United States
Policy Design for Diffusing Hydrogen Economy and Its Impact on the Japanese Economy for Carbon Neutrality by 2050: Analysis Using the E3ME-FTT Model
Nov 2023
Publication
To achieve carbon neutrality in Japan by 2050 renewable energy needs to be used as the main energy source. Based on the constraints of various renewable energies the importance of hydrogen cannot be ignored. This study aimed to investigate the diffusion of hydrogen demand technologies in various sectors and used projections and assumptions to investigate the hydrogen supply side. By performing simulations with the E3ME-FTT model and comparing various policy scenarios with the reference scenario the economic and environmental impacts of the policy scenarios for hydrogen diffusion were analyzed. Moreover the impact of realizing carbon neutrality by 2050 on the Japanese economy was evaluated. Our results revealed that large-scale decarbonization via hydrogen diffusion is possible (90% decrease of CO2 emissions in 2050 compared to the reference) without the loss of economic activity. Additionally investments in new hydrogen-based and other low-carbon technologies in the power sector freight road transport and iron and steel industry can improve the gross domestic product (1.6% increase in 2050 compared to the reference) as they invoke economic activity and require additional employment (0.6% increase in 2050 compared to the reference). Most of the employment gains are related to decarbonizing the power sector and scaling up the hydrogen supply sector while a lot of job losses can be expected in the mining and fossil fuel industries.
Designing Off-grid Green Hydrogen Plants Using Dynamic Polymer Electrolyte Membrane Electrolyzers to Minimize the Hydrogen Production Cost
Oct 2023
Publication
Hydrogen produced from electrolysis is an attractive carbon-free fuel and feedstock but potential benefits depend on the carbon intensity of electricity production. This study uses technoeconomic modeling to analyze the benefits of producing zero-carbon hydrogen through dynamically operated polymer electrolyte membrane electrolyzers connected to photovoltaic and wind variable renewable energy (VRE) sources. Dynamic operation is considered for current densities between 0 and 6 A cm2 and compared to a constant current density of 2 A cm2 for different combinations of VRE to electrolysis (VRE:E) capacity ratios and compositions of photovoltaic and wind energy in four locations across the United States. For optimal VRE:E and wind:photovoltaic capacity ratios dynamic operation is found to reduce the levelized cost of hydrogen by 5%–9% while increasing hydrogen production by 134%–173% and decreasing excess electrical power by 82%–95%. The framework herein may be used to determine the optimal VRE:E capacity and VRE mix for dynamically operated green hydrogen systems.
Hydrogen-Powered Aircraft at Airports: A Review of the Infrastructure Requirements and Planning Challenges
Nov 2023
Publication
Hydrogen-fueled aircraft are a promising innovation for a sustainable future in aviation. While hydrogen aircraft design has been widely studied research on airport requirements for new infrastructure associated with hydrogen-fueled aircraft and its integration with existing facilities is scarce. This study analyzes the current body of knowledge and identifies the planning challenges which need to be overcome to enable the operation of hydrogen flights at airports. An investigation of the preparation of seven major international airports for hydrogen-powered flights finds that although there is commitment airports are not currently prepared for hydrogen-based flights. Major adjustments are required across airport sites covering land use plans airside development utility infrastructure development and safety security and training. Developments are also required across the wider aviation industry including equipment updates such as for refueling and ground support and supportive policy and regulations for hydrogen-powered aircraft. The next 5–10 years is identified from the review as a critical time period for airports given that the first commercial hydrogen-powered flight is likely to depart in 2026 and that the next generation of short-range hydrogen-powered aircraft is predicted to enter service between 2030 and 2035.
Increasing Energy Efficiency of Hydrogen Refueling Stations via Optimal Thermodynamic Paths
Sep 2023
Publication
This work addresses the energy efficiency of hydrogen refueling stations (HRS) using a first principles model and optimal control methods to find minimal entropy production operating paths. The HRS model shows good agreement with experimental data achieving maximum state of charge and temperature discrepancies of 1 and 7% respectively. Model solution and optimization is achieved at a relatively low computational time (40 s) when compared to models of the same degree of accuracy. The entropy production mapping indicates the flow control valve as the main source of irreversibility accounting for 85% of the total entropy production in the process. The minimal entropy production refueling path achieves energy savings from 20 to 27% with respect to the SAE J2601 protocol depending on the ambient temperature. Finally the proposed method under nearreversible refueling conditions shows a theoretical reduction of 43% in the energy demand with respect to the SAE J2601 protocol.
Recent Progress on Rational Design of Catalysts for Fermentative Hydrogen Production
May 2022
Publication
The increasingly severe energy crisis has strengthened the determination todevelop environmentally friendly energy. And hydrogen has emerged as a candi-date for clean energy. Among many hydrogen generation methods biohydrogenstands out due to its environmental sustainability simple operating environ-ment and cost advantages. This review focuses on the rational design of catalystsfor fermentative hydrogen production. The principles of microbial dark fermen-tation and photo-fermentation are elucidated exhaustively. Various strategiesto increase the efficiency of fermentative hydrogen production are summa-rized and some recent representative works from microbial dark fermentationand photo-fermentation are described. Meanwhile perspectives and discussionson the rational design of catalysts for fermentative hydrogen production areprovided.
The Impact of Rock Morphology on Gas Dispersion in Underground Hydrogen Storage
Jul 2025
Publication
Fluid dispersion directly influences the transport mixing and efficiency of hydrogen storage in depleted gas reservoirs. Pore structure parameters such as pore size throat geometry and connectivity influence the complexity of flow pathways and the interplay between advective and diffusive transport mechanisms. Hence these factors are critical for predicting and controlling flow behavior in the reservoirs. Despite its importance the relationship between pore structure and dispersion remains poorly quantified particularly under elevated flow conditions. To address this gap this study employs pore network modeling (PNM) to investigate the influence of sandstone and carbonate structures on fluid flow properties at the micro-scale. Eleven rock samples comprising seven sandstone and four carbonate were analyzed. Pore network extraction from CT images was used to obtain detailed pore structure parameters and their statistical measures. Pore-scale simulations were conducted across 60 scenarios with varying average interstitial velocities and water as the injected fluid. Effluent hydrogen concentrations were measured to generate elution curves as a function of injected pore volumes (PV). This approach enables the assessment of the relationship between the dispersion coefficient and pore structure parameters across all rock samples at consistent average interstitial velocities. Additionally dispersivity and n-exponent values were calculated and correlated with pore structure parameters.
Feasibility of Hydrogen Fuel Cell Technology for Railway Intercity Services: A Case Study for the Piedmont in North Carolina
Jul 2021
Publication
Diesel fuel combustion results in exhaust containing air pollutants and greenhouse gas emissions. Many railway vehicles use diesel fuel as their energy source. Exhaust emissions as well as concerns about economical alternative power supply have driven efforts to move to hydrogen motive power. Hydrogen fuel cell technology applied to railways offers the opportunity to eliminate harmful exhaust emissions and the potential for a low- or zero-emission energy supply chain. Currently only multiple-unit trains with hydrail technology operate commercially. Development of an Integrated Hybrid Train Simulator for intercity railway is presented. The proposed tool incorporates the effect of powertrain components during the wheel-to-tank process. Compared to its predecessors the proposed reconfigurable tool provides high fidelity with medium requirements and minimum computation time. Single train simulation and the federal government’s Greenhouse gases Regulated Emissions and Energy use in Transportation (GREET) model are used in combination to evaluate the feasibility of various train and powertrain configurations. The Piedmont intercity service operating in North Carolina is used as a case study. The study includes six train configurations and powertrain options as well as nine hydrogen supply options in addition to the diesel supply. The results show that a hydrail option is not only feasible but a low- or zero-carbon hydrogen supply chain could be possible.
Grid Ancillary Services using Electrolyzer-based Power-to-Gas Systems with Increasing Renewable Penetration
Nov 2023
Publication
Increasing penetrations of renewable-based generation have led to a decrease in the bulk power system inertia and an increase in intermittency and uncertainty in generation. Energy storage is considered to be an important factor to help manage renewable energy generation at greater penetrations. Hydrogen is a viable long-term storage alternative. This paper analyzes and presents use cases for leveraging electrolyzer-based power-to-gas systems for electric grid support. The paper also discusses some grid services that may favor the use of hydrogenbased storage over other forms such as battery energy storage. Real-time controls are developed implemented and demonstrated using a power-hardware-in-the-loop(PHIL) setup with a 225-kW proton-exchange-membrane electrolyzer stack. These controls demonstrate frequency and voltage support for the grid for different levels of renewable penetration (0% 25% and 50%). A comparison of the results shows the changes in respective frequencies and voltages as seen as different buses as a result of support from the electrolyzers and notes the impact on hydrogen production as a result of grid support. Finally the paper discusses the practical nuances of implementing the tests with physical hardware such as inverter/electrolyzer efficiency as well as the related constraints and opportunities.
A Multi-period Sustainable Hydrogen Supply Chain Model Considering Pipeline Routing and Carbon Emissions: The Case Study of Oman
Nov 2022
Publication
This paper presents a mathematical model for a multi-period hydrogen supply chain design problem considering several design features not addressed in other studies. The model is formulated as a mixed-integer program allowing the production and storage facilities to be extended over time. Pipeline and tube trailer transport modes are considered for carrying hydrogen. The model also allows finding the optimal pipeline routes and the number of transport units. The objective is to obtain an efficient supply chain design within a given time frame in a way that the demand and carbon dioxide emissions constraints are satisfied and the total cost is minimized. A computer program is developed to ease the problem-solving process. The computer program extracts the geographical information from Google Maps and solves the problem using an optimization solver. Finally the applicability of the proposed model is demonstrated in a case study from Oman.
Experimental Comparison of Hydrogen Refueling with Directly Pressurized vs. Cascade Method
Aug 2023
Publication
This paper presents a comparative analysis of two hydrogen station configurations during the refueling process: the conventional “directly pressurized refueling process” and the innovative “cascade refueling process.” The objective of the cascade process is to refuel vehicles without the need for booster compressors. The experiments were conducted at the Hydrogen Research and Fueling Facility located at California State University Los Angeles. In the cascade refueling process the facility buffer tanks were utilized as high-pressure storage enabling the refueling operation. Three different scenarios were tested: one involving the cascade refueling process and two involving compressor-driven refueling processes. On average each refueling event delivered 1.6 kg of hydrogen. Although the cascade refueling process using the high-pressure buffer tanks did not achieve the pressure target it resulted in a notable improvement in the nozzle outlet temperature trend reducing it by approximately 8 ◦C. Moreover the overall hydrogen chiller load for the two directly pressurized refuelings was 66 Wh/kg and 62 Wh/kg respectively whereas the cascading process only required 55 Wh/kg. This represents a 20% and 12% reduction in energy consumption compared to the scenarios involving booster compressors during fueling. The observed refueling range of 150–350 bar showed that the cascade process consistently required 12–20% less energy for hydrogen chilling. Additionally the nozzle outlet temperature demonstrated an approximate 8 ◦C improvement within this pressure range. These findings indicate that further improvements can be expected in the high-pressure region specifically above 350 bar. This research suggests the potential for significant improvements in the high-pressure range emphasizing the viability of the cascade refueling process as a promising alternative to the direct compression approach.
Techno-economic Analysis and Optmization of Intensified, Large-scale Hydrogen Production with Membrane Reactors
Oct 2023
Publication
Steam methane reforming (SMR) currently supplies 76% of the world’s hydrogen (H2) demand totaling ∼70 million tonnes per year. Developments in H2 production technologies are required to meet the rising demand for cleaner less costly H2. Therefore palladium membrane reactors (Pd-MR) have received significant attention for their ability to increase the efficiency of traditional SMR. This study performs novel economic analyses and constrained nonlinear optimizations on an intensified SMR process with a Pd-MR. The optimization extends beyond the membrane’s operation to present process set points for both the conventional and intensified H2 processes. Despite increased compressor and membrane capital costs along with electric utility costs the SMR-MR design offers reductions in the natural gas usage and annual costs. Economic comparisons between each plant show Pd membrane costs greater than $25 000/m2 are required to break even with the conventional design for membrane lifetimes of 1–3 years. Based on the optimized SMR-MR process this study concludes with sensitivity analyses on the design operational and cost parameters for the intensified SMR-MR process. Overall with further developments of Pd membranes for increased stability and lifetime the proposed SMR-MR design is thus profitable and suitable for intensification of H2 production.
Technology Assessment for the Transition to a Renewable Electric Grid
Jun 2024
Publication
To reduce carbon emissions generation of electricity from combustion systems is being replaced by renewable resources. However the most abundant renewable sources – solar and wind – are not dispatchable vary diurnally and are subject to intermittency and produce electricity at times in excess of demand (excess production). To manage this variability and capture the excess renewable energy energy storage technologies are being developed and deployed such as battery energy storage (BES) hydrogen production with electrolyzers (ELY) paired with hydrogen energy storage (HES) and fuel cells (FCs) and renewable natural gas (RNG) production. While BES may be better suited for short duration storage hydrogen is suited for long duration storage and RNG can decarbonize the natural gas system. California Senate Bill 100 (SB100) sets a goal that all retail electricity sold in the State must be sourced from renewable and zero-carbon resources by 2045 raising the questions of which set of technologies and in what proportion are required to meet the 2045 target in the required timeframe as well as the role of the natural gas infrastructure if any. To address these questions this study combines electric grid dispatch modeling and optimization to identify the energy storage and dispatchable technologies in 5-year increments from 2030 to 2045 required to transition from a 60% renewable electric grid in 2035 to a 100% renewable electric grid in 2045. The results show that by utilizing the established natural gas system to store and transmit hydrogen and RNG the deployment of battery energy storage is dramatically reduced. The required capacity for BES in 2045 for example is 40 times lower by leveraging the natural gas infrastructure with a concomitant reduction in cost and associated challenges to transform the electric grid.
Adaptive Network Fuzzy Inference System and Particle Swarm Optimization of Biohydrogen Production Process
Sep 2022
Publication
Green hydrogen is considered to be one of the best candidates for fossil fuels in the near future. Bio-hydrogen production from the dark fermentation of organic materials including organic wastes is one of the most cost-effective and promising methods for hydrogen production. One of the main challenges posed by this method is the low production rate. Therefore optimizing the operating parameters such as the initial pH value operating temperature N/C ratio and organic concentration (xylose) plays a significant role in determining the hydrogen production rate. The experimental optimization of such parameters is complex expensive and lengthy. The present research used an experimental data asset adaptive network fuzzy inference system (ANFIS) modeling and particle swarm optimization to model and optimize hydrogen production. The coupling between ANFIS and PSO demonstrated a robust effect which was evident through the improvement in the hydrogen production based on the four input parameters. The results were compared with the experimental and RSM optimization models. The proposed method demonstrated an increase in the biohydrogen production of 100 mL/L compared to the experimental results and a 200 mL/L increase compared to the results obtained using ANOVA.
Meeting the Challenges of Large-scale Carbon Storage and Hydrogen Production
Mar 2023
Publication
There is a pressing need to rapidly and massively scale up negative carbon strategies such as carbon capture and storage (CCS). At the same time large-scale CCS can enable ramp-up of large-scale hydrogen production a key component of decarbonized energy systems. We argue here that the safest and most practical strategy for dramatically increasing CO2 storage in the subsurface is to focus on regions where there are multiple partially depleted oil and gas reservoirs. Many of these reservoirs have adequate storage capacity are geologically and hydrodynamically well understood and are less prone to injection-induced seismicity than saline aquifers. Once a CO2 storage facility is up and running it can be used to store CO2 from multiple sources. Integration of CCS with hydrogen production appears to be an economically viable strategy for dramatically reducing greenhouse gas emissions over the next decade particularly in oil- and gas-producing countries where there are numerous depleted reservoirs that are potentially suitable for large-scale carbon storage.
Underground Storage of Hydrogen and Hydrogen/methane Mixtures in Porous Reservoirs: Influence of Reservoir Factors and Engineering Choices on Deliverability and Storage Operations
Jul 2023
Publication
Seasonal storage of natural gas (NG) which primarily consists of methane (CH4) has been practiced for more than a hundred years at underground gas storage (UGS) facilities that use depleted hydrocarbon reservoirs saline aquifers and salt caverns. To support a transition to a hydrogen (H2) economy similar facilities are envisioned for long-duration underground H2 storage (UHS) of either H2 or H2/CH4 mixtures. Experience with UGS can be used to guide the deployment of UHS so we identify and quantify factors (formation/fluid properties and engineering choices) that influence reservoir behavior (e.g. viscous fingering and gravity override) the required number of injection/withdrawal wells and required storage volume contrasting the differences between the storage of CH4 H2 and H2/CH4 mixtures. The most important engineering choices are found to be the H2 fraction in H2/CH4 mixtures storage depth and injection rate. Storage at greater depths (higher pressure) but with relatively lower temperature is more favorable because it maximizes volumetric energy-storage density while minimizing viscous fingering and gravity override due to buoyancy. To store an equivalent amount of energy storing H2/CH4 mixtures in UHS facilities will require more wells and greater reservoir volume than corresponding UGS facilities. We use our findings to make recommendations about further research needed to guide deployment of UHS in porous reservoirs.
Supply and Demand Drivers of Global Hydrogen Deployment in the Transition Toward a Decarbonized Energy System
Nov 2023
Publication
The role of hydrogen in energy system decarbonization is being actively examined by the research and policy communities. We evaluate the potential “hydrogen economy” in global climate change mitigation scenarios using the Global Change Analysis Model (GCAM). We consider major hydrogen production methods in conjunction with delivery options to understand how hydrogen infrastructure affects its deployment. We also consider a rich set of hydrogen end-use technologies and vary their costs to understand how demand technologies affect deployment. We find that the availability of hydrogen transmission and distribution infrastructure primarily affects the hydrogen production mix particularly the share produced centrally versus on-site whereas assumptions about end-use technology primarily affect the scale of hydrogen deployment. In effect hydrogen can be a source of distributed energy enabled by on-site renewable electrolysis and to a lesser extent by on-site production at industrial facilities using natural gas with carbon capture and storage (CCS). While the share of hydrogen in final energy is small relative to the share of other major energy carriers in our scenarios hydrogen enables decarbonization in difficult-to-electrify end uses such as industrial high-temperature heat. Hydrogen deployment and in turn its contribution to greenhouse gas mitigation increases as the climate objective is tightened.
Preliminary Study for the Commercialization of a Electrochemical Hydrogen Compressor
Mar 2023
Publication
A global energy shift to a carbon‐neutral society requires clean energy. Hydrogen can accelerate the process of expanding clean and renewable energy sources. However conventional hydrogen compression and storage technology still suffers from inefficiencies high costs and safety concerns. An electrochemical hydrogen compressor (EHC) is a device similar in structure to a water electrolyzer. Its most significant advantage is that it can accomplish hydrogen separation and compression at the same time. With no mechanical motion and low energy consumption the EHC is the key to future hydrogen compression and purification technology breakthroughs. In this study the compression performance efficiency and other related parameters of EHC are investigated through experiments and simulation calculations. The experimental results show that under the same experimental conditions increasing the supply voltage and the pressure in the anode chamber can improve the reaction rate of EHC and balance the pressure difference between the cathode and anode. The presence of residual air in the anode can impede the interaction between hydrogen and the catalyst as well as the proton exchange membrane (PEM) resulting in a decrease in performance. In addition it was found that a single EHC has a better compression ratio and reaction rate than a double EHC. The experimental results were compatible with the theoretical calculations within less than a 7% deviation. Finally the conditions required to reach commercialization were evaluated using the theoretical model.
Minimizing the Cost of Hydrogen Production through Dynamic Polymer Electrolyte Membrane Electrolyzer Operation
Jun 2022
Publication
Growing imbalances between electricity demand and supply from variable renewable energy sources (VREs) create increasingly large swings in electricity prices. Polymer electrolyte membrane (PEM) electrolyzers can help to buffer against these imbalances and minimize the levelized cost of hydrogen (LCOH) by ramping up production of hydrogen through high-current-density operation when low-cost electricity is abundant and ramping down current density to operate efficiently when electricity prices are high. We introduce a technoeconomic model that optimizes current density profiles for dynamically operated electrolyzers while accounting for the potential of increased degradation rates to minimize LCOH for any given time-of-use (TOU) electricity pricing. This model is used to predict LCOH from different methods of operating a PEM electrolyzer for historical and projected electricity prices in California and Texas which were chosen due to their high penetration of VREs. Results reveal that dynamic operation could enable reductions in LCOH ranging from 2% to 63% for historical 2020 pricing and 1% to 53% for projected 2030 pricing. Moreover high-current-density operation above 2.5 A cm2 is increasingly justified at electricity prices below $0.03 kWh1 . These findings suggest an actionable means of lowering LCOH and guide PEM electrolyzer development toward devices that can operate efficiently at a range of current densities.
Techno-economic Assessment of Renewable Methanol from Biomass Gasification and PEM Electrolysis for Decarbonization of the Maritime Sector in California
Mar 2022
Publication
At scale biomass-based fuels are seen as long-term alternatives to conventional shipping fuels to reduce greenhouse gas emissions in the maritime sector. While the operational benefits of renewable methanol as a marine fuel are well-known its cost and environmental performance depend largely on production method and geographic context. In this study a techno-economic and environmental assessment of renewable methanol produced by gasification of forestry residues is performed. Two biorefinery systems are modeled thermody namically for the first time integrating several design changes to extend past work: (1) methanol synthesized by gasification of torrefied biomass while removing and storing underground a fraction of the carbon initially contained in it and (2) integration of a polymer electrolyte membrane (PEM) electrolyzer for increased carbon efficiency via hydrogen injection into the methanol synthesis process. The chosen use case is set in California with forest residue biomass as the feedstock and the ports of Los Angeles and Long Beach as the shipping fuel demand point. Methanol produced by both systems achieves substantial lifecycle greenhouse gas emissions savings compared to traditional shipping fuels ranging from 38 to 165% from biomass roadside to methanol combustion. Renewable methanol can be carbon-negative if the CO2 captured during the biomass conversion process is sequestered underground with net greenhouse gas emissions along the lifecycle amounting to − 57 gCO2eq/MJ. While the produced methanol in both pathways is still more expensive than conventional fossil fuels the introduction of CO2eq abatement incentives available in the U.S. and California could bring down minimum fuel selling prices substantially. The produced methanol can be competitive with fossil shipping fuels at credit amounts ranging from $150 to $300/tCO2eq depending on the eligible credits.
Hydrogen-Powered Aviation: Insights from a Cross-Sectional Scientometric and Thematic Analysis of Patent Claims
May 2025
Publication
Hydrogen-powered aviation is gaining momentum as a sustainable alternative to fossil-fueled flight yet the field faces complex technological and operational challenges. To better understand commercial innovation pathways this study analyzes the claims sections of 166 hydrogen aviation patents issued between 2018 and 2024. Unlike prior studies that focused on patent titles or abstracts this approach reveals the protected technical content driving commercialization. The study classifies innovations into seven domains: fuel storage fuel delivery fuel management turbine enhancement fuel cell integration hybrid propulsion and safety enhancement. Thematic word clouds and term co-occurrence networks based on natural language processing techniques validate these classifications and highlight core technical themes. Scientometric analyses uncover rapid patent growth rising international participation and strong engagement from both established aerospace firms and young companies. The findings provide stakeholders with a structured view of the innovation landscape helping to identify technological gaps emerging trends and areas for strategic investment and policymaking. This claims-based method offers a scalable framework to track progress in hydrogen aviation and is adaptable to other emerging technologies.
Recent Breakthroughs and Future Horizons in Next-generation HT-PEMs for Hydrogen Fuel Cell
Aug 2025
Publication
Aminul Islam,
Mamun Shahriar,
Tarekul Islam,
Md. Tarekul Islam,
Afsana Papia,
Suman Chandra Mohanta,
M. Azizur R. Khan,
Md Aliur Rahman,
Khadiza Tul Kubra,
Md. Munjur Hasan,
Ariyan Islam Rehan,
Mohammed Sohrab Hossain,
Adiba Islam Rasee,
M.A. Shenashen,
Eti Awual,
Md. Chanmiya Sheikh,
Tetsuya Uchida,
R.M. Waliullah,
Md. Shad Salman,
Md. Nazmul Hasan and
Md. Rabiul Awual
High-temperature proton exchange membranes (HT-PEMs) for fuel cells are considered transformative technologies for efficient energy conversion particularly in hydrogen-based transportation owing to their ability to deliver high power density and operational efficiency in harsh environments. However several critical challenges limit their broader adoption notably the limited durability and high costs associated with core components such as membranes and electrocatalysts under elevated temperature conditions. This review systematically addresses these challenges by examining the role of engineered nanomaterials in overcoming performance and stability limitations. The potential of nanomaterials to improve catalytic activity proton conductivity and thermal stability is discussed in detail emphasizing their impact on the optimization of catalyst layer composition including catalysts binders phosphoric acid electrolytes and additives. Recent advancements in nanostructured assemblies and 3D morphologies are explored to enhance fuel cell efficiency through synergistic interactions of these components. Additionally ongoing issues such as catalyst degradation long-term stability and resistance to high-temperature operation are critically analyzed. This manuscript offers a comprehensive overview of current HT-PEMs research and proposes future material design strategies that could bridge the gap between laboratory prototypes and large-scale industrial applications.
Produced Water Use for Hydrogen Production: Feasibility Assessment in Wyoming, USA
May 2025
Publication
This study evaluates the feasibility of repurposing produced water—an abundant byproduct of hydrocarbon extraction—for green hydrogen production in Wyoming USA. Analysis of geospatial distribution and production volumes reveals that there are over 1 billion barrels of produced water annually from key basins with a general total of dissolved solids (TDS) ranging from 35000 to 150000 ppm though Wyoming’s sources are often at the lower end of this spectrum. Optimal locations for hydrogen production hubs have been identified particularly in high-yield areas like the Powder River Basin where the top 2% of fields contribute over 80% of the state’s produced water. Detailed water-quality analysis indicates that virtually all of the examined sources exceed direct electrolyzer feed requirements (e.g. 10% LCOH) are notable electricity pricing (50–70% LCOH) and electrolyzer CAPEX (20–40% LCOH) are dominant cost factors. While leveraging produced water could reduce freshwater consumption and enhance hydrogen production sustainability further research is required to optimize treatment processes and assess economic viability under real-world conditions. This study emphasizes the need for integrated approaches combining water treatment renewable energy and policy incentives to advance a circular economy model for hydrogen production.
Virtual Failure Assessment Diagrams for Hydrogen Transmission Pipelines
Jun 2025
Publication
We combine state-of-the-art thermo-metallurgical welding process modeling with coupled diffusion-elastic– plastic phase field fracture simulations to predict the failure states of hydrogen transport pipelines. This enables quantitatively resolving residual stress states and the role of brittle hard regions of the weld such as the heat affected zone (HAZ). Failure pressures can be efficiently quantified as a function of asset state (existing defects) materials and weld procedures adopted and hydrogen purity. Importantly simulations spanning numerous relevant conditions (defect size and orientations) are used to build Virtual Failure Assessment Diagrams (FADs) enabling a straightforward uptake of this mechanistic approach in fitness-for-service assessment. Model predictions are in very good agreement with FAD approaches from the standards but show that the latter are not conservative when resolving the heterogeneous nature of the weld microstructure. Appropriate mechanistic FAD safety factors are established that account for the role of residual stresses and hard brittle weld regions.
Toward More Efficient Large-Scale Green Hydrogen Systems via Waste Heat Recovery and ORC
May 2025
Publication
This research models a 20 MW PEM hydrogen plant. PEM units operate in the 60 to 80 ◦C range based on their location and size. This study aims to recover the waste heat from PEM modules to enhance the efficiency of the plant. In order to recover the heat two systems are implemented: (a) recovering the waste heat from each PEM module; (b) recovering the heat from hot water to produce electricity utilizing an organic refrigerant cycle (ORC). The model is made by ASPEN® V14. After modeling the plant and utilizing the ORC the module is optimized using Python to maximize the electricity produced by the turbine therefore enhancing the efficiency. The system is a closed-loop cycle operating at 25 ◦C and ambient pressure. The 20 MW PEM electrolyzer plant produces 363 kg/hr of hydrogen and 2877 kg/hr of oxygen. Based on the higher heating value of hydrogen the plant produces 14302.2 kWh of hydrogen energy equivalents. The ORC is maximized by increasing the electricity output from the turbine and reducing the pump work while maintaining energy conservation and mass balance. The results show that the electricity power output reaches 555.88 kW and the pump power reaches 23.47 kW.
Potential Financing Mechanisms for Green Hydrogen Development in Sub-Saharan Africa
Aug 2025
Publication
Green hydrogen is gaining global attention as a zero-carbon energy carrier with the potential to drive sustainable energy transitions particularly in regions facing rising fossil fuel costs and resource depletion. In sub-Saharan Africa financing mechanisms and structured off-take agreements are critical to attracting investment across the green hydrogen value chain from advisory and pilot stages to full-scale deployment. While substantial funding is required to support a green economic transition success will depend on the effective mobilization of capital through smart public policies and innovative financial instruments. This review evaluates financing mechanisms relevant to sub-Saharan Africa including green bonds public–private partnerships foreign direct investment venture capital grants and loans multilateral and bilateral funding and government subsidies. Despite their potential current capital flows remain insufficient and must be significantly scaled up to meet green energy transition targets. This study employs a mixed-methods approach drawing on primary data from utility firms under the H2Atlas-Africa project and secondary data from international organizations and the peer-reviewed literature. The analysis identifies that transitioning toward Net-Zero emissions economies through hydrogen development in sub-Saharan Africa presents both significant opportunities and measurable risks. Specifically the results indicate an estimated investment risk factor of 35% reflecting potential challenges such as financing infrastructure and policy readiness. Nevertheless the findings underscore that green hydrogen is a viable alternative to fossil fuels in subSaharan Africa particularly if supported by targeted financing strategies and robust policy frameworks. This study offers practical insights for policymakers financial institutions and development partners seeking to structure bankable projects and accelerate green hydrogen adoption across the region.
Energy Storage: From Fundamental Principles to Industrial Applications
Jun 2025
Publication
The increasing global energy demand and the transition toward sustainable energy systems have highlighted the importance of energy storage technologies by ensuring efficiency reliability and decarbonization. This study reviews chemical and thermal energy storage technologies focusing on how they integrate with renewable energy sources industrial applications and emerging challenges. Chemical Energy Storage systems including hydrogen storage and power-to-fuel strategies enable long-term energy retention and efficient use while thermal energy storage technologies facilitate waste heat recovery and grid stability. Key contributions to this work are the exploration of emerging technologies challenges in large-scale implementation and the role of artificial intelligence in optimizing Energy Storage Systems through predictive analytics real-time monitoring and advanced control strategies. This study also addresses regulatory and economic barriers that hinder widespread adoption emphasizing the need for policy incentives and interdisciplinary collaboration. The findings suggest that energy storage will be a fundamental pillar of the sustainable energy transition. Future research should focus on improving material stability enhancing operational efficiency and integrating intelligent management systems to maximize the benefits of these technologies for a resilient and low-carbon energy infrastructure.
Hydrogen Energy Storage via Carbon-Based Materials: From Traditional Sorbents to Emerging Architecture Engineering and AI-Driven Optimization
Jul 2025
Publication
Hydrogen is widely recognized as a key enabler of the clean energy transition but the lack of safe efficient and scalable storage technologies continues to hinder its broad deployment. Conventional hydrogen storage approaches such as compressed hydrogen storage cryo-compressed hydrogen storage and liquid hydrogen storage face limitations including high energy consumption elevated cost weight and safety concerns. In contrast solid-state hydrogen storage using carbon-based adsorbents has gained growing attention due to their chemical tunability low cost and potential for modular integration into energy systems. This review provides a comprehensive evaluation of hydrogen storage using carbon-based materials covering fundamental adsorption mechanisms classical materials emerging architectures and recent advances in computationally AI-guided material design. We first discuss the physicochemical principles driving hydrogen physisorption chemisorption Kubas interaction and spillover effects on carbon surfaces. Classical adsorbents such as activated carbon carbon nanotubes graphene carbon dots and biochar are evaluated in terms of pore structure dopant effects and uptake capacity. The review then highlights recent progress in advanced carbon architectures such as MXenes three-dimensional architectures and 3D-printed carbon platforms with emphasis on their gravimetric and volumetric performance under practical conditions. Importantly this review introduces a forward-looking perspective on the application of artificial intelligence and machine learning tools for data-driven sorbent design. These methods enable high-throughput screening of materials prediction of performance metrics and identification of structure– property relationships. By combining experimental insights with computational advances carbon-based hydrogen storage platforms are expected to play a pivotal role in the next generation of energy storage systems. The paper concludes with a discussion on remaining challenges utilization scenarios and the need for interdisciplinary efforts to realize practical applications.
What Will it Take to Get to Net-zero Emissions in California?
Sep 2025
Publication
In this work a new modeling tool called DECAL (DEcarbonize CALifornia) is developed and used to evaluate what it will take to reach California’s climate mandate of net-zero emissions by 2045. DECAL is a scenario-based model that projects emissions society-wide costs and resource consumption in response to user-defined inputs. DECAL has sufficient detail to model true net-zero pathways and reveal fine-grain technology insights. Using DECAL we find the State can achieve 52 % of the emissions abatement needed to meet net-zero by 2045 using technologies that are already commercially available such as electric vehicles heat pumps and renewable electricity & storage. While these technologies are mature the speed and scale of deployment required will still pose significant practical challenges if not technical ones. In addition we find that 25 % of emissions abatement will come from technologies currently at early-stage deployment and 23 % from technologies at research scale motivating the continued research & development of these technologies including zero-emission heavy-duty vehicles carbon capture & sequestration clean industrial heating low global warming potential refrigerants and direct air capture. Significant carbon dioxide removal will also be needed for California to meet its net-zero target on time at least 45 Mt/yr and more likely up to 75 Mt/yr by 2045. Accelerating deployment of mature technologies can further reduce the need for carbon removal nevertheless establishing enforceable carbon removal targets and conducting policy planning to make said goals a reality will be needed if California is to meet its net-zero by 2045 goal.
Relationship Between Clay Minerals and Microorganims in Underground Hydrogen Storage Reservoirs: A Mini Review
Feb 2025
Publication
Hydrogen (H2) will play a vital role in the global shift towards sustainable energy systems. Due to the high cost and challenges associated with storing hydrogen in large quantities for industrial applications Underground Hydrogen Storage (UHS) in geological formations has emerged as a promising solution. Clay minerals abundant in subsurface environments play a critical role in UHS by providing low permeability cation exchange capacity and stability essential for preventing hydrogen leakage. However microorganisms in the subsurface particularly hydrogenotrophic species interact with clay minerals in ways that can affect the integrity of these storage systems. Microbes form biofilms on clay surfaces which can cause pore clogging and reduce the permeability of the reservoir potentially stabilizing H2 storage and limiting injectivity. Microbial-induced chemical weathering through the production of organic acids and redox reactions can degrade clay minerals releasing metal ions and destabilizing the storage site. These interactions raise concerns about the long-term storage capacity of UHS as microbial processes could lead to H2 loss and caprock degradation compromising the storage system’s effectiveness. This mini review aims to cover the current understanding of the interactions between clay minerals and microorganisms and how these dynamics can affect the safe and sustainable deployment of UHS.
Everything About Hydrogen Podcast: LIFTE OFF! Expanding the Hydrogen Market to it's Next Step
Jul 2023
Publication
This week the EAH team discusses LIFTE H2’s plans for the future and discusses the challenges in hydrogen markets expansion and rollout the need for resiliency for offtakers and how to build consumer confidence.
The podcast can be found on their website.
The podcast can be found on their website.
Review - Engineering Challenges in Green Hydrogen Production Systems
May 2022
Publication
Today hydrogen (H2) is overwhelmingly produced through steam methane reforming (SMR) of natural gas which emits about 12 kg of carbon dioxide (CO2) for 1 kg of H2 (∼12 kg-CO2/kg-H2). Water electrolysis offers an alternative for H2 production but today’s electrolyzers consume over 55 kWh of electricity for 1 kg of H2 (>55 kWh/kg-H2). Electric grid-powered water electrolysis would emit less CO2 than the SMR process when the carbon intensity for grid power falls below 0.22 kg-CO2/kWh. Solar- and wind-powered electrolytic H2 production promises over 80% CO2 reduction over the SMR process but large-scale (megawatt to gigawatt) direct solar- or wind-powered water electrolysis has yet to be demonstrated. In this paper several approaches for solar-powered electrolysis are analyzed: (1) coupling a photovoltaic (PV) array with an electrolyzer through alternating current; (2) direct-current (DC) to DC coupling; and (3) direct DC-DC coupling without a power converter. Co-locating a solar or wind farm with an electrolyzer provides a lower power loss and a lower upfront system cost than long-distance power transmission. A load-matching PV system for water electrolysis enables a 10%–50% lower levelized cost of electricity than the other systems and excellent scalability from a few kilowatts to a gigawatt. The concept of maximum current point tracking is introduced in place of maximum power point tracking to maximize the H2 output by solarpowered electrolysis.
A Methodology for Quantitative Risk Assessment of a High-capacity Hydrogen Fueling Station with Liquid Hydrogen Storage
Mar 2025
Publication
Hydrogen fueling stations are critical infrastructure for deploying zero emission hydrogen fuel cell electric vehicles (FCEV). Stations with greater dispensing capacities and higher energy efficiency are needed and cryogenic liquid hydrogen (LH2) has the potential to meet these needs. It is necessary to ensure that hazards and risks are appropriately identified and managed. This paper presents a Quantitative Risk Assessment (QRA) methodology for high-capacity (dispensing >1000 kg/day) hydrogen fueling stations with liquid hydrogen storage and presents the application of that methodology by presenting a Failure Mode and Effect Analysis (FMEA) and data curation for the design developed for this study. This methodology offers a basis for risk and reliability evaluation of these systems as their designs evolve and as operational data becomes available. We developed a generic station design and process flow diagram for a high-capacity hydrogen fueling station with LH2 storage. Following the system description is hazard identification done from FMEA to identify the causes of hydrogen releases and the critical components causing the releases. Finally data collection and curation is discussed including challenges stemming from the limited public availability of reliability data on components used in liquid hydrogen systems. This paper acts as an introduction to the full QRA presented in its companion paper Schaad et al. [1].
Holding the Invisible: Advanced Materials for Hydrogen Storage
Aug 2025
Publication
Hydrogen storage remains the main barrier to the broader use of hydrogen as an energy carrier despite hydrogen’s high energy density and clean combustion. This study presents a comparative evaluation of conventional and emerging storage methods integrating thermodynamic kinetic economic and environmental metrics to assess capacity efficiency cost and reversibility. Physisorption analysis reveals that metal organic frameworks can achieve storage capacities up to 14.0 mmol/g. Chemical storage systems are evaluated including nanostructured MgH2 (7.6 wt%) catalyzed reversible complex hydrides liquid organic hydrogen carriers and clathrate hydrates. Techno-economic analysis shows storage costs from $500–700/kg H2 to $30–50/kg H2 with energy efficiencies of 50%–90%. Life cycle assessment identifies manufacturing as the primary source of emissions with carbon footprints varying from 150 to 2057 kg CO2 -eq/kg H2 . Cryo-compressed is the most practical transportation option while metal hydrides suit stationary use. This study provides a quantitative foundation to guide material selection and system design for next-generation hydrogen storage technologies.
Review of Electrochemical Systems for Grid Scale Power Generation and Conversion: Low- and High-Temperature Fuel Cells and Electrolysis Processes
May 2025
Publication
This review paper presents an overview of fuel cell electrochemical systems that can be used for clean large-scale power generation and energy storage as global energy concerns regarding emissions and greenhouse gases escalate. The fundamental thermochemical and operational principles of fuel cell power generation and electrolyzer technologies are discussed with a focus on high-temperature solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) that are best suited for grid scale energy generation. SOFCs and SOECs share similar promising characteristics and have the potential to revolutionize energy conversion and storage due to improved energy efficiency and reduced carbon emissions. Electrochemical and thermodynamic foundations are presented while exploring energy conversion mechanisms electric parameters and efficiency in comparison with conventional power generation systems. Methods of converting hydrocarbon fuels to chemicals that can serve as fuel cell fuels are also presented. Key fuel cell challenges are also discussed including degradation thermal cycling and long-term stability. The latest advancements including in materials selection research design and manufacturing methods are also presented as they are essential for unlocking the full potential of these technologies and achieving a sustainable near zero-emission energy future.
Long Duration Energy Storage Usin gHydrogen in Metal−Organic Frameworks: Opportunities and Challenges
May 2024
Publication
Materials-based H2 storage plays a critical role infacilitating H2 as a low-carbon energy carrier but there remainslimited guidance on the technical performance necessary for specificapplications. Metal−organic framework (MOF) adsorbents haveshown potential in power applications but need to demonstrateeconomic promises against incumbent compressed H2 storage.Herein we evaluate the potential impact of material propertiescharge/discharge patterns and propose targets for MOFs’ deploy-ment in long-duration energy storage applications including backupload optimization and hybrid power. We find that state-of-the-artMOF could outperform cryogenic storage and 350 bar compressedstorage in applications requiring ≤8 cycles per year but need ≥5 g/Lincrease in uptake to be cost-competitive for applications thatrequire ≥30 cycles per year. Existing challenges include manufacturing at scale and quantifying the economic value of lower-pressure storage. Lastly future research needs are identified including integrating thermodynamic effects and degradation mechanisms.
Differentiating Hydrogen-driven Hazards from Conventional Failure Modes in Hydrogen Infrastructure
Oct 2025
Publication
Hydrogen is a promising carbon-free energy carrier for large-scale applications yet its adoption faces unique safety challenges. Microscopic physicochemical properties such as high diffusivity low ignition energy and distinct chemical pathways alter the safety of hydrogen systems. Analyzing the HIAD 2.0 incident database an occurrence-based review of past hydrogen incidents shows that 59% arise from general industrial failures common to other hydrocarbon carrier systems. Of the remaining 41% only 15% are unequivocally linked to the fuel’s unique properties. This study systematically isolates hazards driven by hydrogen’s intrinsic properties by filtering out confounding factors and provides an original clear characterization of the different failure mechanisms of hydrogen systems. These hydrogen-specific cases are often poorly described limiting their contribution to safety strategies and regulations improvement. A case study on pipeline failures illustrates how distinguishing hydrogen-specific hazards supports targeted risk mitigation. The findings highlight the need for evidence-based regulation over broadly precautionary approaches.
Everything About Hydrogen Podcast: Sustainable Shipping
Nov 2023
Publication
The teams sits down with Johannah Christensen to discuss regulatory policies and risk mitigation for vessel owners switching to green fuels and what we can do to encourage that jump as well as ensure a Just Transition.
The podcast can be found on their website.
The podcast can be found on their website.
Hydrogen Production Efficiency: A Critical Factor in Integrated Planning of Distributed and Transmission System for Large-scale Centralized Offshore Wind-hydrogen System
Dec 2024
Publication
Green hydrogen plays a pivotal role in decarbonizing our energy system and achieving the Net-Zero Emissions goal by 2050. Offshore wind farms (OWFs) dedicated to green hydrogen production are currently recognized as the most feasible solution for scaling up the production of cost-effective electrolytic hydrogen. However the cost associated with distribution and transmission systems constitute a significant portion of the total cost in the large-scale wind-hydrogen system. This study pioneers the simultaneous optimization of the inter-array cable routing of OWFs and the location and capacity of offshore hydrogen production platforms (OHPPs) aiming to minimize the total cost of distribution and transmission systems. Considering the characteristics of hydrogen production efficiency this paper constructs a novel mathematical model for OHPPs across diverse wind scenarios. Subsequently we formulate the joint planning problem as a relaxed mixed-integer second-order cone programming (MISOCP) model and employ the Benders decomposition algorithm for the solution introducing three valid inequalities to expedite convergence. Through validation on real-world large-scale OWFs we demonstrate the validity and rapid convergence of our approach. Moreover we identify hydrogen production efficiency as a major bottleneck cost factor for the joint planning problem it decreases by 1.01% of total cost for every 1% increase in hydrogen production efficiency.
Photoelectrochemical Water Splitting under Concentrated Sunlight: Best Practices and Protocols
Mar 2025
Publication
Photoelectrochemical (PEC) water splitting is a promising technology for green hydrogen production by harnessing solar energy. Traditionally this sustainable approach is studied under light intensity of 100 mW/cm2 mimicking the natural solar irradiation at the Earth’s surface. Sunlight can be easily concentrated using simple optical systems like Fresnel lens to enhance charge carrier generation and hydrogen production in PEC water splitting. Despite the great potentials this strategy has not been extensively studied and faces challenges related to the stability of photoelectrodes. To prompt the investigations and applications this work outlines the best practices and protocols for conducting PEC solar water splitting under concentrated sunlight illumination incorporating our recent advancements and providing some experimental guidelines. The key factors such as light source calibration photoelectrode preparation PEC cell configuration and long-term stability test are discussed to ensure reproducible and high performance. Additionally the challenges of the expected photothermal effect and the heat energy utilization strategy are discussed.
Effect of Hydrogen Addition on Combustion and Thermal Characteristics of Impinging Non-premixed Jet Flames for Various Heating Value Gases
Jun 2023
Publication
This study experimentally investigates the effect of hydrogen addition on combustion and thermal characteristics of impinging non-premixed jet flames for low-heating values gases (LHVGs). We evaluate the flame morphology and stability using a concentric non-premixed combustor with an impingement plate. OH radicals are visualized using the OH* chemiluminescence and OH-planar laser-induced fluorescence (OH-PLIF) system. Emission characteristics are investigated by calculating CO and NOx emission indices. The results show that the flame stability region narrows as the heating value decreases but expands as hydrogen has been added. The low-OH radical intensity of LHVGs increases with the hydrogen addition. EICO and EINOx decrease with the reduction of heating values. EICO rapidly declines near the lifted flame limit due to the premixing of fuel and air downstream of the flame region. The effect of the hydrogen addition on EINOx is insignificant and shows very low emissions. The heat transfer rate into cooling water indicates a linear tendency with thermal power regardless of the fuel type. These findings show that LHVGs can be employed in existing-impinging flame systems so long as they remain within flame sta bility regions. Furthermore hydrogen addition positively affects the expansion of flame stability enhancing the utility of LHVGs.
Underground Hydrogen Storage: Transforming Subsurface Science into Sustainable Energy Solutions
Feb 2025
Publication
As the global economy moves toward net-zero carbon emissions large-scale energy storage becomes essential to tackle the seasonal nature of renewable sources. Underground hydrogen storage (UHS) offers a feasible solution by allowing surplus renewable energy to be transformed into hydrogen and stored in deep geological formations such as aquifers salt caverns or depleted reservoirs making it available for use on demand. This study thoroughly evaluates UHS concepts procedures and challenges. This paper analyzes the most recent breakthroughs in UHS technology and identifies special conditions needed for its successful application including site selection guidelines technical and geological factors and the significance of storage characteristics. The integrity of wells and caprock which is important for safe and efficient storage can be affected by the operating dynamics of the hydrogen cycle notably the fluctuations in pressure and stress within storage formations. To evaluate its potential for broader adoption we also examined economic elements such as cost-effectiveness and the technical practicality of large-scale storage. We also reviewed current UHS efforts and identified key knowledge gaps primarily in the areas of hydrogen–rock interactions geochemistry gas migration control microbial activities and geomechanical stability. Resolving these technological challenges regulatory frameworks and environmental sustainability are essential to UHS’s long-term and extensive integration into the energy industry. This article provides a roadmap for UHS research and development emphasizing the need for further research to fully realize the technology’s promise as a pillar of the hydrogen economy
Recent Advances in Hydrogen Production, Storage and Fuel Cell Technologies with an Emphasis on Inventions, Innovations and Commercialization
Nov 2023
Publication
The future is bright for hydrogen as a clean mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production storage and conversion and highlights recent commercialization efforts to realize its potential. Also the paper presents selected notable patents issued within the last few years. There is no shortage of inventions and innovations in hydrogen technologies in both academia and industry. While metal hydrides and functionalized carbon-based materials have improved tremendously as hydrogen storage materials over the years storing gaseous hydrogen in underground salt caverns has also become feasible in many commercial projects. Production of “blue hydrogen” is rising as a method of producing hydrogen in large quantities economically. Although electric/battery powered vehicles are dominating the green transport today innovative hydrogen fuel cell technologies are knocking at the door because of their lower refueling time compared to EV charging time. However the highest impact of hydrogen technologies in trans portation might be seen in the aviation industry. Hydrogen is expected to play a key role and provides hope in transforming aviation into a zero-carbon emission transportation over the next few decades.
Pipeline Regulation for Hydrogen: Choosing Between Paths and Networks
Oct 2025
Publication
The reliance on hydrogen as part of the transition towards a low-carbon economy will require developing dedicated pipeline infrastructure. This deployment will be shaped by regulatory frameworks governing investment and access conditions ultimately structuring how the commodity is traded. The paper assesses the market design for hydrogen infrastructure assuming the application of unbundling requirements. For this purpose it develops a general economic framework for regulating pipeline infrastructure focusing on asset specificity market power and access rules. The paper assesses the scope of application of infrastructure regulation which can be set to individual pipelines or to entire networks. When treated as entire networks the infrastructure can provide flexibility to enhance market liquidity. However this requires establishing network monopolies which rely on central planning and reduce the overall dynamic efficiency of the sector. The paper further compares the regulation applied to US and EU natural gas pipeline infrastructure. Based on the different challenges faced by the EU hydrogen sector including absence of wholesale concentration and large infrastructure needs the paper draws lessons for a regulatory framework establishing the main building blocks of a hydrogen target model. The paper recommends a review of the current EU regulatory framework in the Hydrogen and Decarbonised Gas Package to enable i) the application of regulation to individual pipelines rather than entire networks; ii) the use of negotiated third-party access light-touch regulation and possibly marketbased coordination mechanisms for the access to the infrastructure and iii) a more significant role for long-term capacity contracts to underpin infrastructure investments.
Factors Affecting Energy Consumption in Hydrogen Liquefaction Plants
Aug 2025
Publication
Hydrogen energy is valued for its diverse sources and clean low-carbon nature and is a promising secondary energy source with wide-ranging applications and a significant role in the global energy transition. Nonetheless hydrogen’s low energy density makes its largescale storage and transport challenging. Liquid hydrogen with its high energy density and easier transport offers a practical solution. This study examines the global hydrogen liquefaction methods with a particular emphasis on the liquid nitrogen pre-cooling Claude cycle process. It also examines the factors in the helium refrigeration cycle—such as the helium compressor inlet temperature outlet pressure and mass—that affect energy consumption in this process. Using HYSYS software the hydrogen liquefaction process is simulated and a complete process system is developed. Based on theoretical principles this study explores the pre-cooling refrigeration and normal-to-secondary hydrogen conversion processes. By calculating and analyzing the process’s energy consumption an optimized flow scheme for hydrogen liquefaction is proposed to reduce the total power used by energy equipment. The study shows that the hydrogen mass flow rate and key helium cycle parameters—like the compressor inlet temperature outlet pressure and flow rate—mainly affect energy consumption. By optimizing these parameters notable decreases in both the total and specific energy consumption were attained. The total energy consumption dropped by 7.266% from the initial 714.3 kW and the specific energy consumption was reduced by 11.94% from 11.338 kWh/kg.
Fuel Cell Technology Review: Types, Economy, Applications, and Vehicle-to-grid Scheme
Feb 2025
Publication
This study conducts a thorough review of fuel cell technology including types economy applications and V2G scheme. Fuel cells have been considered for diverse applications namely electric vehicles specialty vehicles such as warehouse forklifts public transportation including buses trains and ferries. Other applications include grid-related stationary and portable applications. Among available five types of fuel cells PEMFC is presently the optimal choice for electric vehicle usage due to its low operating temperature and durability. Meanwhile high temperature fuel cells such as MCFC and SOFC currently remain the best choice for utility and grid related applications. The economy of fuel cells has been continuously improving and has been illustrated to only grow into a potential main source of sustainable energy soon. With the transportation sector as fuel cell electric ve hicles evolve V2G technology is beneficial towards energy efficiency and fuel cell economy. There is evidence for V2G using FCEV being more advantageous in comparison to conventional BEVs. The costs of the five types of fuel cell vary from US$1784 to US$4500 per kW capacity. The findings are beneficial for researchers and industry professionals who wish to gain comprehensive understanding of fuel cells for adoption and development of the emerging low-emission energy solutions.
Towards Carbon-Neutral Hydrogen: Integrating Methane Pyrolysis with Geothermal Energy
Oct 2025
Publication
Methane pyrolysis produces hydrogen (H2) with solid carbon black as a co-product eliminating direct CO2 emissions and enabling a low-carbon supply when combined with renewable or low-carbon heat sources. In this study we propose a hybrid geothermal pyrolysis configuration in which an enhanced geothermal system (EGS) provides baseload preheating and isothermal holding while either electrical or solar–thermal input supplies the final temperature rise to the catalytic set-point. The work addresses four main objectives: (i) integrating field-scale geothermal operating envelopes to define heatintegration targets and duty splits; (ii) assessing scalability through high-pressure reactor design thermal management and carbon separation strategies that preserve co-product value; (iii) developing a techno-economic analysis (TEA) framework that lists CAPEX and OPEX incorporates carbon pricing and credits and evaluates dual-product economics for hydrogen and carbon black; and (iv) reorganizing state-of-the-art advances chronologically linking molten media demonstrations catalyst development and integration studies. The process synthesis shows that allocating geothermal heat to the largest heat-capacity streams (feed recycle and melt/salt hold) reduces electric top-up demand and stabilizes reactor operation thereby mitigating coking sintering and broad particle size distributions. Highpressure operation improves the hydrogen yield and equipment compactness but it also requires corrosion-resistant materials and careful thermal-stress management. The TEA indicates that the levelized cost of hydrogen is primarily influenced by two factors: (a) electric duty and the carbon intensity of power and (b) the achievable price and specifications of the carbon co-product. Secondary drivers include the methane price geothermal capacity factor and overall conversion and selectivity. Overall geothermal-assisted methane pyrolysis emerges as a practical pathway to turquoise hydrogen if the carbon quality is maintained and heat integration is optimized. The study offers design principles and reporting guidelines intended to accelerate pilot-scale deployment.
Risk Assessment Framework for Green Hydrogen Megaprojects: Balancing Climate Goals with Project Viability
Dec 2024
Publication
Green hydrogen presents a promising solution for decarbonisation but its widespread adoption faces significant challenges. To meet Europe’s 2030 targets a 250-fold increase in electrolyser capacity is required necessitating an investment of €170-240 billion. This involves constructing 20-40 pioneering megaprojects each with a 1-5 GW capacity. Historically pioneering energy projects have seen capital costs double or triple from initial estimates with over 50% failing to meet production goals at startup due to new technology introductions site-specific characteristics and project complexity. Additionally megaprojects costing more than €1 billion frequently succumb to the "iron law" which states they are often over budget take longer than anticipated and yield fewer benefits than expected mainly because key players consistently underestimate costs and risks. Pursuing multiple pioneering megaprojects simultaneously restricts opportunities for iterative learning which raises risks related to untested technologies and infrastructure demands. This vision paper introduces a novel risk assessment framework that combines insights from pioneering and megaprojects with technology readiness evaluations and comparative CO2 reduction analyses to tackle these challenges. The framework aims to guide investment decisions and risk mitigation strategies such as staged scaling and limiting the introduction of new technology. The analysis highlights that using green ammonia for fertiliser production can reduce CO2 emissions by 51 tons of CO2 per ton of hydrogen significantly outperforming hydrogen use in transportation and heating. This structured approach considers risks and environmental benefits while promoting equitable risk distribution between developed and developing nations.
Hydrogen Production Plant via an Intensified Plasma-based Technology
Oct 2025
Publication
Developing cleaner processes via newer technologies will accelerate advancement toward more sustainable energy systems. Hydrogen is an energy carrier and an intermediate molecule in chemical processes. This research investigates an innovative hydrogen production process utilizing a non-thermal Cold Atmospheric Pressure Plasma-based Reformer (CAPR). Exploring environmentally friendly and economically viable pathways for hydrogen production is crucial for addressing climate change and reducing the carbon footprint of industrial processes. The study investigates the conversion of natural gas to hydrogen at ambient temperature and pressure highlighting the ability of plasma-based technology to operate without direct CO2 emissions.<br/>Initially through experimental studies natural gas was passed through the CAPR where the plasma's energetic discharges initiate the reforming process. Subsequently the produced hydrogen along with other light hydrocarbons enters the separation system for producing purified hydrogen. The research focuses on techno-economic analyses and sensitivity assessments to determine the levelized cost of producing hydrogen via a nanosecond plasma-based refining plant and benchmark technologies. Sensitivity analyses identify two primary factors that significantly affect the levelized cost of hydrogen production in a plasma-based reforming system.<br/>The research suggests that instead of producing carbon dioxide and capturing the emitted CO2 utilize processes that do not emit direct CO2. CAPR shows potential for cost competitiveness with conventional hydrogen production methods including steam methane reforming (SMR) and electrolysis. The findings underscore the need for further research to optimize the system's performance and cost-effectiveness positioning CAPR as a potentially transformative technology for the chemical process industry.
Everything About Hydrogen Podcast: COP28 Special
Dec 2023
Publication
To round off Season 5 the team are taking the podcast to COP28 in Dubai and providing listeners with a bit of texture including what the event was like to attend as well as sharing a snapshot of some of the varied voices and discussions that took place. Having had a little time for reflection Alicia Chris and Patrick also offer their thoughts and takeaways on what this COP might mean for the future.
COP28 was the first in nearly 30 years to feature hydrogen as part of the Presidential Action Agenda.
The podcast can be found on their website.
COP28 was the first in nearly 30 years to feature hydrogen as part of the Presidential Action Agenda.
The podcast can be found on their website.
Future of Hydrogen in the U.S. Energy Sector: MARKAL Modeling Results
Mar 2024
Publication
Hydrogen is an attractive energy carrier which could play a role in decarbonizing process heat power or transport applications. Though the U.S. already produces about 10 million metric tons of H2 (over 1 quadrillion BTUs or 1% of the U.S. primary energy consumption) production technologies primarily use fossil fuels that release CO2 and the deployment of other cleaner H2 production technologies is still in the very early stages in the U.S. This study explores (1) the level of current U.S. hydrogen production and demand (2) the importance of hydrogen to accelerate a net-zero CO2 future and (3) the challenges that must be overcome to make hydrogen an important part of the U.S. energy system. The study discusses four scenarios and hydrogen production has been shown to increase in the future but this growth is not enough to establish a hydrogen economy. In this study the characteristics of hydrogen technologies and their deployments in the long-term future are investigated using energy system model MARKAL. The effects of strong carbon constraints do not cause higher hydrogen demand but show a decrease in comparison to the business-as-usual scenario. Further according to our modeling results hydrogen grows only as a fuel for hard-to-decarbonize heavy-duty vehicles and is less competitive than other decarbonization solutions in the U.S. Without improvements in reducing the cost of electrolysis and increasing the performance of near-zero carbon technologies for hydrogen production hydrogen will remain a niche player in the U.S. energy system in the long-term future. This article provides the reader with a comprehensive understanding of the role of hydrogen in the U.S. energy system thereby explaining the long-term future projections.
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