Publications
Experimental Investigation of Hydrogen Production Performance of PEM Electrolyze
Jul 2025
Publication
As global awareness of environmental protection increases hydrogen is seen as a promising solution due to its high energy density and zero-emission combustion. The PEM electrolyze combined with renewable energy power generation is an effective method to solve the problem of hydrogen production. The market competitiveness of PEM electrolyte will be enhanced in the future and the equipment cost can be reduced by 35.8%. The fast dynamic response performance of PEM electrolyzes especially during start-up and shutdown affects system flexibility and stability. The 190 Nm3/h test platform is established to study the fast dynamic response performance considering the cold startup thermal start-up and shutdown behaviors. The results shown that the 190 Nm³/h PEM electrolyze required 6340 s to achieve cold start-up 1100 s to achieve thermal start-up and 855 s to complete shutdown. When operating stably the temperature fluctuation of the PEM remains below 5 °C demonstrating the excellent temperature control performance. However during cold start-up and shutdown the concentrations of hydrogen and oxygen fluctuate significantly which can easily lead to a decrease in system performance. These findings provide guidance for optimizing the design and operating parameters of PEM Electrolyze systems.
Learning in Green Hydrogen Production: Insights from a Novel European Dataset
Jun 2025
Publication
The cost reduction of electrolysers is critical for scaling up green hydrogen production and achieving decarbonization targets. This study presents a novel and comprehensive dataset of electrolyser projects in Europe. It includes full cost and capacity details for each project and capturing project-specific characteristics such as technology type location and project type for the period 2005–2030. We apply the learning curve methodology to assess cost reductions across different electrolyser technologies and project sizes. Our findings indicate a significant learning effect for PEM and AEL electrolysers in the last 20 years with learning rates of 32.1% and 22.9% respectively. While AEL cost reductions are primarily driven by scaling effects PEM electrolysers benefit from both technological advancements and economies of scale. Small-scale electrolysers exhibit a stronger learning effect (25%) whereas large-scale projects show no clear cost reductions due to their early stage of deployment. Projections based on our learning rates suggest that reaching Europe’s 2030 target of 40 GW electrolyser capacity would require an estimated total investment of 14 billion EUR. These results align closely with previous studies and such predictions are closed to estimates from other organization. The dataset is publicly available allowing for further analysis and periodic updates to track cost trends.
Artificial Intelligence-based Multi-objective Optimization of a Solar-driven System for Hydrogen Production with Integrated Oxygen and Power Co-generation Across Different Climates
Oct 2025
Publication
This study develops and optimizes a solar-powered system for hydrogen generation with oxygen and power coproducts addressing the need for efficient scalable carbon-free energy solutions. The system combines a linear parabolic collector a Steam Rankine cycle and a Proton Exchange Membrane Electrolyzer (PEME) to produce electricity for electrolysis. Thermodynamic modeling was accomplished in Engineering Equation Solver while a hybrid Artificial Intelligence (AI) framework combining Artificial Neural Networks and Genetic Algorithms in Statistica coupled with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) decision support optimized technical and economic performance. Optimization considered seven key decision variables covering collector design thermodynamic inputs and component efficiencies. The optimization achieved energy and exergy efficiencies of 30.83 % and 26.32 % costing 47.02 USD/h and avoiding CO2 emissions equivalent to 190 USD/ton. Economic and exergy analyses showed the solar and hydrogen units had the highest costs (38.17 USD/h and 9.61 USD/h) with 4503 kWh of exergy destruction to generate 575 kWh of electricity. A case study across six cities suggested that Perth Bunbury and Adelaide with higher solar irradiance delivered the highest annual power and hydrogen outputs consistent with irradiance–electrolyzer correlation. Unlike conventional single-site studies this work delivers a climate-responsive multi-city analysis integrating solar thermal and PEME within an AI-driven framework. By linking techno-economic performance with quantified environmental value and co-production synergies of hydrogen oxygen and electricity the study highlights a novel pathway for scalable clean hydrogen measurable CO2 reductions and global decarbonization with future work focused on digital twins and dynamic uncertainty-aware optimization.
The Concept of an Infrastructure Location to Supply Buses with Hydrogen: A Case Study of the West Pomeranian Voivodeship in Poland
Jun 2025
Publication
The growing energy crisis and increasing threat of climate change are driving the need to take action regarding the use of alternative fuels in transport including public transport. Hydrogen is undoubtedly a fuel which is environmentally friendly and constitutes an alternative to fossil fuels. The wider deployment of hydrogen-powered vehicles involves the need to adapt infrastructure to support the operation of these vehicles. Such infrastructure includes refuelling stations for hydrogen-powered vehicles. The widespread use of hydrogen-powered vehicles is dependent on the development of a network of hydrogen refuelling stations. The aim of this article is to propose the conceptual location of infrastructure for fuelling public transport vehicles with hydrogen in selected cities of the West Pomeranian Voivodeship in particular the cities of Szczecin and Koszalin. The methodology used to determine the number of refuelling stations is described and the concept of the location for the refuelling stations has been proposed. Based on a set assumptions it was stated that two stations may be located in the Voivodeship in 2025 and seven stations in 2040. The research results will be of interest to infrastructure developers public transport companies and municipalities involved in making decisions related to the purchase and operation of hydrogen-powered buses.
Prospective Life Cycle Assessment of Future Swedish Hydrogen-powered Aviation Pathways
Jun 2025
Publication
Hydrogen-powered aviation is promoted as a low-carbon alternative for future long-distance air travel but its broader environmental impacts remain unclear. This study evaluates the potential environmental impacts of six future air travel pathways in Sweden including e-kerosene liquid hydrogen and fossil kerosene using prospective life cycle assessment. Results show that hydrogen-powered aviation has lower global warming potential than fossil kerosene but higher impacts on other environmental issues such as toxicity and land use. Key hotspots include resources in energy infrastructure and energy use in fuel production and airport operations however resource substitutions and energy efficiency improvements have limits. This study highlights the potential environmental benefits and tradeoffs of hydrogen-powered aviation and also the dependency of aviation on other sectors. Further research should integrate technological innovations in long-distance air travel pathways with scenarios that account for demand-side measures as well as regulatory political and economic barriers.
Technoeconomic analysis of Hydrogen Versus Natural Gas Considering Safety Hazards and Energy Efficiency Indicators
Aug 2025
Publication
Hydrogen (H2) is emerging as a key alternative to fossil fuels in the global energy transition. This study presents a comparative techno-economic analysis of H2 and natural gas (NG) focusing on safety hazards energy output CO2 emissions and cost-effectiveness aspects. Our analysis showed that compared to NG and other highly flammable gases like acetylene (C2 H2) and propane (C3 H8) H2 has a higher hazard potential due to factors such as its wide flammability range low ignition energy and high flame speed. In terms of energy output 1 kg of NG produces 48.60 MJ while conversion to liquefied natural gas (LNG) grey H2 and blue H2 reduces energy output to 45.96 MJ 35.45 MJ and 31.21 MJ respectively. Similarly while unconverted NG emits 2.72 kg of CO2 per kg emissions increase to 3.12 kg for LNG and 3.32 kg for grey H2. However blue H2 significantly reduces CO2 emissions to 1.05 kg per kg due to carbon capture and storage. From an economic perspective producing 1 kg of NG yields a profit of $0.011. Converting NG to grey H2 is most profitable yielding a net profit of $0.609 per kg of NG while blue H2 despite higher production costs remains viable with a profit of $0.390 per kg of NG. LNG conversion also shows profitability with $0.061 per kg of NG. This analysis highlights the trade-offs between energy efficiency environmental impact and economic viability providing valuable insights for stakeholders formulating hydrogen and LNG implementation strategies.
The Need for Change: A Roadmap for the Sustainable Transformation of the Chemical Industry
Jun 2025
Publication
The chemical industry faces major challenges worldwide. Since 1950 production has increased 50-fold and is projected to continue growing particularly in Asia. It is one of the most energy- and resource-intensive industries contributing significantly to greenhouse gas emissions and the depletion of finite resources. This development exceeds planetary boundaries and calls for a sustainable transformation of the industry. The key transformation areas are as follows: (1) Non-Fossil Energy Supply: The industry must transition away from fossil fuels. Renewable electricity can replace natural gas while green hydrogen can be used for high-temperature processes. (2) Circularity: Chemical production remains largely linear with most products ending up as waste. Sustainable product design and improved recycling processes are crucial. (3) Non-Fossil Feedstock: To achieve greenhouse gas neutrality oil gas and coal must be replaced by recycling plastics renewable biomaterials or CO2-based processes. (4) Sustainable Chemical Production: Energy and resource savings can be achieved through advancements like catalysis biotechnology microreactors and new separation techniques. (5) Sustainable Chemical Products: Chemicals should be designed to be “Safe and Sustainable by Design” (SSbD) meaning they should not have hazardous properties unless essential to their function. (6) Sufficiency: Beyond efficiency and circularity reducing overall material flows is essential to stay within planetary boundaries. This shift requires political economic and societal efforts. Achieving greenhouse gas neutrality in Europe by 2050 demands swift and decisive action from industry governments and society. The speed of transformation is currently too slow to reach this goal. Science can drive innovation but international agreements are necessary to establish a binding framework for action.
Energy Storage in the Energy Transition and Blue Economy: Challenges, Innovations, Future Perspectives, and Educational Pathways
Sep 2025
Publication
Transitioning to renewable energy is vital to achieving decarbonization at the global level but energy storage is still a major challenge. This review discusses the role of energy storage in the energy transition and the blue economy focusing on technological development challenges and directions. Effective storage is vital for balancing intermittent renewable energy sources like wind solar and marine energy with the power grid. The development of battery technologies hydrogen storage pumped hydro storage and emerging technologies like sodium-ion and metal-air batteries is discussed for their potential for large-scale deployment. Shortages in critical raw materials environmental impact energy loss and costs are some of the challenges to large-scale deployment. The blue economy promises opportunities for offshore energy storage notably through ocean thermal energy conversion (OTEC) and compressed air energy storage (CAES). Moreover the capacity of datadriven optimization and artificial intelligence to enhance storage efficiency is discussed. Policy interventions and economic incentives are necessary to spur the development and deployment of sustainable energy storage technology. Education and workforce training are also important in cultivating future researchers engineers and policymakers with the ability to drive energy innovation. Merging sustainability training with an interdisciplinary approach can potentially establish an efficient workforce that is capable of addressing energy issues. Future work needs to focus on higher energy density efficiency recyclability and cost-effectiveness of the storage technologies without sacrificing their environmental sustainability. The study underlines the need for converging technological economic and educational approaches to enable a sustainable and resilient energy future.
Day-Ahead Dispatch Optimization of an Integrated Hydrogen–Electric System Considering PEMEL/PEMFC Lifespan Degradation and Fuzzy-Weighted Dynamic Pricing
Sep 2025
Publication
Integrated Hydrogen–Energy Systems (IHES) have attracted widespread attention; however distributed energy sources such as photovoltaics (PV) and wind turbines (WT) within these systems exhibit significant uncertainty and intermittency posing key challenges to scheduling complexity and system instability. As a core mechanism for the integrated operation of IHES electricity price regulation can promote the absorption of renewable energy optimize resource allocation and enhance operational economy. Nevertheless uncertainties in IHES hinder the formulation of accurate electricity prices which easily lead to delays in scheduling responses and an increase in cumulative operating costs. To address these issues this study develops lifespan models for Proton Exchange Membrane Electrolyzers (PEMELs) and Proton Exchange Membrane Fuel Cells (PEMFCs) constructs dynamic equations for the demand side and response side and proposes a fuzzy-weighted dynamic pricing strategy. Simulation results show that compared with fixed pricing the proposed dynamic pricing strategy reduces economic indicators by an average of 15.3% effectively alleviates energy imbalance and optimizes the energy supply of components. Additionally it reduces the lifespan degradation of PEMELs by 21.59% and increases the utilization rate of PEMFCs by 54.8%.
Overcoming Hurdles and Harnessing the Potential of the Hydrogen Transition in Germany
Jun 2025
Publication
Green hydrogen has become a core element of Europe’s energy transition to assist in lowering carbon emissions. However the transition to green hydrogen faces challenges including the cost of production availability of renewable energy sources public opposition and the need for supportive government policies and financial initiatives. While there are other alternatives for producing low-carbon hydrogen for example blue hydrogen German funding favours projects that involve hydrogen production via electrolysis. Beyond climate goals it is anticipated that a green hydrogen industry will create economic benefits and a wide-range of collaborative opportunities with key international partnerships increasing energy security if done appropriately. Germany a leader in green hydrogen technology will need to rely on imports to meet long-term demand due to limited renewable energy capacity. Despite the current obstacles to transitioning to green hydrogen it is felt that ultimately the benefits of this industry and reducing emissions will outweigh the associated costs of production. This study analyses the hydrogen transition in Germany by interviewing 37 European experts guided by the research question: What are the key perceived barriers and opportunities influencing the successful adoption and integration of hydrogen technologies in Germany’s hydrogen transition?
Renewables, Electrification and Flexibility for a Competitive EU Energy System Transformation by 2030
Jun 2025
Publication
The European Union is on a pathway to achieve climate neutrality by 2050. This report explores the historic and necessary efforts to align Europe′s electricity heating and transport systems with transformative EU benchmarks for 2030 to meet that longer-term goal. CO2 emissions have declined significantly in the EU electricity subsystem over the past few decades. This presents an important opportunity to decarbonise rapidly in the near future and to roll out electrification to other sectors while strengthening energy independence security and competitiveness for all EU countries. Through accelerated gains in energy and resource efficiency and the alignment of Member States′ efforts within a more coherent EU energy system the rapid electrification of buildings transport and industry can greatly reduce Europe′s reliance on foreign fossil fuels and unlock critical progress in heating and transport. Over the past five years EU policy frameworks for climate mitigation and energy system transformation have become far more coherent and complete. Infrastructure security and resilience have been bolstered through integrated climate and energy planning in tandem with national and cross-border efforts to ensure sound policy implementation. It is now critical that decision-makers translate objectives and priorities for the energy system transition into actionable measures. This includes crafting fiscal strategies to finance key upfront infrastructure investments; distributing the cost of capital proportionally to not overburden taxpayers; aligning taxation pricing and information signals across the whole energy system; and regularly monitoring and evaluating performance to recalibrate policies when needed.
Effect of Injection Timing on Gas Jet Developments in a Hydrogen Low-pressure Direct-injection Spark-ignition Engine
Sep 2025
Publication
Injection timing in low-pressure hydrogen direct injection (H2LPDI) engines plays a critical role in optimising gas jet structure and mixture formation due to the complex and transient nature of ambient air flow and density inside the cylinder. This study systematically investigates the macroscopic characteristics of gas jet development at five distinct injection timings from 210 to 120 ◦CA bTDC with the intake valve closure (IVC) as a reference point in a motored inline four-cylinder spark-ignition engine at 2000 rpm and 160 Nm load using low-pressure injection of 3.5 MPa. Optical access was made with two endoscopes: one for high-speed imaging and the other for laser insertion to realise laser shadowgraph imaging of the gas jet delivered using a side-mounted outwardopening pintle nozzle injector. The experimental results reveal spatial and temporal variations in jet morphology penetration spreading angle and mixture dispersion as a function of injection timing. Pre-IVC injection (210 ◦CA bTDC) produced a narrow mean cone angle of ~40◦ and the highest penetration-rate proxy (0.49) whereas postIVC injection (120 ◦CA bTDC) retained a wider ~53◦ cone yet reduced the penetration rate to 0.28 while increasing the sheet-based mixing index from − 0.084 to − 0.106. Pre-IVC injection occurring under low ambient pressure and with active intake airflow was found to produce elongated jets with enhanced penetration and mixing rates though accompanied by substantial cyclic variations. Conversely post-IVC injection was strongly influenced by a fully developed tumble flow which redirected the jet trajectory towards the pent-roof and facilitated mixing through increased turbulence. However the elevated air density constrained the jet penetration. At-IVC injection resulted in a more uniform and stable jet structure. However the lack of convective flow constrained the overall mixing effectiveness. Quantitative analysis of jet spreading angle pixel intensity gradient and centroid movement using 100 consecutive cycles confirms the critical role of injection timing in shaping the gas jet development as suggested by the images.
Harnessing Wind for Hydrogen: Comparative MCDM-GIS Assessment of Optimal Plant Locations
Jul 2025
Publication
This research aimed to perform an in-depth comparative analysis of MCDM methods utilizing ArcGIS Pro 3.0.2 to identify the most suitable sites for wind-powered hydrogen production plants in Erbil Governorate Iraq. VIKOR TOPSIS SAW and Weighted Overlay techniques were implemented and applied to evaluate various criteria. A comparative analysis determined that VIKOR had the highest consistency and robustness making it the most suitable approach for selecting a site for windpowered hydrogen facilities. Spatial analysis showed that the southern and southwestern regions of Erbil Governorate were the most favourable areas for hydrogen generation. Wind turbine technical feasibility assessments identified the E112/4500 and V126e3.45 turbine models as the most efficient for these regions with high annual hydrogen production. The spatial configuration including the optimal turbine spacing had a significant effect on the capacity and production potential. ArcPro integration with MCDM significantly enhanced spatial analysis providing high-resolution data processing and advanced visualization capabilities.
Flexible Economic Energy Management Including Environmental Indices in Heat and Electrical Microgrids Considering Heat Pump with Renewable and Storage Systems
Oct 2025
Publication
This study discusses energy management in thermal and electrical microgrids while taking heat pumps renewable sources thermal and hydrogen storages into account. The weighted total of the operating cost grid emissions level voltage and temperature deviation function and other factors makes up the objective function of the suggested method. The restrictions include the operationflexibility model of resources and storages micro-grid flexibility limits and optimum power flow equations. Point Estimation Method is used in this work to simulate load energy price and renewable phenomenon uncertainty. A fuzzy decision-making methodology is used to arrive at a compromise solution that satisfies network operators’ operational environmental and financial goals. The innovations of this paper include energy management of various smart microgrids simultaneous modeling of several indicators especially flexibility investigation of optimal performance of resources and storage devices and modeling of uncertainty considering low computational time and an accurate flexibility model. Numerical findings indicate that the fuzzy decision-making approach has the capability to reach a compromise point in which the objective functions approach their minimum values. The integration of the proposed uncertainty modeling with precise flexibility modeling results in a reduction in computational time when compared to stochastic optimization based on scenarios. For the compromise point and uncertainty modeling with PEM by efficiently managing resources and thermal and hydrogen storages scheme is capable of attaining high flexibility conditions. Compared to load flow studies the approach can enhance the operational environmental and economic conditions of smart microgrids by approximately 33–57% 68% and 33–68% respectively under these circumstances.
Research on Hydrogen Leakage Risk Control Methods in Deck Compartments of Hydrogen Fuel Cell-Powered Ships Based on CFD Simulation and Ventilation Optimization
Oct 2025
Publication
Hydrogen fuel cell vessels represent a vital direction for green shipping but the risk of large-scale hydrogen leakage and diffusion in their enclosed compartments is particularly prominent. To enhance safety a simplified three-dimensional model of the deck-level cabins of the “Water-Go-Round” passenger ship was established using SolidWorks (2023) software. Based on a hydrogen leakage and diffusion model the effects of leakage location leakage aperture and initial ambient temperature on the diffusion patterns and distribution of hydrogen within the cabins were investigated using FLUENT software. The results show that leak location significantly affects diffusion direction with hydrogen leaking from the compartment ceiling diffusing horizontally much faster than from the floor. When leakage occurs at the compartment ceiling hydrogen can reach a maximum horizontal diffusion distance of up to 5.04 m within 540 s; the larger the leak aperture the faster the diffusion with a 10 mm aperture exhibiting a 40% larger diffusion range than a 6 mm aperture at 720 s. The study provides a theoretical basis for the safety design and risk prevention of hydrogen fuel cell vessels.
Preliminary Design of Regional Aircraft—Integration of a Fuel Cell-Electric Energy Network in SUAVE
Mar 2025
Publication
To enable climate-neutral aviation improving the energy efficiency of aircraft is essential. The research project Synergies of Highly Integrated Transport Aircraft investigates cross-disciplinary synergies in aircraft and propulsion technologies to achieve energy savings. This study examines a fuel cell electric powered configuration with distributed electric propulsion. For this a reverse-engineered ATR 72-500 serves as a reference model for calibrating the methods and ensuring accurate performance modeling. A baseline configuration featuring a state-of-the-art turboprop engine with the same entry-into-service is also introduced for a meaningful performance comparison. The analysis uses an enhanced version of the Stanford University Aerospace Vehicle Environment (SUAVE) a Python-based aircraft design environment that allows for novel energy network architectures. This paper details the preliminary aircraft design process including calibration presents the resulting aircraft configurations and examines the integration of a fuel cell-electric energy network. The results provide a foundation for higher fidelity studies and performance comparisons offering insights into the trade-offs associated with hydrogen-based propulsion systems. All fundamental equations and methodologies are explicitly presented ensuring transparency clarity and reproducibility. This comprehensive disclosure allows the broader scientific community to utilize and refine these findings facilitating further progress in hydrogen-powered aviation technologies.
Case Study of a Greenfield Blue Hydrogen Plant: A Comparative Analysis of Production Methods
Jun 2025
Publication
Blue hydrogen is a key pathway for reducing greenhouse gas emissions while utilizing natural gas with carbon capture and storage (CCS). This study conducts a techno-economic and environmental analysis of a greenfield blue hydrogen plant in Saskatchewan Canada integrating both SMR and ATR technologies. Unlike previous studies that focus mainly on production units this research includes all process and utility systems such as H2 and CO2 compression air separation refrigeration co-generation and gas dehydration. Aspen HYSYS simulations revealed ATR’s energy demand is 10% lower than that of SMR. The hydrogen production cost was USD 3.28/kg for ATR and USD 3.33/kg for SMR while a separate study estimated a USD 2.2/kg cost for design without utilities highlighting the impact of indirect costs. Environmental analysis showed ATR’s lower Global Warming Potential (GWP) compared to SMR reducing its carbon footprint. The results signified the role of utility integration site conditions and process selection in optimizing energy efficiency costs and sustainability.
A Review of Green Hydrogen Technologies and Their Role in Enabling Sustainable Energy Access in Remote and Off-Grid Areas Within Sub-Saharan Africa
Sep 2025
Publication
Electricity access deficits remain acute in Sub-Saharan Africa (SSA) where more than 600 million people lack reliable supply. Green hydrogen produced through renewablepowered electrolysis is increasingly recognized as a transformative energy carrier for decentralized systems due to its capacity for long-duration storage sector coupling and near-zero carbon emissions. This review adheres strictly to the PRISMA 2020 methodology examining 190 records and synthesizing 80 peer-reviewed articles and industry reports released from 2010 to 2025. The review covers hydrogen production processes hybrid renewable integration techno-economic analysis environmental compromises global feasibility and enabling policy incentives. The findings show that Alkaline (AEL) and PEM electrolyzers are immediately suitable for off-grid scenarios whereas Solid Oxide (SOEC) and Anion Exchange Membrane (AEM) electrolyzers present high potential for future deployment. For Sub-Saharan Africa (SSA) the levelized costs of hydrogen (LCOH) are in the range of EUR5.0–7.7/kg. Nonetheless estimates from the learning curve indicate that these costs could fall to between EUR1.0 and EUR1.5 per kg by 2050 assuming there is (i) continued public support for the technology innovation (ii) appropriate flexible and predictable regulation (iii) increased demand for hydrogen and (iv) a stable and long-term policy framework. Environmental life-cycle assessments indicate that emissions are nearly zero but they also highlight serious concerns regarding freshwater usage land occupation and dependence on platinum group metals. Namibia South Africa and Kenya exhibit considerable promise in the early stages of development while Niger demonstrates the feasibility of deploying modular community-scale systems in challenging conditions. The study concludes that green hydrogen cannot be treated as an integrated solution but needs to be regarded as part of blended off-grid systems. To improve its role targeted material innovation blended finance and policies bridging export-oriented applications to community-scale access must be established. It will then be feasible to ensure that hydrogen
Operational Optimization of Electricity–Hydrogen Coupling Systems Based on Reversible Solid Oxide Cells
Sep 2025
Publication
To effectively address the issues of curtailed wind and photovoltaic (PV) power caused by the high proportion of renewable energy integration and to promote the clean and lowcarbon transformation of the energy system this paper proposes a “chemical–mechanical” dual-pathway synergistic mechanism for the reversible solid oxide cell (RSOC) and flywheel energy storage system (FESS) electricity–hydrogen hybrid system. This mechanism aims to address both short-term and long-term energy storage fluctuations thereby minimizing economic costs and curtailed wind and PV power. This synergistic mechanism is applied to regulate system operations under varying wind and PV power output and electricity–hydrogen load fluctuations across different seasons thereby enhancing the power generation system’s ability to integrate wind and PV energy. An economic operation model is then established with the objective of minimizing the economic costs of the electricity–hydrogen hybrid system incorporating RSOC and FESS. Finally taking a large-scale new energy industrial park in the northwest region as an example case studies of different schemes were conducted on the MATLAB platform. Simulation results demonstrate that the reversible solid oxide cell (RSOC) system—integrated with a FESS and operating under the dual-path coordination mechanism—achieves a 14.32% reduction in wind and solar curtailment costs and a 1.16% decrease in total system costs. Furthermore this hybrid system exhibits excellent adaptability to the dynamic fluctuations in electricity– hydrogen energy demand which is accompanied by a 5.41% reduction in the output of gas turbine units. Notably it also maintains strong adaptability under extreme weather conditions with particular effectiveness in scenarios characterized by PV power shortage.
Sustainable Transition Pathways for Steel Manufacturing: Low-Carbon Steelmaking Technologies in Enterprises
Jun 2025
Publication
Amid escalating global climate crises and the urgent imperative to meet the Paris Agreement’s carbon neutrality targets the steel industry—a leading contributor to global greenhouse gas emissions—confronts unprecedented challenges in driving sustainable industrial transformation through innovative low-carbon steelmaking technologies. This paper examines decarbonization technologies across three stages (source process and end-of-pipe) for two dominant steel production routes: the long process (BF-BOF) and the short process (EAF). For the BF-BOF route carbon reduction at the source stage is achieved through high-proportion pellet charging in the blast furnace and high scrap ratio utilization; at the process stage carbon control is optimized via bottom-blowing O2-CO2-CaO composite injection in the converter; and at the end-of-pipe stage CO2 recycling and carbon capture are employed to achieve deep decarbonization. In contrast the EAF route establishes a low-carbon production system by relying on green and efficient electric arc furnaces and hydrogen-based shaft furnaces. At the source stage energy consumption is reduced through the use of green electricity and advanced equipment; during the process stage precision smelting is realized through intelligent control systems; and at the end-of-pipe stage a closed-loop is achieved by combining cascade waste heat recovery and steel slag resource utilization. Across both process routes hydrogen-based direct reduction and green power-driven EAF technology demonstrate significant emission reduction potential providing key technical support for the low-carbon transformation of the steel industry. Comparative analysis of industrial applications reveals varying emission reduction efficiencies economic viability and implementation challenges across different technical pathways. The study concludes that deep decarbonization of the steel industry requires coordinated policy incentives technological innovation and industrial chain collaboration. Accelerating large-scale adoption of low-carbon metallurgical technologies through these synergistic efforts will drive the global steel sector toward sustainable development goals. This study provides a systematic evaluation of current low-carbon steelmaking technologies and outlines practical implementation strategies contributing to the industry’s decarbonization efforts.
Optimization Framework for Efficient and Robust Renewable Energy Hub Operation
Oct 2025
Publication
This research proposes an advanced optimization framework for renewable energy hubs within integrated electrical and thermal networks aimed at improving energy management. The motivation stems from the need for a more flexible and efficient solution that addresses the variability of renewable energy sources such as wind and bio-waste units while integrating storage solutions like hydrogen and thermal systems. The hypothesis is that combining a market-clearing price model with robust decision-making frameworks can optimize both economic viability and operational efficiency. The methodology adopts a two-tier optimization approach: the upper tier maximizes hub profits and the lower tier minimizes operational costs through a market-clearing price model. The study also incorporates a robust optimization model that accounts for decision-dependent uncertainties with a novel class of polyhedral uncertainty sets used for improved decision-making. Numerical results from case studies demonstrate that the proposed method increases the objective function by approximately 3% and achieves a 25% faster solution time compared to the Benders decomposition approach. These findings support the conclusion that the proposed framework enhances both flexibility and economic performance of energy hubs offering a viable solution for modern energy systems.
Techno-Economic Environmental Risk Analysis (TERA) in Hydrogen Farms
Sep 2025
Publication
This study presents a techno-economic environmental risk analysis (TERA) of large-scale green hydrogen production using Alkaline Water Electrolysis (AWE) and Proton Exchange Membrane (PEM) systems. The analysis integrates commercial data market insights and academic forecasts to capture variability in capital expenditure (CAPEX) efficiency electricity cost and capacity factor. Using Libya as a case study 81 scenarios were modelled for each technology to assess financial and operational trade-offs. For AWE CAPEX is projected between $311 billion and $905.6 billion for 519 GW (gigawatts) of installed capacity equivalent to 600–1745 $/kW. PEM systems show a wider range of $612 billion to $1020 billion for 510 GW translating to 1200–2000 $/kW. Results indicate that AWE while requiring greater land use provides significant cost advantages due to lower capital intensity and scalability. In contrast PEM systems offer compact design and operational flexibility but at substantially higher costs. The five most economical scenarios for both technologies consistently feature low CAPEX and high efficiency while sensitivity analyses confirm these two parameters as the dominant cost drivers. The findings emphasise that technology choice should reflect context-specific priorities such as land availability budget and performance needs. This study provides actionable guidance for policymakers and investors developing cost-effective hydrogen infrastructure in emerging green energy markets.
Mitigating Microbial Artifacts in Laboratory Research on Underground Hydrogen Storage
Jul 2025
Publication
The global energy sector is aiming to substantially reduce CO2 emissions to meet the UN climate goals. Among the proposed strategies underground storage solutions such as radioactive disposal CO2 NH3 and underground H2 storage (UHS) have emerged as promising options for mitigating anthropogenic emissions. These approaches require rigorous research and development (R&D) often involving laboratory-scale experiments to establish their feasibility before being scaled up to pilot plant operations. Microorganisms which are ubiquitous in laboratory environments can significantly influence geochemical reactions under variable experimental conditions of porous media and a salt cavern. We have selected a consortium composed of Bacillus sp. Enterobacter sp. and Cronobacter sp. bacteria which are typically present in the laboratory environment. These microorganisms can contaminate the rock sample and develop experimental artifacts in UHS experiments. Hence it is pivotal to sterilize the rock prior to conduct experimental research related to effects of microorganisms in the porous media and the salt cavern for the investigation of UHS. This study investigated the efficacy of various disinfection and sterilization methods including ultraviolet irradiation autoclaving oven heating ethanol treatments and gamma irradiation in removing the microorganisms from silica sand. Additionally the consideration of their effects on mineral properties are reviewed. A total of 567 vials each filled with 9 mL of acid-producing bacteria (APB) media were used to test killing efficacy of the cleaning methods. We conducted serial dilutions up to 10−8 and repeated them three times to determine whether any deviation occurred. Our findings revealed that gamma irradiation and autoclaving were the most effective techniques for eradicating microbial contaminants achieving sterilization without significantly altering the mineral characteristics. These findings underscore the necessity of robust cleaning protocols in hydrogeochemical research to ensure reliable reproducible data particularly in future studies where microbial contamination could induce artifacts in laboratory research.
Underground Hydrogen Storage Suitability Index: A Geological Tool for Evaluating and Ranking Storage Sites
Jun 2025
Publication
Underground Hydrogen Storage (UHS) is a promising solution to maximize the use of hydrogen as an energy carrier. This study presents a standardized methodology for assessing UHS quality by introducing the Underground Hydrogen Storage Suitability Index (UHSSI) which integrates three sub-indices: the Caprock Potential Index (CPI) the Reservoir Quality Index (RQI) and the Site Potential Index (SPI). Parameters such as porosity permeability lithology caprock thickness depth temperature and salinity are evaluated and ranked from 0 (unsuitable) to 5 (excellent). The methodology was validated using data from six worldwide sites including salt caverns and aquifers. Sites like Moss Bluff Clemens Dome and Spindletop (USA) scored highly while Teesside (UK) Lobodice (Czech Republic) and Beynes (France) were classified as unsuitable due to shallow depths and microbial activity. A software tool the UHSSI Calculator was developed to automate site evaluations. This approach offers a cost-effective tool for preliminary screening and supports the safer development of UHS.
Exploring the Gas Permeability of Type IV Hydrogen Storage Cylinder Liners: Research and Applications
Jul 2025
Publication
As hydrogen fuel cell vehicles gain momentum as crucial zero-emission transportation solutions the urgency to address hydrogen permeability through the polymer liner becomes paramount for ensuring the safety efficiency and longevity of Type IV hydrogen storage tanks. This paper synthesizes existing research findings analyzes the influence of different materials and structures on gas permeability elucidates the dissolution and diffusion mechanisms of hydrogen in plastic liners and discusses their engineering applications. We focus on measurement methods influencing factors and improvement strategies for liner gas permeability. Additionally we explore the prospects of Type IV hydrogen storage tanks in fields such as automotive aerospace and energy storage industries. Through this comprehensive review of liner gas permeability critical insights are provided to guide the development of efficient and safe hydrogen storage and transportation systems. These insights are vital for advancing the widespread application of hydrogen energy technology and fostering sustainable energy development significantly contributing to efforts aimed at enhancing the performance and safety of Type IV hydrogen storage tanks.
Global Warming Impacts of the Transition from Fossil Fuel Conversion and Infrastructure to Hydrogen
Jul 2025
Publication
Emissions from fossil fuel extraction conveyance and combustion are among the most significant causes of air pollution and climate change leading to arguably the most acute crises mankind has ever faced. The transition from fossil fuel-based energy systems to hydrogen is essential for meeting a portion of global decarbonization goals. Hydrogen offers certain features such as high gravimetric energy density that is required for heavy-duty shipping and freight applications and chemical properties such as high temperature combustion and reducing capabilities that are required for steel chemicals and fertilizer industries. However hydrogen that leaks has indirect climate implications stemming from atmospheric interactions that are emerging as a critical area of research. This study reviews recent literature on hydrogen’s global warming potential (GWP) highlighting its indirect contributions to radiative forcing via methane’s extended atmospheric lifetime tropospheric ozone formation and stratospheric water vapor formation. The 100-year GWP (GWP100) of hydrogen estimated to range between 8 and 12.8 underscores the need to minimize leakage throughout the hydrogen supply chain to maximize the climate benefits of using hydrogen instead of fossil fuels. Comparisons with methane reveal hydrogen’s shorter atmospheric lifetime and reduced long-term warming effects establishing it as a viable substitute for fossil fuels in sectors such as steel cement and heavy-duty transport. The analysis emphasizes the importance of accurate leakage assessments robust policy frameworks and advanced infrastructure to ensure hydrogen realizes its potential as a sustainable energy carrier that displaces the use of fossil fuels. Future research is recommended to refine climate models better understand atmospheric sinks and hydrogen leakage phenomena and develop effective strategies to minimize hydrogen emissions paving the way for environmentally sound use of hydrogen.
Injection Strategies in a Hydrogen SI Engine: Parameter Selection and Comparative Analysis
Oct 2025
Publication
Injection strategies play a crucial role in determining hydrogen engine performance. The diversity of these strategies and the limited number of comparative studies highlight the need for further investigation. This study focuses on the analysis parameter selection and comparison of single early and late direct injection single injection with ignition occurring during injection (the so-called jet-guided operation) and dual injection in a hydrogen spark-ignition engine. The applicability and effectiveness of these injection strategies are assessed using contour maps with ignition timing and start of injection as coordinates representing equal levels of key engine parameters. Based on this approach injection and ignition settings are selected for a range of engine operating modes. Simulations of engine performance under different load conditions are carried out using the selected parameters for each strategy. The results indicate that the highest indicated thermal efficiencies are achieved with single late injection while the lowest occur with dual injection. At the same time both dual injection and jet-guided operation provide advantages in terms of knock suppression peak pressure reduction and reduced nitrogen oxide emissions.
Multi-Objective Optimal Energy Management Strategy for Grid-Interactive Hydrogen Refueling Stations in Rural Areas
Mar 2025
Publication
The transportation sector is a significant contributor to global carbon emissions thus necessitating a transition toward renewable energy sources (RESs) and electric vehicles (EVs). Among EV technologies fuel-cell EVs (FCEVs) offer distinct advantages in terms of refueling time and operational efficiency thus rendering them a promising solution for sustainable transportation. Nevertheless the integration of FCEVs in rural areas poses challenges due to the limited availability of refueling infrastructure and constraints in energy access. In order to address these challenges this study proposes a multi-objective energy management model for a hydrogen refueling station (HRS) integrated with RESs a battery storage system an electrolyzer (EL) a fuel cell (FC) and a hydrogen tank serving diverse FCEVs in rural areas. The model formulated using mixed-integer linear programming (MILP) optimizes station operations to maximize both cost and load factor performance. Additionally bi-directional trading with the power grid and hydrogen network enhances energy flexibility and grid stability enabling a more resilient and self-sufficient energy system. To the best of the authors’ knowledge this study is the first in the literature to present a multi-objective optimal management approach for grid-interactive renewablesupported HRSs serving hydrogen-powered vehicles in rural areas. The simulation results demonstrate that RES integration improves economic feasibility by reducing costs and increasing financial gains while maximizing the load factor enhances efficiency cost-driven strategies that may impact stability. The impact of the EL on cost is more significant while RES capacity has a relatively smaller effect on cost. However its influence on the load factor is substantial. The optimization of RES-supported hydrogen production has been demonstrated to reduce external dependency thereby enabling surplus trading and increasing financial gains to the tune of USD 587.83. Furthermore the system enhances sustainability by eliminating gasoline consumption and significantly reducing carbon emissions thus supporting the transition to a cleaner and more efficient transportation ecosystem.
Hydrogen Generation through Solar Photocatalytic Processes: A Review of the Configuration and the Properties of Effective Metal-Based Semiconductor Nanomaterials
Oct 2017
Publication
Photocatalytic water splitting and organic reforming based on nano-sized composites are gaining increasing interest due to the possibility of generating hydrogen by employing solar energy with low environmental impact. Although great efforts in developing materials ensuring high specific photoactivity have been recently recorded in the literature survey the solar-to-hydrogen energy conversion efficiencies are currently still far from meeting the minimum requirements for real solar applications. This review aims at reporting the most significant results recently collected in the field of hydrogen generation through photocatalytic water splitting and organic reforming with specific focus on metal-based semiconductor nanomaterials (e.g. metal oxides metal (oxy)nitrides and metal (oxy)sulfides) used as photocatalysts under UVA or visible light irradiation. Recent developments for improving the photoefficiency for hydrogen generation of most used metal-based composites are pointed out. The main synthesis and operating variables affecting photocatalytic water splitting and organic reforming over metal-based nanocomposites are critically evaluated.
A Proposal of Hydrogen Safety Technology for Decommissioning of the Fukushima Daiichi Nuclear Power Station
Mar 2025
Publication
The safe removal transportation and long-term storage of fuel debris in the decommissioning of Fukushima Daiichi is the biggest challenge facing Japan. In the nuclear power field passive autocatalytic recombiners (PARs) have become established as a technology to prevent hydrogen explosions inside the containment vessel. To utilize PAR as a measure to reduce the concentration of hydrogen generated in the fuel debris storage canister which is currently an issue it is required to perform in a sealed environment with high doses of radiation low temperature and high humidity and there are many challenges different from conventional PAR. A honeycombshaped catalyst based on automotive catalyst technology has been newly designed as a PAR and research has been conducted to solve unique problems such as high dose radiation low temperature high humidity coexistence of hydrogen and low oxygen and catalyst poisons. This paper summarizes the challenges of hydrogen generation in a sealed container the results of research and a guide to how to use the PAR for fuel debris storage canisters.
Net-Zero Backup Solutions for Green Ammonia Hubs Based on Hydrogen Power Generation
Jun 2025
Publication
This paper explores cleaner and techno-economically viable solutions to provide electricity heat and cooling using green hydrogen (H2) and green ammonia (NH3) across the entire decarbonized value chain. We propose integrating a 100% hydrogen-fueled internal combustion engine (e.g. Jenbacher JMS 420) as a stationary backup solution and comparing its performance with other backup technologies. While electrochemical storage systems or battery energy storage systems (BESSs) offer fast and reliable short-term energy buffering they lack flexibility in relocation and typically involve higher costs for extended backup durations. Through five case studies we highlight that renewable-based energy supply requires additional capacity to bridge longer periods of undersupply. Our results indicate that for cost reasons battery–electric solutions alone are not economically feasible for longterm backup. Instead a more effective system combines both battery and hydrogen storage where batteries address daily fluctuations and hydrogen engines handle seasonal surpluses. Despite lower overall efficiency gas engines offer favorable investment and operating costs in backup applications with low annual operating hours. Furthermore the inherent fuel flexibility of combustion engines eventually will allow green ammonia-based backup systems particularly as advancements in small-scale thermal cracking become commercially available. Future studies will address CO2 credit recognition carbon taxes and regulatory constraints in developing more effective dispatch and master-planning solutions.
Modeling Porosity Distribution Strategies in PEM Water Electrolyzers: A Comparative Analytical and Numerical Study
Jun 2025
Publication
Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology for green hydrogen production. However the adoption of PEMWE-based hydrogen production systems remains limited due to several challenges including high material costs limited performance and durability and difficulties in scaling the technology. Computational modeling serves as a powerful tool to address these challenges by optimizing system design improving material performance and reducing overall costs thereby accelerating the commercial rollout of PEMWE technology. Despite this conventional models often oversimplify key components such as porous transport and catalyst layers by assuming constant porosity and neglecting the spatial heterogeneity found in real electrodes. This simplification can significantly impact the accuracy of performance predictions and the overall efficiency of electrolyzers. This study develops a mathematical framework for modeling variable porosity distributions—including constant linearly graded and stepwise profiles—and derives analytical expressions for permeability effective diffusivity and electrical conductivity. These functions are integrated into a three-dimensional multi-domain COMSOL simulation to assess their impact on electrochemical performance and transport behavior. The results reveal that although porosity variations have minimal effect on polarization at low voltages they significantly influence internal pressure species distribution and gas evacuation at higher loads. A notable finding is that reversing stepwise porosity—placing high porosity near the membrane rather than the channel—can alleviate oxygen accumulation and improve current density. A multi-factor comparison highlights this reversed configuration as the most favorable among the tested strategies. The proposed modeling approach effectively connects porous media theory and systemlevel electrochemical analysis offering a flexible platform for the future design of porous electrodes in PEMWE and other energy conversion systems.
Who Is in and How? A Comprehensive Study on Stakeholder Perspectives in the Green Hydrogen Sector in Luxembourg
Oct 2025
Publication
Green hydrogen has the potential to contribute to the decarbonization of the fossil fuel industry and its development is expected to increase in the coming years. The social dynamics among the various actors in the green hydrogen sector are studied to understand their public perception. Using the technological innovation system research approach for the stakeholder analysis and the qualitative thematic analysis method for the interviews with experts this study presents an overview of the actors in the green hydrogen sector and their relations in Luxembourg. As a central European country with strategic political and geographic relevance Luxembourg offers a timely case for analyzing public perception before the large-scale implementation of green hydrogen. Observing this early stage allows for future comparative insights as the national hydrogen strategy progresses. Results show high expectations for green hydrogen in mobility and industry but concerns persist over infrastructure costs safety and public awareness. Regional stakeholders demonstrate a strong willingness to collaborate recognizing that local public acceptance still requires effort particularly in areas such as clear and inclusive communication sharing knowledge and fostering trust. These findings provide practical insights for stakeholder engagement strategies and theoretical contributions to the study of social dynamics in sustainability transitions.
Socio-political Determinants of Public Acceptance of Green Hydrogen
Mar 2025
Publication
Green hydrogen produced through renewable energy sources is emerging as a pivotal element in global energy transitions. Despite its potential public acceptance remains a critical barrier to its large-scale implementation. This study aims to identify the socio-political and demographic determinants of public acceptance of green hydrogen. Using advanced variable selection methods including ridge lasso and elastic net regression we analyzed perceptions of climate change trust in government policies and demographic characteristics. The findings reveal that individuals prioritizing climate change over economic growth perceiving its impacts as severe and recognizing it as South Korea’s most pressing issue are more likely to accept green hydrogen. Trust in the government’s climate change response also emerged as a key factor. Demographic characteristics such as younger age higher income advanced education smaller family size and conservative political ideology were significantly associated with greater acceptance. These results highlight the importance of raising public awareness about the urgency of climate change and enhancing trust in government policies to promote societal acceptance of green hydrogen. Policymakers should consider these factors when developing strategies to advance the adoption of green hydrogen technologies and foster sustainable energy transitions.
Machine Learning-driven Stochastic Bidding for Hydrogen Refueling Station-integrated Virtual Power Plants in Energy Market
Aug 2025
Publication
Virtual power plants (VPPs) are gaining significance in the energy sector due to their capacity to aggregate distributed energy resources (DERs) and optimize energy trading. However their effectiveness largely depends on accurately modeling the uncertain parameters influencing optimal bidding strategies. This paper proposes a deep learning-based forecasting method to predict these uncertain parameters including solar irradiation temperature wind speed market prices and load demand. A stochastic programming approach is introduced to mitigate forecasting errors and enhance accuracy. Additionally this research assesses the flexibility of VPPs by mapping the flexible regions to determine their operational capabilities in response to market dynamics. The study also incorporates power-to‑hydrogen (P2H) and hydrogen-to-power (H2P) conversion processes to facilitate the integration of hydrogen fuel cell vehicles (HFCVs) into VPPs enhancing both technical and economic aspects. A network-aware VPP connected to generation resources storage facilities demand response programming (DRP) vehicle-to-grid technology (V2G) P2H and H2P is used to evaluate the proposed method. The problem is formulated as a convex model and solved using the GUROBI optimizer. Results indicate that a hydrogen refueling station can increase profits by approximately 49 % compared to the base case of directly selling surplus generation from renewable energy sources (RESs) to the market and profits can further increase to roughly 86 % when other DERs are incorporated alongside the hydrogen refueling station.
Green Hydrogen Generation by Water Photoelectrolysis: Economic and Environmental Analysis
Mar 2025
Publication
Water photoelectrolysis cells based on photoelectrochemical water splitting seem to be an interesting alternative to other traditional green hydrogen generation processes (e.g. water electrolysis). Unfortunately the practical application of this technology is currently hindered by several difficulties: low solar-to-hydrogen (STH) efficiency expensive electrode materials etc. A novel concept based on a tandem photoelectrolysis cell configuration with an anion-conducting membrane separating the photoanode from the photocathode has already been proposed in the literature. This approach allows the use of low-cost metal oxide electrodes and nickel-based co-catalysts. In this paper we conducted a study to evaluate the economic and environmental sustainability of this technology using the environmental life cycle cost. Preliminary results have revealed two main interesting aspects: the negligible percentage of externalities in the total cost.
Assessment of Carbon-abatement Pricing to Maximize the Value of Electrolytic Hydrogen in Emissions-intensive Power Sectors
Aug 2025
Publication
Electrolytic hydrogen can support the decarbonization of the power sector. Achieving cost-effective power-to-gas-to-power (PGP) integration through targeted emissions pricing can accelerate the adoption of electrolytic hydrogen in greenhouse gas-intensive power sectors. This study develops a framework for assessing the economic viability of electrolytic hydrogen-based PGP systems in fossil fuel-dependent grids while considering the competing objectives of the electricity system operator a risk-averse investor and the government. Here we show that given the risk-averse investor’s inherent pursuit of profit maximization a break-even carbon abatement cost of at least 57 Canadian Dollars per tonne of CO₂ by 2030 from the government with a shift in electricity market dispatch rules from sole system marginal pricereduction to system-wide emissions reduction is essential to stimulate price discovery for low-cost hydrogen production and contingency reserve provision by the PGP system. This work can help policymakers capture and incentivize the role of electrolytic hydrogen in low-carbon power sector planning.
Double-Layer Optimal Configuration of Wind–Solar-Storage for Multi-Microgrid with Electricity–Hydrogen Coupling
Oct 2025
Publication
To address the collaborative optimization challenge in multi-microgrid systems with significant renewable energy integration this study presents a dual-layer optimization model incorporating power-hydrogen coupling. Firstly a hydrogen energy system coupling framework including photovoltaics storage batteries and electrolysis hydrogen production/fuel cells was constructed at the architecture level to realize the flexible conversion of multiple energy forms. From a modeling perspective the upper-layer optimization aims to minimize lifecycle costs by determining the optimal sizing of distributed PV systems battery storage hydrogen tanks fuel cells and electrolyzers within the microgrid. At the lower level a distributed optimization framework facilitates energy sharing (both electrical and hydrogen-based) across microgrids. This operational layer maximizes yearly system revenue while considering all energy transactions—both inter-microgrid and grid-to-microgrid exchanges. The resulting operational boundaries feed into the upper-layer capacity optimization with the optimal equipment configuration emerging from the iterative convergence of both layers. Finally the actual microgrid in a certain area is taken as an example to verify the effectiveness of the proposed method.
Influence of Engine Oils on Pre-Ignition Tendency in a Hydrogen–Kerosene Dual-Fuel Engine
Mar 2025
Publication
Reducing CO2 emissions is an increasingly important goal in general aviation. The dual-fuel hydrogen–kerosene combustion process has proven to be a suitable technology for use in small aircraft. This robust and reliable technology significantly reduces CO2 emissions due to the carbon-free combustion of hydrogen during operation while pure kerosene or sustainable aviation fuel (SAF) can be used in safety-critical situations or in the event of fuel supply issues. Previous studies have demonstrated the potential of this technology in terms of emissions performance and efficiency while also highlighting challenges related to abnormal combustion phenomena such as knocking and pre-ignition which limit the maximum achievable hydrogen energy share. However the causes of such phenomena—especially regarding the role of lubricating oils—have not yet been sufficiently investigated in hydrogen engines making this a crucial area for further development. In this paper investigations at the TU Wien Institute of Powertrain and Automotive Technology concerning the role of different engine oils in influencing pre-ignition tendencies in a hydrogen–kerosene dual-fuel engine are described. A specialized test procedure was developed to account for the unique combustion characteristics of the dual-fuel process along with a detailed purge procedure to minimize oil carryover. Multiple engine oils with varying compositions were tested to evaluate their influence on pre-ignition tendencies with a particular focus on additives containing calcium magnesium and molybdenum known for their roles in detergent and anti-wear properties. Additionally the study addressed the contribution of particles to pre-ignition occurrences. The results indicate that calcium and magnesium exhibit no notable impact on pre-ignition behavior; however the addition of molybdenum results in a pronounced reduction in pre-ignition events which could enable a higher hydrogen energy share and thus decrease CO2 emissions in the context of hydrogen dual-fuel aviation applications.
Retrofitted Production of Bio-hydrogen. Large-scale Biowaste Valorization via Solar-based Gasification
Aug 2025
Publication
Hydrogen production from gasification of biowaste generates large volumes of CO2 due to endothermic biowaste decomposition. Alternatively the Sun can provide that energy. To evaluate the yield and performance of solarbased gasifiers at country scale a multi-scale approach is required. First the operation of a solar gasifier is analyzed by developing a two-phase model validated and scaled to industrial level. Next the performance and yield of such technology as a function of the radiation received is studied taking Spain as a case study. The results were promising obtaining a syngas rich in H2. However tar and char were not reduced due to insufficient temperature. Scale-up studies revealed energy losses to the environment in the industrial-scale gasifier which suggested the use of segmented heating. In turn diameters no larger than 0.8 m and biomass feeding rates below 0.85 kg/s highlight the deployment of a modular design due to particle size limitations. Finally the large-scale waste valorization showed that the gasifier can only operate in Spain in the summer months. It can run over 180 h/month and more than 250 days/year only in C´ adiz and Santa Cruz de Tenerife which also showed the highest yearly production capacities.
Digital Twin Framework for Energy Transition in Gas Networks Based on Open-Source Tools: Methodology and Case Study in Southern Italy
Oct 2025
Publication
The ongoing digitalization of energy infrastructure is a crucial enabler for improving efficiency reliability and sustainability in gas distribution networks especially in the context of decarbonization and the integration of alternative energy carriers (e.g. renewable gases including biogas green hydrogen). This study presents the development and application of a Digital Twin framework for a real-world gas distribution network developed using open-source tools. The proposed methodology covers the entire digital lifecycle: from data acquisition through smart meters and GIS mapping to 3D modelling and simulation using tools such as QGIS FreeCAD and GasNetSim. Consumption data are collected processed and harmonized via Python-based workflows hourly simulations of network operation including pressure flow rate and gas quality indicators like the Wobbe Index. Results demonstrate the effectiveness of the Digital Twin in accurately replicating real network behavior and supporting scenario analyses for the introduction of greener energy vectors such as hydrogen or biomethane. The case study highlights the flexibility and transparency of the workflow as well as the critical importance of data quality and availability. The framework provides a robust basis for advanced network management optimization and planning offering practical tools to support the energy transition in the gas sector.
Wetting of the Microporous Layer at the Cathode of an Anion Exchange Membrane Water Electrolyzer
Aug 2025
Publication
Water management is crucial for the performance of anion exchange membrane water electrolyzers (AEM-WEs) to maintain membrane hydration and enable phase separation between hydrogen gas and liquid water. Therefore careful material selection for the anode and cathode is essential to enhance reactant/product transport and optimize water management under ‘dry cathode’ conditions. This study investigates the wetting characteristics of two commercially available porous transport layers (PTLs) used in AEM-WE: carbon paper and carbon paper with a microporous layer (MPL). Wettability was measured under static quasi-static and dynamic conditions to assess the effect of water and electrolytes (NaOH KOH K2CO3) across concentrations (up to 1 M) and operational temperatures (20 °C to 92 °C). Carbon paper exhibits mild hydrophobicity (advancing contact angles of ∼120° however with receding contact angle ∼0°) whereas carbon paper with MPL demonstrates superhydrophobicity (advancing and receding contact angles >145° and low contact angle hysteresis) maintaining a stable Cassie-Baxter wetting state. Dynamic wetting experiments confirmed the robustness of the superhydrophobicity in carbon paper with MPL facilitating phase separation between hydrogen gas and liquid water. The presence of supporting electrolytes did not significantly affect wettability and the materials retained hydrophobic properties across different temperatures. These findings highlight the importance of MPLs in optimizing water transport and gas rejection within AEM-WEs ensuring efficient and stable operation under “dry cathode” conditions. These PTLs (with and without the addition of the MPL) were integrated into AEM-WE and polarization curves were run. Preliminary data in a specific condition suggested the presence of the MPL within the PTL enhance AEM-WE performance.
Stimulating Efficiency for Proton Exchange Membrane Water Splitting Electrolyzers: From Material Design to Electrode Engineering
Jun 2025
Publication
Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology for large-scale hydrogen production yet their industrial deployment is hindered by the harsh acidic conditions and sluggish oxygen evolution reaction (OER) kinetics. This review provides a comprehensive analysis of recent advances in iridium-based electrocatalysts (IBEs) emphasizing novel optimization strategies to enhance both catalytic activity and durability. Specifically we critically examine the mechanistic insights into OER under acidic conditions revealing key degradation pathways of Ir species. We further highlight innovative approaches for IBE design including (i) morphology and support engineering to improve stability (ii) structure and phase modulation to enhance catalytic efficiency and (iii) electronic structure tuning for optimizing interactions with reaction intermediates. Additionally we assess emerging electrode engineering strategies and explore the potential of non-precious metal-based alternatives. Finally we propose future research directions focusing on rational catalyst design mechanistic clarity and scalable fabrication for industrial applications. By integrating these insights this review provides a strategic framework for advancing PEMWE technology through highly efficient and durable OER catalysts.
The Total Costs of Energy Transitions With and Without Nuclear Energy
Oct 2025
Publication
Within energy system analysis there is discourse regarding the role and economic benefits of nuclear energy in terms of overall system costs. The reported findings range from considerable drawbacks to substantial benefits depending on the chosen models scenarios and underlying assumptions. This article addresses existing gaps by demonstrating how subtle variations in model assumptions significantly impact analysis outcomes. Historically uncertainties associated with nuclear energy costs have been well documented whereas renewable energy costs have steadily declined and have been relatively predictable. However as land availability increasingly constrains future renewable expansion development is shifting from onshore to offshore locations where cost uncertainties are greater and anticipated cost reductions are less reliable. This study emphasizes this fundamental shift highlighting how uncertainties in future renewable energy costs could strengthen the economic case of nuclear energy within fully integrated sector-coupled energy systems especially when the costs of all technologies and weather conditions are set in the moderate range. Focusing specifically on Denmark this article presents a thorough sensitivity analysis of renewable energy costs and weather conditions within anticipated future ranges providing a nuanced perspective on the role of nuclear energy. Ultimately the findings underscore that when examining total annual system costs the differences between scenarios with low and high nuclear energy shares are minimal and are within ±5 % for the baseline assumptions while updated adjustments reduce this variation to ±1 %.
Can Hydrogen Be Produced Cost-Effectively from Heavy Oil Reservoirs?
Oct 2025
Publication
The potential for hydrogen production from heavy oil reservoirs has gained significant attention as a dual-benefit process for both enhanced oil recovery and low-carbon energy generation. This study investigates the technical and economic feasibility of producing hydrogen from heavy oil reservoirs using two primary in situ combustion gasification strategies: cyclic steam/air and CO2 + O2 injection. Through a comprehensive analysis of technical barriers economic drivers and market conditions we assess the hydrogen production potential of each method. While both strategies show promise they face considerable challenges: the high energy demands associated with steam generation in the steam/air strategy and the complexities of CO2 procurement capture and storage in the CO2 + O2 method. The novelty of this work lies in combining CMG-STARS reservoir simulations with GoldSim techno-economic modeling to quantify hydrogen yields production costs and oil–hydrogen revenue trade-offs under realistic field conditions. The analysis reveals that under current technological and market conditions the cost of hydrogen production significantly exceeds the market price rendering the process economically uncompetitive. Furthermore the dominance of oil production as the primary revenue source in both methods limits the economic viability of hydrogen production. Unless substantial advancements are made in technology or a more cost-efficient production strategy is developed hydrogen production from heavy oil reservoirs is unlikely to become commercially viable in the near term. This study provides crucial insights into the challenges that must be addressed for hydrogen production from heavy oil reservoirs to be considered a competitive energy source.
Hydrogen Production Power Supply with Low Current Ripple Based on Virtual Impedance Technology Suitable for Offshore Wind–Solar–Storage System
Oct 2025
Publication
Hydrogen production from water electrolysis can not only reduce greenhouse gas emissions but also has abundant raw materials which is one of the ideal ways to produce hydrogen from new energy. The hydrogen production power supply is the core component of the new energy electrolytic water hydrogen production device and its characteristics have a significant impact on the efficiency and purity of hydrogen production and the service life of the electrolytic cell. In essence the DC/DC converter provides the large current required for hydrogen production. For the converter its input still needs the support of a DC power supply. Given the maturity and technical characteristics of new energy power generation integrating energy storage into offshore energy systems enables stable power supply. This configuration not only mitigates energy fluctuations from renewable sources but also further reduces electrolysis costs providing a feasible pathway for large-scale commercialization of green hydrogen production. First this paper performs a simulation analysis on the wind–solar hybrid energy storage power generation system to demonstrate that the wind–solar–storage system can provide stable power support. It places particular emphasis on the significance of hydrogen production power supply design—this focus stems primarily from the fact that electrolyzers impose specific requirements on high operating current levels and low current ripple which exert a direct impact on the electrolyzer’s service life hydrogen production efficiency and operational safety. To suppress the current ripple induced by high switching frequency and high output current traditional approaches typically involve increasing the output inductor. However this method substantially increases the volume and weight of the device reduces the rate of current change and ultimately results in a degradation of the system’s dynamic response performance. To this end this paper focuses on developing a virtual impedance control technology aiming to reduce the ripple amplitude while avoiding an increase in the filter inductor. Owing to constraints in current experimental conditions this research temporarily relies on simulation data. Specifically a programmable power supply is employed to simulate the voltage output of the wind–solar–storage hybrid system thereby bringing the simulation as close as possible to the actual operating conditions of the wind–solar–storage hydrogen production system. The experimental results demonstrate that the proposed method can effectively suppress the ripple amplitude maintain high operating efficiency and ultimately meet the expected research objectives. That makes it particularly suitable as a high-quality power supply for offshore hydrogen production systems that have strict requirements on volume and weight.
Techno-Economic Analysis of Marine Hybrid Clusters for Use in Chile and Mexico
Oct 2025
Publication
This study assesses the feasibility and profitability of marine hybrid clusters combining wave energy converters (WECs) and offshore wind turbines (OWTs) to power households and marine aquaculture. Researchers analyzed two coastal sites: La Serena Chile with high and consistent wave energy resources and Ensenada Mexico with moderate and more variable wave power. Two WEC technologies Wave Dragon (WD) and Pelamis (PEL) were evaluated alongside lithium-ion battery storage and green hydrogen production for surplus energy storage. Results show that La Serena’s high wave power (26.05 kW/m) requires less hybridization than Ensenada’s (13.88 kW/m). The WD device in La Serena achieved the highest energy production while PEL arrays in Ensenada were more effective. The PEL-OWT cluster proved the most cost-effective in Ensenada whereas the WD-OWT performed better in La Serena. Supplying electricity for seaweed aquaculture particularly in La Serena proves more profitable than for households. Ensenada’s clusters generate more surplus electricity suitable for the electricity market or hydrogen conversion. This study emphasizes the importance of tailoring emerging WEC systems to local conditions optimizing hybridization strategies and integrating consolidated industries such as aquaculture to enhance both economic and environmental benefits.
Early Transition to Near-zero Emissions Electricity and Carbon Dioxide Removal is Essential to Achieve Net-zero Emissions at a Low Cost in Australia
Aug 2025
Publication
Achieving net-zero emissions requires major changes across a nation’s economy energy and land systems particularly due to sectors where emissions are difficult to eliminate. Here we adapt two global scenarios from the International Energy Agency—the net-zero emissions by 2050 and the Stated Policies Scenario—using an integrated numerical economic-energy model tailored to Australia. We explore how emissions may evolve by sector and identify key technologies for decarbonisation. Our results show that a rapid shift to near-zero emissions electricity is central to reducing costs and enabling wider emissions reductions. From 2030 onwards carbon removal through land management and engineered solutions such as direct air capture and bioenergy with carbon capture and storage becomes critical. Australia is also well-positioned to become a global supplier of clean energy such as hydrogen made using renewable electricity helping reduce emissions beyond its borders.
Certification Gap Analysis for Normal-Category and Large Hydrogen-Powered Airplanes
Mar 2025
Publication
The transition to hydrogen as an aviation fuel as outlined in current decarbonization roadmaps is expected to result in the entry into service of hydrogen-powered aircraft in 2035. To achieve this evolution certification regulations are key enablers. Due to the disruptive nature of hydrogen aircraft technologies and their associated hazards it is essential to assess the maturity of the existing regulatory framework for certification to ensure its availability when manufacturers apply for aircraft certification. This paper presents the work conducted under the Clean Aviation CONCERTO project to advance certification readiness by comprehensively identifying gaps in the current European regulations. Generic methodologies were developed for regulatory gap and risk analyses and applied to a hydrogen turbine aircraft with non-propulsive fuel cells as the APU. The gap analysis conducted on certification specifications for large and normal-category airplanes as well as engines confirmed the overall adequacy of many existing requirements. However important gaps exist to appropriately address hydrogen hazards particularly concerning fire and explosion hydrogen storage and fuel systems crashworthiness and occupant survivability. The paper concludes by identifying critical areas for certification and highlighting the need for complementary hydrogen phenomenology data which are key to guiding future research and regulatory efforts for certification readiness maturation.
Hydrogen Storage Potential of Salado Formation in the Permian Basin of West Texas, United States
Jun 2025
Publication
Hydrogen (H2) has the potential to become a cleaner fuel alternative to increase energy mix versatility as part of a low-carbon economy. Geological H2 storage represents a key component of the emerging H2 value chain since large-scale energy generation linked to energy generation and large-scale industrial applications will require significant upscaling of geological storage. Geological H2 storage can take place in both salt domes and bedded salt formations. Bedded salt formations offer a significant advantage for H2 storage over salt domes because of their widespread availability. This research focuses on evaluating the H2 storage potential of the Salado Formation a bedded salt deposit in the Permian Basin of West Texas in the United States. Using data from 3268 well logs this study analyzes an area of 136100 km2 to identify suitable depth and net halite thickness for H2 storage in salt caverns. In addition this work applies a novel geostatistical workflow to quantify the uncertainty in the formation’s storage potential. The H2 working gas potential of the Salado Formation ranges from 0.62 to 17.53 Tsm3 (1.75–49.68 PWh of stored energy) across low-risk to high-risk scenarios with a median potential of 1.19 Tsm3 (3.37 PWh). The counties with the largest storage potential are: Lea in New Mexico and Gaines and Andrews in Texas. These three counties account for more than 75 % of the formation’s total storage potential. This is the first study to quantify uncertainty in H2 storage estimates for a bedded salt formation while providing a detailed breakdown of results by county and 1 km2 grid sections. The findings of this work offer critical insights for developing H2 infrastructure in the Permian Basin. The Permian Basin of West Texas has the potential to become an important hub for H2 production from both natural gas and/or renewable energy. Estimating H2 storage potential is an important contribution to assess the feasibility of the entire H2 value chain in Texas. An interactive map accompanies this work allowing the readers to explore the results visually.
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