Canada
Climate Action for the Shipping Industry: Some Perspectives on the Role of Nuclear Power in Maritime Decarbonization
Feb 2023
Publication
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.
Modelling the Impacts of Hydrogen–Methane Blend Fuels on a Stationary Power Generation Engine
Mar 2023
Publication
To reduce greenhouse gas emissions from natural gas use utilities are investigating the potential of adding hydrogen to their distribution grids. This will reduce the carbon dioxide emissions from grid-connected engines used for stationary power generation and it may also impact their power output and efficiency. Promisingly hydrogen and natural gas mixtures have shown encouraging results regarding engine power output pollutant emissions and thermal efficiency in well-controlled on-road vehicle applications. This work investigates the effects of adding hydrogen to the natural gas fuel for a lean-burn spark-ignited four-stroke 8.9 liter eight-cylinder naturally aspirated engine used in a commercial stationary power generation application via an engine model developed in the GT-SUITETM modelling environment. The model was validated for fuel consumption air flow and exhaust temperature at two operating modes. The focus of the work was to assess the sensitivity of the engine’s power output brake thermal efficiency and pollutant emissions to blends of methane with 0–30% (by volume) hydrogen. Without adjusting for the change in fuel energy the engine power output dropped by approximately 23% when methane was mixed with 30% by volume hydrogen. It was found that increasing the fueling rate to maintain a constant equivalence ratio prevented this drop in power and reduced carbon dioxide emissions by almost 4.5%. In addition optimizing the spark timing could partially offset the increases in in-cylinder burned and unburned gas temperatures and in-cylinder pressures that resulted from the faster combustion rates when hydrogen was added to the natural gas. Understanding the effect of fuel change in existing systems can provide insight on utilizing hydrogen and natural gas mixtures as the primary fuel without the need for major changes in the engine.
Hydrogen Recombiners for Non-nuclear Hydrogen Safety Applications
Sep 2023
Publication
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.
Optimizing the Installation of a Centralized Green Hydrogen Production Facility in the Island of Crete, Greece
Apr 2024
Publication
The European Union is committed to a 55% reduction in greenhouse gas emissions by 2030 as outlined in the Green Deal and Climate Law initiatives. In response to geopolitical events the RePowerEU initiative aims to enhance energy self-sufficiency reduce reliance on Russian natural gas and promote hydrogen utilization. Hydrogen valleys localized ecosystems integrating various hydrogen supply chain elements play a key role in this transition particularly benefiting isolated regions like islands. This manuscript focuses on optimizing a Centralized Green Hydrogen Production Facility (CGHPF) on the island of Crete. A mixed-integer linear programming framework is proposed to optimize the CGHPF considering factors such as land area wind and solar potential costs and efficiency. Additionally an in-depth sensitivity analysis is conducted to explore the impact of key factors on the economic feasibility of hydrogen investments. The findings suggest that hydrogen can be sold in Crete at prices as low as 3.5 EUR/kg. Specifically it was found in the base scenario that selling hydrogen at 3.5 EUR/kg the net profit of the investment could be as high as EUR 6.19 million while the capacity of the solar and wind installation supplying the grid hydrogen facility would be 23.51 MW and 52.97 MW respectively. It is noted that the high profitability is justified by the extraordinary renewable potential of Crete. Finally based on our study a policy recommendation to allow a maximum of 20% direct penetration of renewable sources of green hydrogen facilities into the grid is suggested to encourage and accelerate green hydrogen expansion.
Reduction in Greenhouse Gas and Other Emissions from Ship Engines: Current Trends and Future Options
Nov 2022
Publication
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.
Optimizing Renewable Injection in Integrated Natural Gas Pipeline Networks Using a Multi-Period Programming Approach
Mar 2023
Publication
In this paper we propose an optimization model that considers two pathways for injecting renewable content into natural gas pipeline networks. The pathways include (1) power-to-hydrogen or PtH where off-peak electricity is converted to hydrogen via electrolysis and (2) power-to-methane or PtM where carbon dioxide from different source locations is converted into renewable methane (also known as synthetic natural gas SNG). The above pathways result in green hydrogen and methane which can be injected into an existing natural gas pipeline network. Based on these pathways a multi-period network optimization model that integrates the design and operation of hydrogen from PtH and renewable methane is proposed. The multi-period model is a mixed-integer non-linear programming (MINLP) model that determines (1) the optimal concentration of hydrogen and carbon dioxide in the natural gas pipelines (2) the optimal location of PtH and carbon dioxide units while minimizing the overall system cost. We show using a case study in Ontario the optimal network structure for injecting renewable hydrogen and methane within an integrated natural gas network system provides a $12M cost reduction. The optimal concentration of hydrogen ranges from 0.2 vol % to a maximum limit of 15.1 vol % across the network while reaching a 2.5 vol % at the distribution point. This is well below the maximum limit of 5 vol % specification. Furthermore the optimizer realized a CO2 concentration ranging from 0.2 vol % to 0.7 vol %. This is well below the target of 1% specified in the model. The study is essential to understanding the practical implication of hydrogen penetration in natural gas systems in terms of constraints on hydrogen concentration and network system costs.
Recent Advancements of Polymeric Membranes in Anion Exchange Membrane Water Electrolyzer (AEMWE): A Critical Review
Apr 2023
Publication
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.
Fueling Tomorrow's Commute: Current Status and Prospects of Public Bus Transit Fleets Powered by Sustainable Hydrogen
Apr 2024
Publication
Transportation is an economic sector that contributes significantly to global warming due to its high consumption of fossil fuels and sustainably produced hydrogen is a major contender for an alternative clean energy source. Public transit is vital for environmental sustainability via reducing individual vehicle usage and traffic congestion and the prospect of powering buses using hydrogen fuel has been extensively studied lately. This paper seeks to comprehensively review the current status of research on hydrogen-powered buses considering triple bottom line sustainability perspectives. A brief technical overview of prospective environmentally benign hydrogen production processes has been presented. Technological economic and environmental findings and research trends seen in recent analyses on hydrogen-powered buses have been summarized along with the status quo of global hydrogen refuelling stations. Identified focal points for future studies include performance enhancements refuelling infrastructure propagation and policy formulation. The conclusions derived from this review will benefit the accelerated deployment of hydrogen-fuelled public transit fleets.
Hydrogen Fuel Cell Integration and Testing in a Hybrid-electric Propulsion Rig
Jun 2023
Publication
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.
A Techno-economic Study of the Strategy for Hydrogen Transport by Pipelines in Canada
Jan 2023
Publication
Hydrogen as a clean zero-emission energy fuel will play a critical role in energy transition and achievement of the net-zero target in 2050. Hydrogen delivery is integral to the entire value chain of a full-scale hydrogen economy. This work conducted a systematic review and analysis of various hydrogen transportation methods including truck tankers for liquid hydrogen tube trailers for gaseous hydrogen and pipelines by identifying and ranking the main properties and affecting factors associated with each method. It is found that pipelines especially the existing natural gas pipelines provide a more efficient and cheaper means to transport hydrogen over long distances. Analysis was further conducted on Canadian natural gas pipeline network which has been operating for safe effective and efficient energy transport over six decades. The established infrastructure along with the developed operating and management experiences and skillful manpower makes the existing pipelines the best option for transport of hydrogen in either blended or pure form in the country. The technical challenges in repurposing the existing natural gas pipelines for hydrogen service were discussed and further work was analyzed.
Energy Assessment of an Integrated Hydrogen Production System
Dec 2022
Publication
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.
Recent Advances in Power-to-X Technology for the Production of Fuels and Chemicals
Jun 2019
Publication
Environmental issues related to greenhouse gas emissions are progressively pushing the transition toward fossil-free energy scenario in which renewable energies such as solar and wind power will unavoidably play a key role. However for this transition to succeed significant issues related to renewable energy storage have to be addressed. Power-to-X (PtX) technologies have gained increased attention since they actually convert renewable electricity to chemicals and fuels that can be more easily stored and transported. H2 production through water electrolysis is a promising approach since it leads to the production of a sustainable fuel that can be used directly in hydrogen fuel cells or to reduce carbon dioxide (CO2) in chemicals and fuels compatible with the existing infrastructure for production and transportation. CO2 electrochemical reduction is also an interesting approach allowing the direct conversion of CO2 into value-added products using renewable electricity. In this review attention will be given to technologies for sustainable H2 production focusing on water electrolysis using renewable energy as well as on its remaining challenges for large scale production and integration with other technologies. Furthermore recent advances on PtX technologies for the production of key chemicals (formic acid formaldehyde methanol and methane) and fuels (gasoline diesel and jet fuel) will also be discussed with focus on two main pathways: CO2 hydrogenation and CO2 electrochemical reduction.
An Eco-technoeconomic Analysis of Hydrogen Production using Solid Oxide Electrolysis Cells that Accounts for Long-term Degradation
Sep 2022
Publication
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.
Hybrid Renewable Hydrogen Energy Solution for Application in Remote Mines
Dec 2020
Publication
Mining operations in remote locations rely heavily on diesel fuel for the electricity haulage and heating demands. Such significant diesel dependency imposes large carbon footprints to these mines. Consequently mining companies are looking for better energy strategies to lower their carbon footprints. Renewable energies can relieve this over-reliance on fossil fuels. Yet in spite of their many advantages renewable systems deployment on a large scale has been very limited mainly due to the high battery storage system. Using hydrogen for energy storage purposes due to its relatively cheaper technology can facilitate the application of renewable energies in the mining industry. Such cost-prohibitive issues prevent achieving 100% penetration rate of renewables in mining applications. This paper offers a novel integrated renewable–multi-storage (wind turbine/battery/fuel cell/thermal storage) solution with six different configurations to secure 100% off-grid mining power supply as a stand-alone system. A detailed comparison between the proposed configurations is presented with recommendations for implementation. A parametric study is also performed identifying the effect of different parameters (i.e. wind speed battery market price and fuel cell market price) on economics of the system. The result of the present study reveals that standalone renewable energy deployment in mine settings is technically and economically feasible with the current market prices depending on the average wind speed at the mine location.
Development of Risk Mitigation Guidance for Hydrogen Sensor Placement Indoors and Outdoors
Sep 2021
Publication
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.
On the Bulk Transport of Green Hydrogen at Sea: Comparison Between Submarine Pipeline and Compressed and Liquefied Transport by Ship
Jan 2023
Publication
This paper compares six (6) alternatives for green hydrogen transport at sea. Two (2) alternatives of liquid hydrogen (LH2) by ship two (2) alternatives of compressed hydrogen (cH2) by ship and two (2) alternatives of hydrogen by pipeline. The ship alternatives study having hydrogen storage media at both end terminals to reduce the ships’ time at port or prescinding of them and reduce the immobilized capital. In the case of the pipeline new models are proposed by considering pressure costs. One scenario considers that there are compression stations every 500 km and the other one considers that there are none along the way. These alternatives are assessed under nine different scenarios that combine three distances: 100 km 2500 km and 5000 km; and three export rates of hydrogen 100 kt/y 1 Mt/y and 10 Mt/y. The results show including uncertainty bands that for the 100 km of distance the best alternative is the pipeline. For 2500 km and 100 kt/y the top alternative is cH2 shipping without storage facilities at the port terminals. For 2500 km and 1 Mt/y and for 5000 km and 100 kt/y the best alternatives are cH2 or LH2 shipping. For the remaining scenarios the best alternative is LH2 shipping.
Efficiency, Economic and Environmental Impact Assessment of a Newly Developed Rail Engine using Hydrogen and Other Sustainable Fuel Blends
Jan 2023
Publication
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.
Safety Compliance Verification of Fuel Cell Electric Vehicle Exhaust
Sep 2021
Publication
NREL has been developing compliance verification tools for allowable hydrogen levels prescribed by the Global Technical Regulation Number 13 (GTR-13) for hydrogen fuel cell electric vehicles (FCEVs). As per GTR-13 FCEV exhaust is to remain below 4 vol% H2 over a 3-second moving average and shall not at any time exceed 8 vol% H2 and that this requirement is to be verified with an analyzer that has a response time of less than 300 ms. To be enforceable a means to verify regulatory requirements must exist. In response to this need NREL developed a prototype analyzer that meets the GTR metrological requirements for FCEV exhaust analysis. The analyzer was tested on a commercial fuel cell electric vehicle (FCEV) under simulated driving conditions using a chassis dynamometer at the Emissions Research and Measurement Section of Environment and Climate Change Canada and FCEV exhaust was successfully profiled. Although the prototype FCEV Exhaust Analyzer met the metrological requirements of GTR-13 the stability of the hydrogen sensor was adversely impacted by condensed water in the sample gas. FCEV exhaust is at an elevated temperature and nearly saturated with water vapor. Furthermore condensed water is present in the form of droplets. Condensed water in the sample gas collected from FCEV exhaust can accumulate on the hydrogen sensing element which would not only block access of hydrogen to the sensing element but can also permanently damage the sensor electronics. In the past year the design of the gas sampling system was modified to mitigate against the transport of liquid water to the sensing element. Laboratory testing confirmed the effectiveness of the modified sampling system water removal strategy while maintaining the measurement range and response time required by GTR-13. Testing of the upgraded analyzer design on an FCEV operating on a chassis dynamometer is scheduled for the summer of 2021.
Cost and Capacity Requirements of Electrification or Renewable Gas Transition Options that Decarbonize Building Heating in Metro Vancouver, British Columbia
Jun 2022
Publication
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.
Hydrogen Behavior and Mitigation Measures: State of Knowledge and Database from Nuclear Community
Sep 2023
Publication
Hydrogen has become a key enabler for decarbonization as countries pledge to reach net zero carbon emissions by 2050. With hydrogen infrastructure expanding rapidly beyond its established applications there is a requirement for robust safety practices solutions and regulations. Since the 1980s considerable efforts have been undertaken by the nuclear community to address hydrogen safety issues because in severe accidents of water-cooled nuclear reactors a large amount of hydrogen can be produced from the oxidation of metallic components with steam. As evidenced in the Fukushima accident hydrogen combustion can cause severe damage to reactor building structures promoting the release of radioactive fission products to the environment. A number of large-scale experiments were conducted in the framework of national and international projects to understand the hydrogen dispersion and combustion behaviour under postulated accidental conditions. Empirical engineering models and numerical codes were developed and validated for safety analysis. Hydrogen recombiners known as Passive Autocatalytic Recombiner (PAR) were developed and have been widely installed in nuclear containments to mitigate hydrogen risk. Complementary actions and strategies were established as part of severe accident management guidelines to prevent or limit the consequences of hydrogen explosions. In addition hydrogen monitoring systems were developed and implemented in nuclear power plants. The experience and knowledge gained from the nuclear community on hydrogen safety is valuable and applicable for other industries involving hydrogen production transport storage and use.
Optimal Design and Operation of Dual-Ejector PEMFC Hydrogen Supply and Circulation System
Jul 2022
Publication
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.
Perspectives and Prospects of Underground Hydrogen Storage and Natural Hydrogen
Jun 2022
Publication
Hydrogen is considered the fuel of the future due to its cleaner nature compared to methane and gasoline. Therefore renewable hydrogen production technologies and long-term affordable and safe storage have recently attracted significant research interest. However natural underground hydrogen production and storage have received scant attention in the literature despite its great potential. As such the associated formation mechanisms geological locations and future applications remain relatively under-explored thereby requiring further investigation. In this review the global natural hydrogen formation along with reaction mechanisms (i.e. metamorphic processes pyritization and serpentinization reactions) as well as the suitable geological locations (i.e. ophiolites organic-rich sediments fault zones igneous rocks crystalline basements salt bearing strata and hydrocarbon-bearing basins) are discussed. Moreover the underground hydrogen storage mechanisms are detailed and compared with underground natural gas and CO2 storage. Techno-economic analyses of large-scale underground hydrogen storage are presented along with the current challenges and future directions.
The Trajectory of Hybrid and Hydrogen Technologies in North American Heavy Haul Operations
Jul 2021
Publication
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.
Application of Passive Autocatalytic Recombiners for Hydrogen Mitigation: 2D Numerical Modeling and Experimental Validation
Sep 2023
Publication
The widespread production and use of hydrogen (H2) requires safe handling due to its wide range of flammability and low ignition energy. In confined and semi-confined areas such as garages and tunnels a hydrogen leak will create a potential accumulation of flammable gases. Hence forced ventilation is required in such confined spaces to prevent hydrogen hazards. However this practice may incur higher operating costs and could become ineffective during a power outage. Passive Autocatalytic Recombiners (PARs) are defined as safety devices for preventing hydrogen accumulation in confined spaces. PARs have been widely adopted for hydrogen mitigation in nuclear containment buildings in worst case accident scenarios where forced ventilation is not feasible. PARs are equipped with catalyst plates that self-start due to hydrogen reacting with oxygen at relatively low concentrations (<2 vol. % H2 in air). The heat generated from the reaction creates a self-sustained flow continuously supplying the catalyst surface with fresh hydrogen and oxygen. In this study a 2D transient numerical model has been developed in COMSOL Multiphysics to simulate the operation of PARs. The model was used to analyze the effect of surface reactions on the catalyst temperature flow dynamics self-start behaviour forced versus natural convective flow and steady-state hydrogen recombination rates. The model was also used to simulate carbon monoxide poisoning and its influence on the catalyst performance. Experimental data were used for model calibration and validation showing good agreement for different conditions. Overall the model provides novel insights into PARs operation such as radiation and poisoning effects on the catalyst plate. As a next step assessment of the effectiveness of PARs is underway to mitigate hydrogen hazards in selected confined and semi-confined areas including nuclear and non-nuclear applications.
Synergy-based Hydrogen Pricing in Hydrogen-Integrated Electric Power System: Sensititivy Analysis
Nov 2024
Publication
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.
Examining the Nature of Two-dimensional Transverse Waves in Marginal Hydrogen Detonations using Boundary Layer Loss Modeling with Detailed Chemistry
Sep 2023
Publication
Historically it has been a challenge to simulate the experimentally observed cellular structures and marginal behavior of multidimensional hydrogen-oxygen detonations in the presence of losses even with detailed chemistry models. Very recently a quasi-two-dimensional inviscid approach was pursued where losses due to viscous boundary layers were modeled by the inclusion of an equivalent mass divergence in the lateral direction using Fay’s source term formulation with Mirels’ compressible boundary layer solutions. The same approach was used for this study along with the inclusion of thermally perfect detailed chemistry in order to capture the correct ignition sensitivity of the gas to dynamic changes in the thermodynamic state behind the detonation front. In addition the strength of transverse waves and their impact on the detonation front was investigated. Here the detailed San Diego mechanism was applied and it has been found that the detonation cell sizes can be accurately predicted without the need to prescribe specific parameters for the combustion model. For marginal cases where the detonation waves approach their failure limit quasi-stable mode behavior was observed where the number of transverse waves monotonically decreased to a single strong wave over a long enough distance. The strong transverse waves were also found to be slightly weaker than the detonation front indicating that they are not overdriven in agreement with recent studies.
Hydrogen Impact: A Review on Diffusibility, Embrittlement Mechanisms, and Characterization
Feb 2024
Publication
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.
Recent Developments on Carbon Neutrality through Carbon Dioxide Capture and Utilization with Clean Hydrogen for Production of Alternative Fuels for Smart Cities
Jul 2024
Publication
This review comprehensively evaluates the integration of solar-powered electrolytic hydrogen (H2) production and captured carbon dioxide (CO2) management for clean fuel production considering all potential steps from H2 production methods to CO2 capture and separation processes. It is expected that the near future will cover CO2-capturing technologies integrated with solar-based H2 production at a commercially viable level and over 5 billion tons of CO2 are expected to be utilized potentially for clean fuel production worldwide in 2050 to achieve carbon-neutral levels. The H2 production out of hydrocarbon-based processes using fossil fuels emits greenhouse gas emissions of 17-38 kg CO2/kg H2. On the other hand . renewable energy based green hydrogen production emits less than 2 kg CO2/kg H2 which makes it really clean and appealing for implementation. In addition capturing CO2 and using for synthesizing alternative fuels with green hydrogen will help generate clean fuels for smart cities. In this regard the most sustainable and promising CO2 capturing method is post-combustion with an adsorption-separation-desorption processes using monoethanolamine adsorbent with high CO2 removal efficiencies from flue gases. Consequently this review article provides perspectives on the potential of integrating CO2-capturing technologies and renewable energy-based H2 production systems for clean production to create sustainable cities and communities.
Innovations in Hydrogen Storage Materials: Synthesis, Applications, and Prospects
Jul 2024
Publication
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.
Hydrogen Propulsion Systems for Aircraft, a Review on Recent Advances and Ongoing Challenges
Oct 2024
Publication
Air transportation contributes significantly to harmful and greenhouse gas emissions. To combat these issues there has been a recent emergence of aircraft electrification as a potential solution to mitigate environmental concerns and address fuel shortages. However current technologies related to batteries electric machinery and power systems are still in the developmental phase to meet the requirements for power and energy density weight safety and reliability. In the interim there is a focus on the more electric and hybrid electric propulsion systems for aircraft. Hydrogen with its high specific energy and carbon-free characteristics stands out as a promising alternative fuel for aviation. This paper is centred on the application of hydrogen in aircraft propulsion mainly fuel cell hybrid electric (FCHE) propulsion systems. Furthermore application of hydrogen as a fuel for the aircraft propulsion systems is considered. A comprehensive overview of the hydrogen propulsion systems in aviation is presented with an emphasis on the technical aspects crucial for creating a more sustainable and efficient air transportation sector. Additionally the paper acknowledges the technical and regulatory challenges that must be addressed to attain these goals.
Evaluation of Green and Blue Hydrogen Production Potential in Saudi Arabia
Sep 2024
Publication
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.
Quantitative Risk Assessment for Hydrogen Systems: Model Development and Validation
Sep 2023
Publication
Quantitative Risk Assessment (QRA) is a risk-informed approach that considers past performances and the likelihood of events and distinguishes must-haves from nice-to-haves. Following the approach applied for the HyRAM code developed by the Sandia National Laboratories a QRA toolkit for hydrogen systems was developed using MATLAB by Canadian Nuclear Laboratories (CNL). Based on user inputs for system components and their operating parameters the toolkit calculates the consequence of a hydrogen leak from the system. The fatality likelihood can be estimated from the severity of a person’s exposure to radiant heat flux (from a jet fire) and overpressure (from an explosion). This paper presents a verification and validation exercise by comparing the CNL model predictions with the HyRAM code and available experimental data including a QRA case study for a locomotive. The analysis produces risk contours recommending personnel (employees/public) numbers time spent and safe separation distances near the incident (during maintenance or an accident). The case study demonstrated the importance of hydrogen leak sensors’ reliability for leak detection and isolation. The QRA toolkit calculates a more practical value of the safe separation distance for hydrogen installations and provides evidence to support communication with authorities and other stakeholders for decision-making.
The Global Shift to Hydrogen and Lessons from Outside Industry
Sep 2023
Publication
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.
Investigation of a New Holistic Energy System for a Sustainable Airport with Green Hydrogen Fuels
Jun 2024
Publication
The advancement of sustainable solutions through renewable energy sources is crucial to mitigate carbon emissions. This study reports a novel system for an airport utilizing geothermal biomass and PV solar energy sources. The proposed system is capable of producing five useful outputs including electrical power hot water hydrogen kerosene and space heating. In open literature there has been no system reported with these combination of energy sources and outputs. The system is considered for Vancouver Airport using the most recent statistics available. The geothermal sub-system introduced is also unique which utilizes carbon dioxide captured as the heat transfer medium for power generation and heating. The present system is considered using thermodynamic analysis through energetic and exergetic approaches to determine the variation in system performance based on different annual climate conditions. Biomass gasification and kerosene production are evaluated based on the Aspen Plus models. The efficiencies of the geothermal system with the carbon dioxide reservoir are found to have energetic and energetic efficiencies of 78 % and 37 % respectively. The total hydrogen production projection is obtained to be 452 tons on an annual basis. The kerosene production mass flow rate is reported as 0.112 kg/s. The overall energetic and exergetic efficiencies of the system are found to be 41.8 % and 32.9 % respectively. This study offers crucial information for the aviation sector to adopt sustainable solutions more effectively.
Investigation of a Community-based Clean Energy System Holistically with Renewable and Hydrogen Energy Options for Better Sustainable Development
Jan 2024
Publication
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 Energy Systems: Technologies, Trends, and Future Prospects
May 2024
Publication
This review critically examines hydrogen energy systems highlighting their capacity to transform the global energy framework and mitigate climate change. Hydrogen showcases a high energy density of 120 MJ/kg providing a robust alternative to fossil fuels. Adoption at scale could decrease global CO2 emissions by up to 830 million tonnes annually. Despite its potential the expansion of hydrogen technology is curtailed by the inefficiency of current electrolysis methods and high production costs. Presently electrolysis efficiencies range between 60 % and 80 % with hydrogen production costs around $5 per kilogram. Strategic advancements are necessary to reduce these costs below $2 per kilogram and push efficiencies above 80 %. Additionally hydrogen storage poses its own challenges requiring conditions of up to 700 bar or temperatures below −253 °C. These storage conditions necessitate the development of advanced materials and infrastructure improvements. The findings of this study emphasize the need for comprehensive strategic planning and interdisciplinary efforts to maximize hydrogen's role as a sustainable energy source. Enhancing the economic viability and market integration of hydrogen will depend critically on overcoming these technological and infrastructural challenges supported by robust regulatory frameworks. This comprehensive approach will ensure that hydrogen energy can significantly contribute to a sustainable and low-carbon future.
A Review of Hydrogen Leak Detection Regulations and Technologies
Aug 2024
Publication
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.
Look-ahead Scheduling of Energy-Water Nexus Integrated with Power2X Conversion Technologies under Multiple Uncertainties
Aug 2023
Publication
Co-optimizing energy and water resources in a microgrid can increase efficiency and improve economic performance. Energy-water storage (EWS) devices are crucial components of a high-efficient energy-water microgrid (EWMG). The state of charge (SoC) at the end of the first day of operation is one of the most significant variables in EWS devices since it is used as a parameter to indicate the starting SoC for the second day which influences the operating cost for the second day. Hence this paper examines the benefits and applicability of a lookahead optimization strategy for an EWMG integrated with multi-type energy conversion technologies and multienergy demand response to supply various energy-water demands related to electric/hydrogen vehicles and commercial/residential buildings with the lowest cost for two consecutive days. In addition a hybrid info-gap/robust optimization technique is applied to cover uncertainties in photovoltaic power and electricity prices as a tri-level optimization framework without generating scenarios and using the probability distribution functions. Duality theory is also used to convert the problem into a single-level MILP so that it can be solved by CPLEX. According to the findings the implemented energy-water storage systems and look-ahead strategy accounted for respectively 4.03% and 0.43% reduction in the total cost.
Energy Sustainability: A Pragmatic Approach and Illustrations
Mar 2009
Publication
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.
Overview of International Activities in Hydrogen System Safety in IEA Hydrogen TCP Task 43
Sep 2023
Publication
Safety and reliability have long been recognized as key issues for the development commercialization and implementation of new technologies and infrastructure and hydrogen systems are no exception to this rule. Reliability engineering quantitative risk assessment (QRA) and knowledge exchange each play a key role in proactive addressing safety – before problems happen – and help us learn from problems if they happen. Many international research activities are focusing on both reliability and risk assessment for hydrogen systems. However the element of knowledge exchange is sometimes less visible. To support international collaboration and knowledge exchange the International Energy Agency (IEA) convened a new Technology Collaboration Program “Task 43: Safety and Regulatory Aspects of Emerging Large Scale Hydrogen Energy Applications” started in June 2022. Within Task 43 Subtask E focuses on Hydrogen Systems Safety. This paper discusses the structure of the Hydrogen Systems Safety subtask and the aligned activities and introduces opportunities for future work.
Strategic Analysis of Hydrogen Market Dynamics Across Collaboration Models
Oct 2024
Publication
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.
Component and System Levels Limitations in Power-Hydrogen Systems: Analytical Review
Jun 2024
Publication
This study identifies limitations and research and development (R&D) gaps at both the component and system levels for hydrogen energy systems (HESs) and specifies how these limitations impact HES adoption within the electric power system (EPS) decarbonization roadmap. To trace these limitations and potential solutions an analytical review is conducted in electrification and integration of HESs renewable energy sources (RESs) and multi-carrier energy systems (MCESs) in sequence. The study also innovatively categorizes HES integration challenges into component and system levels. At the component level technological aspects of hydrogen generation storage transportation and refueling are explored. At the system level HES coordination hydrogen market frameworks and adoption challenges are evaluated. Findings highlight R&D gaps including misalignment between HES operational targets and techno-economic development integration insufficiency model deficiencies and challenges in operational complexity. This study provides insights for sustainable energy integration by supporting the transition to a decarbonized energy system.
Advances in Hospital Energy Systems: Genetic Algorithm Optimization of a Hybrid Solar and Hydrogen Fuel Cell Combined Heat and Power
Sep 2024
Publication
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.
Case Study: Quantitative Risk Assessment of Hydrogen Blended Natural Gas for an Existing Distribution Network and End-use Equipment in Fort Saskatchewan, Alberta
Sep 2023
Publication
In a first-of-its-kind project for Alberta ATCO Gas and Pipelines Ltd. (ATCO) began delivering a 5% blend of hydrogen (H2) in natural gas into a subsection of the existing Fort Saskatchewan natural gas distribution system (approximately 2100 customers). The project was commissioned in October 2022 with the intention of increasing the blend to 20% H₂ in 2023. As part of project due diligence ATCO in partnership with DNV undertook Quantitative Risk Assessments (QRAs) to understand any risks associated with the introduction of blended gas into its existing distribution system and to its customers. This paper describes key findings from the QRAs through the comparison of risks associated with H2 blended natural gas at concentrations of 5% and 20% H₂ and the current natural gas configuration. The impact of operating pressure and hydrogen blend composition formed a sensitivity study completed as part of this work. To provide context and to help interpret the results an individual risk (IR) level of 1 × 10-6 per year was utilised as a reference threshold for the limit of the ‘broadly acceptable’ risk level and juxtaposed against comparable risk scenarios. Although adding hydrogen increases the IR of ignited releases from mains services meters regulators and end user appliances the ignited release IR was always well below the broadly acceptable reference criterion for all operating pressures and blend cases considered as part of the project. The IR associated with carbon monoxide poisoning dominates the overall IR and the results demonstrate that the reduction in carbon monoxide poisoning associated with the introduction of H₂ blended natural gas negates any incremental risk associated with ignited releases due to H₂ blended gas. The paper also explains how the results of the QRA were incorporated into Engineering Assessments as per the requirements of CSA Z662:19 [1] to justify the conversion of existing natural gas infrastructure to H₂ blended gas infrastructure.
An Overview of Application-orientated Multifunctional Large-scale Stationary Battery and Hydrogen Hybrid Energy Storage System
Dec 2023
Publication
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.
An Artificial Neural Network-Based Fault Diagnostics Approach for Hydrogen-Fueled Micro Gas Turbines
Feb 2024
Publication
The utilization of hydrogen fuel in gas turbines brings significant changes to the thermophysical properties of flue gas including higher specific heat capacities and an enhanced steam content. Therefore hydrogen-fueled gas turbines are susceptible to health degradation in the form of steam-induced corrosion and erosion in the hot gas path. In this context the fault diagnosis of hydrogen-fueled gas turbines becomes indispensable. To the authors’ knowledge there is a scarcity of fault diagnosis studies for retrofitted gas turbines considering hydrogen as a potential fuel. The present study however develops an artificial neural network (ANN)-based fault diagnosis model using the MATLAB environment. Prior to the fault detection isolation and identification modules physics-based performance data of a 100 kW micro gas turbine (MGT) were synthesized using the GasTurb tool. An ANN-based classification algorithm showed a 96.2% classification accuracy for the fault detection and isolation. Moreover the feedforward neural network-based regression algorithm showed quite good training testing and validation accuracies in terms of the root mean square error (RMSE). The study revealed that the presence of hydrogen-induced corrosion faults (both as a single corrosion fault or as simultaneous fouling and corrosion) led to false alarms thereby prompting other incorrect faults during the fault detection and isolation modules. Additionally the performance of the fault identification module for the hydrogen fuel scenario was found to be marginally lower than that of the natural gas case due to assumption of small magnitudes of faults arising from hydrogen-induced corrosion.
Net-zero Energy Management through Multi-criteria Optimizations of a Hybrid Solar-Hydrogen Energy Production System for an Outdoor Laboratory in Toronto
Apr 2024
Publication
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.
Role of a Unitized Regenerative Fuel Cell in Remote Area Power Supply: A Review
Aug 2023
Publication
This manuscript presents a thorough review of unitized regenerative fuel cells (URFCs) and their importance in Remote Area Power Supply (RAPS). In RAPS systems that utilize solar and hydrogen power which typically include photovoltaic modules a proton exchange membrane (PEM) electrolyzer hydrogen gas storage and PEM fuel cells the cost of these systems is currently higher compared to conventional RAPS systems that employ diesel generators or batteries. URFCs offer a potential solution to reduce the expenses of solar hydrogen renewable energy systems in RAPS by combining the functionalities of the electrolyzer and fuel cell into a single unit thereby eliminating the need to purchase separate and costly electrolyzer and fuel cell units. URFCs are particularly well-suited for RAPS applications because the electrolyzer and fuel cell do not need to operate simultaneously. In electrolyzer mode URFCs function similarly to stand-alone electrolyzers. However in fuel cell mode the performance of URFCs is inferior to that of stand-alone fuel cells. The presented review summarizes the past present and future of URFCs with details on the operating modes of URFCs limitations and technical challenges and applications. Solar hydrogen renewable energy applications in RAPS and challenges facing solar hydrogen renewable energy in the RAPS is discussed in detail.
Hydrogen Equipment Enclosure Risk Reduction through Earlier Detection of Component Failures
Sep 2023
Publication
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.
A Review of Hydrogen-based Hybrid Renewable Energy Systems: Simulation and Optimization with Artificial Intelligence
Nov 2021
Publication
With the massive use of traditional fossil fuels greenhouse gas emissions are increasing and environmental pollution is becoming an increasingly serious problem which led to an imminent energy transition. Therefore the development and application of renewable energy are particularly important. This paper reviews a wide range of issues associated with hybrid renewable energy systems (HRESs). The issues concerning system configurations energy storage options simulation and optimization with artificial intelligence are discussed in detail. Storage technology options are introduced for stand-alone (off-grid) and grid-connected (on-grid) HRESs. Different optimization methodologies including classical techniques intelligent techniques hybrid techniques and software tools for sizing system components are presented. Besides the artificial intelligence methods for optimizing the solar/wind HRESs are discussed in detail.
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