Hydrogen Production Cost Research Articles

Solar PV- and PEM electrolyzer-based green hydrogen production cost for a selected location in Bangladesh

Solar PV- and PEM electrolyzer-based green hydrogen production cost for a selected location in Bangladesh

Green hydrogen levelized cost assessment from wind energy in Argentina with dispatch constraints

This study assesses the optimal levelized cost of hydrogen (LCOH) production from wind farms. The study investigates 84 locations in the south of Argentina with nodes spaced 100 km apart, as well as one location each in Chile, the USA, Spain, Japan, and Australia. A model is presented to optimize the design of the wind farm, electrolyzer plant, compressor station, and storage capacity (gaseous 160 bar), with different hydrogen demands (hydrogen dispatch constraints) and minimizing the LCOH. Hourly data for wind resources from NASA is used to define a characteristic year. The model involves energy and mass balances in hourly basis for the whole year. Sequential solution procedures with heuristic rules are implemented. The optimal costs and their relation to the main variables, as well as production and storage, are analyzed. By imposing dispatch constraints, increase in levelized cost ranges from 25 % to 40 %, and decrease in annual hydrogen production ranges from 5 % to 30 %. Best levelized cost without considering electric transport between wind farm and electrolyzer plant is 2700 USD/t.

Design and Optimization of an Alkaline Electrolysis System for Small-Scale Hydropower Integration

Alkaline electrolysis systems are currently considered to be suitable for large-scale hydrogen production. Previous research has primarily focused on integrating renewable energy sources such as solar and wind into water electrolysis systems. However, intermittent issues stemming from the sporadic nature of renewable energy sources have led to the introduction of energy storage systems (ESSs) to address these intermittent challenges. Extensive research has been conducted on the efficiency and operational aspects of these systems. In contrast to other renewable energy sources, hydropower offers the advantages of stable output and high utilization, making it a promising solution for overcoming intermittent issues. In this study, we propose the design of an optimized alkaline electrolysis system tailored for small-scale hydropower generation. This approach allowed us to confirm the efficiency of a small-scale hydropower-based hydrogen production facility and the analysis of hydrogen production costs under diverse scenarios. Notably, the optimal selling price per kilogram of hydrogen was determined to be USD 15.6 when the operational time exceeded 20 h, albeit indicating a challenging market supply. Under the consideration of various scenarios and government subsidies, this study revealed that a USD 10/kgH2 subsidy or 24 h of continuous operation achieved break-even points in the sixth and eighth years, respectively. Ultimately, the findings underscore the necessity for essential measures, including government backing and technological advancements in small-scale hydropower facilities, to enhance the economic viability of the green hydrogen market in South Korea.

Techno-economic and environmental assessment of solar-based electrical vehicles charging stations integrated with hydrogen production

With the growing interest in adopting both commercial and residential electric vehicles (EVs) utilizing green renewable energy, the techno-economic assessment of EV charging stations with solar energy is a critical aspect of the transition to sustainable transportation. However, battery storage capacity for variable solar energy production is becoming increasingly less cost-effective due to the higher Lithium price. Complementing solar energy production and battery storage, the potential of combining green hydrogen fuel energy integration with solar energy for EV charging stations can provide a sustainable alternative to reach carbon-free transportation. This research aims to assess the technical and economic viability of grid-connected Photovoltaic (PV)-based EV charging stations across Kentucky based on existing EV load profiles. The study considers different PV system sizes, locations, orientations, and the impact of net metering policies and electricity tariffs on the profitability of the PV systems. Using excess PV energy, Lithium-Ion batteries will be charged, which will be assessed considering the techno-economic and environmental impacts of green EV charging stations. To further enhance green renewable energy production, we also investigated the feasibility of on-grid PV-based EV charging stations with Lithium-Ion batteries charged during low tariff periods. In comparison with these scenarios, we studied the potential benefits of integrating green hydrogen energy production using excess solar energy with and without governmental incentives. Furthermore, we assess the environmental impact of these green EV charging stations across Kentucky. Our study indicates that EV stations across Kentucky have similar techno-economic feasibility with insignificant deviation in the levelized cost of electricity, payback period, and PV energy fraction with/without Li-Ion batteries. However, with green hydrogen production, the marginal H2 production cost indicates the first scenario (on-grid PV energy charging) is the most significant, roughly 10 USD/Kg, which is ∼1.5 times higher than the second (charging during low-tariff periods) and the third scenarios (power grid to satisfy the demand deficit – approximately 6.5 USD/Kg). From the environmental perspective, the second scenario would be a good option for either hybrid EV/H2 or EV charging stations in Kentucky, factoring in the hydrogen production cost and the carbon footprint.

Energy, Exergy and Thermoeconomic Analyses on Hydrogen Production Systems Using High-Temperature Gas-Cooled and Water-Cooled Nuclear Reactors

The use of nuclear energy is inevitable to reduce the dependence on fossil fuels in the energy sector. High-temperature gas-cooled reactors (HTGRs) are considered as a system suitable for the purpose of reducing the use of fossil fuels. Furthermore, eco-friendly mass production of hydrogen is crucial because hydrogen is emerging as a next-generation energy carrier. The unit cost of hydrogen production by the levelized cost of energy (LCOE) method varies widely depending on the energy source and system configuration. In this study, energy, exergy, and thermoeconomic analyses were performed on the hydrogen production system using the HTGR and high-temperature water-cooled nuclear reactor (HTWR) to calculate reasonable unit cost of the hydrogen produced using a thermoeconomic method called modified production structure analysis (MOPSA). A flowsheet analysis was performed to confirm the energy conservation in each component. The electricity generated from the 600 MW HTGR system was used to produce 1.28 kmol/s of hydrogen by electrolysis to split hot water vapor. Meanwhile, 515 MW of heat from the 600 MW HTWR was used to produce 8.10 kmol/s of hydrogen through steam reforming, and 83.6 MW of electricity produced by the steam turbine was used for grid power. The estimated unit cost of hydrogen from HTGR is approximately USD 35.6/GJ with an initial investment cost of USD 2.6 billion. If the unit cost of natural gas is USD 10/GJ, and the carbon tax is USD 0.08/kg of carbon dioxide, the unit cost of hydrogen produced from HTWR is approximately USD 13.92/GJ with initial investment of USD 2.32 billion. The unit cost of the hydrogen produced in the scaled-down plant was also considered.

Enhancing Oxygen Evolution Reaction Performance: Electrochemical Activation of the Biphasic CoNi/Zn(Fe,Al,Cr)2O4 via Controlled Aluminum Leaching Facilitated Surface Reconstruction

AbstractGiven that the oxygen evolution reaction (OER) faces challenges due to its sluggish kinetics, development of efficient and robust OER catalytic electrodes is critical for reducing the cost of hydrogen production through electrochemical water splitting. In this study, a biphasic CoNi/Zn(Fe,Al,Cr)2O4 coating, characterized by a densely organized stalagmite‐like microarray structure, is deposited on a commercial pure titanium plate, creating an exceptionally effective OER catalytic electrode. The formation of numerous metal/spinel oxide heterogeneous interfaces is demonstrated to enhance its electron transfer ability and conductivity. At high potentials, aluminum leaching and lattice oxygen consumption can facilitate deep surface reconstruction of highly active Fe‐doped CoNiOOH phase inducing electrochemical activation, further optimizing thermodynamic barrier of the fundamental reaction step. Ultimately, this electrode showcases exceptional OER catalytic performance (low overpotential of 248 and 335 mV to deliver the current density of 10 and 100 mA cm−2) compared to commercial IrO2 catalyst (overpotential of ≈310 mV at 10 mA cm−2). Moreover, it demonstrates high current stability sustaining a current density of 500 mA cm−2 for 100 h. This work deepens the comprehension of the surface reconstruction process in OER and, more broadly, introduces a new avenue for designing and enhancing the performance of catalytic materials.

Mitigating emissions in the global steel industry: Representing CCS and hydrogen technologies in integrated assessment modeling

We conduct a techno-economic assessment of two low-emissions steel production technologies and evaluate their deployment in emissions mitigation scenarios utilizing the MIT Economic Projection and Policy Analysis (EPPA) model. Specifically, we assess direct reduced iron-electric arc furnace with carbon capture and storage (DRI-EAF with CCS) and H2-based direct reduced iron-electric arc furnace (H2 DRI-EAF) which utilizes low carbon hydrogen to reduce CO2 emissions. Our techno-economic analysis based on the current state of technologies found that DRI-EAF with CCS increased costs ∼7% relative to the conventional steel technology. H2 DRI-EAF increased costs by ∼18% when utilizing Blue hydrogen and ∼79% when using Green hydrogen. The exact pathways for hydrogen production in different world regions, including the extent of CCS and hydrogen deployment in steelmaking are highly speculative at this point. In illustrative scenarios using EPPA, we find that, using base cost assumptions, switching from BF-BOF to DRI-EAF or scrap EAF can provide significant emissions mitigation within steelmaking. With further reductions in the cost of advanced steelmaking, we find a greater role for DRI-EAF with CCS, whereas reductions in both the cost of advanced steelmaking and hydrogen production lead to a greater role for H2 DRI-EAF. Our findings can be used to help decision-makers assess various decarbonization options and design economically efficient pathways to reduce emissions in the steel industry. Our cost evaluation can also be used to inform other energy-economic and integrated assessment models designed to provide insights about future decarbonization pathways.

Techno-economic analysis of hydrogen production via photovoltaic, battery and electrolysis: plant sizing and hydrogen cost.

Photovoltaic reached more than 20% panel efficiency and less than 20% system efficiency losses and 1 M€/MW cost. Similar cost is reached by electrolyzer meanwhile the efficiency can be more than 60% from 3% to 110% of the nominal power. Battery cost reached less than 0.5 M€/MWh meanwhile efficiency is higher and lifetime has reached more than 20.000 cycle if uses are within 20-80% of the state of charge. With these values the battery can be downsized (owing to the large % of electrolyzer nominal power) but still hydrogen production cost from photovoltaic is not competitive. These paper analyses what can be the better size among photovoltaic, battery and electrolyzer in order to reach the lowest hydrogen production cost with a sensitivity analysis on representative parameters (efficiencies, CAPEX and OPEX) for these technologies.

Designing Efficient Non-Precious Metal Electrocatalysts for High-Performance Hydrogen Production: A Comprehensive Evaluation Strategy.

Developing abundant Earth-element and high-efficient electrocatalysts for hydrogen production is crucial in effectively reducing the cost of green hydrogen production. Herein, a strategy by comprehensively considering the computational chemical indicators for H* adsorption/desorption and dehydrogenation kinetics to evaluate the hydrogen evolution performance of electrocatalysts is proposed. Guided by the proposed strategy, a series of catalysts are constructed through a dual transition metal doping strategy. Density Functional Theory (DFT) calculations and experimental chemistry demonstrate that cobalt-vanadium co-doped Ni3N is an exceptionally ideal catalyst for hydrogen production from electrolyzed alkaline water. Specifically, Co,V-Ni3N requires only 10 and 41mV in alkaline electrolytes and alkaline seawater, respectively, to achieve a hydrogen evolution current density of 10mAcm-2. Moreover, it can operate steadily at a large industrial current density of 500mAcm-2 for extended periods. Importantly, this evaluation strategy is extended to single-metal-doped Ni3N and found that it still exhibits significant universality. This study not only presents an efficient non-precious metal-based electrocatalyst for water/seawater electrolysis but also provides a significant strategy for the design of high-performance catalysts of electrolyzed water.

Electrolyzers as smart loads, preserving the lifetime

As it is known, the operation of electrolyzers with variable currents allows for a reduction in green hydrogen production costs. Indeed, operating electrolyzers as variable loads enables the better use of renewable energy resources but also contributes to the power quality of the network where electrolyzers are connected. However, with extreme winds such as those in Patagonia, this mode of operation affects the lifetime of the equipment. In this regard, this work considers the variable operation mode of electrolyzers, but also, for preserving their lifetime, a control strategy based on concepts of Passivity and anti-windup is presented. Time responses over realistic wind show good behaviors of the technique and demonstrate the possibility of maximizing the contribution of electrolyzers to the electrical grid.

Heterostructured FeP4/CoP@NF as trifunctional electrocatalysts for energy-efficient hydrogen production

The developing of efficient and cost-effective electrocatalysts for hydrogen evolution is of great significance to the development of hydrogen energy. It is believed that the efficient hydrogen generation of water cracking is restricted from the slow oxygen evolution reaction (OER) process. Consequently, it is highly recommended to find alternative anodizing to produce hydrogen to reduce electricity consumption. Urea oxidation reaction (UOR) is an alternative to the traditional anodic OER. In this paper, an electrocatalyst FeP4/CoP@NF-7.5 supported on nickel foam (NF) was designed by using a template-directed growth and low-temperature phosphating method. The FeP4/CoP@NF-7.5 with a rich interface gives it more active sites and enhances mass transfer and conductivity, possessing excellent catalytic performance against hydrogen evolution reaction (HER), OER and UOR in alkaline electrolyte. Thanks to the abundant interface and bimetallic synergy, the designed catalyst exhibits the overpotentials of 45 mV and 259 mV for HER and OER to transfer 10 mA cm−2. In addition, FeP4/CoP@NF-7.5 also possesses significant catalytic activity against UOR of 136 mV (j10) in 1 M KOH with 0.33 M urea, which provides another alternative to the low efficiency of OER through the reduction of hydrogen production costs. Finally, the overall water splitting test was undertaken in 1 M KOH containing/free of 0.33 M urea. Remarkably, only 1.43 V is required to drive on urea electrolyzer (j10 = 10 mA cm−2), while 1.52 V are gained on water electrolyzer. This paper lays the foundation for the developing of high-active transition bimetallic phosphide electrocatalysts for energy-saving hydrogen production.

Techno-economic viability and future price projections of photovoltaic-powered green hydrogen production in strategic regions of Turkey

This study assesses the economic feasibility of utilizing photovoltaic power for producing green hydrogen in Mersin, Çeşme, and Bandırma. We considered the factors for site selection, such as regional hydrogen demand, solar energy potential, water availability, export opportunities, and existing infrastructure. The research focuses on generating electricity, hydrogen, and oxygen using a 5 MW photovoltaic system. The research finds that the capacity factor for Çeşme, Mersin, and Bandırma is 18.9%, 17.7%, and 15.4% respectively, determining the optimal electrolyzer size. A comprehensive cost analysis is conducted. We employed two methodologies to evaluate the levelized cost of hydrogen. The first approach integrates the levelized cost of electricity for the photovoltaic system, while the second approach considers the annualized capital and operational expenditure for all system components. The analysis highlights the impact of electrolyzer efficiency and timeframe on hydrogen production costs. Estimated costs for Bandırma in 2023 are US$6.8 per kilogram at 70% electrolyzer efficiency, projected to decrease by 2050. With 80% electrolyzer efficiency, costs in 2023 would be US$5.87 per kilogram, with further reductions projected for 2050. We have observed similar trends for Çeşme and Mersin. In conclusion, this study provides a comprehensive cost estimation, taking into account varying discount rates, energy purchase agreement prices, CAPEX and OPEX values, revenues, and site selection, while considering electrolyzer efficiency, to enhance the economic feasibility of photovoltaic-electrolyzer systems.

Synthesis and characterization of non-noble metal cathode electrocatalysts for PEM water electrolysis

The development of new cathode materials for electrolyzers is one of the important current challenges to lower the costs of green hydrogen (H2) production. In this work, a new and easy route for Fe2P-based electrocatalysts synthesis was proposed and studied for its application in the hydrogen evolution reaction (HER). The materials were prepared from an iron salt and activated biocarbon, involving different chemical and thermal treatments. The samples were characterized by chemical, morphological, structural and textural analysis. The electrocatalytical performance of the samples was tested in acid media by linear voltammetry experiments, electrochemical impedance spectroscopy (EIS) and chronoamperometric analysis, and compared with a commercial Pt/C electrocatalyst. The Fe(20)/CHP700 sample presented the lower Eonset (-179 mV vs. RHE), a Tafel slope of 108 mV dec−1, a charge transfer resistance about 1.7 Ω cm2 with a good electrocatalytic stability. However, these results are worse than those presented by the commercial Pt/C. EIS results reveals that the best performance of the electrocatalysts can be related with a higher surface capacitance of the sample. H2 production evaluation in galvanostatic mode reveals a direct proportion between the FE values with the applied current density, reaching a maximum of 84 % at -344.8 mA cm−2 for our used measurement setup. In conclusion, the synthesis proposed in this article allowed to obtain promising free noble metal based electrocatalyst for HER, but its requires improvements in some of the aforementioned aspects to be used in PEM water electrolysis.

Techno‐economic viability analysis of a downdraft gasification system for hydrogen production from date molasses waste in Iraq

AbstractIn the current study, a fixed‐bed downdraft gasifier was used, in addition to gas cleaning and treatment units, to evaluate hydrogen production from the waste from a date molasses factory. Date pits and pomace were gasified at a temperature of 800°C with oxygen‐rich air and standard air as the gasifying agents. Simulations were performed using the Cycle‐Tempo simulation tool. The impact of many process parameters (air–fuel ratio, gasification temperature, moisture content, oxygen concentration and temperature of the water–gas shift) on gas composition was investigated. The economic evaluation of hydrogen production is also discussed in this paper. Depending on the operating conditions, the results indicate that gasification of biomass in oxygen‐rich air improves hydrogen yield compared with air gasification of biomass. Over the range of operating conditions examined, the maximum hydrogen production reached 45.86% for pits and 35.81% for pomace from gasification with oxygen‐rich air while the H2 content reached 36.71 and 28.72% respectively for air gasification of pits and pomace. The cost analysis for the date waste gasification unit showed that the hydrogen production cost is $3/kg for date pits and $4/kg for pomace. The production of hydrogen from date molasses manufacturing waste helps to lessen reliance on fossil fuels and is an environmentally beneficial alternative source of renewable energy.

Optimization of alkaline electrolyzer operation in renewable energy power systems: A universal modeling approach for enhanced hydrogen production efficiency and cost-effectiveness

This study presents a comprehensive analysis of an Alkaline Water Electrolysis System (AWES) for hydrogen production, focusing on thermal balance, operating conditions, efficiency, and lifecycle cost. A thermal balance model was developed and further refined using machine learning techniques based on experimental data, to accurately calculate electrolysis power, cooling requirements, and temperature maintenance, enabling cost-effective operation. This study provides insights for optimizing AWES performance and economic feasibility in hydrogen production. Selecting appropriate operating conditions considering current density, inlet temperature, and electricity price is crucial. Implementing these optimizations improves energy efficiency, reduces lifecycle hydrogen production costs, and enables integration with renewable energy systems.

Increasing the production capacity of the chp by introducing fuel cells

RELEVANCE. Improving the efficiency of the plant with an increase in operating capacity is one of the priority tasks of the development of power plants. One of the solutions to this issue is the introduction of fuel cells as the main or additional source of power and heat. The development of a high-quality scheme for the introduction of fuel cells into thermal power plants will increase their production capacity with the possibility of further reducing the carbon footprint by reducing the consumption of natural gas.THE PURPOSE. To develop thermal power plant schemes in combination with fuel cells to increase the thermal efficiency of the thermal power plant. To consider the types of fuel cells and the principle of their operation and to analyze their effectiveness with justification of the choice of a specific type for further calculations. To study the methods and principles of hydrogen extraction with the choice of the optimal solution directly within the framework of this work. Perform a technical and economic analysis of the introduction of fuel cells to the station.METHODS. When solving this problem, we used a method based on the law of conservation of energy under stationary operating conditions of the circuits was used. The chosen calculation method was implemented using MatLab, DvigWT and Microsoft Excel software.RESULTS. This article presents three types of thermal power plant schemes in a layout with fuel cells and an indication of their specific advantages and disadvantages. The analysis of methods of hydrogen extraction with the choice of one of them by performing an estimate of the cost of hydrogen production is carried out. A technical and economic analysis of the introduction of fuel cells at the plant has been carried out, taking into account the cost of hydrogen production. The carbon footprint from the introduction of fuel cells at the station has been calculated.CONCLUSION. Using fuel cells at the CHP increases the production efficiency of electricity generation by more than 20%, and the power of the power generation unit increases by more than 30 MW. Calculations have shown that the use of fuel cells leads to a significant increase in production capacity, but it is necessary to study in more detail the methodology for calculating the fuel cells themselves and the ways of hydrogen production.

Economic evaluation of hydrogen production in second and third units of Bushehr nuclear power plant regarding future need of nuclear fission technology

Today, the most important challenge for hydrogen production is the use of suitable energy source for sustainable production. The dual use of nuclear power plants allows them to expand into other markets by eliminating greenhouse gas emissions from processes such as hydrogen production. The significance of this matter especially in countries with ongoing new nuclear power plants is high and shows the future need for nuclear fission technology. In this paper, an economic assessment of hydrogen production in the second and third units of the Bushehr nuclear power plant (BNPP) with the Hydrogen Economy Evaluation Program (HEEP) is carried out and a comparison of CO2 emission in nuclear and non-nuclear methods of hydrogen production is presented. Most nuclear reactors, including Advanced Pressurized WaterReactor (APWR), High Temperature Gas Reactor (HTGR), and Water-Water EnergeticReactor (WWER), can be used as a source of thermal and electrical energy for the process of hydrogen production. In this research, hydrogen production processes based on the Conventional Electrolysis (CE), High Temperature Steam Electrolysis (HTSE), and Sulfur-Iodine (SI) Process using different storage and transportation options are compared to choose the cost-effective method for coupling with the WWER1000 reactor. Hydrogen production, thermal energy, and electricity costs have been calculated and explained in detail. The results showed that the cost-effective option for hydrogen production is using the High Temperature Steam Electrolysis (HTSE) method, Compressed Gas (CG) storage, and pipeline transportation, by 2.88 $/kg. Also, applying this method to produce hydrogen, the nuclear power plant thermal efficiency, and the hydrogen plant efficiency are kept in the best possible conditions by 51.98% and 58.21%, respectively.

Green hydrogen for energy storage and natural gas system decarbonization: An Italian case study

The increase of the electricity production from non-programmable and intermittent Renewable Energy Sources (RESs) generates criticalities in the balance between the energy supply and demand, requiring significant energy storage capabilities for the next future. The exploitation of the available NG Transmission Network (NGTN) by implementing the Power to Gas (PtG) technology is particularly promising since it allows a massive energy storage capability and the decarbonization of the NGTN by green hydrogen injection into the grid with growing percentages up to 100%. The objective of this work is to analyse the actual feasibility of distributed green hydrogen generation and its injection into the national NGTN. A mathematical model has been developed to assess the dynamic operation of a PtH2 integrated system to produce green hydrogen using photovoltaic-powered electrolysers and to inject it into the NGTN upstream of a Regulating and Measuring Station (RMS) located in central Italy. Three different surface sizes are considered for the installation of PV panels (100 m2, 300 m2 and 500 m2) and the optimal hydrogen accumulation size has been calculated in order to ensure the uniformity of the supplied mixture throughout the year. Obtained results show that employing the optimal accumulation size, hydrogen percentage in the NG-H2 mixture ranges between 0% and 0.90% by volume. In the best-case scenario (i.e., when considering a surface area of 500 m2), the cost of hydrogen production is 5.10 EUR/kg H2 and the PtH2 plant allows to save 32.348 tonnes of CO2 emissions every year.

Effects of geological heterogeneity on gas mixing during underground hydrogen storage (UHS) in braided-fluvial reservoirs

Hydrogen, as an energy carrier, is at the centre of research attention for its potential advantages over electricity to transport and store excessive renewable energy at the GW scale as part of the energy transition. To store energy at such a large scale and in a seasonal manner, energy storage technologies such as compressed air storage and high-temperature aquifer thermal storage are proposed, where Underground Hydrogen Storage (UHS) in porous reservoirs may be an important technology for hydrogen economy. Research studies suggest the necessity of using alternative gas to hydrogen as cushion gas due to the very low density at reservoir conditions and the high production cost of hydrogen. In addition, the potentially lower development cost of UHS in existing depleted natural gas reservoirs or former sites for underground gas storage compared to that of saline aquifers makes gas mixing a real possibility for future UHS operations. However, this topic is rarely studied, let alone its geological governing factors. In this study, we focus on the most likely geological settings for early UHS projects (Depleted gas fields in high permeability braided fluvial reservoirs) to understand the potential impacts of geological heterogeneity on project economics.To quantify the possible gas mixing induced by macro-scale heterogeneity and find the dominant factors that affect storage performance, in this study, we start by building synthetic high permeability water-gas reservoir model with geological characteristics of braided-fluvial systems often encountered in the oil and gas industry. Then we examine the effects of structural and litho-facies heterogeneity on gas mixing processes during typical UHS projects (10 mol% hydrogen-methane mixture as stored gas) via compositional numerical simulation. Homogeneous cases with different injection/production rates are also part of the sensitivity analysis. The cumulative days hydrogen fraction in produced stream is used as the metric for quantifying gas mixing during this process. Our results show that, compared to the homogeneous cases, macro-scale geological heterogeneity will intensify gas mixing and degrade the hydrogen fraction in the produced stream, affecting up to 15.8% of the recovery in 10 years (6% more than the homogeneous cases). Geological structure (reservoir dip angle and closure area) is a first-order determining factor above facies heterogeneity (braided channel dimensions). It determines the level of methane breakthrough during UHS projects in all the test cases, leading to contrasting gas mixing behaviors. Our study hereby provides a systematic method for evaluating gas mixing in UHS projects and facilitates future UHS techno-economic analysis.

Designing off-grid green hydrogen plants using dynamic polymer electrolyte membrane electrolyzers to minimize the hydrogen production cost

Designing off-grid green hydrogen plants using dynamic polymer electrolyte membrane electrolyzers to minimize the hydrogen production cost