Canada

This study explores the potential of renewable seafood shell waste for sustainable energy conversion and longterm storage particularly for isolated communities. Despite its rich chitin and protein composition seafood shell waste is often neglected. The research evaluates and compares three advanced gasification technologies: biomass gasification plasma gasification and chemical looping to convert seafood shell waste into syngas and H2. The study uses validated Aspen Plus models to optimize feedstock blending ratios and operational parameters. Results show that feedstocks high in lobster and shrimp shells yield higher H2 outputs and improved syngas quality compared to clam-dominated blends. For instance biomass gasification at 1200 ◦C yielded approximately 500 kg/h of H2 from pure lobster or shrimp feeds while plasma gasification at 4500 ◦C achieved yields near 730 kg/ h. Plasma gasification when integrated with fuel cell conversion and heat recovery systems can generate over 10000 kWh during a 6-hour peak period enough to power over 1100 single-detached homes. Its levelized cost of hydrogen (LCOH) varies from $5.72-$8.37/kg H2 making it less expensive than chemical looping and biomass gasification. Plasma gasification also has the lowest global warming potential (GWP) at 6 kg CO2e/kg H2. Combining plasma gasification with carbon capture and storage may reduce GWP to 0.3 kg CO2e/kg H2 and can be further explored. These findings underscore the technical and economic viability of converting seafood shell renewable waste into H2 advancing sustainable energy transitions and supporting net-zero goals.

Ternary I-III-VI quantum dots (QDs) have recently received wide attention in solar energy conversion technologies because of their non-toxicity tunable band gap and composition-dependant optical properties. However their complex non-stoichiometry induces high density of surface traps/defects which significantly affects solar energy conversion efficiencies and long-term stability. This work presents an in-situ growth passivation approach to encapsulate ternary Cu:ZnInSe with ZnSeS alloyed shell (CZISe/ZSeS QDs) as light harvesters for solar-driven photoelectrochemical (PEC) hydrogen (H2) production. The engineered CZISe/ZSeS QDs coupled with TiO2- MWCNTs hybrid photoanode exhibit a high photocurrent density of 13.15 mA/cm2 at 0.8 V vs RHE under 1 sun illumination which is 20.5 % higher than bare CZISe QDs/TiO2 photoanode based device. In addition we observed a 48 % enhancement in the long-term stability with ~88 % current retained after 6000 s. These results indicate that the effective shell passivation has mitigated the surface traps/defects leading to suppressed charge recombination and improved charge transfer efficiency as confirmed by optoelectronic carrier dynamics measurements and theoretical simulations. The findings hold great promise on improving the performance of ternary/multinary eco-friendly colloidal QDs by surface engineering for effective utilization in solar energy conversion technologies.

Hydrogen production via water splitting is a crucial strategy for addressing the global energy crisis and promoting sustainable energy solutions. This review systematically examines water-splitting mechanisms with a focus on photocatalytic and electrochemical methods. It provides in-depth discussions on charge transfer reaction kinetics and key processes such as the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Various electrode synthesis techniques including hydrothermal methods chemical vapor deposition (CVD) pulsed laser deposition (PLD) and radio frequency sputtering (RF) are reviewed for their advantages and limitations. The role of carbon-based materials such as graphene biochar and graphitic carbon nitride (g-C3N4) in photocatalytic and photoelectrochemical (PEC) water splitting is also highlighted. Their exceptional conductivity tunable band structures and surface functionalities contribute to efficient charge separation and enhanced light absorption. Further advancements in heterojunctions doped systems and hybrid composites are explored for their ability to improve photocatalytic and PEC performance by minimizing charge recombination optimizing electronic structures and increasing active sites for hydrogen and oxygen evolution reactions. Key challenges including material stability cost scalability and solar spectrum utilization are critically analyzed along with emerging strategies such as novel synthesis approaches and sustainable material development. By integrating water splitting mechanisms electrode synthesis techniques and advancements in carbon-based materials this review provides a comprehensive perspective on sustainable hydrogen production bridging previously isolated research domains.

Underground hydrogen storage (UHS) in basaltic rocks offers a scalable solution for large-scale sustainable energy needs yet its efficiency is limited by poorly constrained pore-scale hysteresis during cyclic hydrogenbrine flow. While basaltic rocks have been extensively studied for carbon sequestration and critical mineral extraction the pore-scale physics governing cyclic hydrogen-brine interactions particularly the roles of snap-off wettability and hysteresis remain inadequately understood. This knowledge gap hinders the development of predictive models and optimization strategies for UHS performance. This study presents a pore-scale investigations of cyclic hydrogen-brine flow in basaltic formations combining micro-computed tomography imaging with pore network modelling. A systematic workflow is employed to evaluate the effects of repeated drainage-imbibition cycles on multiphase flow properties under varying wetting regimes with emphasis on hysteresis evolution and its influence on recoverable hydrogen. Model validation is achieved through a novel benchmarking approach that incorporates synthetic fractures and morphological scaling enabling calibration against experimental capillary pressure and relative permeability. Results show that hydrogen trapping is primarily governed by snap-off and pore-body isolation particularly within large angular pores exhibiting high aspect ratios and limited connectivity. Strong hysteresis is observed between drainage and imbibition with hydrogen saturations averaging 85% predominantly in larger pore spaces compared to a residual saturation of 61% following imbibition. Repeated cycling leads to a gradual increase in residual saturation which eventually stabilizes indicating the onset of a hysteresis equilibrium state. Wettability emerges as a critical second-order control on displacement dynamics. Shifting from strongly to weakly water-wet conditions reduces capillary entry pressures enhances brine re-invasion and increases hydrogen recovery efficiency by ∼6%. These findings offer mechanistic insights into capillary trapping and wettability effects providing a framework for optimizing UHS reactive and abundant yet underutilized basalt formations and supporting ongoing global decarbonization efforts through reliable subsurface hydrogen storage.

This study presents a holistic technoeconomic analysis of solar photovoltaic-based green hydrogen production facilities assessing hydrogen output potential and cost structures under various facility configurations. Four system cases are defined based on the inclusion of new photovoltaic (PV) panels and hydrogen storage (HS) subsystems considering Southern Ontario solar data and a 30-year operational lifespan. Through a system level modeling we incorporate the initial costs of sub-systems (PV panels power conditioning devices electrolyser battery pack and hydrogen storage) operating and maintenance expenses and replacement costs to determine the levelized cost of hydrogen (LCOH). The results of this study indicate that including hydrogen storage significantly impacts optimal electrolyser sizing creating a production bottleneck around 400 kW for a 1 MWp PV system (yielding approximately 590 tons H2 over a period of 30 years) whereas systems without storage achieve higher yields (about 1080 tons of H2) with larger electrolysers (approximately 620 kW). The lifetime cost analysis reveals that operating and maintenance cost constitutes the dominant expenditure (68–76 %). Including hydrogen storage increases the minimum LCOH and sharply penalizes electrolyser oversizing relative to storage capacity. For a 1 MWp base system minimum LCOH ranged from approximately $3.50/kg (existing PV no HS) to $6/kg (existing PV with HS) $11–12/kg (new PV no HS) and $22–25/kg (new PV with HS). Leveraging existing PV infrastructure drastically reduces LCOH. Furthermore significant economies of scale are observed with increasing PV facility capacity potentially lowering LCOH below $2/kg at the 100 MWp scale. The study therefore underscores that there is a critical interplay between system configuration component sizing operating and maintenance management and facility scale in determining the economic viability of solar hydrogen production.

The present work aims to develop a uniquely designed experimental test rig for hydrogen (H2) production from hydrogen sulfide (H2S) and perform performance tests. The experimental activity focuses on the FeCl3 hybrid process for H2S cracking followed by H2S absorption sulfur purification and electrolysis for efficient H2 production. Hydrogen production is studied using KOH and FeCl3 electrolytes under varying temperatures between 20-80 ◦C. An electrochemical impedance spectroscopy (EIS) is employed to characterize the electrochemical cell under potentiostatic (0.5-2.0 V) and galvanostatic (0-0.5 mA) modes to analyze the system’s electrochemical response. The study results showed that hydrogen production increased by over 426 % from 20 ◦C to 80 ◦C. EIS analysis under potentiostatic mode showed Nyquist semicircle diameter reduced as the applied voltage increased from 0.5 V to 1.5 V and phase angle shifted from -5.59◦ to -1.27◦ confirming enhanced conductivity. Under galvanostatic mode the impedance dropped from ~25 Ω to ~21 Ω as current increased demonstrating improved kinetics for efficient H2 production.

Long-term reliability and accuracy of pressure valves are critical for hydrogen infrastructure and applications particularly in hydrogen-powered vehicles exposed to extreme weather conditions like cold winters and hot summers. This study evaluates such valves using the Endurance Test specified in European Commission Regulation (EU) No 406/2010 fulfilling Regulation (EC) No 79/2009 requirements for hydrogen vehicle type approval. A long short-term memory (LSTM) network accelerates valve development and validation by simulating endurance tests. The LSTM model with three inputs and one output predicts valve outlet pressure responses using experimental data collected at 25 ◦C 85 ◦C and − 40 ◦C simulating a 20-year lifecycle of 75000 cycles. At 25 ◦C the model achieves optimal performance with 40000 training cycles and an R2 of 0.969 with R2 values exceeding 0.960 across all temperatures. This efficient robust approach accelerates testing enabling realtime diagnostics and advancing hydrogen technologies for a sustainable future.

This Review provides an overview of the emerging concepts of catalystsmembranes and membrane electrode assemblies (MEAs) for water electrolyzers with anion-exchange membranes (AEMs) also known as zero-gap alkaline water electrolyzers. Much ofthe recent progress is due to improvements in materials chemistry MEA designs andoptimized operation conditions. Research on anion-exchange polymers (AEPs) has focusedon the cationic head/backbone/side-chain structures and key properties such as ionicconductivity and alkaline stability. Several approaches such as cross-linking microphase andorganic/inorganic composites have been proposed to improve the anion-exchangeperformance and the chemical and mechanical stability of AEMs. Numerous AEMs nowexceed values of 0.1 S/cm (at 60−80 °C) although the stability specifically at temperaturesexceeding 60 °C needs further enhancement. The oxygen evolution reaction (OER) is still alimiting factor. An analysis of thin-layer OER data suggests that NiFe-type catalysts have thehighest activity. There is debate on the active-site mechanism of the NiFe catalysts and their long-term stability needs to beunderstood. Addition of Co to NiFe increases the conductivity of these catalysts. The same analysis for the hydrogen evolutionreaction (HER) shows carbon-supported Pt to be dominating although PtNi alloys and clusters of Ni(OH) 2 on Pt show competitiveactivities. Recent advances in forming and embedding well-dispersed Ru nanoparticles on functionalized high-surface-area carbonsupports show promising HER activities. However the stability of these catalysts under actual AEMWE operating conditions needsto be proven. The field is advancing rapidly but could benefit through the adaptation of new in situ techniques standardizedevaluation protocols for AEMWE conditions and innovative catalyst-structure designs. Nevertheless single AEM water electrolyzercells have been operated for several thousand hours at temperatures and current densities as high as 60 °C and 1 A/cm 2 respectively.

Electrochemical energy conversion systems are recognized as sustainable options for clean power generation. In conjunction with this the current hydrogen storage methods often suffer from limited storage density stability or high cost which motivate the search for alternative fuels with improved performance. This study is designed to investigate ammonium formate as an effective hydrogen storage medium and an efficient electrochemical fuel in electrochemical energy conversion systems. In order to perform the experimental tests stainless steel-stainless steel and aluminum-stainless steel electrode pairs are selected and examined under varying concentrations of potassium hydroxide sodium chloride and hydrogen peroxide at 80 ◦C and the system responses are then evaluated through voltage–time monitoring and polarization curve analysis. The aluminum-stainless steel configuration achieves the highest performance under 0.1 M potassium hydroxide and 10 % hydrogen peroxide reaching the voltages near ~ 900 mV and current densities of ~ 340 mA cm− 2 ; and the sodium chloride systems produce up to ~ 820 mV and ~ 310 mA cm− 2 while higher additive levels result in decreasing the voltages below 500 mV due to losses and side reactions. These findings confirm that moderate additive concentrations and optimized electrode pairing significantly enhance efficiency positioning ammonium formate as a low-cost energy-dense fuel suitable for decentralized and portable applications.

Underground hydrogen storage is critical for supporting the transition to renewable energy systems addressing the intermittent nature of solar and wind power. Despite its promise as a carbon-neutral energy carrier there remains limited understanding of the geomechanical behavior of subsurface reservoirs under hydrogen storage conditions. This knowledge gap is particularly significant for fast-cycling operations which have yet to be implemented on a large scale. This review evaluates current knowledge on the geomechanics of underground hydrogen storage focusing on risks and challenges in geological formations such as salt caverns depleted hydrocarbon reservoirs saline aquifers and lined rock caverns. Laboratory experiments field studies and numerical simulations are synthesized to examine cyclic pressurization induced seismicity thermal stresses and hydrogen-rock interactions. Notable challenges include degradation of rock properties fault reactivation micro-seismic activity in porous reservoirs and mineral dissolution/precipitation caused by hydrogen exposure. While salt caverns are effective for low-frequency hydrogen storage their behavior under fast-cyclic loading requires further investigation. Similarly the mechanical evolution of porous and fractured reservoirs remains poorly understood. Key findings highlight the need for comprehensive geomechanical studies to mitigate risks and enhance hydrogen storage feasibility. Research priorities include quantifying cyclic loading effects on rock integrity understanding hydrogen-rock chemical interactions and refining operational strategies. Addressing these uncertainties is essential for enabling large-scale hydrogen integration into global energy systems and advancing sustainable energy solutions. This work systematically focuses on the geomechanical implications of hydrogen injection into subsurface formations offering a critical evaluation of current studies and proposing a unified research agenda.

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.

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.

The synergy between hydrogen and water is crucial in moving towards a sustainable energy future. This study explores the integration of geothermal energy with desalination and hydrogen production systems to address water and clean energy demands. Two configurations one using multi-effect distillation (MED) and the other reverse osmosis (RO) were designed and compared. Both configurations utilized geothermal energy with MED directly using geothermal heat and RO converting geothermal energy into electricity to power desalination. The systems are evaluated based on various performance indicators including net power output desalinated water production hydrogen production exergy efficiency and levelized costs. Multi-objective optimization using an artificial neural network (ANN) and genetic algorithm (GA) was conducted to identify optimal operational conditions. Results highlighted that the RO-based system demonstrated higher water production efficiency achieving a broader range of optimal solutions and lower levelized costs of water (LCOW) and hydrogen production while the MED-based system offered economic advantages under specific conditions. A case study focused on Canada illustrated the potential benefits of these systems in supporting hydrogen-powered vehicles and residential water needs emphasizing the significant impact of using high-quality desalinated water to enhance the longevity and efficiency of proton exchange membrane electrolyzers (PEME). This research provides valuable insights into the optimal use of geothermal energy for sustainable water and hydrogen production.

With the issue of energy shortages becoming increasingly serious the need to shift to sustainable and clean energy sources has become urgent. However due to the intermittent nature of most renewable energy sources developing underground hydrogen storage (UHS) systems as backup energy solutions offers a promising solution. The thick and regionally extensive salt deposits in Unit B of Southern Ontario Canada have demonstrated significant potential for supporting such storage systems. Based on the stratigraphy statistics of unit B this study investigates the feasibility and stability of underground hydrogen storage (UHS) in salt caverns focusing on the effects of cavern shape geometric parameters and operating pressures. Three cavern shapes—cylindrical cone-shaped and ellipsoid-shaped—were analyzed using numerical simulations. Results indicate that cylindrical caverns with a diameter-to-height ratio of 1.5 provide the best balance between storage capacity and structural stability while ellipsoid-shaped caverns offer reduced stress concentration but have less storage space posing practical challenges during leaching. The results also indicate that the optimal pressure range for maintaining stability and minimizing leakage lies between 0.4 and 0.7 times the vertical in situ stress. Higher pressures increase storage capacity but lead to greater stress displacements and potential leakage risks while lower pressure leads to internal extrusion tendency for cavern walls. Additionally hydrogen leakage rate drops with the maximum working pressure yet total leakage mass keeps a growing trend.

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.

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.

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.

Hydrogen produced from renewable sources is crucial for decarbonizing hard-to-abate sectors and achieving netzero targets. This study examines hydrogen production through the novel thermo-catalytic reforming (TCR) process using agricultural and forestry residues. The research aims to develop and optimize regression models that integrate feedstock properties (ash hydrogen-to-carbon molar ratio and lignin) and process parameters (reactor and reformer temperatures) to predict yields of hydrogen (H2) syngas methane (CH4) and carbon dioxide (CO2). Three biomass feedstocks – softwood pellets (SWPs) hardwood pellets (HWPs) and wheat straw pellets (WSPs) – were analyzed at reactor temperatures of 400–550 ◦C and reformer temperatures of 500–700 ◦C. Predictive models for H2 (R2 = 0.9642 RMSE = 1.0639) and syngas (R2 = 0.9894 RMSE = 0.0140) yields show strong agreement and accuracy between the predicted and experimental values. In contrast the models for CH4 and CO2 yields show higher variability in the predictions. Reformer temperature was the most significant parameter influencing the yields of H2 and syngas. The optimal H2 yields predicted for the model were obtained for HWPs at 550/700 ◦C (26.67 g H2/kg dry biomass) followed by SWPs at 550/700 ◦C (24.11 g H2/kg dry biomass) and WSPs at 550/685.2 ◦C (18.78 g H2/kg dry biomass). The volumetric syngas yields were highest for HWPs at 550/700 ◦C (0.831 Nm3 /kg dry biomass) followed by SWPs (0.777 Nm3 /kg dry biomass) and WSPs (0.634 Nm3 /kg dry biomass). This study demonstrates that regression modelling accurately predicts H2 and syngas yields which would help to expand the applicability of TCR technology for large-scale hydrogen production contributing to the decarbonization of the energy sector.

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

Solar photovoltaic (PV)-based electricity production has gained significant attention for residential applications in recent years. However the sustainability and economic feasibility of PV systems are highly dependent on their grid-connected opportunities which may diminish with the increasing penetration of renewable energy sources into the grid. Therefore securing reliable energy storage is crucial for both grid-connected and off-grid PV-based residential facilities. Given the high capital costs and environmental issues associated with batteries hydrogen energy emerges as a superior option for medium to large residential applications. This paper proposes an innovative concept for PV-based green hydrogen production storage and utilization using solid oxide cells within residential micro-grids. It includes comprehensive techno-economic and environmental analyses of the proposed system utilizing dynamic solar data with a case study focusing on Calgary. The results indicate that seasonal hydrogen storage significantly enhances the feasibility of meeting the electricity demand of an off-grid residential community consisting of 525 households connected to a 4.6 MW solar farm. With the inclusion of Canadian clean hydrogen tax incentives the monthly cost per household is approximately $319 potentially decreasing to $239 with advancements in solid oxide cell technology and extended lifetimes of up to 80000 h. Furthermore implementing this system in Calgary could result in a monthly reduction of at least 250 kg of CO2 emissions per household.

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

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.

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.

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.

Developing a green energy strategy for municipalities requires creating a framework to support the local production storage and use of renewable energy and green hydrogen. This framework should cover essential components for small-scale applications including energy sources infrastructure potential uses policy backing and collaborative partnerships. It is deployed as a small-scale renewable and green hydrogen unit in a municipality or building demands meticulous planning and considering multiple elements. Municipality can promote renewable energy and green hydrogen by adopting policies such as providing financial incentives like property tax reductions grants and subsidies for solar wind and hydrogen initiatives. They can also streamline approval processes for renewable energy installations invest in hydrogen refueling stations and community energy projects and collaborate with provinces and neighboring municipalities to develop hydrogen corridors and large-scale renewable projects. Renewable energy and clean hydrogen have significant potential to enhance sustainability in the transportation building and mining sectors by replacing fossil fuels. In Canada where heating accounts for 80% of building energy use blending hydrogen with LPG can reduce emissions. This study proposes a comprehensive approach integrating renewable energy and green hydrogen to support small-scale applications. The study examines many scenarios in a building as a case study focusing on economic and greenhouse gas (GHG) emission impacts. The optimum scenario uses a hybrid renewable energy system to meet two distinct electrical needs with 53% designated for lighting and 10% for equipment with annual saving CAD$ 87026.33. The second scenario explores utilizing a hydrogen-LPG blend as fuel for thermal loads covering 40% and 60% of the total demand respectively. This approach reduces greenhouse gas emissions from 540 to 324 tCO2/year resulting in an annual savings of CAD$ 251406. This innovative approach demonstrates the transformative potential of renewable energy and green hydrogen in enhancing energy efficiency and sustainability across sectors including transportation buildings and mining.

The NREL Hydrogen Sensor Laboratory is comprised of researchers dedicated to furthering hydrogen sensor technology and detection methodology. NREL has teamed up with researchers at Environment and Climate Change Canada (ECCC) and Transport Canada (TC) to conduct research to quantify hydrogen emissions from Fuel Cell Electric Vehicles (FCEV). Test protocols will have a large effect on monitoring and regulating the hydrogen emissions from FCEVs. How emissions are tested will play an important role when understanding the safety and environmental implications of using FCEVs. NREL Sensor Laboratory personnel have partnered with other entities to conduct multiple variations of emissions testing for FCEVs. This experimentation includes testing different models of FCEVs under various driving conditions while monitoring the hydrogen concentration of the exhaust using several different test methods and apparatus. Researchers look to support regulatory bodies by providing useful data that can support more consistent and relevant safety and environmental standards. We plan to present on the current test methods and results from recent emissions measurements at ECCC.

Life cycle assessment which evaluates the complete life cycle of a product is considered the standard methodological framework to evaluate the environmental performance of climate change solutions. However significant challenges exist related to datasets used to quantify these environmental indicators. Although extensive research and commercial data on climate change technologies pathways and facilities exist they are not readily available to practitioners of life cycle assessment in the right format and structure using an open platform. In this study we propose a new open data hub platform for life cycle assessment considering a hierarchical data flow starting with raw data collected on climate change technologies at laboratory pilot demonstration or commercial scales to provide the information required for policy and decision-making. This platform makes data accessible at multiple levels for practitioners of life cycle assessment while making data interoperable across platforms. The proposed data hub platform and workflow are explained through the polymer electrolyte membrane electrolysis hydrogen production as a case study. The climate change environment impact of 1.17 ± 0.03 kg CO2 eq./kg H2 was calculated for the case study. The current data hub platform is limited to evaluating environmental impacts; however future additions of economic and social aspects are envisaged.

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.

Underground coal gasification (UCG) is an emerging clean energy technology with significant potential for enhanced hydrogen production especially when coupled with water injection. Previous lab-scale studies have explored this potential but the mechanisms driving water-assisted hydrogen enhancement in large-scale deep UCG settings remain unclear. This study addresses this gap using numerical simulations of a large-scale deep coal model designed for hydrogen-oriented UCG. We investigated single-point and multipoint water injection stra tegies to optimize hydrogen production. Additionally we developed a retractable water injection technique to ensure sustained hydrogen output and effective cavity control. Our results indicate that the water–gas shift re action is crucial for increasing hydrogen production. Multipoint injection has been proven to be more effective than single-point injection increasing hydrogen production by 11% with an equal amount of steam. The introduction of retractable injection allows for continuous and efficient hydrogen generation with daily hydrogen production rates of approximately five times that of a conventional injection scheme and an increase in cumulative hydrogen production of approximately 105% over the same time period. Importantly the mul tipoint injection method also helped limit vertical cavity growth mitigating the risk of aquifer contamination. These findings support the potential of UCG as a low-carbon energy source in the transition to a hydrogen economy

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%.

Hydrogen is widely recognized as a key component of a decarbonized global energy system serving as both a fuel source and an energy storage medium. While current hydrogen production relies almost entirely on emissionsintensive processes two low-emissions production pathways – natural-gas-derived production combined with carbon capture and storage and electrolysis using carbon-free electricity – are poised to change the global supply mix. Our study assesses the financial conditions under which natural-gas-based hydrogen production combined with carbon capture and storage would be available at a cost lower than hydrogen produced through electrolysis and the degree to which these conditions are likely to arise in a transition to a net-zero world. We also assess the degree to which emissions reduction policies namely carbon pricing and carbon capture and storage tax credits affect the relative costs of hydrogen production derived from different pathways. We show that while carbon pricing can improve the relative cost of both green and blue hydrogen production compared with unabated grey hydrogen targeted tax credits favouring either blue or green hydrogen explicitly may increase emissions and/or increase the costs of the energy transition.

Pipelines represent the most economical and efficient means for transporting hydrogen in large volumes across vast distances contributing to accelerated realization of hydrogen economy. Nowadays the development of hydrogen pipeline projects including repurposing existing pipelines for hydrogen service has become a global interest especially in those major energy-producing and energy-consuming countries. However steel pipelines are susceptible to hydrogen embrittlement (HE) in high-pressure hydrogen gas environments potentially leading to pipeline failures. In this review we establish a comprehensive knowledge base for comprehending testing and evaluating the gaseous HE in pipelines by a thorough examination of relevant research work. In addition to an overview of some major hydrogen pipeline projects in the world the article consists of four integral parts essential to gaseous HE studies namely methods for exposure of steels to high-pressure hydrogen gas; measurements of the quantity of H atoms inside the steels; stress-strain behavior of pipeline steels under highpressure hydrogen gas exposure; and fracture and fatigue testing of pre-cracked steels within gaseous environments. Further research into gaseous HE in pipelines focuses on developing standardized quantitative and consistent methods to assess and define the susceptibility of pipelines to gaseous HE.

Solar hydrogen and electricity are promising high energy-density renewable sources. Although photochemistry or photovoltaics are attractive routes special challenge arises in sunlight conversion efficiency. To improve efficiency various semiconductor materials have been proposed with selective sunlight absorption. Here we reported a hybrid system synergizing photo-thermochemical hydrogen and photovoltaics harvesting full-spectrum sunlight in a cascade manner. A simple suspension of Au-TiO2 in water/methanol serves as a spectrum selector absorbing ultraviolet-visible and infrared energy for rapid photo-thermochemical hydrogen production. The transmitted visible and near-infrared energy fits the photovoltaic bandgap and retains the high efficiency of a commercial photovoltaic cell under different solar concentration values. The experimental design achieved an overall efficiency of 4.2% under 12 suns solar concentration. Furthermore the results demonstrated a reduced energy loss in full-spectrum energy conversion into hydrogen and electricity. Such simple integration of photo-thermochemical hydrogen and photovoltaics would create a pathway toward cascading use of sunlight energy.

The transition towards clean and economically viable hydrogen production is crucial for ensuring energy sustainability and mitigating climate change. This transition can be effectively facilitated by using renewable energy sources and advanced hydrogen production methods. Methane pyrolysis and water electrolysis emerge as crucial techniques for achieving hydrogen production with minimal carbon intensity. Recognizing the unique opportunity presented by solar energy for both processes this study presents a comparative techno-economic analysis between solar-based molten salt methane pyrolysis (SMSMP) and solar-based solid oxide electrolyzer cell (SSOEC). This study offers a guideline for selecting SMSMP vs SSOEC for cities across theworld. In particular a comprehensive case study including five cities worldwide—San Antonio Edmonton Auckland Seville and Lyon—is conducted utilizing their dynamic solar data and localized prices of methane and electricity to provide a realistic comparison. The results indicate the superior economic feasibility of SMSMP across all case studies. Among different case studies San Antonio and Auckland have the lowest hydrogen costs for SMSMP (2.31 $/kgH2) and SSOEC (5.19 $/kgH2) respectively. It was also concluded that SMSMP is preferred over SSOEC in average to ideal solar conditions given its full dependency on solar thermal energy. However the SSOEC has the potential to achieve better economic feasibility by incorporating clean hydrogen tax incentives and reducing the costs associated with renewable energy infrastructure in the future.

This study investigates the light gas dispersion behaviour in a maintenance garage with natural or forced ventilation. A scaled-down garage model (0.71 m high 3.07 m long and 3.36 m wide) equipped with gas and velocity sensors was used in the experiments. The enclosure had four rectangular vents at the ceiling and four at the bottom on two opposing side walls. The experiments were performed by injecting helium continuously through a 1-mm downward-facing nozzle until a steady state was reached. The sensitivity parameters included helium injection rate the elevation of the injection nozzle and forced flow speeds. Exhaust fans were placed at one or all of the top vent(s) to mimic forced ventilation. Numerical simulations conducted using GOTHIC a general-purpose thermal-hydraulic code and calculations with engineering models were compared with experimental measurements to determine the relative suitability of each approach to predict the light gas transport behaviour. The GOTHIC simulations captured the trends of the helium distribution gas movement in the enclosure and the passive vent flows reasonably well. Lowesmith’s model predictions for the helium transients in the upper uniform layer were also in good agreement with the natural venting experiments.

Electric bus transit is crucial in reducing greenhouse gas (GHG) emissions decreasing fossil fuel reliance and combating climate change. However the transition to electric-powered buses demands a comprehensive plan for optimal resource allocation technology choice infrastructure deployment and component sizing. This study develops system configuration optimization models for battery electric buses (BEBs) and hydrogen fuel cell buses (HFCBs) minimizing all related costs (i.e. capital and operational costs). These models optimize component sizing of the charging/refueling stations fleet configuration and energy/fuel management system in three operational schemes: BEBs opportunity charging BEBs overnight charging and electrolysis-powered HFCBs overnight refueling. The results indicate that the BEB opportunity system is the most economically viable choice. Meanwhile HFCB requires a higher cost (134.5%) and produces more emissions (215.7%) than the BEB overnight charging system. A sensitivity analysis indicates that a significant reduction in the HFCB unit and electricity costs is required to compete economically with BEB systems.

Many small Canadian communities lack access to electricity grids relying instead on costly and polluting diesel generators despite the local availability of renewable energies like solar and wind. The intermittent nature of these sources limits reliable power supply; thus hydrogen is proposed as a cost-effective and ecofriendly long-term energy storage solution. However it remains uncertain whether hydrogen storage can significantly contribute to a 100% renewable energy system (100RES) given the diverse characteristics of these communities. Additionally the potential for fully renewable infrastructure to reduce costs mitigate adverse environmental impacts and enhance social impact is still unclear. A multi-period optimization model that balances economic environmental and social objectives to determine the optimal configuration of 100RESs for isolated communities is introduced and utilized to evaluate hydrogen as an energy storage solution to seasonal fluctuations. By identifying the best combinations of technologies tailored to local conditions and priorities this study offers valuable insights for policymakers supporting the transition to sustainable energy and achieving national climate goals. The results demonstrate that hydrogen could serve as an excellent longterm energy storage option to address energy shortages during the winter. Different combinations and sizes of energy generation and storage technologies are selected based on the characteristics of each community. For instance a community in the northern territories with high wind speeds low solar radiation extremely low temperatures and limited biomass resources should optimally rely on wind turbines to meet 80.7% of its total energy demand resulting in a 62.0% cost reduction and a 49.5% decrease in environmental impact compared to the existing diesel-based system. By 2050 all communities are projected to reduce energy costs per capita with northern territories achieving 33% and coastal areas achieving 55% cost reductions eventually leading to the utilization of hydrogen as the main energy storage medium.

Trains have been a crucial part of modern transport and their high energy efficiency and low greenhouse gas emissions make them ideal candidates for the future transport system. Transitioning from diesel trains to hydrogen fuel cell electric trains is a promising way to decarbonize rail transport. That’s because the fuel cell electric trains have several advantages over other electric trains such as lower life-cycle emissions and shorter refueling time than battery ones and less requirements for wayside infrastructure than the ones with overhead electric wires. However hydrogen fuel technology still needs to be advanced in areas including hydrogen production storage refueling and on-board energy management. Currently there are several pilot projects of hydrogen fuel cell electric trains across the globe especially in developed countries including one commercialized and permanent route in Germany. The experiences from the pilot projects will promote the technological and economic feasibility of hydrogen fuel in rail transport.

The industry is advancing decarbonization in hydrogen production through water splitting technologies like water electrolysis which involves the hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode. Alkaline water electrolyser (AWE) is particularly suited for industrial applications due to its use of cost-effective and abundant nickel-based electrodes. However AWE faces significant challenges including energy losses from gas bubble coverage and poor detachment known as “bubble resistance”. Recent research highlights the role of power ultrasound in mitigating these issues by leveraging Bjerknes forces. These forces facilitate the ejection of larger bubbles and the coalescence of smaller ones enhancing gas removal. Additionally ultrasound improves mass transfer from the electrolyte to electrodes and boosts heat transfer via acoustic streaming and acoustic cavitation which the latter also enhances electrocatalytic properties for both HER and OER. However employing ultrasonic fields presents both benefits and challenges for scaling the system.

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 great number of large-scale experiments have been conducted in the framework of national and international projects to understand the hydrogen dispersion and combustion behavior under postulated accidental conditions. Empirical engineering models and computer codes have been developed and validated for safety analysis. Hydrogen recombiners known as Passive Autocatalytic Recombiners (PARs) 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 have been 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.

This study investigates hydrogen (H2) as a supplementary fuel in heavy-duty diesel engines using pre-manifold injection. A H2-diesel dual-fuel (H2DF) system was implemented on a commercial class-8 heavy-duty diesel truck without modifying the original diesel injection system and engine control unit (ECU). Tests were conducted on a chassis dynamometer at engine speeds between 1000 and 1400 rpm with driver-demanded torques from 10 to 75%. The hydrogen energy fraction (HEF) was strategically controlled in the range between 10 and 30%. Overall CO2 reduction (comparable to the HEF level) was achieved with similar brake-specific energy consumption (BSEC) at all loads and speeds. To maintain the same shaft torque the driver-demanded torque was reduced in H2DF operation which resulted in a lower boost pressure. At higher loads engine-out BSNOx slightly decreased while BSCO and black carbon (BC) increased significantly due to lower oxygen concentration resulting from the lower boost pressure. At lower loads engine-out BSCO and BSBC decreased moderately while NO2/NO ratio increased substantially in H2DF operation. Deliberate air path and diesel injection control are expected to enable higher HEF and GHG reductions.

Hydrogen is a potential source of imminent clean energy in the future with its transportation playing a crucial role in allowing large-scale deployment. The challenge lies in selecting an effective sustainable and scalable transportation alternative. This study develops a multi-criteria decision-making (MCDM) framework based on the intuitionistic fuzzy analytic hierarchy process (IF-AHP) to evaluate land-based hydrogen transportation alternatives across Canada. The framework includes uncertainty and decision-maker hesitation through the application of triangular intuitionistic fuzzy numbers (TIFNs). Seven factors their subsequent thirty-three subfactors and three alternatives to hydrogen transportation were identified through a literature review. Pairwise comparison was aggregated among factors subfactors and alternatives from three decision makers using an intuitionistic fuzzy weighted average and priority weights were computed using entropy-based weight. The results show that safety and economic efficiency emerged as the most influential factors in the evaluation of hydrogen transportation alternatives followed by environmental impact security and social impact and public health in ascending order. Among the alternatives tube truck transport obtained the highest overall weight (0.3551) followed by pipelines (0.3272) and rail lines (0.3251). The findings suggest that the tube ruck is currently the most feasible transport option for land-based hydrogen distribution that aims to provide a transition of Canada’s energy mix.

The integration of renewable resources with advanced storage technologies is critical for sustainable energy systems. In this paper a planning framework for an energy hub incorporating hydrogen and renewable energy systems is developed with the objective of minimizing operational costs while participating in flexible ramping product (FRP) markets. The energy hub is designed to utilize a hybrid storage system comprising multi-type battery energy storage (BESS) accounting for diverse chemistries and degradation behaviors and hydrogen storage (HS) to meet concurrent electric and hydrogen demands. To address uncertainties in renewable generation and market prices a stochastic optimization model is developed to determine the optimal investment capacities while optimizing operational decisions under uncertainty using scenario-based stochastic programming. Financial risks associated with price and renewable variability are mitigated through the Conditional Value-at-Risk (CVaR) metric. Case studies demonstrate that hybrid storage systems including both BESS and HS can reduce total costs by 23.62% compared to single-storage configurations that rely solely on BESS. Based on the results BESS participates more in providing flexible ramp-up services while HS plays a major role in providing flexible ramp-down services. The results emphasize the critical role of co-optimized hydrogen and multi-type BESS in enhancing grid flexibility and economic viability.

Natural hydrogen or "white hydrogen" has recently garnered attention as a viable and cost-effective energy resource due to its low-carbon footprint and high energy density positioning it as a key contributor to the transition towards a sustainable low-carbon energy system. This study represents Alberta’s first systematic effort to evaluate natural hydrogen potential in the province using publicly available geological geospatial and gas composition datasets. By mapping hydrogen occurrences against key geological features in the Western Canadian Sedimentary Basin (WCSB) we identify regions with strong geological potential for natural hydrogen generation migration and accumulation while addressing data uncertainties. Within the WCSB formations like the Montney Cardium Bearpaw Manville Belly River McMurray and Lea Park are identified as zones likely for hydrogen generation by prominent mechanisms including hydrocarbon decomposition water-rock reactions with iron-rich sediments and organic pyrolysis. Formation proximity to the underlying Canadian Shield may also suggest potential for basement-derived hydrogen migration via deep-seated faults and shear zones. Salt deposits (Elk Point Group - Prairie evaporites Cold Lake and Lotsberg) and deep shales (e.g. Kaskapau Lea Park Wapiabi) provide effective cap rock potential while reservoirs like porous sandstone (e.g. Dunvegan Spirit River Cardium) and fractured carbonate (e.g. Keg River) formations offer favorable accumulation conditions. Hydrogen occurrences in relation to geological features identify Southern Eastern and West-Central plains as prominent natural Hydrogen generation and accumulation areas. Alberta’s established energy infrastructure as well as subsurface expertise positions it as a potential leader in natural hydrogen exploration. As Alberta’s first systematic investigation this study provides a preliminary assessment of natural hydrogen potential and outlines recommended next steps to guide future exploration and research. Targeted research on specific generation and accumulation mechanisms and source identification through isotopic and geochemical fingerprinting will be crucial for exploration de-risking and viability assessment in support of net-zero emission initiatives.

This paper compares national hydrogen (H2) infrastructure plans in Canada the United States (the USA) Singapore and Sri Lanka four countries with varying geographic and economic outlooks but shared targets for reaching net-zero emissions by 2050. It examines how each country approaches hydrogen production pipeline infrastructure policy incentives and international collaboration. Canada focuses on large-scale hydrogen production utilizing natural resources and retrofitted natural gas pipelines supplemented by carbon capture technology. The USA promotes regional hydrogen hubs with federal investment and intersectoral collaboration. Singapore suggests an innovation-based import-dominant strategy featuring hydrogen-compatible infrastructure in a land-constrained region. Sri Lanka maintains an import-facilitated pilot-scale model facilitated by donor funding and foreign collaboration. This study identifies common challenges such as hydrogen embrittlement leakages and infrastructure scalability as well as fundamental differences based on local conditions. Based on these findings strategic frameworks are proposed including scalability adaptability partnership policy architecture digitalization and equity. The findings highlight the importance of localized hydrogen solutions supported by strong international cooperation and international partnerships.

Underground hydrogen storage (UHS) in salt caverns is emerging as a promising solution for the transition to a sustainable energy future. However a thorough understanding of hydrogen flow mechanisms through salt rock is essential to ensure safe and efficient storage operations. In this study we conducted hydrogen flow experiments in salt rocks using the pressure pulse decay (PPD) method covering a range of hydrogen pore pressures from 0.4 MPa to 7.5 MPa within the slip and transitional flow regimes (Knudsen numbers between 0.04 and 1.5). The Knudsen numbers were determined by measuring the pore size distribution (PSD) of the salt rock samples and assigning an average pore size to each sample based on the measured PSD. Our results indicate that the intrinsic permeability of the tested salt rock samples ranges from 5 × 10− 21 m2 to 1.0 × 10− 20 m2 . However a significant enhancement in apparent permeability up to 10 times the intrinsic permeability was observed particularly at lower pressures. This permeability enhancement is attributed to the nanoscale pore structure of salt rocks where the mean free path of hydrogen becomes comparable to the pore sizes leading to a shift from slip flow to the transitional flow regime. The results further reveal that the first-order slip model underestimates the apparent permeability in the transitional flow regime despite its satisfactory accuracy in the slip region. Moreover the higher-order slip model demonstrates acceptable accuracy across both the slip and transitional flow regimes.

With the transition to a fully renewable energy grid arises the need for a green source of stability and baseload support which classical renewable generation such as wind and solar cannot offer due to their uncertain and highly-variable generation. In this paper we study whether green hydrogen can close this gap as a source of supplemental generation and storage. We design a two-stage mixed-integer stochastic optimization model that accounts for uncertainties in renewable generation. Our model considers the investment in renewable plants and hydrogen storage as well as the operational decisions for running the hydrogen storage systems. For the data considered we observe that a fully renewable network driven by green hydrogen has a greater potential to succeed when wind generation is high. In fact the main investment priorities revealed by the model are in wind generation and in liquid hydrogen storage. This long-term storage is more valuable for taking full advantage of hydrogen than shorter-term intraday hydrogen gas storage. In addition we note that the main driver for the potential and profitability of green hydrogen lies in the electricity demand and prices as opposed to those for gas. Our model and the investment solutions proposed are robust with respect to changes in the investment costs. All in all our results show that there is potential for green hydrogen as a source of baseload support in the transition to a fully renewable-powered energy grid.

As hydrogen fuel cell vehicles gain momentum as crucial zero-emission transportation solutions the urgency to address hydrogen permeability through the polymer liner becomes paramount for ensuring the safety efficiency and longevity of Type IV hydrogen storage tanks. This paper synthesizes existing research findings analyzes the influence of different materials and structures on gas permeability elucidates the dissolution and diffusion mechanisms of hydrogen in plastic liners and discusses their engineering applications. We focus on measurement methods influencing factors and improvement strategies for liner gas permeability. Additionally we explore the prospects of Type IV hydrogen storage tanks in fields such as automotive aerospace and energy storage industries. Through this comprehensive review of liner gas permeability critical insights are provided to guide the development of efficient and safe hydrogen storage and transportation systems. These insights are vital for advancing the widespread application of hydrogen energy technology and fostering sustainable energy development significantly contributing to efforts aimed at enhancing the performance and safety of Type IV hydrogen storage tanks.

Hydrogen is increasingly recognized as a key energy vector for achieving deep decarbonization across urban and industrial sectors. Supporting global efforts to reduce greenhouse gas (GHG) emissions and achieve the Sustainable Development Goals (SDGs) it is essential to understand the multi-sectoral role of the hydrogen value chain spanning production storage and end-use applications with particular emphasis on smart city systems and industrial processes. Green hydrogen production technologies including alkaline water electrolysis (AWE) proton exchange membrane (PEM) electrolysis anion exchange membrane (AEM) electrolysis and solid oxide electrolysis cells (SOECs) are evaluated in terms of efficiency scalability and integration potential. Storage pathways are examined across physical storage (compressed gas cryo-compressed and liquid hydrogen) material-based storage (solid-state absorption in metal hydrides and chemical carriers such as LOHCs and ammonia) and geological storage (salt caverns depleted gas reservoirs and deep saline aquifers) highlighting their suitability for urban and industrial contexts. In the smart city domain hydrogen is analyzed as an enabler of zero-emission transportation low-carbon residential and commercial heating and renewable-integrated smart grids with long-duration storage capabilities. System-level studies demonstrate that coordinated integration of these applications can deliver higher overall energy efficiency deeper reductions in life-cycle GHG emissions and improved resilience of urban energy systems compared with sector-specific approaches. Policy frameworks safety standards and digitalization strategies are reviewed to illustrate how hydrogen infrastructure can be embedded into interconnected urban energy systems. Furthermore industrial applications focus on hydrogen’s potential to decarbonize energy-intensive processes and enable sector coupling between electricity heat and manufacturing. The environmental implications of hydrogen deployment are also considered including resource efficiency life-cycle emissions and ecosystem impacts. In contrast to reviews addressing isolated aspects of hydrogen technologies this study synthesizes technological infrastructural and policy dimensions integrating insights from over 400 studies to highlight the multifaceted role of hydrogen in sustainable urban development and industrial decarbonization and the added benefits achievable through coordinated cross-sector deployment strategies.

The transportation industry significantly contributes to greenhouse gas (GHG) emissions. Federal and provincial governments have implemented strategies to decrease dependence on gasoline and diesel fuels. This encompasses promoting the adoption of electric cars (EVs) and biofuel alternatives investing in renewable energy sources and enhancing public transit systems. There is a growing focus on enhancing infrastructure to facilitate active transportation modes like cycling and walking which provide the combined advantages of decreasing emissions and advancing public health. In this paper we propose a System Dynamics simulation model for evaluating factors for the adoption of alternative-fuel vehicles such as EVs biofuel vehicles bus bikes and hydrogen vehicles. Five factors— namely customer awareness government initiatives cost of vehicles cost of fuels and infrastructure developments—to increase the adoption of alternative-fuel vehicles are studied. Two scenarios are modeled: A baseline scenario that follows the existing trends in transportation (namely the use of gasoline vehicles) Scenario 1 which prioritizes greater adoption of electric vehicles (EVs) and biofuel-powered vehicles and Scenario 2 which prioritizes hydrogen fuel-based vehicles and improves biking culture. The simulation findings show that all scenarios achieve reductions in GHG emissions compared to the baseline with Scenario 2 showing the lowest emissions. The proposed work is useful for transport decision makers and municipal administrators in devising policies for reducing overall GHG emissions and this also aligns with Canada’s net zero goals.