Canada

This paper investigates an integrated system where solar energy system (with 75MWp bifacial PV arrays) and nuclear power plant (with 2×10MWt HTR-10 type pebble bed reactors) are hybridized and integrated with a 72MWe capacity high-temperature solid oxide electrolysis (SOE) unit to produce hydrogen fresh water and electrical power. Bifacial PV plant is integrated to system for supplying electricity with a low LCOE and zero-carbon system. A Rankine cycle is integrated to generate power from the steam that generated from nuclear heat. According to the available irradiance; the steam is diverted between steam turbine and high-temperature electrolyzer for hydrogen and power generation. Multi-effect desalination unit is integrated to exploit the excess heat to generate fresh water. A system performance assessment is carried out by energy and exergy efficiencies thermodynamically. The bifacial PV plant is analyzed in six selected latitudes in order to assess the feasibility and applicability of the system. Numerous time-dependent analyses are carried out to study the effects of varying inputs such as solar radiation intensity. For 20MWt nuclear 75MWp solar capacity; hydrogen productions are found to be between 0.036 and 0.562kg/s. Among the Northern Hemisphere latitudes the peak daily hydrogen production rate is expected to reach 25.9 tons of hydrogen per day for the 75 °N case mostly with the influence of low temperature and high albedo. The pitch distance change is increased the hydrogen production rate by 28% between 3 m and 7 m tracker spacing. The overall system energy efficiency is obtained between 21.8% and 24.2% where the overall system exergy efficiency is found between 18.6% and 21.1% under dynamic conditions for the 45°N latitude case.

In this paper we report the effect of adding Zr + V or Zr + V + Mn to TiFe alloy on microstructure and hydrogen storage properties. The addition of only V was not enough to produce a minimum amount of secondary phase and therefore the first hydrogenation at room temperature under a hydrogen pressure of 20 bars was impossible. When 2 wt.% Zr + 2 wt.% V or 2 wt.% Zr + 2 wt.% V + 2 wt.% Mn is added to TiFe the alloy shows a finely distributed Ti₂Fe-like secondary phase. These alloys presented a fast first hydrogenation and a high capacity. The rate-limiting step was found to be 3D growth diffusion controlled with decreasing interface velocity. This is consistent with the hypothesis that the fast reaction is likely to be the presence of Ti₂Fe-like secondary phases that act as a gateway for hydrogen.

Mg-based materials are one of the most promising hydrogen storage candidates due to their high hydrogen storage capacity environmental benignity and high Clarke number characteristics. However the limited thermodynamics and kinetic properties pose major challenges for their engineering applications. Herein we review the recent progress in improving their thermodynamics and kinetics with an emphasis on the models and the influence of various parameters in the calculated models. Subsequently the impact of alloying composite and nano-crystallization on both thermodynamics and dynamics are discussed in detail. In particular the correlation between various modification strategies and the hydrogen capacity dehydrogenation enthalpy and temperature hydriding/dehydriding rates are summarized. In addition the mechanism of hydrogen storage processes of Mg-based materials is discussed from the aspect of classical kinetic theories and microscope hydrogen transferring behavior. This review concludes with an outlook on the remaining challenge issues and prospects.

In recent years the need to reduce environmental impacts and increase flexibility in the energy sector has led to increased penetration of renewable energy sources and the shift from concentrated to decentralized generation. A fuel cell is an instrument that produces electricity by chemical reaction. Fuel cells are a promising technology for ultimate energy conversion and energy generation. We see that this system is integrated where we find that the wind and photovoltaic energy system is complementary between them because not all days are sunny windy or night so we see that this system has higher reliability to provide continuous generation. At low load hours PV and electrolysis units produce extra power. After being compressed hydrogen is stored in tanks. The purpose of this study is to separate the Bahr AL-Najaf Area from the main power grid and make it an independent network by itself. The PEM fuel cells were analyzed and designed and it were found that one layer is equal to 570.96 Watt at 0.61 volts and 1.04 A/Cm2 . The number of layers in one stack is designed to be equal to 13 layers so that the total power of one stack is equal to 7422.48 Watt. That is the number of stacks required to generate the required energy from the fuel cells is equal to 203 stk. This study provided an analysis of the hybrid system to cover the electricity demand in the Bahr AL-Najaf region of 1.5 MW the attained hybrid power system TNPC cost was about 9573208 USD whereas the capital cost and energy cost (COE) were about 7750000 USD and 0.169 USD/kWh respectively for one year.

Interest in hydrogen as an energy carrier is growing as countries look to reduce greenhouse gas (GHG) emissions in hard-to-abate sectors. Previous works have focused on hydrogen production well-to-wheel analysis of fuel cell vehicles and vehicle refuelling costs and emissions. These studies use high-level estimates for the hydrogen transportation systems that lack sufficient granularity for techno-economic and GHG emissions analysis. In this work we assess and compare the unit costs and emission footprints (direct and indirect) of 32 systems for hydrogen transportation. Process-based models were used to examine the transportation of pure hydrogen (hydrogen pipeline and truck transport of gaseous and liquified hydrogen) hydrogen-natural gas blends (pipeline) ammonia (pipeline) and liquid organic hydrogen carriers (pipeline and rail). We used sensitivity and uncertainty analyses to determine the parameters impacting the cost and emission estimates. At 1000 km the pure hydrogen pipelines have a levelized cost of $0.66/kg H2 and a GHG footprint of 595 gCO2eq/kg H2. At 1000 km ammonia liquid organic hydrogen carrier and truck transport scenarios are more than twice as expensive as pure hydrogen pipeline and hythane and more than 1.5 times as expensive at 3000 km. The GHG emission footprints of pure hydrogen pipeline transport and ammonia transport are comparable whereas all other transport systems are more than twice as high. These results may be informative for government agencies developing policies around clean hydrogen internationally.

A methodology for assessing the sustainability of hydrogen production using solid fuels is introduced in which three sustainability dimensions (ecological sociological and technological) are considered along with ten indicators for each dimension. Values for each indicator are assigned on a 10-point scale based on a high of 1 and a low of 0 depending on the characteristic of the criteria associated with each element or process utilizing data reported in the literature. An illustrative example is presented to compare two solid fuels for hydrogen production: coal and biomass. The results suggest that qualitative sustainability indicators can be reasonably defined based on evaluations of system feasibility and that adequate flexibility and comprehensiveness is provided through the use of ten indicators for each of the dimensions for every process or element involved in hydrogen production using solid fuels. Also the assessment index values suggest that biomasses have better sustainability than coals and that it may be advantageous to use coals in combination with biomass to increase their ecological and social sustainability. The sustainability assessment methodology can be made increasingly quantitative and is likely extendable to other energy systems but additional research and development is needed to lead to a more fully developed approach.

North American and European jurisdictions are considering repurposing natural gas infrastructure to deliver a lower carbon blend of natural gas and hydrogen; this paper evaluates the greenhouse gas reduction potential and cost-effectiveness of the repurposing. The analysis uses a bottom-up economy-wide energy-systems model of an emission-intensive jurisdiction Alberta Canada to evaluate 576 long-term scenarios from 2026 to 2050. Many scenarios were included to give the analysis broad international applicability and differ by sector hydrogen blending intensity carbon policy and hydrogen infrastructure development. Twelve hydrogen production technologies are compared in a long-term greenhouse gas and cost analysis including advanced technologies. Autothermal reforming with carbon capture provides both lower-carbon and lower-cost hydrogen compared to most other technologies in most futures even with high fugitive natural gas production emissions. Using hydrogen-natural gas blends for end-use energy applications eliminates 1–2% of economy-wide GHG emissions and marginal GHG abatement costs become negative at carbon prices over $300/tonne. The findings are useful for stakeholders expanding the international low-carbon hydrogen economy and governments engaged in formulating decarbonization policies and are considering hydrogen as an option.

This paper aims to holistically study hydrogen production options essential for a sustainable and carbon-free future. This study also outlines the benefits and challenges of hydrogen production methods to provide sustainable alternatives to fossil fuels by meeting the global energy demand and net-zero targets. In this study sixteen hydrogen production methods are selected for sustainability investigation based on seven different criteria. The criteria selected in the comparative evaluation cover various dimensions of hydrogen production in terms of economic technical environmental and thermodynamic aspects for better sustainability. The current study results show that steam methane reforming with carbon capture could provide sustainable hydrogen in the near future while the other technologies’ maturity levels increase and the costs decrease. In the medium- and long-terms photonic and thermal-based hydrogen production methods can be the key to sustainable hydrogen production.

This review critically analyses various aspects of the most promising thermochemical cycles for clean hydrogen production. While the current hydrogen market heavily relies on fossil-fuel-based platforms the thermochemical water-splitting systems based on the reduction-oxidation (redox) looping reactions have a significant potential to significantly contribute to the sustainable production of green hydrogen at scale. However compared to the water electrolysis techniques the thermochemical cycles suffer from a low technology readiness level (TRL) which retards the commercial implementation of these technologies. This review mainly focuses on identifying the capability of the state-of-the-art thermochemical cycles to deploy large-scale hydrogen production plants and their techno-economic performance. This study also analyzed the potential integration of the hybrid looping systems with the solar and nuclear reactor designs which are evidenced to be more cost-effective than the electrochemical water-splitting methods but it excludes fossil-based thermochemical processes such as gasification steam methane reforming and pyrolysis. Further investigation is still required to address the technical issues associated with implementing the hybrid thermochemical cycles in order to bring them to the market for sustainable hydrogen production.

Anode recirculation with periodic purge is commonly used in polymer electrolyte fuel cell systems to control the accumulation of nitrogen water and other impurities that are present in the fuel or diffuse through the membrane from the cathode compartment. In this work we develop a simple generalized analytical model that simulates the time dependence of the accumulation of inert impurities in the anode compartment of such a system. It is shown that when there is transport out of the anode chamber the inert species is expected to accumulate exponentially until equilibrium is reached when the rate of inert entering the anode in the fuel supply and/or via crossover from the cathode is balanced by the rate of leakage and/or crossover to the cathode. The model is validated using recently published experimental data for the accumulation of N2 CH4 and CO2 in a recirculated system. The results show that nitrogen accumulation needs to be taken into account to properly adjust system parameters such as purge rate purge volume and recirculation rate. The use of this generalized analytical model is intended to aid the selection of these system parameters to optimize performance in the presence of inerts.

Hydrogen combustion inside a post-accident nuclear reactor containment may pose a challenge to the containment integrity which could alter the fission-product release source term to the public. Combustion-generated overpressures may be relieved by venting to adjacent compartments through relief panels or existing openings. Thus an improved understanding of the propagation of lean hydrogen deflagrations in inter-connected compartments is essential for the development of appropriate management strategies. GOTHIC is a general purpose lumped parameter thermal-hydraulic code for solving multi-phase compressible flows which is accepted as an industry-standard code for containment safety analyses. Following the Fukushima accident the application of three-dimensional computational fluid dynamics methods to high-fidelity detailed analysis of hydrogen combustion processes has become more widespread. In this study a recently developed large-eddy-simulation (LES) capability is applied to the prediction of lean premixed hydrogen deflagrations in large-scale vented vessels of various configurations. The LES predictions are compared with GOTHIC predictions and experimental data obtained from the large-scale vented combustion test facility at the Canadian Nuclear Laboratories. The LES methodology makes use of a flamelet- or a progress-variable-based combustion model. An empirical burning velocity model is combined with an advanced finite-volume framework and a mesh-independent subfilter-scale model. Descriptions of the LES and GOTHIC modelling approaches used to simulate the hydrogen reactive flows in the vented vessels along with the experimental data sets are given. The potential and limitations of the lumped parameter and LES approaches for accurately describing lean premixed hydrogen deflagrations in vented vessels are discussed.

As result of the adverse effects caused by climate change the nations have decided to accelerate the transition of the energy matrix through the use of non-conventional sources free of polluting emissions. One of these alternatives is green hydrogen. In this context Chile stands out for the exceptional climate that makes it a country with a lot of renewable resources. Such availability of resources gives the nation clear advantages for hydrogen production strong gusts of wind throughout the country the most increased solar radiation in the world lower cost of production of electrical supplies among others. Due to this the nation would be between the lowest estimated cost for hydrogen production i.e. 1.5 USD/kg H2 approximately scenario that would place it as one of the cheapest green hydrogen producer in the world.

Hydrogen vehicles encompassing fuel cell electric vehicles (FCEVs) are pivotal within the UK’s energy landscape as it pursues the goal of net-zero emissions by 2050. By markedly diminishing dependence on fossil fuels FCEVs including hydrogen vehicles wield substantial influence in shaping the circular economy (CE). Their impact extends to optimizing resource utilization enabling zero-emission mobility facilitating the integration of renewable energy sources supplying adaptable energy storage solutions and interconnecting diverse sectors. The widespread adoption of hydrogen vehicles accelerates the UK’s transformative journey towards a sustainable CE. However to fully harness the benefits of this transition a robust investigation and implementation of safety measures concerning hydrogen vehicle (HV) use are indispensable. Therefore this study takes a holistic approach integrating quantitative risk assessment (QRA) and an adaptive decision-making trial and evaluation laboratory (DEMATEL) framework as pragmatic instruments. These methodologies ensure both the secure deployment and operational excellence of HVs. The findings underscore that the root causes of HV failures encompass extreme environments material defects fuel cell damage delivery system impairment and storage system deterioration. Furthermore critical driving factors for effective safety intervention revolve around cultivating a safety culture robust education/training and sound maintenance scheduling. Addressing these factors is pivotal for creating an environment conducive to mitigating safety and risk concerns. Given the intricacies of conducting comprehensive hydrogen QRAs due to the absence of specific reliability data this study dedicates attention to rectifying this gap. A sensitivity analysis encompassing a range of values is meticulously conducted to affirm the strength and reliability of our approach. This robust analysis yields precise dependable outcomes. Consequently decision-makers are equipped to discern pivotal underlying factors precipitating potential HV failures. With this discernment they can tailor safety interventions that lay the groundwork for sustainable resilient and secure HV operations. Our study navigates the intersection of HVs safety and sustainability amplifying their importance within the CE paradigm. Using the careful amalgamation of QRA and DEMATEL methodologies we chart a course towards empowering decision-makers with the insights to steer the hydrogen vehicle domain to safer horizons while ushering in an era of transformative eco-conscious mobility.

This study presents an enhancement to the Switch optimization model for hydrogen energy planning by integrating the capability to consider the construction and operation of hydrogen electrolysis plants and the operation of water distribution systems. This integration was achieved through the addition of two new modules and their effectiveness is demonstrated through their application in a case study for Durham region. The study highlights the significance of incorporating water distribution systems into energy planning demonstrating how optimal locations for hydrogen plants can significantly influence water and power demand as well as alter the total operating costs. The enhanced Switch model showcases its improved capability to assist policymakers and stakeholders in transitioning towards a sustainable energy future.

Based on the concept of sustainable development to promote the development and application of renewable energy and enhance the capacity of renewable energy consumption this paper studies the design and optimization of renewable energy hydrogen production systems. For this paper six different scenarios for grid-connected and off-grid renewable energy hydrogen production systems were designed and analyzed economically and technically and the optimal grid-connected and off-grid systems were selected. Subsequently the optimal system solution was optimized by analyzing the impact of the load data and component capacity on the grid dependency of the grid-connected hydrogen production system and the excess power rate of the off-grid hydrogen production system. Based on the simulation results the most matched load data and component capacity of different systems after optimization were determined. The grid-supplied power of the optimized grid-connected hydrogen production system decreased by 3347 kWh and the excess power rate of the off-grid hydrogen production system decreased from 38.6% to 10.3% resulting in a significant improvement in the technical and economic performance of the system.

Hydrogen is gaining prominence as a sustainable energy source in the UK aligning with the country’s commitment to advancing sustainable development across diverse sectors. However a rigorous examination of the interplay between the hydrogen economy and the Sustainable Development Goals (SDGs) is imperative. This study addresses this imperative by comprehensively assessing the risks associated with hydrogen production storage transportation and utilization. The overarching aim is to establish a robust framework that ensures the secure deployment and operation of hydrogen-based technologies within the UK’s sustainable development trajectory. Considering the unique characteristics of the UK’s energy landscape infrastructure and policy framework this paper presents practical and viable recommendations to facilitate the safe and effective integration of hydrogen energy into the UK’s SDGs. To facilitate sophisticated decision making it proposes using an advanced Decision-Making Trial and Evaluation Laboratory (DEMATEL) tool incorporating regret theory and a 2-tuple spherical linguistic environment. This tool enables a nuanced decision-making process yielding actionable insights. The analysis reveals that Incident Reporting and Learning Robust Regulatory Framework Safety Standards and Codes are pivotal safety factors. At the same time Clean Energy Access Climate Action and Industry Innovation and Infrastructure are identified as the most influential SDGs. This information provides valuable guidance for policymakers industry stakeholders and regulators. It empowers them to make well-informed strategic decisions and prioritize actions that bolster safety and sustainable development as the UK transitions towards a hydrogen-based energy system. Moreover the findings underscore the varying degrees of prominence among different SDGs. Notably SDG 13 (Climate Action) exhibits relatively lower overall distinction at 0.0066 and a Relation value of 0.0512 albeit with a substantial impact. In contrast SDG 7 (Clean Energy Access) and SDG 9 (Industry Innovation and Infrastructure) demonstrate moderate prominence levels (0.0559 and 0.0498 respectively) each with its unique influence emphasizing their critical roles in the UK’s pursuit of a sustainable hydrogen-based energy future.

Aerospace parts made of high strength steels such as landing gears and helicopter transmissions are often electroplated to satisfy various engineering specifications. However plated parts are occasionnaly rejected because of hydrogen embrittlement and the industry has few means of evaluating quantitatively the actual damage caused by hydrogen. In the present article we developed a novel method to measure the stress intensity threshold for hydrogen embrittlement (Kth) in industrial plating conditions. The method consists in plating side-grooved CT samples in industrial plating baths and measuring Kth with an incremental step loading methodology. We validated the method with a benchmark case known to produce embrittlement (omitted post-plating bake) and we used the method on a test case for which the level of embrittlement was unknown (delayed bake). For the benchmark case we measured a Kth of 49.0 MPa m0.5 for non-baked samples. This value is significantly lower than the fracture toughness of the unplated material which is 63.8 MPa m0.5 . We conclude that this novel combination of geometry and test method is efficient in quantifying hydrogen embrittlement of samples plated in industrial conditions. For the test case the Kth are respectively 57.9 MPa m0.5 and 58.8 MPa m0.5 for samples baked 100 h and 4 h after plating. We conclude that delaying the post-plating bake does not cause hydrogen embrittlement in the studied conditions. Using a finite element hydrogen diffusion analysis we argue that the side grooves on CT samples increase the sensitivity to hydrogen embrittlement in comparison to smooth samples. In smooth samples a zone of plane stress at the surface of the specimen shields hydrogen from penetrating to the center of the specimen a phenomenon which is alleviated with machining side grooves.

A process where power and biomass are converted to Fischer-Tropsch liquid fuels (PBtL) is compared to a conventional Biomass-to-Liquid (BtL) process concept. Based on detailed process models it is demonstrated that the carbon efficiency of a conventional Biomass to Liquid process can be increased from 38 to more than 90% by adding hydrogen from renewable energy sources. This means that the amount of fuel can be increased by a factor of 2.4 with the same amount of biomass. Electrical power is applied to split water/steam at high temperature over solid oxide electrolysis cells (SOEC). This technology is selected because part of the required energy can be replaced by available heat. The required electrical power for the extra production is estimated to be 11.6 kWh per liter syncrude (C ) 5+ . By operating the SOEC iso-thermally close to 850 °C the electric energy may be reduced to 9.5 kWh per liter which is close to the energy density of jet fuel. A techno-economic analysis is performed where the total investments and operating costs are compared for the BtL and PBtL. With an electrical power price of 0.05 $/kWh and with SOEC investment cost of the 1000 $/kW(el) the levelized cost of producing advanced biofuel with the PBtL concept is 1.7 $/liter which is approximately 30% lower than for the conventional BtL. Converting excess renewable electric power to advanced biofuel in a PBtL plant is a sensible way of storing energy as a fuel with a relatively high energy density.

Environmental issues related to greenhouse gases (GHG) emissions have pushed the development of new technologies that will allow the economic production of low-carbon energy vectors such as hydrogen (H2 ) methane (CH4 ) and liquid fuels. Dry reforming of methane (DRM) has gained increased attention since it uses CH4 and carbon dioxide (CO2 ) which are two main greenhouse gases (GHG) as feedstock for the production of syngas which is a mixture of H2 and carbon monoxide (CO) and can be used as a building block for the production of fuels. Since H2 has been identified as a key enabler of the energy transition a lot of studies have aimed to benefit from the environmental advantages of DRM and to use it as a pathway for a sustainable H2 production. However there are several challenges related to this process and to its use for H2 production such as catalyst deactivation and the low H2/CO ratio of the syngas produced which is usually below 1.0. This paper presents the recent advances in the catalyst development for H2 production via DRM the processes that could be combined with DRM to overcome these challenges and the current industrial processes using DRM. The objective is to assess in which conditions DRM could be used for H2 production and the gaps in literature data preventing better evaluation of the environmental and economic potential of this process.

Electrolytic hydrogen produced from wind and solar energy is considered a long-term option for multi-sectoral decarbonization. The study objective is to develop a framework for assessing country-level hydrogen technical potential from wind and solar energy. We apply locational suitability and zonal statistical analyses methods in a geographic information system-based environment to derive granular insights on non-captive technically exploitable hydrogen potential in high-resource locations. Seven setback factors were considered for locational suitability and integrated with modules developed for evaluating the wind and solar resource penetration from open-source theoretical renewable resource geospatial data and electricity-to-hydrogen conversion analyses. The technique applied in this study would be a relevant contribution to determining national and regional-wide electrolytic hydrogen production potentials in other jurisdictions with requisite adjustments to data and technical constraints. The results from the case study country Canada – a major hydrogen-producing country – show that the technical hydrogen potentials from wind and solar energy are approximately 1897 and 448 million metric tonnes per year respectively at least 6.3 times greater than global hydrogen demand in 2019. When we integrated locational data on enabling infrastructure we discovered that the lack of access to power transmission lines in low-population-density areas of the country significantly reduces the exploitable wind- and solar-based hydrogen potential by over 80% and 6% respectively. The findings of this study show that in the absence of spatial data on infrastructural constraints the exploitable hydrogen potential in a jurisdiction can be overestimated leading to improper guidance for policy and decision-makers.

Severe accidents in nuclear power plants are potentially dangerous to both humans and the environment. To prevent and/or mitigate the consequences of these accidents it is paramount to have adequate accident management measures in place. During a severe accident combustible gases — especially hydrogen and carbon monoxide — can be released in significant amounts leading to a potential explosion risk in the nuclear containment building. These gases need to be managed to avoid threatening the containment integrity which can result in the releases of radioactive material into the environment. The main objective of the AMHYCO project is to propose innovative enhancements in the way combustible gases are managed in case of a severe accident in currently operating reactors. For this purpose the AMHYCO project pursues three specific activities including experimental investigations of relevant phenomena related to hydrogen / carbon monoxide combustion and mitigation with PARs (Passive Autocatalytic Recombiners) improvement of the predictive capabilities of analysis tools used for explosion hazard evaluation inside the reactor containment as well as enhancement of the Severe Accident Management Guidelines (SAMGs) with respect to combustible gases risk management based on theoretical and experimental results. Officially launched on 1 October 2020 AMHYCO is an EU-funded Horizon 2020 project that will last 4 years from 2020 to 2024. This international project consists of 12 organizations (six from European countries and one from Canada) and is led by the Universidad Politécnica de Madrid (UPM). AMHYCO will benefit from the worldwide experts in combustion science accident management and nuclear safety in its Advisory Board. The paper will give an overview of the work program and planned outcome of the project.

The MC method refuelling protocol in SAE J2601 has been published by the Society of Automotive Engineers (SAE) in order to safely and quickly refuel hydrogen vehicles. For the calculation method of the pressure target to control the refuelling stop we introduced a dual-zone dual-temperature model that distinguishes the hydrogen temperature in the tank from the wall temperature to replace the dual-zone single-temperature model of the original MC method. The total amount of heat transferred by convection between hydrogen and the inner tank wall during the filling process was expressed as an equation of final hydrogen temperature final wall temperature final refuelling time tank inner surface area and the correction factor. The correction factor equations were determined by fitting simulation data from the 0D1D model where hydrogen inside the tank is lumped parameter model (0D) and the tank wall is a one-dimensional model (1D). For the correction factor of the linear equation its first-order coefficient and constant term have a linear relationship with the initial pressure of the storage tank and their R2 values obtained from the fitting are greater than 0.99. Finally we derived a new equation to calculate the final hydrogen temperature which can be combined with the 100% SOC inside the vehicle tank to determine the pressure target. The simulation results show that the final SOC obtained are all greater than 96% using the modified pressure target and the correction factor of the linear equation.

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.

Due to the increase in electric energy consumption and the significant growth in the number of electric vehicles (EV) at the level of the distribution network new networks have started using new fuels such as hydrogen to improve environmental indicators and at the same time better efficiency from the excess capacity of renewable resources. In this article the services that can be provided by hydrogen refueling stations and charging electric vehicles in the optimal performance of microgrids have been investigated. The model proposed in this paper includes a two-stage stochastic framework for scheduling resources in microgrids especially hydrogen refueling stations and electric vehicle charging. In this model two main goals of cost minimization and greenhouse gas emissions are considered. In the proposed framework and in the first stage the service range of microgrids is determined precisely according to the electrical limitations of distribution systems in emergency situations. Then in the second stage the problem of energy management in each microgrid will be solved centrally. In this situation various indicators including the output energy of renewable sources smart charging of hydrogen and electric vehicle charging stations (EV/FCV) and flexible loads (FL) are evaluated. The final mathematical model is implemented as a multivariate integer multiple linear problem (MILP) using the GUROBI solver in GAMS software. The simulation results on the modified IEEE 118-Bus network show the positive effect of the presence of flexible loads and smart charging strategies by charging stations. Also the numerical derivation shows that the operating costs of the entire system can be reduced by 4.77% and the use of smart charging strategies can reduce greenhouse gas emissions by 49.13%.

The world is rapidly adopting renewable energy alternatives at a remarkable rate to address the ever-increasing environmental crisis of CO2 emissions. Renewable Energy Systems (RES) offers enormous potential to decarbonize the environment because they produce no greenhouse gases or other polluting emissions. However the RES relies on natural resources for energy generation such as sunlight wind water geothermal which are generally unpredictable and reliant on weather season and year. To account for these intermittencies renewable energy can be stored using various techniques and then used in a consistent and controlled manner as needed. Several researchers from around the world have made substantial contributions over the last century to developing novel methods of energy storage that are efficient enough to meet increasing energy demand and technological break-throughs. This review attempts to provide a critical review of the advancements in the Energy Storage System (ESS) from 1850–2022 including its evolution classification operating principles and comparison

The shipping industry is a major enabler of globalization trade commerce and human welfare. But it is still heavily served by fossil fuels which make it one of the foremost greenhouse gas emitting sectors operational today. It is also one of the hardest to abate segments of the transport industry. As part of the economy-wide climate change mitigation and adaptation efforts it is necessary to consider a low carbon energy transition for this segment as well. This study examines the potential role of nuclear power and cogeneration towards greening this sector and identifies the associated techno-commercial and policy challenges associated with the transition. Quantitative estimates of the economics and investments associated with some of the possible routes are also presented. Alternatives such as nuclear-powered ships along commercial maritime trading routes ships working on nuclear derived green hydrogen ammonia or other sustainable power fuels will enable not only decarbonization of the shipping industry but also allow further diversification of the nuclear industry through non-electric applications of nuclear power and new sector coupling opportunities. In the run-up to the UNFCCC-COP28 meeting in 2023 in UAE nuclear equipped nations heavily engaged in and dependent on maritime trade and commerce should definitely consider nuclear driven decarbonization of shipping and some of the options presented here as part of their climate action strategies.

Hydrogen recombiners are catalyst-based hydrogen mitigation systems that have been successfully implemented in the nuclear industry but have not yet received serious interest from the hydrogen industry. Recombiners have been installed in the containment buildings of many nuclear power plants to prevent the accumulation of hydrogen in potential accidents. The attractiveness of hydrogen recombiners for the nuclear industry is due to the confined state of the containment building where hydrogen cannot be vented easily and its passive design where no power or actions are needed for the unit to operate. Alternatively in the hydrogen industry most applications utilize ventilation to mitigate potential hydrogen accumulation in confined areas and passive safety is not essential. However many applications in the hydrogen industry may utilize hydrogen recombiners from a different approach. For instance recombiners could be utilized in emerging hydrogen areas to minimize the costs of ventilation upgrades or built into hydrogen appliances to avoid vent connections. The potential applications for recombiners in the hydrogen industry have different atmospheric conditions than the nuclear industry which may impact the catalyst in the units and render them less effective. Thus experiments have been performed to investigate the limits of the recombiner catalyst and if modifications to the catalyst can extend their use to the hydrogen industry. This paper will present and discuss the applications of interest conditions that may affect the catalyst and results from experiments investigating the catalyst behaviour at temperatures less than 0 °C and carbon monoxide concentrations up to 1000 ppm.

The impact of ship emission reductions can be maximised by considering climate health and environmental effects simultaneously and using solutions fitting into existing marine engines and infrastructure. Several options available enable selecting optimum solutions for different ships routes and regions. Carbon-neutral fuels including low-carbon and carbon-negative fuels from biogenic or non-biogenic origin (biomass waste renewable hydrogen) could resemble current marine fuels (diesel-type methane and methanol). The carbon-neutrality of fuels depends on their Well-to-Wake (WtW) emissions of greenhouse gases (GHG) including carbon dioxide (CO2) methane (CH4) and nitrous oxide emissions (N2O). Additionally non-gaseous black carbon (BC) emissions have high global warming potential (GWP). Exhaust emissions which are harmful to health or the environment need to be equally removed using emission control achieved by fuel engine or exhaust aftertreatment technologies. Harmful emission species include nitrogen oxides (NOx) sulphur oxides (SOx) ammonia (NH3) formaldehyde particle mass (PM) and number emissions (PN). Particles may carry polyaromatic hydrocarbons (PAHs) and heavy metals which cause serious adverse health issues. Carbon-neutral fuels are typically sulphur-free enabling negligible SOx emissions and efficient exhaust aftertreatment technologies such as particle filtration. The combinations of carbon-neutral drop-in fuels and efficient emission control technologies would enable (near-)zero-emission shipping and these could be adaptable in the short- to mid-term. Substantial savings in external costs on society caused by ship emissions give arguments for regulations policies and investments needed to support this development.

The formation of green hydrogen from water electrolysis is one of the supreme methodologies for understanding the well-organized consumption of sporadic renewable energies and the carbon-free future. Among the different electrolysis techniques the evolving anion exchange membrane water electrolysis (AEMWE) shows the utmost promise for manufacturing green hydrogen in an inexpensive way. In the present review we establish the most current and noteworthy achievements of AEMWE which include the advancements in increasing the ionic conductivity and understanding the mechanism of degradation of AEM and the most important topics regarding the designing of the electrocatalyst. The crucial issues that affect the AEMWE behavior are highlighted and future constraints and openings are also discussed. Furthermore this review article provides the appreciated strategies for producing extremely dynamic and robust electrocatalysts and evolving the construction of AEMWE equipment.

On the road towards greener aviation hybrid-electric propulsion systems have emerged as a viable solution. In this paper a system based on hydrogen fuel cells is proposed and evaluated in a laboratory setting with its future integration in a propulsive system in mind and main focus on the ability to lessen the power demand on the opposing side of the bench. The setup consists in a parallel architecture with two power sources: a hydrogen fuel cell and a battery. First the performance of the fuel cell and its capability to provide power to one of the motors are analyzed. Then the entire parallel hybrid system is evaluated. Although the experimental setup was shown to be sub-optimal the results demonstrated the ability of this greener alternative to reduce power demand on the opposing side of the parallel configuration with a reduction of up to 40.3% in the highest load scenario and maximum power output on the fuel cell of 257.8 W. The stack performance was also concluded to be very dependent on the operating temperature.

Hydrogen is believed to be the future energy carrier that will reduce environmental pollution and solve the current energy crisis especially when produced from a renewable energy source. Solar energy is a renewable source that has been commonly utilized in the production process of hydrogen for years because it is inexhaustible clean and free. Generally hydrogen is produced by means of a water splitting process mainly electrolysis which requires energy input provided by harvesting solar energy. The proposed model integrates the solar harvesting system into a conventional Rankine cycle producing electrical and thermal power used in domestic applications and hydrogen by high temperature electrolysis (HTE) using a solid oxide steam electrolyzer (SOSE). The model is divided into three subsystems: the solar collector(s) the steam cycle and an electrolysis subsystem where the performance of each subsystem and their effect on the overall efficiency is evaluated thermodynamically using first and second laws. A parametric study investigating the hydrogen production rate upon varying system operating conditions (e.g. solar flux and area of solar collector) is conducted on both parabolic troughs and heliostat fields as potential solar energy harvesters. Results have shown that heliostat-based systems were able to attain optimum performance with an overall thermal efficiency of 27% and a hydrogen production rate of 0.411 kg/s whereas parabolic trough-based systems attained an overall thermal efficiency of 25.35% and produced 0.332 kg/s of hydrogen.

This paper presents an eco-technoeconomic analysis (eTEA) of hydrogen production via solid oxide electrolysis cells (SOECs) aimed at identifying the economically optimal size and operating trajectories for these cells. Notably degradation effects were accounted by employing a data-driven degradationbased model previously developed by our group for the analysis of SOECs. This model enabled the identification of the optimal trajectories under which SOECs can be economically operated over extended periods of time with reduced degradation rate. The findings indicated that the levelized cost of hydrogen (LCOH) produced by SOECs (ranging from 2.78 to 11.67 $/kg H2) is higher compared to gray hydrogen generated via steam methane reforming (SMR) (varying from 1.03 to 2.16 $ per kg H2) which is currently the dominant commercial process for large-scale hydrogen production. Additionally SOECs generally had lower life cycle CO2 emissions per kilogram of produced hydrogen (from 1.62 to 3.6 kg CO2 per kg H2) compared to SMR (10.72–15.86 kg CO2 per kg H2). However SOEC life cycle CO2 emissions are highly dependent on the CO2 emissions produced by its power source as SOECs powered by high-CO2-emission sources can produce as much as 32.22 kg CO2 per kg H2. Finally the findings of a sensitivity analysis indicated that the price of electricity has a greater influence on the LCOH than the capital cost.

Guidance on Sensor Placement remains one of the top priorities for the safe deployment of hydrogen and fuel cell equipment in the commercial marketplace. Building on the success of Phase l work reported at TCHS20l9 and published in TJHE this paper discusses the consecutive steps to further develop and validate such guidance for mechanically ventilated enclosures. The key step included a more in-depth analysis of sensitivity to variation of physical parameters in a small enclosure. and finally expansion of the developed approach to confined spaces in an outdoor environment.

Locomotives still use antiqued engines such as internal combustion engines operated by fossil fuels which cause global warming due to their significant emissions. This paper continues investigating the newly hybridized locomotive engine containing a gas turbine system solid oxide fuel cell system energy saving system and on-board hydrogen production system. This new engine is operated using five fuel blends composed of five alternative fuels such as hydrogen methane methanol ethanol and dimethyl ether. The current investigation involves exergy analysis exergo-economic analysis and exergo-environmental analysis to assess the engine from three perspectives: efficiency/irreversibility cost and environmental impact. The study results show that the net power of this new engine is 4948.6 kW and it has an exergetic efficiency of 62.7% according to the fuel and product principle. This engine weighs about 9 tons and costs about $10.2M with a levelized cost rate of 147 $/h and 14.06 mPt/h of overall component-related environmental rate. The average overall specific fuel and product exergy costs are about 37 $/GJ and 60 $/GJ and the minimum values are 13.3 $/GJ and 21.8 $/GJ using methane and hydrogen blend respectively. Also the average overall specific fuel and product exergo-environmental impact are about 15 and 23 mPt/MJ respectively. The on-board hydrogen production has an average exergy cost of 274 $/GJ and an environmental impact of 52 mPt/MJ. Hydrogen blended with methane or methanol is found to be more economic and has less environmental impact.

Northern countries face a unique challenge in decarbonizing heating demands. This study compares two pathways to reduce carbon emissions from building heating by (1) replacing natural gas heaters with electric heat pumps or (2) replacing natural gas with renewable gas. Optimal annual system cost and capacity requirements for Metro Vancouver Canada are assessed for each pathway under nine scenarios. Results show that either pathway can be lower cost but the range of costs is more narrow for the renewable gas pathway. System cost is sensitive to heat demand with colder temperatures favouring the renewable gas pathway and milder temperatures favouring the electrification pathway. These results highlight the need for a better understanding of heating profiles and associated energy system requirements.

A proton exchange membrane fuel cell (PEMFC) system requires an adequate hydrogen supply and circulation to achieve its expected performance and operating life. An ejector-based hydrogen circulation system can reduce the operating and maintenance costs noise and parasitic power consumption by eliminating the recirculation pump. However the ejector’s hydrogen entrainment capability restricted by its geometric parameters and flow control variability can only operate properly within a relatively narrow range of fuel cell output power. This research introduced the optimal design and operation control methods of a dual-ejector hydrogen supply/circulation system to support the full range of PEMFC system operations. The technique was demonstrated on a 70 kW PEMFC stack with an effective hydrogen entrainment ratio covering 8% to 100% of its output power. The optimal geometry design ensured each ejector covered a specific output power range with maximized entrainment capability. Furthermore the optimal control of hydrogen flow and the two ejectors’ opening and closing times minimized the anode gas pressure fluctuation and reduced the potential harm to the PEMFC’s operation life. The optimizations were based on dedicated computational fluid dynamics (CFD) and system dynamics models and simulations. Bench tests of the resulting ejector-based hydrogen supply/circulation system verified the simulation and optimization results.

The central aim of this paper is to provide an up-to-date snapshot of hybrid and hydrogen technology-related developments and activities in the North American heavy haul railway setting placed in the context of the transportation industry more broadly. An overview of relevant alternative propulsion technologies is provided including a discussion of applicability to the transportation sector in general and heavy haul freight rail specifically. This is followed by a discussion of current developments and research in alternative and blended fuels discussed again in both general and specific settings. Key factors and technical considerations for heavy haul applications are reviewed followed by a discussion of non-technical and human factors that motivate a move toward clean energy in North American Heavy Haul systems. Finally current project activities are described to provide a clear understanding of both the status and trajectory of hybrid and hydrogen technologies in the established context.

Hydrogen price significantly impacts its potential as a viable alternative in the sustainable energy transition. This study introduces a synergy-based Hydrogen Pricing Mechanism (HPM) within an integrated framework. The HPM leverages synergy between a Renewable-Penetrated Electric Power System (RP-EPS) and a Hydrogen Energy System (HES). Utilizing the Alternating Direction Method of Multipliers (ADMM) it facilitates data exchange quantifying integration levels and simplifying the complexities. The study assesses the HPM’s operational sensitivity across various scenarios of hydrogen generation transportation and storage. It also evaluates the benefits of synergy-based versus stand-alone HPMs. Findings indicate that the synergy-based HPM effectively integrates infrastructure and operational improvements from both EPS and HES leading to optimized hydrogen pricing.

Hydrogen embrittlement (HE) is a broadly recognized phenomenon in metallic materials. If not well understood and managed HE may lead to catastrophic environmental failures in vessels containing hydrogen such as pipelines and storage tanks. HE can affect the mechanical properties of materials such as ductility toughness and strength mainly through the interaction between metal defects and hydrogen. Various phenomena such as hydrogen adsorption hydrogen diffusion and hydrogen interactions with intrinsic trapping sites like dislocations voids grain boundaries and oxide/matrix interfaces are involved in this process. It is important to understand HE mechanisms to develop effective hydrogen resistant strategies. Tensile double cantilever beam bent beam and fatigue tests are among the most common techniques employed to study HE. This article reviews hydrogen diffusion behavior mechanisms and characterization techniques.

Hydrogen globally recognized as the most efficient and clean energy carrier holds the potential to transform future energy systems through its use as a fuel and chemical resource. Although progress has been made in reversible hydrogen adsorption and release challenges in storage continue to impede widespread adoption. This review explores recent advancements in hydrogen storage materials and synthesis methods emphasizing the role of nanotechnology and innovative synthesis techniques in enhancing storage performance and addressing these challenges to drive progress in the field. The review provides a comprehensive overview of various material classes including metal hydrides complex hydrides carbon materials metal-organic frameworks (MOFs) and porous materials. Over 60 % of reviewed studies focused on metal hydrides and alloys for hydrogen storage. Additionally the impact of nanotechnology on storage performance and the importance of optimizing synthesis parameters to tailor material properties for specific applications are summarized. Various synthesis methods are evaluated with a special emphasis on the role of nanotechnology in improving storage performance. Mechanical milling emerges as a commonly used and cost-effective method for fabricating intermetallic hydrides capable of adjusting hydrogen storage properties. The review also explores hydrogen storage tank embrittlement mechanisms particularly subcritical crack growth and examines the advantages and limitations of different materials for various applications supported by case studies showcasing real-world implementations. The challenges underscore current limitations in hydrogen storage materials highlighting the need for improved storage capacity and kinetics. The review also explores prospects for developing materials with enhanced performance and safety providing a roadmap for ongoing advancements in the field. Key findings and directions for future research in hydrogen storage materials emphasize their critical role in shaping future energy systems.

The Kingdom of Saudi Arabia has rich renewable energy resources specifically wind and solar in addition to geothermal beside massive natural gas reserves. This paper investigates the potential of both green and blue hydrogen production for five selected cities in Saudi Arabia. To accomplish the said objective a techno-economic model is formulated. Four renewable energy scenarios are evaluated for a total of 1.9 GW installed capacity to reveal the best scenario of Green Hydrogen Production (GHP) in each city. Also Blue Hydrogen Production (BHP) is investigated for three cases of Steam Methane Reforming (SMR) with different percentages of carbon capture. The economic analysis for both GHP and BHP is performed by calculating the Levelized Cost of Hydrogen (LCOH) and cash flow. The LCOH for GHP range for all cities ($3.27/kg -$12.17/kg)) with the lowest LCOH is found for NEOM city (50% PV and 50% wind) ($3.27/kg). LCOH for BHP are $0.534/kg $0.647/kg and $0.897/kg for SMR wo CCS/U SMR 55% CCS/U and SMR 90% CCS/U respectively.

The recognition of hydrogen as a technically viable combustion fuel and as an alternative to more carbon intensive technologies for all forms of industrial applications has resulted in significant global interest leading to both public and private investment. As with most shifts in technology public acceptance and its safe production and handling will be key to its growth as a widespread energy vector. Specific properties of hydrogen that may prompt concern from the public and that need to be considered in terms of its use and safe handling include the following:<br/>• Hydrogen in its natural state is a colourless odourless and tasteless gas that is combustible with very low ignition energy burns nearly invisibly and is explosive at a very wide range of concentrations with an oxidate.<br/>• Hydrogen as any other gas except oxygen is an asphyxiant in a confined space.<br/>• Hydrogen is an extremely small molecule and interacts with many materials which over time can alter the physical properties and can lead to embrittlement and failure. Additionally due to the small molecular size its permeation and diffusion characteristics make it more difficult to contain compared to other gases.<br/>As hydrogen production use and storage increases these properties will come under greater scrutiny and may raise questions surrounding the cost/benefit of the technology. Understanding how the public sees this technology in relation to their safety and daily lives is important in hydrogen’s adoption as a low carbon alternative. A review of deployable experience relevant to the handling of hydrogen in other industries will help us to understand the technology and experience necessary for ensuring the success of the scaling up of a hydrogen economy. The social considerations of the impacts should also be examined to consider acceptance of the technology as it moves into the mainstream.

This study develops a novel community-based integrated energy system where hydrogen and a combination of renewable energy sources are considered uniquely for implementation. In this regard three different communities situated in Kenya the United States and Australia are studied for hydrogen production and meeting the energy demands. To provide a variety of energy demands this study combines a multigenerational geothermal plant with a hybrid concentrated solar power and photovoltaic solar plant. Innovations in hydrogen production and renewable energy are essential for reducing carbon emissions. By combining the production of hydrogen with renewable energy sources this system seeks to move away from the reliance on fossil fuels and toward sustainability. The study investigates various research subjects using a variety of methods. The performance of the geothermal source is considered through energetic and exergetic thermodynamic analysis. The software System Advisor Model (SAM) and RETscreen software packages are used to analyze the other sub-systems including Concentrate Solar PV solar and Combined Heat and Power Plant. Australian American and Kenyan communities considered for this study were found to have promising potential for producing hydrogen and electricity from renewable sources. The geothermal output is expected to be 35.83 MW 122.8 MW for space heating 151.9 MW for industrial heating and 64.25 MW for hot water. The overall geothermal energy and exergy efficiencies are reported as 65.15% and 63.54% respectively. The locations considered are expected to have annual solar power generation and hydrogen production capacities of 158MW 237MW 186MW 235 tons 216 tons and 313 tons respectively.

Hydrogen (H2 ) is positioned as a key solution to the decarbonization challenge in both the energy and transportation sectors. While hydrogen is a clean and versatile energy carrier it poses significant safety risks due to its wide flammability range and high detonation potential. Hydrogen leaks can occur throughout the hydrogen value chain including production storage transportation and utilization. Thus effective leak detection systems are essential for the safe handling storage and transportation of hydrogen. This review aims to survey relevant codes and standards governing hydrogen-leak detection and evaluate various sensing technologies based on their working principles and effectiveness. Our analysis highlights the strengths and limitations of the current detection technologies emphasizing the challenges in achieving sensitive and specific hydrogen detection. The results of this review provide critical insights into the existing technologies and regulatory frameworks informing future advancements in hydrogen safety protocols.

Many factors to be appropriately addressed in moving towards energy sustainability are examined. These include harnessing sustainable energy sources utilizing sustainable energy carriers increasing efficiency reducing environmental impact and improving socioeconomic acceptability. The latter factor includes community involvement and social acceptability economic affordability and equity lifestyles land use and aesthetics. Numerous illustrations demonstrate measures consistent with the approach put forward and options for energy sustainability and the broader objective of sustainability. Energy sustainability is of great importance to overall sustainability given the pervasiveness of energy use its importance in economic development and living standards and its impact on the environment.

The global energy landscape is experiencing a transformative shift with an increasing emphasis on sustainable and clean energy sources. Hydrogen remains a promising candidate for decarbonization energy storage and as an alternative fuel. This study explores the landscape of hydrogen pricing and demand dynamics by evaluating three collaboration scenarios: market-based pricing cooperative integration and coordinated decision-making. It incorporates price-sensitive demand environmentally friendly production methods and market penetration effects to provide insights into maximizing market share profitability and sustainability within the hydrogen industry. This study contributes to understanding the complexities of collaboration by analyzing those structures and their role in a fast transition to clean hydrogen production by balancing economic viability and environmental goals. The findings reveal that the cooperative integration strategy is the most effective for sustainable growth increasing green hydrogen’s market share to 19.06 % and highlighting the potential for environmentally conscious hydrogen production. They also suggest that the coordinated decision-making approach enhances profitability through collaborative tariff contracts while balancing economic viability and environmental goals. This study also underscores the importance of strategic pricing mechanisms policy alignment and the role of hydrogen hubs in achieving sustainable growth in the hydrogen sector. By highlighting the uncertainties and potential barriers this research offers actionable guidance for policymakers and industry players in shaping a competitive and sustainable energy marketplace.

This paper presents an innovative Fuel Cell Combined Heat and Power (FC–CHP) system designed to enhance energy efficiency in hospital settings. The system primarily utilizes solar energy captured through photovoltaic (PV) panels for electricity generation. Excess electricity is directed to an electrolyzer for water electrolysis producing hydrogen which is stored in high-pressure tanks. This hydrogen serves a dual purpose: it fuels a boiler for heating and hot water needs and powers a fuel cell for additional electricity when solar production is low. The system also features an intelligent energy management system that dynamically allocates electrical energy between immediate consumption hydrogen production and storage while also managing hydrogen release for energy production. This study focuses on optimization using genetic algorithms to optimize key components including the peak power of photovoltaic panels the nominal power of the electrolyzer fuel cell and storage tank sizes. The objective function minimizes the sum of investment and electricity costs from the grid considering a penalty coefficient. This approach ensures optimal use of renewable energy sources contributing to energy efficiency and sustainability in healthcare facilities.

The imperative to address traditional energy crises and environmental concerns has accelerated the need for energy structure transformation. However the variable nature of renewable energy poses challenges in meeting complex practical energy requirements. To address this issue the construction of a multifunctional large-scale stationary energy storage system is considered an effective solution. This paper critically examines the battery and hydrogen hybrid energy storage systems. Both technologies face limitations hindering them from fully meeting future energy storage needs such as large storage capacity in limited space frequent storage with rapid response and continuous storage without loss. Batteries with their rapid response (90%) excel in frequent short-duration energy storage. However limitations such as a selfdischarge rate (>1%) and capacity loss (~20%) restrict their use for long-duration energy storage. Hydrogen as a potential energy carrier is suitable for large-scale long-duration energy storage due to its high energy density steady state and low loss. Nevertheless it is less efficient for frequent energy storage due to its low storage efficiency (~50%). Ongoing research suggests that a battery and hydrogen hybrid energy storage system could combine the strengths of both technologies to meet the growing demand for large-scale long-duration energy storage. To assess their applied potentials this paper provides a detailed analysis of the research status of both energy storage technologies using proposed key performance indices. Additionally application-oriented future directions and challenges of the battery and hydrogen hybrid energy storage system are outlined from multiple perspectives offering guidance for the development of advanced energy storage systems.

Hydrogen production and storage in hybrid systems is a promising solution for sustainable energy transition decoupling the energy generation from its end use and boosting the deployment of renewable energy. Nonetheless the optimal and cost-effective design of hybrid hydrogen-based systems is crucial to tackle existing limitations in diffusion of these systems. The present study explores net-zero energy management via a multi-objective optimization algorithm for an outdoor test facility equipped with a hydrogen-based hybrid energy production system. Aimed at enabling efficient integration of hydrogen fuel cell system the proposed solution attempts to maximize the renewable factor (RF) and carbon mitigation in the hybrid system as well as to minimize the grid dependency and the life cycle cost (LCC) of the system. In this context the techno-enviroeconomic optimization of the hybrid system is conducted by employing a statistical approach to identify optimal design variables and conflictive objective functions. To examine interactions in components of the hybrid system a series of dynamic simulations are carried out by developing a TRNSYS code coupled with the OpenStudio/EnergyPlus plugin. The obtained results indicate a striking disparity in the monthly RF values as well as the hydrogen production rate and therefore in the level of grid dependency. It is shown that the difference in LCC between optimization scenarios suggested by design of experiments could reach $15780 corresponding to 57% of the mean initial cost. The LCOE value yielded for optimum scenarios varies between 0.389 and 0.537 $/kWh. The scenario with net-zero target demonstrates the lowest LCOE value and the highest carbon mitigation i.e. 828 kg CO2/yr with respect to the grid supply case. However the LCC in this scenario exceeds $57370 which is the highest among all optimum scenarios. Furthermore it was revealed that the lowest RF in optimal scenarios is equal to 66.2% and belongs to the most economical solution.

Hydrogen component reliability and the hazard associated with failure rates is a critical area of research for the successful implementation and growth of hydrogen technology across the globe. The research team has partnered to quantify system risk reduction through earlier detection of hydrogen component failures. A model of hydrogen dispersion in a hydrogen equipment enclosure has been developed utilizing experimentally quantified hydrogen component leak rates as inputs. This model provides insight into the impact of hydrogen safety sensors and ventilation on the flammable mass within a hydrogen equipment enclosure. This model also demonstrates the change in safety sensor response time due to detector placement under various leak scenarios. The team looks to improve overall hydrogen system safety through an improved understanding of hydrogen component reliability and risk mitigation methods. This collaboration fits under the work program of IEA Hydrogen Task 43 Subtask E Hydrogen System Safety.