Refueling Stations Research Articles

From Curtailed Renewable Energy to Green Hydrogen: Infrastructure Planning for Hydrogen Fuel-Cell Vehicles

Problem definition: Hydrogen fuel-cell vehicles (HFVs) have been proposed as a promising green transportation alternative. For regions experiencing renewable energy curtailment, promoting HFVs can achieve the dual benefit of reducing curtailment and developing sustainable transportation. However, promoting HFVs faces several major hurdles, including uncertain vehicle adoption, the lack of refueling infrastructure, the spatial mismatch between hydrogen demand and renewable sources for hydrogen production, and the strained power transmission infrastructure. In this paper, we address these challenges and study how to promote HFV adoption by deploying HFV infrastructure and utilizing renewable resources. Methodology/results: We formulate a planning model that jointly determines the location and capacities of hydrogen refueling stations (HRSs) and hydrogen plants as well as electricity transmission and grid upgrade. Despite the complexity of explicitly considering drivers’ HFV adoption behavior, the bilevel optimization model can be reformulated as a tractable mixed-integer second-order cone program. We apply our model calibrated with real data to the case of Sichuan, a province in China with abundant hydro resources and a vast amount of hydropower curtailment. Managerial implications: We obtain the following findings. (i) The optimal deployment of HRSs displays vastly different spatial patterns depending on the HFV adoption target. The capital city, a transportation hub, is excluded from the plan under a low target and only emerges as the center of HFV adoption under a high target. (ii) Promoting the HFV adoption can overall help reduce hydropower curtailment, but the effectiveness depends on factors such as the adoption target and the grid upgrade cost. (iii) Being a versatile energy carrier, hydrogen can be transported to various locations, which allows for strategic placement of HRSs in locations distinct from hydrogen plant sites. This flexibility offers HFVs greater potential cost savings and curtailment reduction compared with other alternative fuel vehicles (e.g., electric vehicles) under current cost estimates. Funding: W. Qi acknowledges the support from the National Natural Science Foundation of China [Grants 72242106 and 72188101] and the Natural Sciences and Engineering Research Council of Canada [Grant RGPIN-2019-04769]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2022.0381 .

The AI circular hydrogen economist: Hydrogen supply chain design via hierarchical deep multi-agent reinforcement learning

Hydrogen supply chain (HSC) consists of various production, conditioning, transportation, storage, and distribution processes, all of which require extensive computational resources for precise modelling. In this context, artificial intelligence (AI) is emerging as a pivotal tool for addressing model-based decision-making challenges, courtesy of its rapid and efficient computational capabilities. This paper proposes a comprehensive HSC model consisting of an economic policy planner, a wholesale hydrogen market, a power supply system, a hydrogen distribution system (HDS), and hydrogen refueling stations (HRSs). It leverages an AI circular hydrogen economist approach based on a hierarchical deep multi-agent reinforcement learning (MARL) algorithm, offering a new alternative to traditional multi-objective bi-level optimization platforms. The model incorporates green, blue, and gray hydrogen production processes as viable hydrogen production pathways, with the hierarchical MARL’s agents representing the HDS and HRSs at two decision-making levels. Energy requirements are met through a combination of on-site renewable energy sources, the main power grid, or distributed power generation systems. Several HSC scenarios are examined with respect to various combinations of green hydrogen supply rates and carbon credits granted to them under optimum conditions. The results showed that the developed hierarchical MARL has the potential to replace mathematical programming (MP), uncovering a new economic-environmental trade-off between profit of HDS and operational costs of HRSs. Notably, green hydrogen transactions exponentially increase within the supply chain as the carbon credits exceed $1 per kilogram of hydrogen. While this research focuses on optimizing daily operations within the HSC, future efforts can aim to extend this optimization to forecasted annual operations.

Dynamic risk analysis of hydrogen refueling station gas cloud explosions based upon the bow-tie perspective

The rapid development of hydrogen refueling station (HRS) has induced potentially serious risk exposure to public safety. Consequently, the safety issues associated with HRS have become a research hotspot. A comprehensive methodology for risk analysis of hydrogen facilities was proposed. A failure tree analysis (FTA) was used for hazard analysis while a bow-tie diagram and Bayesian network were applied to model the worst-case accident scenario and to analyse the risks of root event. In addition, the fuzzy set theory combined with FTA was employed to calculate the failure probability of the hydrogen facilities. The risk analysis of a HRS was implemented with the proposed method. The results showed that the vapour cloud explosion (VCE) of compressors in the gas HRS was the most risky scenario with the probability of 8.12E–04 before taking safety measures. The death, severely injured, and minor injured radius of the VCE from compressors was 35.5, 20.0, and 10.3 m, respectively. Results also revealed that after taking several safety barriers, the risk level converted from an intolerable risk level to a tolerable risk with control level.

The impact of hydrogen fuel cell heavy-duty trucks purchase subsidies on air quality.

The pollutant emissions of diesel-powered heavy-duty trucks (HDTs) seriously damage the air quality. The promotion of hydrogen fuel cell HDTs through purchase subsidy policy to reduce emissions has become an important approach to control air pollution. This study focuses on the impact of hydrogen fuel cell HDT purchase subsidies on air quality in the context of China, covering the panel data of 31 Chinese cities from 2014 to 2021 and applying a two-way fixed effects model to analyze the contribution of purchase subsidies and hydrogen refueling station construction subsidies to air quality. Results show that (1) the increase in purchase subsidies could improve the air quality by around 6.1% and there is a lag effect. (2) Purchase subsidies make a larger contribution to air quality compared with construction subsidies. (3) Purchase subsidies can improve air quality by reducing carbon emissions in transport industry. In sight of these results, policy makers should emphasize the implementation of purchase subsidies and hydrogen refueling station construction subsidies and stimulate manufacturers to improve the performance of hydrogen fuel cell so as to contribute more to the environment.

Prediction of Hydrogen Storage Vessel Explosion with Blast Wall using Machine Learning

We present a prediction of hydrogen storage vessel explosion using machine learning. A neural network model is trained to learn the waveform of a hydrogen explosion with a blast wall and used to predict the waveform with arbitrary blast wall position. The initial training revealed one of the features, blast wall distance, greatly affects the blast waveform. To emphasize the effect of that feature, feature multiplication is used instead of normalization and this enabled the training to learn the waveform correctly. The trained model can predict the blast waveform with an arbitrarily located blast wall. The result can be used in structural analysis and this will help to construct the blast wall in the hydrogen refuelling station. This research uses the CFD (Computational Fluid Dynamics) simulation by Pukyong University, South Korea, as training data.

Characterization of WO3/Silicone Rubber Composites for Hydrogen-Sensitive Gasochromic Application.

WO3 and silicone rubber (SR)-based gasochromic composites were fabricated to detect hydrogen leaks at room temperature. WO3 rod-like nanostructures were uniformly distributed in the SR matrix, with a particle size of 60-100 nm. The hydrogen permeability of these composites reached 1.77 cm3·cm/cm2·s·cmHg. At a 10% hydrogen concentration, the visible light reflectance of the composite decreased 49% during about 40 s, with a color change rate of 6.4% s-1. Moreover, the composite detected hydrogen concentrations as low as 0.1%. And a color scale was obtained for easily assessing hydrogen concentrations in the environment based on the color of composites. Finally, the composite materials as disposable sensors underwent testing at several Sinopec hydrogen refueling stations.

Exploring hydrogen storage safety research by bibliometric analysis

The application of hydrogen energy is affected by the safety of hydrogen storage system. To grasp the current status of research and application in the research field of hydrogen storage safety and explore its research development trend, data analysis techniques, such as co-occurrence, co-citation, and burst detection, were adopted to conduct bibliometric analysis of the relevant literature. The study results show that the research hotspots of hydrogen storage safety mainly concentrate on six aspects: the stability of metal hydride hydrogen storage materials, the study of thermal management and stress relief in metal hydride reactors, the safety analysis of hydrogen fuel cells and hydrogen leakage monitoring, the analysis of leakage and explosion risks in hydrogen refueling stations, the study of filling pressure and temperature distribution in hydrogen storage tanks, and the study of safety issues in underground hydrogen storage. Mg-based hydride stability and underground hydrogen storage risk analyses are current research frontiers in hydrogen storage safety.

Economic and technical evaluation of on-site electrolysis solar hydrogen refueling station in Corsica: A case study of Ajaccio

The European Union's ambitious target of achieving climate neutrality by 2050 necessitates a transition away from fossil fuels towards renewable energy sources. Hydrogen has emerged as a promising alternative, particularly as a fuel for large-scale transportation, including heavy-duty vehicles. The fleet buses in Ajaccio travel 1 494 007.9 km per year, responsible for 1453.67 tonnes of CO2 emissions annually. Utilizing green hydrogen, derived from renewable sources, can reduce these emissions by 87.3 %. This paper conducts a comprehensive techno-economic analysis of a hydrogen refueling station, aiming to foster the adoption of this technology and gain widespread acceptance. Our objective is to determine the economic viability of a hydrogen station capable of producing 440 kg of hydrogen daily. The Levelized Hydrogen Cost (LHC) is found to be 6.95 €/kg over a 20-year lifespan with electrolyzers operating at a power of 4.5 MW. The total installation cost amounts to 22 324 617 €. Remarkably, the return on investment is realized in the 11th year of operation. Electrolyzers account for 46 % of the system's total CAPEX and 29 % of its OPEX, indicating that advancements in electrolyzer technology will play a crucial role in reducing production costs. Our findings underscore the economic viability of the hydrogen refueling station, with a compelling LHC value indicative of its cost-effectiveness. The successful return on investment within a relatively short timeframe highlights the project's potential as a financially sound and sustainable initiative.

Methodology for optimally designing hydrogen refueling station barriers using RSM and ANN: Considering explosion and jet fire

Hydrogen is gaining attention as a sustainable energy source with the potential to replace fossil fuels. Due to its high diffusivity and wide flammability range, hydrogen can easily ignite with minimal electrical energy, leading to explosion and fires with minimal friction. Effective blast walls can restrict the dispersion of hydrogen, reducing the explosion overpressure due to delayed ignition. In addition, firewalls can improve safety by minimizing the impact behind the walls, thereby reducing the radiant heat caused by jet fires. This study proposes to optimize the distance between leak sources and barriers, as well as the height and width of barriers, to address explosion overpressure and radiation heat at hydrogen refueling stations (HRS). The optimization was carried out using Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) and validated by simulations. This study confirms the feasibility of the barrier design at HRS and contributes to the improvement of safety.

Design and techno-economic analysis of solar energy based on-site hydrogen refueling station

This paper presents a detailed techno-economic review and assessment of a hydrogen refueling station (HRS) powered by a grid-connected photovoltaic (PV) system to address the issues of carbon emissions and energy sustainability in transportation. In the study, the HRS system with 1, 3 and 5 MW PV installed capacity for Ankara, the capital city of Türkiye, is considered for different system lifetimes. In the proposed HRS, on-site hydrogen production is achieved through anion exchange membrane water electrolysis (AEMWE) using a grid-connected PV system, and the produced hydrogen is stored in a cascaded storage system and is utilized at the HRS station. In order to evaluate the cost competitiveness and economic viability of the designed HRS system, the levelized cost of hydrogen (LCOH) is determined by considering the initial investment costs, operating expenses and potential revenue streams. The results show that the HRS capacity, PV installed capacity and system lifetime significantly impact the LCOH. The technoeconomic analysis results show that the best system configuration was determined as 8.54 €/kg H2 in the 20-year long term refueling scenario for a 5 MW installed PV capacity with a daily refueling capacity of 170 kg H2. This study contributes to the development of sustainable energy infrastructure by providing a comprehensive framework for the design, calculation and economic evaluation of PV-integrated hydrogen refueling stations. The results provide valuable information for policymakers, industry stakeholders, and researchers to help achieve a carbon-neutral transportation sector and promote energy sustainability.

Multi-period urban hydrogen refueling stations site selection and capacity planning with many-objective optimization for hydrogen supply chain

The location and quantity of hydrogen refueling stations (HRSs) play a crucial role in the development and promotion of hydrogen fuel cell vehicles (HFCVs). This study proposes a multi-period urban HRSs site selection and capacity planning with many-objective optimization framework for hydrogen supply chain (HSC). Firstly, the city's multi-period hydrogen requirement is predicted based on a generalized Bass diffusion model. Using publicly available data, including gas station network data, geographic information system (GIS) data, population data, and regional economic data, a spatially aggregated demand model is established to allocate hydrogen requirement at candidate sites in the city of the geographic grid model with a 1 km resolution. On this basis, four interrelated objective functions (total investment cost, hydrogen requirement coverage, risk coefficient, and environmental factors) are developed. The third-generation non-dominated sorting genetic algorithm (NSGA-III) and the technique for order preference by similarity to an ideal solution (TOPSIS) are employed to achieve multi-period urban HRSs site selection and capacity planning with many-objective optimization for HSC. By comparing the results of single-objective optimization focusing on minimum cost and maximum hydrogen requirement coverage, it is observed that many-objective optimization achieves a better balance among the four conflicting objectives. After comprehensive analysis, the distribution of HRSs exhibits a clustered structure, influenced by the population and economic structure of the city. In the initial stages of HFCV development, most stations serve the peripheral areas around the city center; while n the later stages of the optimization period, a few high-capacity HRSs begin to concentrate in the city center.

Cross-national examination of facilitators and hindrances to the public acceptance of hydrogen refuelling facilities

Recognising the factors that shape the public acceptance of hydrogen refuelling facilities is essential for gaining social support for the widespread implementation of hydrogen infrastructure. This study applies a cross-national research perspective to investigate the public acceptance of hydrogen refuelling facilities using stated-preference survey data. Moreover, multidimensional explanatory variables encompassing hydrogen energy awareness levels, hydrogen refuelling station configurations, residential characteristics, car ownership and use, and sociodemographics are used to interpret public acceptance. The data revealed that 21.1 %, 45.5 %, and 31.5 % of the respondents in Japan, Spain, and Norway expressed support for such facilities near their residences, respectively. An important discovery was the validation of nonproportional odds in acceptance measurements across countries, which challenges the conventional assumptions of parallel regression and suggests that distinct behavioural determinants shape positive, negative, and neutral attitudes. Consequently, a generalised ordinal logistic regression approach was applied to identify the determinants of varying acceptance levels and mitigate the biases from nonproportional odds. In addition to identifying facilitators and hindrances, the results highlight several predictors with polarising effects. These findings provide public feedback for enhancing the planning of hydrogen infrastructure and offer potential pathways for hydrogen risk communication and policymaking.

Energy-Efficient and Sustainable Design of a Hydrogen Refueling Station Utilizing the Cold Energy of Liquid Hydrogen

Energy-Efficient and Sustainable Design of a Hydrogen Refueling Station Utilizing the Cold Energy of Liquid Hydrogen

How structural health monitoring can be embedded in a digital quality infrastructure: an example.

The digital Quality Infrastructure (QI) initiative “QI-Digital” in Germany is focusing on implementing new technologies and approaches to ensure that the task of quality assurance is more efficient and ready for the digital and green transformation of the economy. The implementation of quality control key elements, such as Smart Standards, Digital Certificates and QI-cloud solutions shall contribute to solving the socio-economic, ecological, and technological challenges of our time. Hydrogen is a key energy carrier and has the potential to play a significant role in the energy transition, especially in mobility. An essential factor for the broad acceptance of hydrogen-based mobility is the availability of refueling stations that operate reliably and safely. Using the example of a Hydrogen Refueling Station (HRS) build within the QI-Digital initative, the Federal Institute for Material Research and Testing (BAM) aims to establish a real laboratory where modern measurement techniques and new digital methods are implemented to enhance operational safety, availability, and economic efficiency and render the technology more attractive for the industry. In this work, we present an approach to establish a Structural Health Monitoring (SHM) system on a high-pressure buffer inside HRS and show how it could be embedded into a digital QI. The high-pressure buffers are essential components of the plant which are currently inspected periodically without regard to their operating history. Focusing on the transition to a continuous and digitally supported monitoring of the component’s integrity during operation the novel inspection scheme will be linked to a completely digitalized component-related documentation and tested using digital certificates. This allows the operational safety and, if necessary, the remaining useful lifetime to be assessed on an ongoing basis and to be a valuable contribution to increase the sustainability.

Application of deep learning for structural health monitoring of a composite overwrapped pressure vessel undergoing cyclic loading

Structural Health Monitoring (SHM) using ultrasonic-guided waves (UGWs) enables continuous monitoring of components with complex geometries and provides extensive information about their structural integrity and their overall condition. Composite Overwrapped Pressure Vessels (COPVs) used for storing hydrogen gases at very high pressures are an example of a critical infrastructure that could benefit significantly from SHM. This can be used to increase the periodic inspection intervals, ensure safe operating conditions by early detection of anomalies, and ultimately estimate the remaining lifetime of COPVs. Therefore, in the Digital Quality Infrastructure Initiative (QI-Digital) in Germany, an SHM system is being developed for COPVs used in a hydrogen refueling station. In this study, the results of a lifetime fatigue test on a Type IV COPV subjected to many thousands of load cycles under different temperatures and pressures are presented to demonstrate the strengths and challenges associated with such an SHM system. During the cyclic testing up to the final material failure of the COPV, a sensor network of fifteen surface-mounted piezoelectric (PZT) wafers was used to collect the UGW data. However, the pressure variations, the aging process of the COPV, the environmental parameters, and possible damages simultaneously have an impact on the recorded signals. This issue and the lack of labeled data make signal processing and analysis even more demanding. Thus, in this study, semi-supervised, and unsupervised deep learning approaches are utilized to separate the influence of different variables on the UGW data with the final aim of detecting and localizing the damage before critical failure.

Failure analysis and maintenance of hydrogen refueling stations

Failure analysis and maintenance of hydrogen refueling stations

Developing China's Hydrogen Economy: National Regulation Through Local Experimentation

AbstractHydrogen is playing an increasingly important role in China's energy and climate policy, with significant implications for the development of a global hydrogen industry. However, China's approach to the regulation of hydrogen, and, in particular, the role of local authorities in promoting hydrogen refuelling stations and fuel cell vehicles, has so far received limited scholarly attention. This article aims to contribute to the literature on hydrogen regulation and to the transnational environmental law scholarship on decentralization by examining how China promotes hydrogen at the national and local levels. The case of China shows how, in jurisdictions with a sufficient degree of decentralization, local initiatives can play a key role in driving the development of hydrogen. By testing different approaches to hydrogen regulation, local experimentation helps to manage the uncertainties associated with this new energy source. At the same time, China's experience confirms the ‘environmental federalism’ theory on the importance of regulatory harmonization to reduce transaction costs and local protectionism. As the Chinese government develops its national regulatory approach on hydrogen, it has the opportunity to take into account both local and international experience and engage with other major economies in an effort to promote an internationally harmonized regulatory landscape.

Study on Hazard Identification (HAZID) for Subterranean Liquefied Hydrogen Refueling Stations

To reduce carbon emissions globally, hydrogen fuel has emerged as a promising contender for environmentally sustainable energy transport and storage. However, hydrogen possesses several inherent safety challenges such as its propensity for rapid diffusion, a broad flammability range when mixed with air, and hydrogen embrittlement, a phenomenon where hydrogen diffuses into metals, compromising their structural integrity. Consequently, safety considerations are paramount. This study presents a hazard identification (HAZID) analysis to evaluate the feasibility of a subterranean liquid hydrogen refueling station as an alternative to conventional above-ground gaseous hydrogen refueling stations. Through this analysis, four representative accident scenarios were identified, and 17 mitigation recommendations were proposed. The implementation of these recommendations is anticipated to significantly reduce the potential for accident-related damage in subterranean liquid hydrogen refueling stations.

Multi-objective optimization of a hydrogen supply chain network: Wind and solid biomass as primary energy sources for the public transport in Sicily

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

Enhancing safety in hydrogen refuelling stations: Computational analysis of hydrogen explosion hazards

AbstractThis paper aims to enhance the understanding of hydrogen explosions in hydrogen refuelling stations and evaluate associated risk factors using computational fluid dynamics simulations. The model is first validated against the measured data for hydrogen dispersion and explosion. Different scenarios are then modelled to understand the ignition timing and location. The study estimates acceptable distances to minimize asset damage and human injury from explosion incidents. It has been found that higher wind speeds lead to faster and more extensive dispersion of the hydrogen gas released during a leak. In addition, since strong wind can act as a powerful driving force for the shock wave, the impact of the explosion is found to be less. Interestingly, moving the source of ignition to regions with higher hydrogen concentration has a marginal impact on overpressure and temperature; however, the blockage ratio can significantly amplify the overpressure. It is found that cases with high blockage, including storage room, and cases with large volumes of flammable cloud, including leakage from compressor towards the ground, have the highest hazards. The findings will provide valuable insights into fire and explosion prevention in various areas of hydrogen refuelling stations and contribute to safer hydrogen infrastructure construction.