Hydrogen Station Research Articles

Vehicle choice modeling for emerging zero-emission light-duty vehicle markets in California

To predict the market dynamics of various zero-emission vehicle (ZEV) technologies, this study introduces a dynamic discrete vehicle choice model (VCM) that investigates the probabilities associated with 14 decision factors, applying these to the purchase of ZEVs from 2020 to 2040. Market share and penetration results are presented under eight scenarios, that vary by vehicle costs infrastructure development and incentive strategies. The findings suggest that in the early years, incentives alone may not generate significant market penetration of ZEVs before the infrastructure meets the basic convenience for daily use, especially for fuel cell vehicles (FCVs). However, in later years, incentives play a more important role in the market penetration of ZEVs under well-defined infrastructure networks. By 2040, battery electric vehicles (BEVs) are projected to dominate the market in California. Plug-in hybrid electric vehicles (PHEVs) and FCVs may experience a decline in market share due to improved charging convenience, which benefits the market penetration of BEVs. However, fuel cell plug-in hybrid electric vehicles (FC-PHEVs) could still be beneficial if accessible models are available, considering the limited availability of hydrogen refueling stations. The goal set by the California Air Resources Board (CARB) is achievable, but it requires a sustained combination of measures; no single effort can achieve it. These measures include technological improvements to reduce the cost of ZEVs, a wider range of models available for consumers to choose from based on their desired performance, the establishment of infrastructure (battery chargers and hydrogen dispensers), and attractive incentives aimed at promoting ZEV adoption. The proposed methodology can be adapted for other regions in the United States and globally by carefully examining the inputs for each decision factor at the desired scale.

Real-time energy management strategy of the hydrogen-coupled microgrid based on Informer model prediction results and deep reinforcement learning

Abstract Microgrids (MG) powered by emerging distributed energy resources (DERs) are increasingly pivotal in driving the decarbonization of the power system. Due to the uncertainty of renewable energy sources, electricity generated from wind and solar is typically stored, either in batteries or in the form of high-pressure hydrogen gas within hydrogen storage tanks to meet the refuelling requirements of fuel cell vehicles (FCVs). For FCVs, the substantial operational expenses associated with hydrogen refuelling stations pose a significant barrier to their widespread adoption, with a notable portion of these costs attributed to hydrogen transportation. To address this challenge, this paper employs the Informer model based on a transformer for day-ahead prediction of photovoltaic power generation, as well as load demand forecasting. Subsequently, the Twin-delayed deep deterministic (TD3) policy gradient algorithm is used for real-time energy management of the microgrid. While ensuring that the State of Charge (SOC) remains above 45% daily to meet future hydrogen demands, the MG pursues an optimal strategy to minimize the total daily cost, including electricity procurement, carbon emissions and equipment degradation. Compared to outcomes derived from rule-based approaches, the algorithm introduced in this paper minimizes solar waste and equipment degradation, facilitating hydrogen production during low-cost electricity periods and enhancing economic feasibility.

Mapping Hydrogen Initiatives in Italy: An Overview of Funding and Projects

The global momentum towards hydrogen has led to various initiatives aimed at harnessing hydrogen’s potential. In particular, low-carbon hydrogen is recognized for its crucial role in reducing greenhouse gas emissions across hard-to-abate sectors such as steel, cement and heavy-duty transport. This study focuses on the presentation of all hydrogen-related financing initiatives in Italy, providing a comprehensive overview of the various activities and their geographical locations. The examined funding comes from the National Recovery and Resilience Plan (PNRR), from projects directly funded through the Important Projects of Common European Interest (IPCEI) and from several initiatives supported by private companies or other funding sources (hydrogen valleys). Specific calls for proposals within the PNRR initiative outline the allocation of funds, focusing on hydrogen production in brownfield areas (52 expected hydrogen production plants by 2026), hydrogen use in hard-to-abate sectors and the establishment of hydrogen refuelling stations for both road (48 refuelling stations by 2026) and railway transport (10 hydrogen-based railway lines). A detailed description of the funded initiatives (150 in total) is presented, encompassing their geographical location, typology and size (when available), as well as the funding they have received. This overview sheds light on regions prioritising decarbonisation efforts in heavy-duty transport, especially along cross-border commercial routes, as evident in northern Italy. Conversely, some regions concentrate more on local transport, typically buses, or on the industrial sector, primarily steel and chemical industries. Additionally, the study presents initiatives aimed at strengthening the national manufacturing capacity for hydrogen-related technologies, alongside new regulatory and incentive schemes for hydrogen. The ultimate goal of this analysis is to foster connections among existing and planned projects, stimulate new initiatives along the entire hydrogen value chain, raise an awareness of hydrogen among stakeholders and promote cooperation and international competitiveness.

A multi-stage framework for coordinated scheduling of networked microgrids in active distribution systems with hydrogen refueling and charging stations

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%.

4E analysis of novel direct expansion cycle-organic Rankine cycle-integrated hydrogen refueling station system using liquid hydrogen cold energy

The global supply of fuel cell vehicles (FCEVs) is expected to increase to reduce carbon emissions. The number of hydrogen refueling stations (HRSs) is increasing annually, and liquid hydrogen (LH2) is attracting attention as an alternative to overcome the transport and storage limitations of gaseous hydrogen (GH2). If LH2 is supplied to the market, the existing GH2-HRSs can potentially become obsolete because they are not as economically feasible compared with LH2-HRSs. Therefore, in this study, we proposed a new HRS system that integrates direct expansion cycle (DEC) and organic Rankine cycle (ORC) using LH2 cold energy to increase the utilization and economic feasibility of GH2-HRSs. The proposed design was validated through 4E (energy, exergy, economy, and environmental impact) analysis. Compared to the basic design, which did not include LH2 as cold energy, the specific energy consumption (SEC) and exergy efficiency of the proposed design improved by 38.6% and 9.8% to 0.81 kWh/kg H2 and 89.1%, respectively. The minimum selling price improved by 8.3% to $ 1.02/kg H2. In addition, greenhouse gas emissions decreased by 11% from 2.9 kg CO2-eq/kg H2 to 2.6 kg CO2-eq/kg H2, and the life cycle cost (LCC) reduced by 10.5%. Finally, the net present value of the proposed design increased by $535,000, and the payback period decreased by 1 year, indicating that the proposed design was more economically feasible than the basic design. In conclusion, the proposed ORC-DEC-integrated model is practical and feasible in terms of exergy, energy, economy, and environmental impact, allowing the current GH2-HRSs to be used if LH2 becomes the main hydrogen energy.

Investigation of the minimum filling amount of ionic liquid in the multi-stage ionic liquid compressor

Ionic liquid compressors are the ideal solution for hydrogen refueling stations, and multi-stage compression is an inevitable choice for achieving high-pressure refueling, such as 90 MPa level. However, the initial filling amount of the ionic liquid in the compression chamber is lacking basis as the characteristics of gas-liquid two-phase flow during the reciprocating movement of the liquid piston are not understood. This study numerically investigates the variation characteristics of the gas-liquid interface in the compression chambers under different structural and operating parameters of a five-stage ionic liquid compressor. Based on the fluctuation feature of the phase interface, the minimum liquid piston heights in each stage that ensure effective sealing for the compression chamber with different stroke-to-diameter ratios (r) are determined. Finally, the mathematical relationship for calculating the minimum ionic liquid filling amount related to structural parameter r and suction pressure is established, which provides guidance for the design of the ionic liquid compressor.

Towards safer hydrogen refuelling stations: Insights from computational fluid dynamics on LH₂ leakage

Scaling hydrogen as a key clean energy carrier necessitates a comprehensive understanding of the safety aspects of hydrogen including liquid hydrogen (LH₂). Hence, this study presents a detailed computational fluid mechanics analysis to explore accidental LH₂ leakage and dispersion in a hydrogen refuelling station under varied conditions which is essential to prevent fire and explosion. The correlated impact of influential parameters including wind direction, wind velocity, leak direction, and leak rate were analysed. The study shows that hydrogen dispersion is significantly impacted by the combined effect of wind direction and surrounding structures. Additionally, the leak rate and leak direction have a significant effect on the development of the flammable cloud volume (FCV), which is critical for estimating the explosion hazards. Increasing wind velocity from 2 to 4 m/s at a constant leak rate of 0.06 kg/s results in an 82% reduction in FCV. The minimum FCV occurs when leak and wind directions oppose at 4 m/s. The most critical situation concerning FCV arises when the leak and wind directions are perpendicular, with a leak rate of 0.06 kg/s and a wind velocity of 2 m/s. These findings can aid in the development of optimised sensing and monitoring systems and operational strategies to reduce the risk of catastrophic fire and explosion consequences.

Optimization of hydrogen refueling strategy: Based on energy consumption and refueling demand

The energy and economic viability of hydrogen refueling stations (HRSs) hold significant importance during their promotion. The cascade hydrogen storage system is advantageous in reducing energy consumption and finds widespread application in HRS. Within the cascade hydrogen storage system, varying pressure switch difference values (PSDVs) correspond to different energy consumptions. Simultaneously, HRS must meet the demand for hydrogen refueling. Therefore, the primary objective of this study is to establish an optimization method for PSDV, aiming to optimize energy consumption while satisfying hydrogen refueling demand. In this study, an HRS simulation model was established using the MATLAB/SIMULINK platform to evaluate the effects of PSDV on energy consumption and refueling time. Accordingly, a BPNN proxy model was built to predict these outcomes. On the basis of the proxy model, the Pareto solution set of PSDV was obtained through NSGA-Ⅱ. Finally, the ideal point estimation method was integrated to assist the decision-makers in determining the refueling strategy. The proposed optimization strategy is capable of reducing energy consumption while still meeting the hydrogen refueling demands of HRS, resulting in a maximum energy reduction of 10.76%.

On-site hydrogen refuelling station techno-economic model for a fleet of fuel cell buses

Fuel cell electric buses (FCBs) have proven to be a technically viable solution for transportation, owing to various advantages, such as reliability, simplicity, better energy efficiency, and quietness of operation. However, large-scale adoption of FCBs is hindered by the lack of extensive and structured infrastructure and the high cost of clean hydrogen. Many studies agree that one of the significant contributors to the lack of competitiveness of green hydrogen is the cost of electricity for its production, followed by transportation costs. On the one hand, to reduce the investment cost of the electrolyzer, high operating hours should be achieved; on the other, as the number of operating hours decreases, the impact of the electricity costs declines. This paper presents an innovative algorithm for a scalable hydrogen refuelling station (HRS) capable of successfully matching and identifying the most cost-efficient levelized cost of hydrogen (LCOH) produced via electrolysis and connected to the grid, based on the HRS components' cost curves and the hourly average electricity price profile. The objective is to identify the least-cost range of LCOH by considering both the electric energy and the investment costs associated with a hydrogen demand given by different FCB sizes and electrolyzer rated powers. In addition, sensitivity analyses have been conducted to quantify the technology cost margins, and a cost comparison between the refuelling of an FCB fleet and the recharging infrastructure required for an equivalent fleet of Battery Electric Buse (BEB) has been performed. An LCOH of around 10.5 €/kg varying from 12 €/kg (2 FCB) to 10.2 €/kg (30 FCB) has been found for the best-optimized configurations. The final major conclusion of this paper is that FCB technology is currently not economically competitive. Still, a cost contraction of the electric energy price and the electrolyzer capital investment would lead to a 50% decrease in the LCOH. Furthermore, increasing renewable energies into the grid may shift the electricity cost curve, resulting in higher prices when the BEB recharging demand is more significant. This impact, in addition to the peak power load and longer recharging times, might contribute to bridging the gap with FCBs.

Techno-Economic Assessment of a Full-Chain Hydrogen Production by Offshore Wind Power

Offshore wind power stands out as a promising renewable energy source, offering substantial potential for achieving low carbon emissions and enhancing energy security. Despite its potential, the expansion of offshore wind power faces considerable constraints in offshore power transmission. Hydrogen production derived from offshore wind power emerges as an efficient solution to overcome these limitations and effectively transport energy. This study systematically devises diverse hydrogen energy supply chains tailored to the demands of the transportation and chemical industries, meticulously assessing the levelized cost of hydrogen (LCOH). Our findings reveal that the most cost-efficient means of transporting hydrogen to the mainland is through pipelines, particularly when the baseline distance is 50 km and the baseline electricity price is 0.05 USD/kWh. Notably, delivering hydrogen directly to the port via pipelines for chemical industries proves considerably more economical than distributing it to hydrogen refueling stations, with a minimal cost of 3.6 USD/kg. Additionally, we assessed the levelized cost of hydrogen (LCOH) for supply chains that transmit electricity to ports via submarine cables before hydrogen production and subsequent distribution to chemical plants. In comparison to offshore hydrogen production routes, these routes exhibit higher costs and reduced competitiveness. Finally, a sensitivity analysis was undertaken to scrutinize the impact of delivery distance and electricity prices on LCOH. The outcomes underscore the acute sensitivity of LCOH to power prices, highlighting the potential for substantial reductions in hydrogen prices through concerted efforts to lower electricity costs.

Multi-period hydrogen supply chain planning for advancing hydrogen transition roadmaps

The global commitment to the Paris Agreement has triggered the development of national hydrogen strategies and roadmaps in numerous countries. For seamless execution of a hydrogen strategy, the model employed in roadmap optimization must consider intricate operational details. This study offers a comprehensive multi-period model for hydrogen supply chain (HSC) expansion planning, spanning production to distribution. The model optimizes facility timing, location, type, and capacity while considering efficient operational strategies. Hydrogen, sourced diversely, anchors the supply chain, supported by precise calculations for road-based transport and pipelines. Storage facilities adapt to supply sources and transportation methods, addressing supply-demand fluctuations and transport interruptions. Hydrogen refueling stations (HRS) are optimized for efficient urban distribution. Analyzing South Korea's HSC in this model reveals a shift towards green hydrogen in later stages, initially relying on refineries and imports. Investments transition from pipelines to liquid (LH2) and gaseous (GH2) hydrogen trucks in the early phases, eventually incorporating NH3 tanker trucks. The model predicts a decreasing levelized cost of hydrogen (LCOH), reaching $3.89/kg through HSC expansion planning. The model predicts a decreasing LCOH, reaching $3.89/kg through strategic HSC expansion. Transportation costs, playing a significant role in the final LCOH, are crucial for South Korea to achieve its target of 3000 KRW/kg. These results offer valuable insights for nations advancing hydrogen initiatives, providing a detailed cost breakdown model to guide policy planning and achieve HSC and LCOH objectives effectively. Also, the study showcases Korea's adeptness in transitioning to a hydrogen-based economy.

Optimization of Renewable Energy Hydrogen Production Systems Using Volatility Improved Multi-Objective Particle Swarm Algorithm

Optimizing the energy structure to effectively enhance the integration level of renewable energy is an important pathway for achieving dual carbon goals. This study utilizes an improved multi-objective particle swarm optimization algorithm based on load fluctuation rates to optimize the architecture and unit capacity of hydrogen production systems. It investigates the optimal configuration methods for the architectural model of new energy hydrogen production systems in Xining City, Qinghai Province, as well as the internal storage battery, ALK hydrogen production equipment, and PEM hydrogen production equipment, aiming at various scenarios of power sources such as wind, solar, wind–solar complementary, and wind–solar–storage complementary, as well as intermittent hydrogen production scenarios such as hydrogen stations, hydrogen metallurgy, and continuous hydrogen production scenarios such as hydrogen methanol production. The results indicate that the fluctuation of hydrogen load scenarios has a significant impact on the installed capacity and initial investment of the system. Compared with the single-channel photovoltaic hydrogen production scheme, the dual-channel hydrogen production scheme still reduces equipment capacity by 6.04% and initial investment by 6.16% in the chemical hydrogen scenario with the least load fluctuation.

Multi-objective optimization of membrane cavity curve of diaphragm compressor and its verification

According to the trend of compressor upgrades in hydrogen refueling stations, this article optimizes the single exponential curve of membrane chamber volume and diaphragm stress that performs poorly. First, set the optimization goals as the membrane cavity volume and the arc length of the curve, use the MOPSO algorithm to optimize the curve, and fit the optimization results to obtain a new curve mathematical model. Then, select three curves for comparison. Theoretical calculations and finite element simulations were performed on the membrane cavity volume and diaphragm stress, and the theoretical calculation methods and results were verified with the help of existing experiments. Finally, it was found that the new curve can increase the membrane cavity volume and reduce the diaphragm stress requirement by changing its own parameters, and the new curve has a small amount of cavity volume near the transition point, which has little impact on the membrane cavity volume. Under the same maximum radial stress, the membrane cavity volume of the new curve can be increased by 5.56% compared to the single exponential curve, while under the same membrane cavity volume, the new curve can reduce the maximum stress on the gas side by 8.9% compared with the single exponential curve, and the maximum stress on the oil sides is reduced by 9.8%.

An optimal standalone wind-photovoltaic power plant system for green hydrogen generation: Case study for hydrogen refueling station

Sustainability goals include the utilization of renewable energy resources to supply the energy needs in addition to wastewater treatment to satisfy the water demand. Moreover, hydrogen has become a promising energy carrier and green fuel to decarbonize the industrial and transportation sectors. In this context, this research investigates a wind-photovoltaic power plant to produce green hydrogen for hydrogen refueling station and to operate an electrocoagulation water treatment unit in Ostrava, Czech Republic's northeast region. The study conducts a techno-economic analysis through HOMER Pro® software for optimal sizing of the power station components and to investigate the economic indices of the plant. The power station employs photovoltaic panels and wind turbines to supply the required electricity for electrolyzers and electrocoagulation reactors. As an off-grid system, lead acid batteries are utilized to store the surplus electricity. Wind speed and solar irradiation are the key role site dependent parameters that determine the cost of hydrogen, electricity, and wastewater treatment. The simulated model considers the capital, operating, and replacement costs for system components. In the proposed system, 240 kg of hydrogen as well as 720 kWh electrical energy are daily required for the hydrogen refueling station and the electrocoagulation unit, respectively. Accordingly, the power station annually generates 6,997,990 kWh of electrical energy in addition to 85595 kg of green hydrogen. Based on the economic analysis, the project's NPC is determined to be €5.49 M and the levelized cost of Hydrogen (LCH) is 2.89 €/kg excluding compressor unit costs. This value proves the effectiveness of this power system, which encourages the utilization of green hydrogen for fuel-cell electric vehicles (FCVs). Furthermore, emerging electrocoagulation studies produce hydrogen through wastewater treatment, increasing hydrogen production and lowering LCH. Therefore, this study is able to provide practicable methodology support for optimal sizing of the power station components, which is beneficial for industrialization and economic development as well as transition toward sustainability and autonomous energy systems.

Designing an optimal multi-energy system with fast charging and hydrogen refueling station under uncertainties

As the demand for battery-powered and hydrogen-based electric vehicles continues to rise, the need for integrated charging and refueling systems with energy systems becomes more critical. Therefore, it is crucial to consider the stations serving diverse vehicle users during the system design process. This paper presents an optimal sizing strategy for a multi-energy system that covers clean energy sources and two energy storage technologies under the presence of a fast-charging station and a hydrogen refueling station for various types of car users. For the considered system, the optimal sizing problem aims to minimize the loss of power supply probability (LPSP) and annualized total life cycle cost (TLCC) through a two-stage stochastic programming-based multi-objective optimization approach. Using a scenario-based approach, the study considers the uncertainties associated with renewables, homeowner’s vehicle demands, and energy demands from homes and stations. Different cases are produced to evaluate the impacts of the different stations with the availability of various electric vehicle profiles under different levels of reliability. The TLCC decreases if LPSP increases in each case. Also, the cost of installing a fast charging station is significantly lower than that of a hydrogen refueling station for all LPSP limits. Moreover, the overall cost of the system design is at its lowest when homeowners’ vehicles provide vehicle-to-grid services. It is worth noting that when the station loads which come from the customers’ vehicle increase by 10%, the TLCC increases by 1.19%. Additionally, the revenue from hydrogen refueling station is approximately 70% less than the fast charging station.

Green hydrogen as a source of renewable energy: a step towards sustainability, an overview

AbstractHydrogen has emerged as a promising energy source for a cleaner and more sustainable future due to its clean-burning nature, versatility, and high energy content. Moreover, hydrogen is an energy carrier with the potential to replace fossil fuels as the primary source of energy in various industries. In this review article, we explore the potential of hydrogen as a part of the global energy mix and the current state of its development. The majority of hydrogen production currently occurs through steam methane reforming, which produces significant greenhouse gas emissions and limits the potential of hydrogen as a clean energy source. Significant investment and advancements in renewable hydrogen production through electrolysis are necessary to overcome this limitation. There is also a growing demand for hydrogen infrastructure, including hydrogen refueling stations and storage and transportation systems, which are crucial for the growth and success of the hydrogen industry. The future of hydrogen as a part of the global energy mix will depend on continued investment and commitment to develop and commercialize this promising energy source. Our review also explores the relationship between eco-industrial parks and hydrogen production, including the benefits and challenges of hydrogen production in EIPs and the various technologies being developed to facilitate this process.

A novel type of additively manufactured high pressure mini-channel heat exchanger for precooling in hydrogen refueling stations

During refueling supercritical hydrogen into high pressure storage tanks, the fluid has to be cooled down to temperatures between -33°C and -40°C before entering the vehicle fuel tank. This cooling takes place while the hydrogen is at a pressure of up to 87.5 MPa. The requirements for the heat exchanger performing this task are very high. It has to be pressure resistant, compact enough to fit in the dispenser column and provide a high thermal performance to ensure a fast refueling with high mass flow rates. Only few conventional manufactured heat exchangers are able to fulfil these requirements. With the rise of additive manufacturing technology, especially laser powder bed fusion, new heat exchangers produced without use of conventional joining technologies can be realized. This manuscript presents a new type additively manufactured of mini-channel heat exchanger. It is developed in a joint research project involving the Leibniz University Hanover and an industrial heat exchanger manufacturer. The apparatus has a design pressure of 105 MPa and will be suited to be used in hydrogen refueling stations. The thermal requirements and the design of the apparatus are described. Thermal power and pressure drop for the full-size heat exchanger are calculated via a cell model. Scaled smaller heat exchangers made of 1.4404 stainless steel are additively manufactured via laser powder bed fusion (LPBF). The thermofluiddynamical performance of the scaled apparatus is measured in a testbench to verify the applicability of the used correlations. Deviations in hydraulic diameter and surface roughness are taken into account. Existing correlations are fitted to the new geometry.

Performance improvement of metal hydride hydrogen compressors using electromagnetic induction heating

While there are some hydrogen refueling stations (HRS) functioning in different parts of the world, their use is not widespread enough, primarily due to their expensive cost. Hydrogen compression is a main contributor to the capital and operation costs of the HRS. By improving H2 compression technology, it is possible to optimize the infrastructure for refueling with hydrogen in terms of cost and performance. The use of metal hydride hydrogen compressors (MHHCs), which have the potential to be inexpensive and have the ability to use waste heat and renewable energy sources for the H2 compression, is a promising solution to overcome this issue. The duration of the H2 compression cycle is nevertheless a serious challenge due to the metal hydride (MH) bed's low heat conductivity. As a heating technique to improve the performance of MHHCs, electromagnetic induction (EMI) is examined numerically for the first time in this work. The dynamic behavior of a two-stage MHHC with each MH reactor having an external heat exchanger and being ringed by a copper coil traversed by an alternating current is described by a two-dimensional mathematical model, which was established and successfully verified by the reference data. Numerical simulations were performed with the help of this model, and the findings showed that the EMI heating method is faster than the heat transfer fluid (HTF) heating technique. For instance, at a delivery temperature of 373 K and a supply pressure of 20 bar, it is possible to produce 106 NL H2 per kilogram of HPMH at a pressure of 97 bar with a 74 % shorter compression time than with the HTF heating technique.

Analysis of Hydrogen Value Chain Events: Implications for Hydrogen Refueling Stations’ Safety

Renewable hydrogen is emerging as the key to a sustainable energy transition with multiple applications and uses. In the field of transport, in addition to fuel cell vehicles, it is necessary to develop an extensive network of hydrogen refueling stations (hereafter HRSs). The characteristics and properties of hydrogen make ensuring the safe operation of these facilities a crucial element for their successful deployment and implementation. This paper shows the outcomes of an analysis of hydrogen incidents and accidents considering their potential application to HRSs. For this purpose, the HIAD 2.0 was reviewed and a total of 224 events that could be repeated in any of the major industrial processes related to hydrogen refueling stations were analyzed. This analysis was carried out using a mixed methodology of quantitative and qualitative techniques, considering the following hydrogen value chain: production, storage, delivery and industrial use. The results provide general information segmented by event frequency, damage classes and failure typology. The analysis shows the main processes of the value chain allow the identification of key aspects for the safety management of refueling facilities.

Optimal techno-economic design of PV-wind hydrogen refueling stations (HRFS) for 20 selected Saudi sites

The current study proposes a model of an autonomous HRFS installed on different sites in 20 Saudi cities powered by renewable clean energy sources. The station is fully powered by photovoltaic (PV) panels and wind turbines involving an electrolyzer and hydrogen tank for producing and storing hydrogen. Three scenarios are investigated to propose an optimized model, namely Scenario 1 containing (PV-Wind-Battery) system, Scenario 2 with (Wind-Battery) technologies, and Scenario 3 with (PV-Battery) components. The HRFS is expected to feed the load hydrogen demand of 25 hydrogen cars with a storage tank capacity of 5 kg. The simulation is carried out using the well-known HOMER software and the description of the technical parameters of the renewable plant together with a detailed economic feasibility for the investigated cities are also performed. Furthermore, the optimization process executed demonstrates a competitive levelized cost of energy (LCOE) and levelized cost of hydrogen (LCOH) especially for the third scenario with a LCOH varying within $12–15.9/kg and LCOE in range $ 0.332–0.414/kWh, for all 20 cities. For instance, encouraging lowest values of net present cost (NPC) and LCOE are obtained for the futuristic NEOM mega city relatively to the first and third scenarios with values (NPC = $1,576,000, LCOE = $ 0.627/kWh) and (NPC = $830,494, LCOE = $ 0.332/kWh), respectively. On another hand, thorough analysis of PV/Wind hydrogen technoeconomic operation is provided including improvements recommendations, scenarios comparison and environmental impact discussion.