital oxygen (GHO2) and excess wind energy. A life cycle assessment (LCA) was performed to quantify material and emission flows throughout the H2 production chain. A zero-net hydrogen price scenario was tested to evaluate the feasibility of its use in urban transportation. Results: The production of GH2 in Brazil using alkaline electrolysis powered by wind energy proved to be economically viable for fueling a hydrogen-powered bus fleet. For production volumes ranging from 8.89 to 88.9 kg H2/h the sensitivity analysis revealed high economic performance achieving a net present value (NPV) between USD 19.4 million and USD 21.8 million a payback period of 1–4 years an internal rate of return (IRR) of 24–90% and a return on investment (ROI) of 300–1400%. The LCOH decreased with increased production ranging from 56 to 25 USD/MWh. Over the project timeline GH2 production and use in the bus fleet reduced CO2 emissions by 53000–287000 t CO2 eq. The fuel cell bus fleet project demonstrated viability through fuel cost savings and revenue from carbon credit sales highlighting the economic social and environmental sustainability of GH2 use in urban transportation in Brazil.

The combustion and emission characteristics of a hydrogen engine were investigated through experimental analysis using a GDI engine. To enable hydrogen in-cylinder direct injection a specialized hydrogen gas injector was employed. A comparative analysis of the combustion performance between gasoline and hydrogen fuels in a spark-ignited engine was conducted. Additionally the study experimentally explored the thermal efficiency and emission reduction potential of hydrogen engines in lean combustion modes. The results indicated a significant improvement in the combustion rate when hydrogen fuel was utilized in the spark-ignited engine. However the effective thermal efficiency was found to be lower than that of gasoline fuel due to the delayed MBF50 under stoichiometric conditions. Furthermore when compared to gasoline fuel the reduction of CO and THC emissions was accompanied by an increase in NOx emissions. Nevertheless optimizing the air dilution ratio in hydrogen engines led to an improvement in the effective thermal efficiency. Specifically under medium load conditions a Lambda value of 2.7 resulted in an effective thermal efficiency of 43.5%. Additionally under ultra-lean conditions (Lambda > 2.3) NOx emissions could be reduced to below 50 ppm reaching as low as 44 ppm. This study highlights the potential of improving combustion efficiency and reducing emissions by utilizing hydrogen fuel particularly in lean combustion modes. It contributes to the continuous development of hydrogen engine technology and promotes the implementation of cleaner and more efficient energy solutions.

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies using hydrogen (H2 ) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions making it a promising option for diesel engines. Due to the importance and novelty of this the continuation of ongoing research and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design operating conditions fuel mixing ratios and supplying techniques on the CO CO2 NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However using hydrogen with diesel reduces CO CO2 and HC emissions but increases NOx. On the other hand HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately resulting in decreased emissions of CO CO2 HC and NOx. The inclusion of hydrogen improves combustion efficiency reduces ignition delay and enhances heat release and in-cylinder pressure. Additionally operational parameters such as engine power speed load air–fuel ratio compression ratio and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

The road transport sector is one of the major contributors to greenhouse gas emissions as it still largely relies on traditional powertrain solutions. While some progress has been made in the passenger car sector with the diffusion of battery electric vehicles heavy-duty transport remains predominantly dependent on diesel internal combustion engines. This research aims to evaluate and compare three potential solutions for the decarbonisation of heavy-duty freight transport from an economic perspective: Battery Electric Trucks (BETs) Fuel Cell Electric Trucks (FCETs) and Hydrogen-fuelled Internal Combustion Engine Trucks (H2ICETs). The study focuses on the Finnish market and road network where affordable and low-carbon electricity creates an ideal environment for the development of alternative powertrain vehicles. The analysis employs the Total Cost of Ownership (TCO) method which allows for a comprehensive assessment of all cost components associated with the vehicles throughout their entire lifecycle encompassing both initial expenses and operational costs. Among the several factors affecting the results the impact of the three powertrain technologies on the admissible payloads has been taken into account. The study specifically focuses on the costs directly incurred by the truck owner. Additionally to evaluate the cost effectiveness of the proposed powertrain technologies under different scenarios a sensitivity analysis on electricity and hydrogen prices is conducted. The outcomes of this study reveal that no single powertrain solution emerges as universally optimal as the most cost-effective choice depends strongly on the truck type and its use (i.e. daily mileage). For relatively small trucks (18 t) covering short driving distances (approximately 100 to 200 km/day) BETs prove to be the best solution due to their higher efficiency and lower vehicle costs compared to FCETs. Conversely for larger trucks (42 and 76 t) engaged in longer hauls (>300 km/day) H2ICETs exhibit larger cost benefits due to their lower vehicle costs among the three options under investigation. Finally for small trucks (18 t) travelling long distances (200 km/day or more) FCETs represent a competitive choice due to their high efficiency and costeffective energy storage system. Considering future advancements in FCETs and BETs in terms of improved performance and reduced investment cost the fuel cell-based solution is expected to emerge as the best option across various combinations of truck sizes and daily mileages.

The ambitious targets set by the International Maritime Organization for reducing greenhouse gas emissions from shipping require radical actions by all relevant stakeholders. In this context the interest in high efficiency and low emissions (even zero in the case of hydrogen) fuel cell technology for maritime applications has been rising during the last decade pushing the research developed by academia and industries. This paper aims to present a comparative review of the fuel cell systems suitable for the maritime field focusing on PEMFC and SOFC technologies. This choice is due to the spread of these fuel cell types concerning the other ones in the maritime field. The following issues are analyzed in detail: (i) the main characteristics of fuel cell systems; (ii) the available technology suppliers; (iii) international policies for fuel cells onboard ships; (iv) past and ongoing projects at the international level that aim to assess fuel cell applications in the maritime industry; (v) the possibility to apply fuel cell systems on different ship types. This review aims to be a reference and a guide to state both the limitations and the developing potential of fuel cell systems for different maritime applications.

The hydrogen internal combustion engine (H2-ICE) is proposed as a robust and viable solution to decarbonise the heavy-duty on- and off-road as well as the light-duty automotive sectors of the transportation markets and is therefore the subject of rapidly growing research interest. With the potential for engine performance improvement by controlling the internal mixture formation and avoiding combustion anomalies hydrogen direct injection (H2DI) is a promising combustion mode. Furthermore the H2-ICE poses an attractive proposition for original equipment manufacturers (OEMs) and their suppliers since the fundamental base engine design components and manufacturing processes are largely unchanged. Nevertheless to deliver the highest thermal efficiency and zero-harm levels of tailpipe emissions moderate adaptations are needed to the engine control air path fuel injection and ignition systems. Therefore in this article critical design features fuel-air mixing combustion regimes and exhaust after-treatment systems (EATS) for H2DI engines are carefully assessed.

This study introduces a novel hybrid solar–biomass cogeneration power plant that efficiently produces heat electricity carbon dioxide and hydrogen using concentrated solar power and syngas from cotton stalk biomass. Detailed exergy-based thermodynamic economic and environmental analyses demonstrate that the optimized system achieves an exergy efficiency of 48.67% and an exergoeconomic factor of 80.65% and produces 51.5 MW of electricity 23.3 MW of heat and 8334.4 kg/h of hydrogen from 87156.4 kg/h of biomass. The study explores four scenarios for green hydrogen production pathways including chemical looping reforming and supercritical water gasification highlighting significant improvements in levelized costs and the environmental impact compared with other solar-based hybrid systems. Systems 2 and 3 exhibit superior performance with levelized costs of electricity (LCOE) of 49.2 USD/MWh and 55.4 USD/MWh and levelized costs of hydrogen (LCOH) of between 10.7 and 19.5 USD/MWh. The exergoenvironmental impact factor ranges from 66.2% to 73.9% with an environmental impact rate of 5.4–7.1 Pts/MWh. Despite high irreversibility challenges the integration of solar energy significantly enhances the system’s exergoeconomic and exergoenvironmental performance making it a promising alternative as fossil fuel reserves decline. To improve competitiveness addressing process efficiency and cost reduction in solar concentrators and receivers is crucial.

In response to environmental concerns related to carbon and nitrogen emissions hydrogen-powered aircraft (HPA) are poised for significant development over the coming decades driven by advances in power electronics technology. However HPA systems present complex multi-domain challenges encompassing electrical hydraulic mechanical and chemical disciplines necessitating efficient modeling and robust validation platforms. This paper introduces a physics-informed machine learning (PIML) approach for multi-domain HPA system modeling enhanced by hardware accelerated parallel hardware emulation to construct a real-time digital twin. It delves into the physical analysis of various HPA subsystems whose equations form the basis for both traditional numerical solution methods like Euler’s and Runge-Kutta methods (RKM) as well as the physics-informed neural networks (PINN) components developed herein. By comparing physics-feature neural networks (PFNN) and PINN with conventional neural network strategies this paper elucidates their advantages and limitations in practical applications. The final implementation on the Xilinx® UltraScale+™ VCU128 FPGA platform showcases the PIML method’s high efficiency accuracy data independence and adherence to established physical laws demonstrating its potential for advancing real-time multi-domain HPA emulation.

Hydrogen-fueled internal combustion engines are a promising CO2-free and zero-impact emission alternative to battery or fuel cell electric powertrains. Advantages include long service life robustness against fuel impurities and a strong infrastructural base with existing production lines and workshop stations. In order to make hydrogen engines harmless in terms of pollutant emissions as well NOX emissions at the tailpipe must be reduced as low as the zero-impact emission level. Here the application of selective catalytic reduction (SCR) catalysts is a promising solution that can be rapidly adopted from conventional diesel engines. This paper therefore investigates the influences of the hydrogen concentration in the raw exhaust gas of the NO2/NOX ratio and of the space velocity on the performance of two different SCR technologies. The results show that both types of SCR copper-zeolite and vanadium-based have their advantages and drawbacks. Copper-based SCR catalysts have an early light-off temperature and reach maximum efficiencies of up to >99%. On the other hand vanadium systems promise almost no secondary N2O emissions. As a result we combined both approaches to create a superior solution with high efficiency and lowest secondary emissions.

Hydrogen energy represents an ideal medium for energy storage. By integrating hydrogen power conversion utilization and storage technologies with distributed wind and photovoltaic power generation techniques it is possible to achieve complementary utilization and synergistic operation of multiple energy sources in the form of microgrids. However the diverse operational mechanisms varying capacities and distinct forms of distributed energy sources within hydrogen-coupled microgrids complicate their operational conditions making fine-tuned scheduling management and economic operation challenging. In response this paper proposes an energy management method for hydrogen-coupled microgrids based on the deep deterministic policy gradient (DDPG). This method leverages predictive information on photovoltaic power generation load power and other factors to simulate energy management strategies for hydrogen-coupled microgrids using deep neural networks and obtains the optimal strategy through reinforcement learning ultimately achieving optimized operation of hydrogen-coupled microgrids under complex conditions and uncertainties. The paper includes analysis using typical case studies and compares the optimization effects of the deep deterministic policy gradient and deep Q networks validating the effectiveness and robustness of the proposed method.

The surge in interest surrounding renewable energy stems from concerns regarding pollution and the finite supply ofnonrenewable resources. Solar PV and wind hybrid renewable energy systems (HRES) are increasingly recognized as practicaland cost-effective solutions particularly in remote areas. However the intermittent nature of solar and wind power presents achallenge. To address this incorporating a hydrogen source into the system has been proposed. This study focuses onmodelling and sizing a hybrid energy system tailored for remote areas accommodating both home and electric vehicle loads.The simulation is conducted for Siliguri West Bengal India with the goal of optimizing productivity minimizing expensesand considering economic factors using HOMER Pro software. The integration of green hydrogen-based power generationwith photovoltaic and wind HRES emerges as an effective solution. Solar power in particular showcases promisingopportunities for the electrolysis process and HRES systems. The presented work facilitates the modelling of a green hydrogen-based green energy system taking into account capacity cost and emission constraints. Various case studies are conducted toenhance system efficiency and reduce the costs of energy (COE). In this paper three cases of grid-connected and three cases ofoff-grid or grid-disconnected systems are considered for highlighting the benefits of hydrogen energy incorporation in bothtypes of systems. This research contributes to sustainable energy solutions advancing a greener and more efficient energylandscape especially in addressing the recent development in load combinations of home and electric vehicle loads in bothgrid-connected as well as grid-disconnected system.

The use of compression ignition engines (CIEs) is associated with increased greenhouse gas emissions. It is therefore necessary to research sustainable solutions and reduce the negative environmental impact of these engines. A widely studied alternative is the use of H2 in dual-fuel mode. This review has been developed to include the most recent studies on the subject to collect and compare their main conclusions on performance and emissions. Moreover this study includes most relevant emission control strategies that have not been extensively analyzed in other reviews on the subject. The main conclusion drawn from the literature is the negative effect of the addition of H2 on NOx. This is due to the increase in temperature during combustion which increases NOx formation as the thermal mechanism predominates. Therefore to reduce these emissions three strategies have been studied namely exhaust gas recirculation (EGR) water injection (WI) and compression ratio (CR) reduction. The effect of these techniques on NOx reduction together with their effect on other analyzed performance parameters have been deeply analyzed. The studies reviewed in this work indicate that hydrogen is an alternative fuel for CIEs when used in conjunction with techniques that have proven to be effective in reducing NOx.

The introduction of several alternative marine fuels is considered an important strategy for maritime decarbonization. These alternative marine fuels include liquefied natural gas (LNG) liquefied biogas (LBG) hydrogen ammonia methanol ethanol hydrotreated vegetable oil (HVO) etc. In some studies nuclear power and electricity are also included in the scope of alternative fuels for merchant ships. However the operation of alternative-fuel-powered ships has some special risks such as fuel spills vapor dispersion and fuel pool fires. The existing international legal framework does not address these risks sufficiently. This research adopts the method of legal analysis to examine the existing international legal regime for regulating the development of alternative-fuel-powered ships. From a critical perspective it evaluates and predicts the consequences of these policies together with their shortcomings. Also this research explores the potential solutions and countermeasures that might be feasible to deal with the special marine environmental risks posed by alternative-fuel-powered ships in the future.

Hydrogen is the energy vector that will lead us toward a more sustainable future. It could be the fuel of both fuel cells and internal combustion engines. Internal combustion engines are today the only motors characterized by high reliability duration and specific power and low cost per power unit. The most immediate solution for the near future could be the application of hydrogen as a fuel in modern internal combustion engines. This solution has advantages and disadvantages: specific physical chemical and operational properties of hydrogen require attention. Hydrogen is the only fuel that could potentially produce no carbon carbon monoxide and carbon dioxide emissions. It also allows high engine efficiency and low nitrogen oxide emissions. Hydrogen has wide flammability limits and a high flame propagation rate which provide a stable combustion process for lean and very lean mixtures. Near the stoichiometric air–fuel ratio hydrogen-fueled engines exhibit abnormal combustions (backfire pre-ignition detonation) the suppression of which has proven to be quite challenging. Pre-ignition due to hot spots in or around the spark plug can be avoided by adopting a cooled or unconventional ignition system (such as corona discharge): the latter also ensures the ignition of highly diluted hydrogen–air mixtures. It is worth noting that to correctly reproduce the hydrogen ignition and combustion processes in an ICE with the risks related to abnormal combustion 3D CFD simulations can be of great help. It is necessary to model the injection process correctly and then the formation of the mixture and therefore the combustion process. It is very complex to model hydrogen gas injection due to the high velocity of the gas in such jets. Experimental tests on hydrogen gas injection are many but never conclusive. It is necessary to have a deep knowledge of the gas injection phenomenon to correctly design the right injector for a specific engine. Furthermore correlations are needed in the CFD code to predict the laminar flame velocity of hydrogen–air mixtures and the autoignition time. In the literature experimental data are scarce on air–hydrogen mixtures particularly for engine-type conditions because they are complicated by flame instability at pressures similar to those of an engine. The flame velocity exhibits a non-monotonous behavior with respect to the equivalence ratio increases with a higher unburnt gas temperature and decreases at high pressures. This makes it difficult to develop the correlation required for robust and predictive CFD models. In this work the authors briefly describe the research path and the main challenges listed above.

To reach climate neutrality by 2050 a goal that the European Union set itself it is necessary to change and modify the whole EU’s energy system through deep decarbonization and reduction of greenhouse-gas emissions. The study presents a current insight into the global energy-transition pathway based on the hydrogen energy industry chain. The paper provides a critical analysis of the role of clean hydrogen based on renewable energy sources (green hydrogen) and fossil-fuels-based hydrogen (blue hydrogen) in the development of a new hydrogen-based economy and the reduction of greenhouse-gas emissions. The actual status costs future directions and recommendations for low-carbon hydrogen development and commercial deployment are addressed. Additionally the integration of hydrogen production with CCUS technologies is presented.

Public transport plays a prominent role with respect to mitigating transport-related environmental effects by improving passenger transport efficiency and the quality of life in cities. Batteries and fuel cells are at the forefront of the technological shift to zero-emission powertrains. Within the scope of the German-funded project BIC H2 corresponding systems analysis research focuses on the market introduction of fuel cell–electric buses in the Rhine–Ruhr Metropolitan Region through 2035. This study presents the related methods and major outcomes of this techno-economic research which spans spatially-resolved hydrogen demand modeling of all relevant sectors to hydrogen refueling stations and upstream infrastructure modeling to scenario-based analyses. The latter builds upon an empirical study supporting the development of the Hydrogen Roadmap of the State of North Rhine–Westphalia (NRW). Our results show that the demand in NRW alone is expected to account for one third of total German hydrogen use. Hydrogen bus refueling could substantially support market introduction during its early phases. In the long term however hydrogen demand in industry is significantly higher compared to that in the transport sector. Furthermore spatial analysis identifies regions with pronounced hydrogen demands that could therefore be candidates for initial infrastructure investments. With the Cologne area showing the highest hydrogen demand levels such regions can offer particularly high infrastructure utilization e.g. for bus refueling. On the infrastructure side trailers for transporting gaseous hydrogen to refueling stations are the most favorable option through 2035. Pipelines would be the preferred solution soon after 2035 due to increased hydrogen demand. If effectively deployed converted natural gas pipelines would be the most cost-effective option even earlier.

Current hydrogen stations are using a constant dispenser pressure ramp rate method. When a flow rate increases for heavy duty vehicle a large pressure loss occurs and it slows down refueling. This study developed a new method (cTPR method) that has the constant pressure ramp rate in the tank by compensating for the tube pressure loss without any feedback from the vehicle. A refueling simulation confirmed that a refueling was shortened − 49s with a lower ending gas temperature. Testing confirmed that the cTPR method can be realized simply by changing the control without any hardware modification.

The paper provides an economic model for the assessment of hydrogen production at the site of an existing thermal power plant which is then integrated into the existing gas grid. The model uses projections of electricity prices natural gas prices and CO2 prices as well as estimates of the cost of building a power-to-gas system for a 25-year period. The objective of this research is to calculate the yellow hydrogen production price for each lifetime year of the Power-to-gas system to evaluate yellow hydrogen competitiveness compared to the fossil alternatives. We test if an incentive scheme is needed to make this technology economically viable. The research also provides several sensitivity scenarios of electricity natural gas and CO2 price changes. Our research results clearly prove that yellow hydrogen is not yet competitive with fossil alternatives and needs incentive mechanisms for the time being. At given natural gas and CO2 prices the incentive for hydrogen production needs to be 52.90 EUR/MWh in 2025 and 36.18 EUR/MWh in 2050. However the role of hydrogen in the green transition could be very important as it provides ancillary services and balances energy sources in the power system.

Because the new energy is intermittent and uncertain it has an influence on the system’s output power stability. A hydrogen energy storage system is added to the system to create a wind light and hydrogen integrated energy system which increases the utilization rate of renewable energy while encouraging the consumption of renewable energy and lowering the rate of abandoning wind and light. Considering the system’s comprehensive operation cost economy power fluctuation and power shortage as the goal considering the relationship between power generation and load assigning charging and discharging commands to storage batteries and hydrogen energy storage and constructing a model for optimal capacity allocation of wind–hydrogen microgrid system. The optimal configuration model of the wind solar and hydrogen microgrid system capacity is constructed. A particle swarm optimization with dynamic adjustment of inertial weight (IDW-PSO) is proposed to solve the optimal allocation scheme of the model in order to achieve the optimal allocation of energy storage capacity in a wind–hydrogen storage microgrid. Finally a microgrid system in Beijing is taken as an example for simulation and solution and the results demonstrate that the proposed approach has the characteristics to optimize the economy and improve the capacity of renewable energy consumption realize the inhibition of the fluctuations of power reduce system power shortage and accelerate the convergence speed.

The current need to reduce carbon emissions makes hydrogen use essential for selfconsumption in microgrids. To make a profitability analysis of a microgrid the influence of equipment costs and the electricity price must be known. This paper studies the cost-effective electricity price (EUR/kWh) for a microgrid located at ‘’La Rábida Campus” (University of Huelva south of Spain) for two different energy-management systems (EMSs): hydrogen-priority strategy and batterypriority strategy. The profitability analysis is based on one hand on the hydrogen-systems’ cost reduction (%) and on the other hand considering renewable energy sources (RESs) and energy storage systems (ESSs) on cost reduction (%). Due to technological advances microgrid-element costs are expected to decrease over time; therefore future profitable electricity prices will be even lower. Results show a cost-effective electricity price ranging from 0.61 EUR/kWh to 0.16 EUR/kWh for hydrogen-priority EMSs and from 0.4 EUR/kWh to 0.17 EUR/kWh for battery-priority EMSs (0 and 100% hydrogen-system cost reduction respectively). These figures still decrease sharply if RES and ESS cost reductions are considered. In the current scenario of uncertainty in electricity prices the microgrid studied may become economically competitive in the near future

In view of the European Union’s strategy on hydrogen for decarbonization and buildings’ decarbonization targets the use of hydrogen in buildings is expected in the future. Backup power in buildings is usually provided with diesel generators (DGs). In this study the use of a hydrogen fuel cell (HFC) power supply backup system is studied. Its operation is compared to a DG and a techno-economic analysis of the latter’s replacement with an HFC is conducted by calculating relevant key performance indicators (KPIs). The developed approach is presented in a case study on a school building in Greece. Based on the school’s electricity loads which are calculated with a dynamic energy simulation and power shortages scenarios the backup system’s characteristics are defined and the relevant KPIs are calculated. It was found that the HFC system can reduce the annual CO2 emissions by up to 400 kg and has a lower annual operation cost than a DG. However due to its high investment cost its levelized cost of electricity is higher and the replacement of an existing DG is unviable in the current market situation. The techno-economic study reveals that subsidies of around 58–89% are required to foster the deployment of HFC backup systems in buildings.

Hydrogen is considered a promising alternative to fossil fuels in an integrated energy system (IES). In order to reduce the cost of hydrogen energy utilization and the carbon emissions of the IES this paper proposes a low-carbon dispatching strategy for a coordinated integrated energy system using green hydrogen and blue hydrogen. The strategy takes into account the economic and low-carbon complementarity between hydrogen production by water electrolysis and hydrogen production from natural gas. It introduces the green hydrogen production–storage–use module (GH-PSUM) and the blue hydrogen production–storage–use module (BH-PSUM) to facilitate the refined utilization of different types of hydrogen energy. Additionally the flexibility in hydrogen load supply is analyzed and the dynamic response mechanism of the hydrogen load supply structure (DRM-HLSS) is proposed to further reduce operating costs and carbon emissions. Furthermore a carbon trading mechanism (CTM) is introduced to constrain the carbon emissions of the integrated energy system. By comprehensively considering the constraints of each equipment the proposed model aims to minimize the total economic cost which includes wind power operation and curtailment penalty costs energy purchase costs blue hydrogen purification costs and carbon transaction costs. The rationality of the established scheduling model is verified through a comparative analysis of the scheduling results across multiple operating scenarios.

All diesel-only trains in the UK will be removed from services by 2040. High volumetric density rapid refuelling ability and sophisticated experience in infrastructure and logistics make ammonia a perfect hydrogen carrying fuel for rail freight which urgently requires an economically viable solution. This study conducted a novel techno-economic study of ammonia-fuelled fuel cell powertrains to be compared with current diesel engine-based system and emerging direct hydrogen-fuelled fuel cell system. The results demonstrate that hydrogen-fuelled Proton Exchange Membrane Fuel Cells (PEMFCs) and ammonia-fuelled PEMFCs (using an ammonia cracker) are more cost-effective in terms of Levelized Cost of Electricity. The ammonia fuel storage requires 61.5-75 % less space compared to the hydrogen storage. Although the ammonia-fuelled Solid Oxide Fuel Cells (SOFCs) powertrain has the highest electricity generation efficiency (56%) the overall cost requires a major reduction by 70% before it could be considered as an economically viable solution.