Applications & Pathways

Limiting global warming and the pursuit of a net-zero global society by 2050 emphasizes the need to transform the hard-to-abate industrial sectors. The cement sector is the second-largest source of global industrial emissions accounting for 8% of worldwide greenhouse gas emissions. Fuel switching in the cement sector is a decarbonization pathway that has not been explored in detail; previous studies involving fuel switching in the sector either view it from an energy efficiency lens or focus on a single technology. In this study a framework is developed to evaluate and directly compare six fuel switching options (including hydrogen biomass municipal solid waste and natural gas) from 2020 to 2050. Capital costs non-energy operating costs energy costs and carbon costs are used to calculate marginal abatement costs and emulate cost based-market decisions. The developed framework is used to conduct a case study for Canada using the LEAP-Canada model. This study shows that cumulative energy-related greenhouse gas emissions can be reduced by up to 21% between 2020 and 2050 with negative marginal abatement costs. Multiple fuel switching decarbonization pathways were established reducing the likelihood that locality prevents meaningful emissions reduction and suggesting that with low-carbon fuel and electricity policies the sector can take significant steps towards emissions reduction. The developed framework can be applied to jurisdictions around the world for decision making as nations move towards eliminating emissions from cement production.

Fuel cell electric vehicles (FCEVs) provide a viable answer to transportation issues caused by fossil fuel limitations and environmental concerns. This review presents a thorough evaluation of the most recent advances in FCEV durability research. It addresses 4 major topics: component upgrades technical control techniques test optimization and durability prediction. Upgrades to components include improved catalysts bipolar plates gas diffusion layers proton exchange membranes and plant balancing. Technical control solutions include power energy temperature ventilation and control management. Stress acceleration and cold start tests are examples of test optimization whereas durability prediction requires parameter selection real-time monitoring dynamic modeling and lifespan prediction. This review also makes some novel recommendations targeted at improving the endurance of FCEVs. These include measures for raising public awareness lowering prices while increasing performance improving subsystems for greater durability updating health diagnostics to prevent performance deterioration and implementing supporting regulations to encourage industry upgrading. These findings are expected to accelerate the adoption of FCEVs and the transition to a more sustainable transportation system.

Desulphurization of oil-based fuels is common practice to mitigate the ecological burden to ecosystems and human health of SOx emissions. In many countries fuels for vehicles are restricted to 10 ppm sulphur. For marine fuels low sulphur contents are under discussion. The environmental impact of desulphurization processes is however quite high: (1) The main current source for industrial hydrogen is Steam Methane Reforming (SMR) with a rather high level of CO2 emissions (2) the hydrotreating process especially below 150 ppm needs a lot of energy. These two issues lead to three research questions: (a) What is the overall net ecological benefit of the current desulphurization practice? (b) At which sulfphur ppm level in the fuel is the additional ecological burden of desulphurization higher than the additional ecological benefit of less SOx pollution from combustion? (c) To what extent can cleaner hydrogen processes improve the ecological benefit of diesel desulphurization? In this paper we use LCA to analyze the processes of hydrotreatment the recovery of sulphur via amine treating of H2S and three processes of hydrogen production: SMR without Carbon Capture and Sequestration (CCS) SMR with 53% and 90% CCS and water electrolysis with two types of renewable energy. The prevention-based eco-costs system is used for the overall comparison of the ecological burden and the ecological benefit. The ReCiPe system was applied as well but appeared not suitable for such a comparison (other damage-based indicators cannot be applied either). The overall conclusion is that (1) the overall net ecological benefit of hydrogen-based Ultra Low Sulphur Diesel is dependent of local conditions but is remarkably high (2) desulphurization below 10 ppm is beneficial for big cities and (3) cleaner production of hydrogen reduces eco-cost by a factor 1.8–3.4.

This paper proposes and assesses three different control approaches for the hydrocarbon natural gas (HCNG) penetrated integrated energy system (IES). The three control approaches adopt mixed integer linear programing conditional value at risk (CVaR) and robust optimization (RO) respectively aiming to mitigate the renewable generation uncertainties. By comparing the performance and efficiency the most appropriate control approach for the HCNG penetrated IES is identified. The numerical analysis is conducted to evaluate the three control approaches in different scenarios where the uncertainty level of renewable energy (within the HCNG penetrated IES) varies. The numerical results show that the CVaR-based approach outperforms the other two approaches when renewable uncertainty is high (approximately 30%). In terms of the cost to satisfy the energy demand the operational cost of the CVaR-based method is 8.29% lower than the RO one while the RO-based approach has a better performance when the renewable uncertainty is medium (approximately 5%) and it is operational is 0.62% lower than that of the CVaR model. In both evaluation cases mixed integer linear programing approach cannot meet the energy demand. This paper also compares the operational performance of the IES with and without HCNG. It is shown that the IES with HCNG can significantly improve the capability to accommodate renewable energy with low upgrading cost.

Green hydrogen (H2) produced from renewable energy sources (RES) through electrolysis offers a promising solution to decarbonize hard-to-abate sectors paving the way for H2 hubs. The agility of electrolyzers especially proton-exchange membrane (PEM) technology can be leveraged to provide flexibility to future integrated electricity and H2 systems. More flexibility can be unlocked by optimizing the designs of H2 hubs which generally consist of electrolyzers H2 storage tanks H2 liquefiers and battery energy storage systems (BESSs). This paper introduces a generic optimization framework for finding the least-cost designs of H2 hubs that also minimizes system operating costs under arbitrary H2 demand profiles. The proposed electrolyzer model incorporates a variable efficiency to avoid overestimating the power consumption and the true size of electrolyzers. In RES-rich countries like Australia envisaged H2 export demand may constitute a significant source of demand flexibility. The proposed framework is therefore demonstrated on a case study involving the Australian National Electricity Market (NEM) under a future large-scale green H2 export scenario assessing the impact of three different H2 export profile assumptions on H2 hub investment costs system operating costs and system flexibility. These profiles include: (a) a realistic one based on historical liquefied natural gas (LNG) ship schedules and a pilot H2 export project (b) an inflexible constant demand across the year and (c) a flexible monthly target without intraday and interday restrictions. Numerical analysis demonstrates that the optimal H2 hub designs obtained under the more realistic H2 export profile assumptions enjoy the lowest system operating costs and the highest flexibility the latter of which is evidenced by a substantial increase in availability of reserves.

On the path towards decarbonisation of the steel industry the use of H2 /NG blends in furnaces where high temperatures are needed is one of the alternatives that needs to be carefully studied. The present paper shows the CFD study carried out for a full-scale reheating furnace burner case. The real operating conditions as well as experimental measurements provided by the furnace operator were used to validate the results and reduce simulation uncertainties. The burner under consideration (2.5 MW) works in flameless mode with natural gas and preheated air (813 K). Starting from this point another three fuel blends with volumetric percentages of 23% (also known as G222) 50% and 75% of H2 in natural gas were considered. For this purpose the open source CFD code OpenFOAM was used where the novel NE-EDC turbulence-chemistry interaction model was implemented which has already been successfully validated specifically for flameless combustion in a furnace. The implementation incorporated an enhanced approach for calculating the chemical time-scale coupled with a specific post-processing solver to predict NO emissions. The study analyses the relative impact of the considered fuel blends on NO formation and flameless regime. The modelling results demonstrated the burner’s capability to operate efficiently with high concentrations of hydrogen maintaining flameless regime in all cases. This condition ensured uniform temperature distributions and low levels of NO emissions reaching a maximum value of 86 mg/m3 . These results indicated the proper functionality of the existing natural gas-based burner with H2 /NG blends which was the primary requirement for the conversion process.

At present transportation energy comes primarily from fossil fuels. In order to mitigate the effects of greenhouse gas emissions it is necessary to transition to low-carbon transportation technologies. These technologies can include battery electric vehicles fuel cell vehicles and biofuel vehicles. This transition includes not only the development and production of suitable vehicles but also the development of appropriate infrastructure. For example in the case of battery electric vehicles this infrastructure would include additional grid capacity for battery charging. For fuel cell vehicles infrastructure could include facilities for the production of suitable electrofuels which again would require additional grid capacity. In the present paper we look at some specific examples of infrastructure requirements for battery electric vehicles and vehicles using hydrogen and other electrofuels in either internal combustion engines or fuel cells. Analysis includes the necessary additional grid capacity energy storage requirements and land area associated with renewable energy generation by solar photovoltaics and wind. The present analysis shows that the best-case scenario corresponds to the use of battery electric vehicles powered by electricity from solar photovoltaics. This situation corresponds to a 47% increase in grid electricity generation and the utilization of 1.7% of current crop land.

The current literature on solid oxide fuel cell and internal combustion engine (SOFC-ICE) integration is focused on the application of advanced combustion technologies operating as bottoming cycles to generate a small load share. This integration approach can pose challenges for ships such as restricted dynamic capabilities and large space and weight requirements. Furthermore the potential of SOFC-ICE integration for marine power generation has not been explored. Consequently the current work proposes a novel approach of SOFC-ICE integration for maritime applications which allows for high-efficiency power generation while the SOFC anode-off gas (AOG) is blended with natural gas (NG) and combusted in a marine spark-ignited (SI) engine for combined power generation. The objective of this paper is to investigate the potential of the proposed SOFC-ICE integration approach with respect to system efficiency emissions load sharing space and weight considerations and load response. In this work a verified zero-dimensional (0-D) SOFC model engine experiments and a validated AOG-NG mean value engine model is used. The study found that the SOFC-ICE integration with a 67–33 power split at 750 kWe power output yielded the highest efficiency improvement of 8.3% over a conventional marine natural gas engine. Simulation results showed that promising improvements in efficiency of 5.2% UHC and NOx reductions of about 30% and CO2 reductions of about 12% can be achieved from a 33–67 SOFC-ICE power split with comparatively much smaller increments in size and weight of 1.7 times. Furthermore the study concluded that in the proposed SOFC-ICE system for maritime applications a power split that favours the ICE would significantly improve the dynamic capabilities of the combined system and that the possible sudden and large load changes can be met by the ICE.

To reduce hydrogen consumption by hydrogen fuel cell vehicles (HFCVs) an adaptive power-following control strategy based on gated recurrent unit (GRU) neural network operating condition recognition was proposed. The future vehicle speed was predicted based on a GRU neural network and a driving cycle condition recognition model was established based on k-means cluster analysis. By predicting the speed over a specific time horizon feature parameters were extracted and compared with those of typical operating conditions to determine the categories of the parameters thus the adjustment of the power-following control strategy was realized. The simulation results indicate that the proposed control strategy reduces hydrogen consumption by hydrogen fuel cell vehicles (HFCVs) by 16.6% with the CLTC-P driving cycle and by 4.7% with the NEDC driving cycle compared to the conventional power-following control strategy. Additionally the proposed strategy effectively stabilizes the battery’s state of charge (SOC).

The continuous increase of energy demand with the subsequent huge fossil fuel consumption is provoking dramatic environmental consequences. The main challenge of this century is to develop and promote alternative more eco-friendly energy production routes. In this framework Solid Oxide Cells (SOCs) are a quite attractive technology which could satisfy the users’ energy request working in reversible operation. Two operating modes are alternated: from “Gas to Power” when SOCs work as fuel cells fed with hydrogen-rich mixture to provide both electricity and heat to “Power to Gas” when SOCs work as electrolysers and energy is supplied to produce hydrogen. If solid oxide fuel cells are an already mature technology with several stationary and mobile applications the use of solid oxide electrolyser cells and even more reversible cells are still under investigation due to their insufficient lifetime. Aiming at providing a better understanding of this new technological approach the study presents a detailed description of cell operation in terms of electrochemical behaviour and possible degradation highlighting which are the most commonly used performance indicators. A thermodynamic analysis of system efficiency is proposed followed by a comparison with other available electrochemical devices in order to underline specific solid oxide cell advantages and limitations.

Maximizing hydrogen utilization is crucial for improving the efficiency of proton exchange membrane (PEM) fuel cell systems. Ideally all supplied hydrogen reacts within the fuel cell. However nitrogen and water backdiffusion necessitate periodic purging of the anode recirculation path. Excessive purging leads to hydrogen losses while insufficient purging increases side reactions lowering fuel cell voltage and directly reducing effi ciency. This study investigates optimizing both hydrogen utilization and stack efficiency by adjusting purge valve actuation in a PEM fuel cell system. Results show that reducing purging from the reference increases hydrogen utilization by 0.79% points to 98.2% resulting in efficiency improvement of 0.72% points to 47.21% based on higher heating value. Moreover adjusting the purge valve actuation is the sole method for controlling the hydrogen stoichiometric ratio in ejector-based anode recirculation systems. Therefore precise purge valve operation is critical for maximizing both hydrogen utilization and PEM fuel cell efficiency.

Through mathematical modeling this paper integrates economic safety and environmental assessments to evaluate alternative hydrogen supply options (on-site production and external supply) and various hydrogenbased system configurations for decarbonizing energy-intensive industries. The model is applied to a case study in the glass sector. While reliance on natural gas remains the most cost-effective and safest solution it does not align with decarbonization objectives. Assuming a complete hydrogen transition on-site production reduces emissions by 85 % compared to current levels and improves safety performance over external supply. External supply of grey hydrogen becomes counterproductive increasing emissions by 68 % compared to natural gas operations. Nevertheless hydrogen cost rises from 3.6 €/kg with external supply to 4.2 €/kg with on-site production doubling the fuel cost relative to natural gas. To address the trade-offs the paper explores how specific constraints influence system design. A sensitivity analysis on key factors affecting hydrogen-related decisions provides additional support for strategic decision-making.

This article provides an overview of current hydrogen technologies used in road transport with particular emphasis on their potential for decarbonizing the mobility sector. The author analyzes both fuel cells and hydrogen combustion in internal combustion engines as two competing approaches to using hydrogen as a fuel. He points out that although fuel cells offer higher efficiency hydrogen combustion technologies can be implemented more quickly because of their compatibility with existing drive systems. The article emphasizes the importance of hydrogen’s source—so-called green hydrogen produced from renewable energy sources has the greatest ecological potential. Issues related to the storage distribution and safety of hydrogen use in transport are also analyzed. The author also presents the current state of refueling infrastructure and forecasts for its development in selected countries until 2030. He points to the need to harmonize legal regulations and to support the development of hydrogen technologies at the national and international levels. He also highlights the need to integrate the energy and transport sectors to effectively utilize hydrogen as an energy carrier. The article presents a comprehensive analysis of technologies policies and markets identifying hydrogen as a key link in the energy transition. In conclusion the author emphasizes that the future of hydrogen transport depends not only on technical innovations but above all on coherent strategic actions and infrastructure investments.

Energy scheduling for hybrid unmanned aerial vehicles (UAVs) is of critical importance to their safe and stable operation. However traditional approaches predominantly rule-based often lack the dynamic adaptability and stability necessary to address the complexities of changing operational environments. To overcome these limitations this paper proposes a novel energy scheduling framework that integrates the Model Predictive Control (MPC) with a Deep Reinforcement Learning algorithm specifically the Deep Deterministic Policy Gradient (DDPG). The proposed method is designed to optimize energy management in hydrogen-powered UAVs across diverse flight missions. The energy system comprises a proton exchange membrane fuel cell (PEMFC) a lithium-ion battery and a hydrogen storage tank enabling robust optimization through the synergistic application of MPC and DDPG. The simulation results demonstrate that the MPC effectively minimizes electric power consumption under various flight conditions while the DDPG achieves convergence and facilitates efficient scheduling. By leveraging advanced mechanisms including continuous action space representation efficient policy learning experience replay and target networks the proposed approach significantly enhances optimization performance and system stability in complex continuous decision-making scenarios.

The integration of renewable energy sources such as wind and solar power at high proportions has become an inevitable trend in the development of power systems under the new power system framework. The construction of a microgrid system incorporating hydrogen energy storage and battery energy storage can leverage the complementary advantages of long-term and short-term hybrid storage achieving power and energy balance across multiple time scales in the power system. To prevent frequent startstop cycles of hydrogen storage devices and lithium battery storage under overcharge and overdischarge conditions a coordinated control strategy for power distribution in a microgrid with hydrogen storage is proposed. First a fuzzy control algorithm is used for power distribution between hydrogen storage and lithium battery storage. Then the hydrogen storage tank’s state of health (SOH) and the lithium battery’s state of charge (SOC) are compared with the goal of selecting a multi-stack fuel cell system operating at its optimal efficiency point where each fuel cell stack outputs 10 kW. This further ensures that the SOC and SOH remain within reasonable ranges. Finally simulations are conducted in MATLAB/Simulink R2018b to verify that the proposed strategy maintains stability in the DC bus and alleviates issues of overcharge and overdischarge ensuring that both the system’s SOC and SOH remain within a reasonable range thereby enhancing equipment lifespan and system stability

The adoption of low-carbon fuels in maritime propulsion requires operational autonomy material suitability and compliance with safety standards making liquid fuels like LNG and LH2 the most viable options. LNG is widely used for reducing GHG NOx and SOx emissions while LH2 though new to the maritime sector leverages aerospace experience. This paper explores the operational requirements and challenges of LH2 cryogenic handling systems using LNG practices as a reference. Key comparisons are made between LNG and LH2 supply systems focusing on cryogenic materials hydrogen embrittlement and structural integrity under maritime conditions. Most maritime-approved materials are suitable for cryogenic use and hydrogen embrittlement is less critical at cryogenic temperatures due to reduced atomic mobility. Risk assessments suggest LH2’s safety record stems from limited operational data rather than superior inherent safety. The paper also addresses crucial safety and regulatory considerations for both fuels underscoring the need for strict adherence to standards to ensure the safe and compliant integration of LH2 in the maritime industry.

This paper proposes a novel dual-fuel dual-mode dual-thermodynamic cycle aviation propulsion system for the first time and conducts theoretical research on it based on a moderately simplified mathematical model. It is specifically designed to significantly reduce carbon emissions for wide-body aircraft. A comprehensive thermodynamic model is developed for this hybrid power system which integrates a high-temperature proton exchange membrane fuel cell with a dual-rotor turbofan engine. The matching characteristics between aircraft and engine performance are analyzed by systematically varying the fuselage length of the dual-fuel aircraft configuration. Results show that the specific fuel consumption of the proposed engine is decreased by 12.6% compared with that of the traditional turbofan engine as the Mach number increases. Conversely as the relative physical rotational speed decreases the thrust of the novel engine is increased by 10%. With a 20 % extension in fuselage length the dual-fuel aircraft operating on 100 % hydrogen fuel can achieve an endurance exceeding 17 h representing a 20 % endurance improvement over conventional aviation kerosene-powered aircraft. In this case the aircraft weight can be reduced by 96.79 tons and CO2 emissions can be decreased by 301.65 tons.

Reducing greenhouse gas emissions in the transport sector is known to be an important contribution to climate change mitigation. Some parts of the transport sector are particularly difficult to decarbonize; this includes the heavy-duty vehicle sector which is considered one of the “hardto-abate” sectors of the economy. Transitioning from diesel trucks to hydrogen fuel cell trucks has been identified as a potential way to decarbonize the sector. However the current and future costs and efficiencies of the enabling technologies remain unclear. In light of these uncertainties this paper investigates the investments required to decarbonize New Zealand’s heavy-duty vehicle sector with green hydrogen. By combining system dynamics modelling literature and hydrogen transition modelling literature a customized methodology is developed for modelling hydrogen transitions with system dynamics modelling. Results are presented in terms of the investments required to purchase the hydrogen production capacity and the investments required to supply electricity to the hydrogen production systems. Production capacity investments are found to range between 1.59 and 2.58 billion New Zealand Dollars and marginal electricity investments are found to range between 4.14 and 7.65 billion New Zealand Dollars. These investments represent scenarios in which 71% to 90% of the heavy-duty vehicle fleet are replaced with fuel cell trucks by 2050. The wide range of these findings reflects the large uncertainties in estimates of how hydrogen technologies will develop over the course of the next thirty years. Policy recommendations are drawn from these results and a clear opportunity for future work is outlined. Most notably the results from this study should be compared with research investigating the investments required to decarbonize the heavy-duty vehicle sectors with alternative technologies such as battery-electric trucks biodiesel and catenary systems. Such a comparison would ensure that the most cost effective decarbonization strategy is employed.

We present an optimization model of an energy district in South Italy that supplies baseload electricity and hydrogen services. The district is sized such that a nuclear reactor could provide these services. We define scenarios for 2050 to explore the system effects of discount rate sensitivity vetoes on technologies and cost uncertainties. We address the following issues relevant to decarbonization in South Italy: land-based wind and solar vs. exclusive solar rooftop extra cost of a veto on nuclear conservative assumptions on future storage technology and the role of pumped hydro storage lack of low-cost geological storage of hydrogen and the industrial competitiveness of this carrier and the methanation synergy with the agroforestry sector. Our results quantify the high system cost of vetoes on land-based wind and solar. Nuclear may enter the optimal mix only with a veto against onshore wind and a hypothesis of equal project risk hence an equal discount rate with renewables. Scenarios with land-based wind and solar obtain low-cost hydrogen and thus allow industrial uses for this carrier. The methanation synergy with the agroforestry sector does not offer a system cost advantage but improves the district’s configuration. The extra cost of full decarbonization relative to unregulated fossil gas is small with land-based wind and solar and significant with vetoes to these technologies.

The iron and steel industry contributes approximately 25% of global industrial CO2 emissions necessitating substantial decarbonisation efforts. Hydrogen-based iron and steel plants (HISPs) which utilise hydrogen-based direct reduction of iron ore followed by electric arc furnace steelmaking have attracted substantial research interest. However commercialisation of HISPs faces economic feasibility issues due to the high electricity costs of hydrogen production. To improve economic feasibility HISPs are jointly powered by local renewable generators and bulk power grid i.e. by a grid-assisted renewable energy system. Given the variability of renewable energy generation and time-dependent electricity prices flexible scheduling of HISP production tasks is essential to reduce electricity costs. However cost-effectively scheduling of HISP production tasks is non-trivial as it is subject to critical operational constraints arising from the tight coupling and distinct operational characteristics of HISPs sub-processes. To address the above issues this paper proposes an integrated resource-task network (RTN) to elaborately model the critical operational constraints such as resource balance task execution and transfer time. More specifically each sub-process is first modelled as an individual RTN which is then seamlessly integrated through boundary dependency constraints. By embedding the formulated operational constraints into optimisation a cost-effective scheduling model is developed for HISPs powered by the grid-assisted renewable energy system. Numerical results demonstrate that compared to conventional scheduling approaches the proposed method significantly reduces total operational costs across various production scales.

This study examines the steps to lower air emissions in South Korea’s domestic shipping sector. It highlights the significant contributions of the sector to air pollution and greenhouse gas emissions emphasizing its impact on environmental sustainability and climate change mitigation. By looking at the current shipping energy use and emissions the research identifies ways to reduce the environmental impact of domestic shipping. Data was collected from domestic ferry routes and the fuel use was reviewed with respect to existing global technologies for reducing emissions. The results show that operational changes and current energy-efficient technologies can quickly cut emissions. Furthermore a long-term plan is suggested involving the development of new ship designs and the use of net-zero fuels like biofuels methanol hydrogen and ammonia. These efforts aim to meet climate goals targeting a 40% reduction in greenhouse emissions by 2030 and a 70% reduction by 2050 making South Korea’s shipping industry more sustainable and resilient.

Compression ignition engines will still be predominant in the naval sector: their high efficiency high torque and heavy weight perfectly suit the demands and architecture of ships. Nevertheless recent emission legislations impose limitations to the pollutant emissions levels in this sector as well. In addition to post-treatment systems it is necessary to reduce some pollutant species and therefore the study of combustion strategies and new fuels can represent valid paths for limiting environmental harmful emissions such as CO2 . The use of methane in dual fuel mode has already been implemented on existent vessels but the progressive decarbonization will lead to the utilization of carbon-neutral or carbon-free fuels such as in the last case hydrogen. Thanks to its high reactivity nature it can be helpful in the reduction of exhaust CH4 . On the contrary together with the high temperatures achieved by its oxidation hydrogen could cause uncontrolled ignition of the premixed charge and high emissions of NOx. As a matter of fact a source of ignition is still necessary to have better control on the whole combustion development. To this end an optimal and specific injection strategy can help to overcome all the before-mentioned issues. In this study three-dimensional numerical simulations have been performed with the ANSYS Forte® software (version 19.2) in an 8.8 L dual fuel engine cylinder supplied with methane hydrogen or hydrogen–methane blends with reference to experimental tests from the literature. A new kinetic mechanism has been used for the description of diesel fuel surrogate oxidation with a set of reactions specifically addressed for the low temperatures together with the GRIMECH 3.0 for CH4 and H2 . This kinetics scheme allowed for the adequate reproduction of the ignition timing for the various mixtures used. Preliminary calculations with a one-dimensional commercial code were performed to retrieve the initial conditions of CFD calculations in the cylinder. The used approach demonstrated to be quite a reliable tool to predict the performance of a marine engine working under dual fuel mode with hydrogen-based blends at medium load. As a result the system modelling shows that using hydrogen as fuel in the engine can achieve the same performance as diesel/natural gas but when hydrogen totally replaces methane CO2 is decreased up to 54% at the expense of the increase of about 76% of NOx emissions.

The road-transport is one of the major contributors to greenhouse global gas (GHG) emissions where hydrogen (H2) combustion engines can play a crucial role in the path towards the sector’s decarbonization goal. This study focuses on comparing the performance and emissions of port-fuel injection (PFI) and direct injection (DI) in a spark ignited combustion engine when is fuelled by hydrogen and other noteworthy fuels like methane and coke oven gas (COG). Computational fluid dynamic simulations are performed at optimal spark advance and air-fuel ratio (λ) for engine speeds between 2000 and 5000 rpm. Analysis reveals that brake power increases by 40% for DI attributed to 30.6% enhanced volumetric efficiency while the sNOx are reduced by 36% compared to PFI at optimal λ = 1.5 for hydrogen. Additionally H2 results in 71.8% and 67.2% reduction in fuel consumption compared to methane and COG respectively since the H2 lower heating value per unit of mass is higher.

The agro-livestock sector produces about one third of global greenhouse gas (GHG) emissions. Since more energy is needed to meet the growing demand for food and the industrial revolution in agriculture renewable energy sources could improve access to energy resources and energy security reduce dependence on fossil fuels and reduce GHG emissions. Hydrogen production is a promising energy technology but its deployment in the global energy system is lagging. Here we analyzed the theoretical and practical application of green hydrogen generated by electrolysis of water powered by renewable energy sources in the agro-livestock sector. Green hydrogen is at an early stage of development in most applications and barriers to its large-scale deployment remain. Appropriate policies and financial incentives could make it a profitable technology for the future.

Of all the alternatives to hydrocarbon fuels hydrogen offers the greatest long-term potential to radically reduce the many problems inherent in fuel used for transportation. Hydrogen vehicles have zero tailpipe emissions and are very efficient. If the hydrogen is made from renewable sources such as nuclear power or fossil sources with carbon emissions captured and sequestered hydrogen use on a global scale would produce almost zero greenhouse gas emissions and greatly reduce air pollutant emissions. The aim of this work is to realise a traceability chain for hydrogen flow metering in the range typical for fuelling applications in a wide pressure range with pressures up to 875 bar (for Hydrogen Refuelling Station - HRS with Nominal Working Pressure of 700 bar) and temperature changes from −40 °C (pre-cooling) to 85 °C (maximum allowed vehicle tank temperature) in accordance with the worldwide accepted standard SAE J2601. Several HRS have been tested in Europe (France Netherlands and Germany) and the results show a good repeatability for all tests. This demonstrates that the testing equipment works well in real conditions. Depending on the installation configuration some systematic errors have been detected and explained. Errors observed for Configuration 1 stations can be explained by pressure differences at the beginning and end of fueling in the piping between the Coriolis Flow Meter (CFM) and the dispenser: the longer the distance the bigger the errors. For Configuration 2 where this distance is very short the error is negligible.

To address the issues of diverse energy supply demands and power fluctuations in integrated energy systems (IESs) this study takes an IES composed of power-generation units such as wind and photovoltaic units along with various energy-storage systems including electrical thermal and hydrogen storage as the research subject. A collaborative control strategy is proposed for the IES which comprehensively considers the status of diverse energy-storage systems like battery packs thermal tanks and hydrogen tanks. First a mathematical model of the IES is constructed. Then a dual-layer collaborative control strategy is designed considering different operating modes of the IES which includes a multi-energy-storage power allocation control layer based on second-order power-frequency processing and distribution and an adaptive adjustment layer for adjusting powerfrequency coefficients based on adaptive fuzzy control. Finally MATLAB is used to simulate and validate the proposed strategy. The results indicate that the collaborative control strategy based on variable-frequency coefficients optimizes the allocation of fluctuating power among multiple energy-storage systems enhances the stability of bus voltage reduces the deep charge and discharge time of battery packs and extends the service life of battery packs.

In the vehicle-to-everything scenario the fuel cell bus can accurately obtain the surrounding traffic information and quickly optimize the energy management problem while controlling its own safe and efficient driving. This paper proposes an energy management strategy (EMS) that considers speed control based on deep reinforcement learning (DRL) in complex traffic scenarios. Using SUMO simulation software (Version 1.15.0) a two-lane urban expressway is designed as a traffic scenario and a hydrogen fuel cell bus speed control and energy management system is designed through the soft actor–critic (SAC) algorithm to effectively reduce the equivalent hydrogen consumption and fuel cell output power fluctuation while ensuring the safe efficient and smooth driving of the vehicle. Compared with the SUMO–IDM car-following model the average speed of vehicles is kept the same and the average acceleration and acceleration change value decrease by 10.22% and 11.57% respectively. Compared with deep deterministic policy gradient (DDPG) the average speed is increased by 1.18% and the average acceleration and acceleration change value are decreased by 4.82% and 5.31% respectively. In terms of energy management the hydrogen consumption of SAC–OPT-based energy management strategy reaches 95.52% of that of the DP algorithm and the fluctuation range is reduced by 32.65%. Compared with SAC strategy the fluctuation amplitude is reduced by 15.29% which effectively improves the durability of fuel cells.

In Austria one of the highest priorities of hydrogen usage lies in the industrial sector particularly as a feedstock and for high-temperature applications. Connecting hydrogen producers with consumers is challenging and requires comprehensive research to outline the advantages and challenges associated with various hydrogen supply options. This study focuses on techno-economic assessment of different supply solutions for industrial sites mainly depicted in two categories: providing hydrogen by transport means and via on-site production. The technologies needed for the investigation of these scenarios are identified based on the predictions of available technologies in near future (2030). The transportation options analyzed include delivering liquid hydrogen by truck liquid hydrogen by railway and gaseous hydrogen via pipeline. For on-site low-carbon hydrogen production a protonexchange membrane (PEM) electrolysis was selected as resent research suggests lower costs for PEM electrolysis compared to alkaline electrolysis (AEL). The frequency of deliveries and storage options vary by scenario and are determined by the industrial demand profile transport capacity and electrolyser production capacity. The assessment evaluates the feasibility and cost-effectiveness of each option considering factors such as infrastructure requirements energy efficiency and economic viability. At a hydrogen demand of 80 GWh the transport options indicate hydrogen supply costs in the range of 14–24 ct/kWh. In contrast the scenarios investigating on-site production of hydrogen show costs between 29 and 49 ct/ kWh. Therefore transport by truck rail or pipeline is economically advantageous to own-production under the specific assumptions and conditions. However the results indicate that as energy demand increases on-site production becomes more attractive. Additionally the influence of electricity prices and the hydrogen production/import price were identified as decisive factors for the overall hydrogen supply costs.

CO2 emissions have been identified as the main driver for climate change with devastating consequences for the global natural environment. The steel industry is responsible for ~7–11% of global CO2 emissions due to high fossil-fuel and energy consumption. The onus is therefore on industry to remedy the environmental damage caused and to decarbonise production. This desk research report explores the Bio Steel Cycle (BiSC) and proposes a seven-step-strategy to overcome the emission challenges within the iron and steel industry. The true levels of combined CO2 emissions from the blast-furnace and basic-oxygen-furnace operation at 4.61 t of CO2 emissions/t of steel produced are calculated in detail. The BiSC includes CO2 capture implementing renewable energy sources (solar wind green H2 ) and plantation for CO2 absorption and provision of biomass. The 7-step-implementation-strategy starts with replacing energy sources develops over process improvement and installation of flue gas carbon capture and concludes with utilising biogas-derived hydrogen as a product from anaerobic digestion of the grown agrifood in the cycle. In the past CO2 emissions have been seemingly underreported and underestimated in the heavy industries and implementing the BiSC using the provided seven-steps-strategy will potentially result in achieving net-zero CO2 emissions in steel manufacturing by 2030.

Electro-fuels (E-fuels) represent a potential solution for decarbonizing the maritime sector including pleasure vessels. Due to their large energy requirements direct electrification is not currently feasible. E-fuels such as synthetic diesel methanol ammonia methane and hydrogen can be used in existing internal combustion engines or fuel cells in hybrid configurations with lithium batteries to provide propulsion and onboard electricity. This study confirms that there is no clear winner in terms of efficiency (the power-to-power efficiency of all simulated cases ranges from 10% to 30%) and the choice will likely be driven by other factors such as fuel cost onboard volume/mass requirements and distribution infrastructure. Pure hydrogen is not a practical option due to its large storage necessity while methanol requires double the storage volume compared to current fossil fuel solutions. Synthetic diesel is the most straightforward option as it can directly replace fossil diesel and should be compared with biofuels. CO2 emissions from E-fuels strongly depend on the electricity source used for their synthesis. With Italy’s current electricity mix E-fuels would have higher impacts than fossil diesel with potential increases between +30% and +100% in net total CO2 emissions. However as the penetration of renewable energy increases in electricity generation associated E-fuel emissions will decrease: a turning point is around 150 gCO2/kWhel.

This study represents a thermodynamic evaluation and carbon footprint analysis of the application of hydrogen based energy storage systems in residential buildings. In the system model buildings are equipped with photovoltaic (PV) modules and a hydrogen storage system to conserve excess PV electricity from times with high solar irradiation to times with low solar irradiation. Short-term storages enable a degree of self-sufficiency of approximately 60% for a single-family house (SFH) [multifamily house (MFH): 38%]. Emissions can be reduced by 40% (SFH) (MFH: 30%) compared to households without PV modules. These results are almost independent of the applied storage technology. For seasonal storage the degree of self-sufficiency ranges between 57 and 83% (SFH). The emission reductions highly depend on the storage technology as emissions caused by manufacturing the storage dominate the emission balance. Compressed gas or liquid organic hydrogen carriers are the best options enabling emission reductions of 40%.

This paper offers a set of comprehensive guidelines aimed at facilitating the widespread adoption of hydrogen in the industrial hard-to-abate sectors. The authors begin by conducting a detailed analysis of these sectors providing an overview of their unique characteristics and challenges. This paper delves into specific elements related to hydrogen technologies shedding light on their potential applications and discussing feasible implementation strategies. By exploring the strengths and limitations of each technology this paper offers valuable insights into its suitability for specific applications. Finally through a specific analysis focused on the steel sector the authors provide in-depth information on the potential benefits and challenges associated with hydrogen adoption in this context. By emphasizing the steel sector as a focal point the authors contribute to a more nuanced understanding of hydrogen’s role in decarbonizing industrial processes and inspire further exploration of its applications in other challenging sectors.

Europe’s heavy reliance on diesel power for nearly half of its railway lines for both goods and passengers has significant implications for carbon emissions. To address this challenge the European Union advocates for a shift towards hydrogen-based mobility necessitating the development of robust and cost-effective hydrogen supply chains at regional and national levels. Leveraging renewable energy sources such as wind farms and solid biomass could foster the transition to sustainable hydrogen-based transportation. In this study a mixed-integer linear programming approach integrated with an external heavy-duty refueling station analysis model is employed to address the optimal design of a new hydrogen supply chain. Through multi-objective optimization this study aimed to minimize the overall daily costs and emissions of the supply chain. By applying the model to a case study in Sicily different scenarios with varying supply chain configurations and wind curtailment factors were explored. The findings revealed that increasing the wind curtailment factor from 1% to 2% led to reductions of 12% and 15% in the total daily emission costs and network costs respectively. Additionally centralized biomass-based plants dominated hydrogen production accounting for 96% and 94% of the total production under 1% and 2% wind curtailment factors respectively. Furthermore transporting gaseous hydrogen via tube trailers proved more cost effective than using tanker trucks for liquid hydrogen when compressed gaseous hydrogen is required at the dispenser of forecourt refueling stations. Finally the breakdown of the levelized cost for the hydrogen refuelling station strongly depends on the form of hydrogen received at the gate namely liquid or gaseous. Specifically for the former the dispenser accounts for 60% of the total cost whereas for the latter the compressor is responsible for 58% of the total cost. This study highlights the importance of preliminary and quantitative analyses of new hydrogen supply chains through model-based optimization.

The low-carbon construction of integrated energy systems is a crucial path to achieving dual carbon goals with the power-generation side having the greatest potential for emissions reduction and the most direct means of reduction which is a current research focus. However existing studies lack the precise modeling of carbon capture devices and the cascaded utilization of hydrogen energy. Therefore this paper establishes a carbon capture power plant model based on a comprehensive flexible operational mode and a coupled model of a two-stage P2G (Power-to-Gas) device exploring the “energy time-shift” characteristics of the coupled system. IGDT (Information Gap Decision Theory) is used to discuss the impact of uncertainties on the power generation side system. The results show that by promoting the consumption of clean energy and utilizing the high energy efficiency of hydrogen while reducing reliance on fossil fuels the proposed system not only meets current energy demands but also achieves a more efficient emission reduction laying a solid foundation for a sustainable future. By considering the impact of uncertainties the system ensures resilience and adaptability under fluctuating renewable energy supply conditions making a significant contribution to the field of sustainable energy transition.

A large portion of astronomy’s carbon footprint stems from fossil fuels supplying the power demand of astronomical observatories. Here we explore various isolated low-carbon power system setups for the newly planned Atacama Large Aperture Submillimeter Telescope and compare them to a business-as-usual diesel power generated system. Technologies included in the designed systems are photovoltaics concentrated solar power diesel generators batteries and hydrogen storage. We adapt the electricity system optimization model highRES to this case study and feed it with the telescope’s projected energy demand cost assumptions for the year 2030 and site-specific capacity factors. Our results show that the lowest-cost system with LCOEs of $116/MWh majorly uses photovoltaics paired with batteries and fuel cells running on imported and on-site produced green hydrogen. Some diesel generators run for backup. This solution would reduce the telescope’s power-side carbon footprint by 95% compared to the businessas-usual case.

Air compressors in hydrogen fuel cell vehicles play a crucial role in ensuring the stability of the cathode air system. However they currently face challenges related to low efficiency and poor stability. To address these issues the experimental setup for the pneumatic performance of air compressors is established. The effects of operational parameters on energy consumption efficiency and mass flow rate of the air compressor are revealed based on a Morris global sensitivity analysis. Considering a higher flow rate larger efficiency and lower energy consumption simultaneously the optimal operating combination of the air compressor is determined based on grey relational multi-objective optimization. The optimal combination of operational parameters consisted of a speed of 80000 rpm a pressure ratio of 1.8 and an inlet temperature of 18.3 °C. Compared to the average values the isentropic efficiency achieved a 48.23% increase and the mass flow rate rose by 78.88% under the optimal operational combination. These findings hold significant value in guiding the efficient and stable operation of air compressors. The comprehensive methodology employed in this study is applicable further to investigate air compressors for hydrogen fuel cell vehicles.

The automotive industry is undergoing a profound transformation driven by the need for sustainable and environmentally friendly transportation solutions [1]. In this context fuel cell technology has emerged as a promising alternative offering clean efficient and high-performance power sources for vehicles [2]. Fuel cell vehicles are electric vehicles that use fuel cell systems as a single power source or as a hybrid power source in combination with rechargeable energy storage systems. A typical fuel cell system for electric vehicle is exhibited in Figure 1 which provides a comprehensive demonstration of this kind of complex system. Hydrogen energy is a crucial field in the new energy revolution and will become a key pillar in building a green efficient and secure new energy system. As a critical field for hydrogen utilization fuel cell vehicles will play an important role in the transformation and development of the automotive industry. The development of fuel cell vehicles offers numerous advantages such as strong power outputs safety reliability and economic energy savings [3]. However improvements must urgently be made in existing technologies such as fuel cell stacks (including proton exchange membranes catalysts gas diffusion layers and bipolar plates) compressors and onboard hydrogen storage systems [4]. The advantages and current technological status are analyzed here.

Given the urgency to combat climate change and ensure environmental sustainability this review examines the transition to net-zero emissions in chemical and process industries. It addresses the core areas of carbon emissions reduction efficient energy use and sustainable practices. What is new however is that it focuses on cutting-edge technologies such as biomass utilization biotechnology applications and waste management strategies that are key drivers of this transition. In particular the study addresses the unique challenges faced by industries such as cement manufacturing and highlights the need for innovative solutions to effectively reduce their carbon footprint. In particular the role of hydrogen as a clean fuel is at the heart of revolutionizing the chemical and process sectors pointing the way to cleaner and greener operations. In addition the manuscript explores the immense importance of the European Green Deal and the Sustainable Development Goals (SDGs) for the chemical industry. These initiatives provide a clear roadmap and framework for advancing sustainability driving innovation and reducing the industry’s environmental impact and are a notable contribution to the existing body of knowledge. Ultimately alignment with the European Green Deal and the SDGs can bring numerous benefits to the chemical industry increasing its competitiveness promoting societal well-being and supporting cross-sector collaboration to achieve shared sustainability goals. By highlighting the novelty of integrating cutting-edge technologies addressing unique industrial challenges and positioning global initiatives this report offers valuable insights to guide the chemical and process industries on their transformative path to a sustainable future.

With the goal of achieving “carbon peak in 2030 and carbon neutrality in 2060” as clearly proposed by China the transportation sector will face long–term pressure on carbon emissions and the application of hydrogen fuel cell vehicles will usher in a rapid growth period. However true “zero carbon” emissions cannot be separated from “green hydrogen”. Therefore it is of practical significance to explore the feasibility of renewable energy hydrogen production in the context of hydrogen refueling stations especially photovoltaic hydrogen production which is applied to hydrogen refueling stations (hereinafter referred to “photovoltaic hydrogen refueling stations”). This paper takes a hydrogen refueling station in Shanghai with a supply capacity of 500 kg/day as the research object. Based on a characteristic analysis of the hydrogen demand of the hydrogen refueling station throughout the day this paper studies and analyzes the system configuration operation strategy environmental effects and economics of the photovoltaic hydrogen refueling station. It is estimated that when the hydrogen price is no less than 6.23 USD the photovoltaic hydrogen refueling station has good economic benefits. Additionally compared with the conventional hydrogen refueling station it can reduce carbon emissions by approximately 1237.28 tons per year with good environmental benefits.

The article examines the feasibility of implementing standalone hydrogen-based renewable energy systems in Spanish residential buildings specifically analyzing the optimization of a solar-battery and solar-hydrogen system for a building with 20 dwellings in Spain. The study initially assesses two standalone setups: solarbattery and solar-hydrogen. Subsequently it explores scenarios where these systems are connected to the grid to only generate and sell surplus energy. A scenario involving grid connection for self-consumption without storage serves as a benchmark for comparison. All system optimizations are designed to meet energy demands without interruptions while minimizing costs as determined by a techno-economic analysis. The systems are sized using custom software that incorporates an energy management system and employs the Jaya algorithm for optimization. The findings indicate that selling surplus energy can be economically competitive and enhance the efficiency of grid-connected self-consumption systems representing the study’s main innovation. The conclusion highlights the economic and technical potential of an autonomous hybrid energy system that includes hydrogen with the significant remaining challenge being the development of a regulatory framework to support its technical feasibility in Spain.

Rapid urbanization and globalization are causing a rise in the energy demand within the residential sector. Currently majority of the energy demand for the residential sector being supplied from fossil fuels these sources account for greenhouse gas emissions responsible for anthropogenic-driven climate change. About 85 % of the world’s energy demands are being met by non-renewable sources of energy. An immediate need to shift towards renewable energy sources to generate electricity is the need of the hour. These long-standing renewable energy sources including solar hydropower and wind energy have been crucial pillars of sustainable energy for years. However as their implementation has matured we are increasingly recognizing their limitations. Issues such as the scarcity of suitable locations and the significant carbon footprint associated with constructing renewable energy infrastructure are becoming more apparent. Hydrogen has been found to play a vital role as an energy carrier in framing the energy picture in the 21st century. Currently about 1 % of the global energy demands are being met by hydrogen energy harnessed through renewable methods. Its low carbon emissions when compared to other methods lower comparative production costs and high energy efficiency of 40–60 % make it a suitable choice. Integrating hydrogen production systems with other renewable source of energy such as solar and wind energy have been discussed in this review in detail. With the concepts of green buildings or net zero energy buildings gaining attraction integration of hydrogen-based systems within residential and office sectors through the use of devices such as micro–Combined Heat and Power devices (mCHP) have proven to be effective and efficient. These devices have been found to save the consumed energy by 22 % along with an effective reduction in carbon emissions of 18 % when used in residential sectors. Using the rejected energy from other processes these mCHP devices can prove to be vital in meeting the energy demands of the residential sector. Through the support of government schemes mCHP devices have been widely used in countries such as Japan and Finland and have benefitted from the same. Hydrogen storage is critical for efficient operation of the integrated renewable systems as improper storage of the hydrogen produced could lead to human and environmental disasters. Using boron hydrides or ammonia (121 kg H2/m3 ) or through organic carriers hydrogen can be stored safely and easily regenerated without loss of material. A thorough comparison of all the renewable sources of energy that are used extensively is required to evaluate the merits of using hydrogen as an energy carrier which has been addressed in this review paper. The need to address the research gap in application of mCHP devices in the residential sector and the benefits they provide has been addressed in this review. With about 2500 GW of energy ready to be harnessed through the mCHP devices globally the potential of mCHP systems globally are discussed in detail in this paper. This review discusses challenges and solutions to hydrogen production storage and ways to implement hydrogen technology in the residential sector. This review allows researchers to build a renewable alternative with hydrogen as a clean energy vector for generating electricity in residential systems.

An energy systems comparison of grid-electricity derived liquid hydrogen (LH2) and liquid ammonia (LNH3) is conducted to assess their relative potential in a low-carbon future. Under various voyage weather conditions their performance is analysed for use in cargo transport energy vectors for low-carbon electricity transport and fuel supply. The analysis relies on literature projections for technological development and grid decarbonisation towards 2050. Various voyages are investigated from regions such as North America (NA) Europe (E) and Latin America (LA) to regions projected to have a higher electricity and fuel grid carbon intensity (CI) (i.e. Asia Pacific Africa the Middle-East and the CIS). In terms of reducing the CI of electricity and fuel at the destination port use of LH2 is predicted to be favourable relative to LNH3 whereas LNH3 is favourable for low-carbon transport of cargo. As targeted by the International Maritime Organisation journeys of LNH3 cargo ships originating in NA E and LA achieve a reduction in volumetric energy efficiency design index (kg-CO2/m3 -km) of at least 70% relative to 2008 levels. The same targets can be met globally if LH2 is supplied to high CI regions for production of LNH3 for cargo transport. A future shipping system thus benefits from the use of both LH2 and LNH3 for different functions. However there are additional challenges associated with the use of LH2. Relative to LNH3 1.6 to 1.7 times the number of LH2 ships are required to deliver the same energy. Even when reliquefaction is employed their success is reliant on the avoidance of rough sea states (i.e. Beaufort Numbers >= 6) where fuel depletion rates during a voyage are impractical.

This paper describes a renewable energy system incorporating a hydrogen production unit to address the imbalance between energy supply and demand. The system utilizes renewable energy and hydrogen production energy to release energy to fill the power gap during peak demand power supply for demand peaking and valley filling. The system is optimized by analyzing marine predator behavioral logic and optimizing the system for maximum operational efficiency and best economic value. The results of the study show that after the optimized scheduling of the hydrogen production coupled renewable energy integrated energy system using the improved marine predator optimization algorithm the energy distribution of the whole energy system is good with the primary energy saving rate maintained at 24.75% the CO2 emission reduction rate maintained at 42.32% and the cost saving rate maintained at 0.78%. In addition this paper uses the Adaboost-BP prediction model to predictively analyze the system. The results show that as the price of natural gas increases the advantages of the combined hydrogen production renewable integrated energy system proposed in this paper become more obvious and the cumulative cost over three years is better than other related systems. These research results provide an important reference for the application and development of the system.

Hydrogen fuel has shown promise as a clean alternative fuel aiding in the reduction of fossil fuel dependence within the transportation sector. However hydrogen refueling stations and infrastructure remains a barrier and are a prerequisite for consumer adoption of low-cost and low-emission fuel cell electric vehicles (FCEVs). The costs for FCEV fueling include both station capital costs and operation and maintenance (O&M) costs. Contributing to these O&M costs unscheduled maintenance is presently more costly and more frequent than for similar gasoline fueling infrastructure and is asserted to be a limiting factor in achieving FCEV customer acceptance and cost parity. Unscheduled maintenance leads to longer station downtime therefore causing an increase in missed fueling opportunities which forces customers to seek refueling at other operable stations that may be significantly farther away. This research proposes a framework for a hydrogen station prognostics health monitoring (H2S PHM) model that can minimize unexpected downtime by predicting the remaining useful life for primary hydrogen station components within the major station subsystems. The H2S PHM model is a data-driven statistical model based on O&M data collected from 34 retail hydrogen stations located in the U.S. The primary subcomponents studied are the dispenser compressor and chiller. The remaining useful life calculations are used to decide whether or not maintenance should be completed based on the prediction and expected future station use. This paper presents the background method and results for the H2S PHM model as for a means for improving station availability and customer confidence in FCEVs and hydrogen infrastructure

This article presents a comprehensive description of the safety system of a real installation that comprises PV panels lithium-ion batteries an electrolyzer H2 storage a fuel cell and a barium chloride/ammonia thermochemical prototype for heat recovery and cooling production. Such a system allows for the increase of the overall efficiency of the H2 chain by exploiting the waste heat and transforming it into a cooling effect particularly useful in tropical regions like French Polynesia. The study provides a great deal of detail regarding practical aspects of the system implementation and a consistent reference to the relevant standards and regulations applicable to the subject matter. More specifically the study covers the ATEX classification of the site the safety features of each component the electrical power distribution the main safety instrumented system fire safety and the force ventilation system. The study also includes safety assessment and a section on lessons learned that could serve as guidance for future installations. In addition an extensive amount of technical data is readily available to the reader in repository (P&ID electrical diagrams etc.).

The shipping sector is facing increasing pressure to implement clean fuels and drivetrains. Especially hydrogen fuel cell drivetrains seem attractive. Although several studies have been conducted to assess the carbon footprint of hydrogen and its application in ships their results remain hard to interpret and compare. Namely it is necessary to include a variety of drivetrain solutions and different studies are based on various assumptions and are expressed in other units. This paper addresses this problem by offering a three-step meta-review of life cycle assessment studies. First a literature review was conducted. Second results from the literature were harmonized to make the different analyses comparable serving cross-examination. The entire life cycle of both the fuels and drivetrains were included. The results showed that the dominant impact was fuel use and related fuel production. And finally life-cycle hot spots have been identified by looking at the effect of specific configurations in more detail. Hydrogen production by electrolysis powered by wind has the most negligible impact. For this ultra-low carbon pathway the modes of hydrogen transport and the use of specific materials and components become relevant.

This study identifies supply options for sustainable urban energy systems which are robust to external system changes. A multi-criteria optimization model is used to minimize greenhouse gas (GHG) emissions and financial costs of a reference system. Sensitivity analyses examine the impact of changing boundary conditions related to GHG emissions energy prices energy demands and population density. Options that align with both financial and emission reduction and are robust to system changes are called “no-regret” options. Options sensitive to system changes are labeled as “potential-risk” options.<br/>There is a conflict between minimizing GHG emissions and financial costs. In the reference case the emission-optimized scenario enables a reduction of GHG emissions (-93%) but involves higher costs (+160%) compared to the financially-optimized scenario.<br/>No-regret options include photovoltaic systems decentralized heat pumps thermal storages electricity exchange between sub-systems and with higher-level systems and reducing energy demands through building insulation behavioral changes or the decrease of living space per inhabitant. Potential-risk options include solar thermal systems natural gas technologies high-capacity battery storages and hydrogen for buildiing energy supply.<br/>When energy prices rise financially-optimized systems approach the least-emission system design. The maximum profitability of natural gas technologies was already reached before the 2022 European energy crisis.

The pressing global challenge of climate change necessitates a concerted effort to limit greenhouse gas emissions particularly carbon dioxide. A critical pathway is to replace fossil fuel sources by electrification including transportation. While electrification of light-duty vehicles is rapidly expanding the heavy-duty vehicle sector is subject to challenges notably the logistical drawbacks of the size and weight of high-capacity batteries required for range as well as the time for battery charging. This Perspective highlights the potential of hydrogen fuel-cell vehicles as a viable alternative for heavy-duty road transportation. We evaluate the implications of hydrogen integration into the freight economy energy dynamics and CO2 mitigation and envision a roadmap for a holistic energy transition. Our critical opinion presented in this Perspective is that federal incentives to produce hydrogen could foster growth in the nascent hydrogen economy. The pathway that we propose is that initial focus on operators of large fleets that could control their own fueling infrastructure. This opinion was formed from private discussions with numerous stakeholders during the formation of one of the awarded hydrogen hubs if they focus on early adopters that could leverage the hydrogen supply chain.

A wide range of aircraft propulsion technologies is being investigated in current research to reduce the environmental impact of commercial aviation. As the implementation of purely hydrogenpowered aircraft may encounter various challenges on the airport and vehicle side combined hydrogen and kerosene energy sources may act as an enabler for the first operations with liquid hydrogen propulsion technologies. The presented studies describe the conceptual design of such a dual-fuel regional aircraft featuring a retrofit derived from the D328eco under development by Deutsche Aircraft. By electrically assisting the sustainable aviation fuel (SAF) burning conventional turboprop engines with the power of high-temperature polymer-electrolyte fuel cells the powertrain architecture enables a reduction of SAF consumption. All aircraft were modeled and investigated using the Bauhaus Luftfahrt Aircraft Design Environment. A description of this design platform and the incorporated methods to model the hydrogen-hybrid powertrain is given. Special emphasis was laid on the implications of the hydrogen and SAF dual-fuel system design to be able to assess the potential benefits and drawbacks of various configurations with the required level of detail. Retrofit assumptions were applied particularly retaining the maximum takeoff mass while reducing payload to account for the propulsion system mass increase. A fuel cell power allocation of 20% led to a substantial 12.9% SAF consumption decrease. Nonetheless this enhancement necessitated an 18.1% payload reduction accompanied by a 34.5% increment in propulsion system mass. Various additional studies were performed to assess the influence of the power split. Under the given assumptions the design of such a retrofit was deemed viable.

Battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) whose exhaust pipes emit nothing are examples of zero-emission automobiles. FCEVs should be considered an additional technology that will help battery-powered vehicles to reach the aspirational goal of zero-emissions electric mobility particularly in situations where the customers demand for longer driving ranges and where using batteries would be insufficient due to bulky battery trays and time-consuming recharging. This study stipulates a current evaluation of the status of development and challenges related to (i) research gap to promote fuel-cell based HEVs (ii) key barriers of fuel-cell based HEVs (iii) advancement of electric mobility and their power drive (iv) electrochemistry of fuel cell technology for FCEVs (v) power transformation topologies communication protocols and advanced charging methods (vi) recommendations and future prospects of fuel-cell HEVs and (vii) current research trends of EVs and FCEVs. This article discusses key challenges with fuel cell electric mobility such as low fuel cell performance cold starts problems with hydrogen storage cost-reduction safety concerns and traction systems. The operating characteristics and applications of several fuel-cell technologies are investigated for FCEVs and FCHEVs. An overview of the fuel cell is provided which serves as the primary source of energy for FCHEVs along with comparisons and its electrochemistry. The study of power transformation topologies communication protocols and enhanced charging techniques for FCHEVs has been studied analytically. Recent technology advancements and the prospects for FCHEVs are discussed in order to influence the future vehicle market and to attain the aim of zero emissions.