Applications & Pathways
Comparative Analysis of the Alternative Energy: Case of Reducing GHG Emissions of Estonian Pilot Fleet
Feb 2025
Publication
The FuelEU Maritime Regulation part of the European Union’s (EU’s) Fit for 55 initiative aims to achieve significant reductions in greenhouse gas (GHG) emissions within the maritime sector. This study assesses the feasibility of alternative fuels for the Estonian pilot fleet using a Well-to-Wake (WtW) life cycle assessment (LCA) methodology. Operational data from 18 vessels sourced from the Estonian State Fleet’s records were analyzed including technical specifications fuel consumption patterns and operational scenarios. The study focused on marine diesel oil (MDO) biomethane hydrogen biodiesel ammonia and hydrotreated vegetable oil (HVO) each presenting distinct trade-offs. Biomethane achieved a 59% GHG emissions reduction but required a volumetric storage capacity up to 353% higher compared to MDO. Biodiesel reduced GHG emissions by 41.2% offering moderate compatibility with existing systems while requiring up to 23% larger storage volumes. HVO demonstrated a 43.6% emissions reduction with seamless integration into existing marine engines. Ammonia showed strong potential for long-term decarbonization but its adoption is hindered by low energy density and complex storage requirements. This research underscores the importance of a holistic evaluation of alternative fuels taking into account technical economic and environmental factors specific to regional and operational contexts. The findings offer a quantitative basis for policymakers and maritime stakeholders to develop effective decarbonization strategies for the Baltic Sea region.
Design and Analysis of an Integrated Renewable Hydrogen Production and Storage System for Hydrogen Refueling Station in a Sustainable Community
Aug 2025
Publication
This research designs a conceptual system where both solar and biomass energy subsystems are uniquely integrated to turn wastewater into useful outputs such as hydrogen fresh water and heat to achieve sustainable communities where renewable energy is utilized with the wastewater treated effectively. The system integrates several subsystems including a reheat Rankine cycle an organic Rankine cycle a multi-stage flash desalination system and a biohydrogen production unit employing a microbial electrolysis process. In order to study a potential application of this conceptually developed system the city of Oshawa in Ontario Canada is identified with its wastewater treatment facility which is designed to produce clean biohydrogen that is liquefied and stored for distribution to refueling stations for hydrogen-based transportation. In this regard thermodynamic analysis and assessment studies are conducted using the Engineering Equation Solver and demonstrating that the system achieves the overall energetic and exergetic efficiencies of 34.94% and 32.84% respectively. Furthermore the system produces freshwater at a rate of 5.36 kg/s and biohydrogen at 0.03 kg/s contributing to environmental sustainability and efficient resource utilization in addition to the heat recovered and used in the community as a useful output. This research highlights the potential of the system to significantly reduce greenhouse gas emissions while promoting sustainable energy and transportation developments in Oshawa and similar regions.
Research Progress of Fuel Cell Technology in Marine Applications: A Review
Apr 2025
Publication
With the increasing severity of global environmental issues and the pressure from the strict pollutant emission regulations proposed by the International Maritime Or‑ ganization (IMO) the shipping industry is seeking new types of marine power systems that can replace traditional propulsion systems. Marine fuel cells as an emerging energy technology only emit water vapor or a small amount of carbon dioxide during operation and have received widespread attention in recent years. However research on their appli‑ cation in the shipping industry is relatively limited. Therefore this paper collects relevant reports and literature on the use of fuel cells on ships over the past few decades and con‑ ducts a thorough study of typical fuel cell‑powered vessels. It summarizes and proposes current design schemes and optimization measures for marine fuel cell power systems pro‑ viding directions for further improving battery performance reducing carbon emissions and minimizing environmental pollution. Additionally this paper compares and analyzes marine fuel cells with those used in automotive aviation and locomotive applications of‑ fering insights and guidance for the development of marine fuel cells. Although hydrogen fuel cell technology has made significant progress in recent years issues still exist regard‑ ing hydrogen production storage and related safety and standardization concerns. In terms of comprehensive performance and economics it still cannot effectively compete with traditional internal combustion engines. However with the continued rapid devel‑ opment of fuel cell technology marine fuel cells are expected to become a key driver for promoting green shipping and achieving carbon neutrality goals.
Development, Application and Optimization of Hydrogen Refueling Processes for Railway Vehicles
Apr 2025
Publication
In recent years numerous hydrogen-powered rail vehicles have been developed and their deployment within public transport is steadily increasing. To avoid disadvantages compared to diesel vehicles refueling times of 15 min are stated in the industry as target independent of climate zones or vehicle configurations. As refueling time varies with these parameters this work presents the corresponding refueling times and defines optimization potentials. A simulation model was set up and parametrized with a reference vehicle and hydrogen refueling station from the FCH2RAIL project. Measurement data from this station and vehicle were analyzed and compared to simulation results for model validation. The results show that at high ambient temperature pre-cooling reduces refueling time by 71 % and type 4 tanks increase refueling time by 20 % compared to type 3. Overall optimized tank design and thermal management reduce the refueling time for rail vehicles from over 2 h to 15 min.
Hydrogen-powered Vessels in Green Maritime Decarbonization: Policy Drivers, Technological Frontiers and Challenges
May 2025
Publication
The global shipping industry is transitioning toward decarbonization with hydrogen-powered vessels emerging as a key solution to meet international emission reduction targets particularly the IMO’s goal of reducing emissions by 50% by 2050. As a zero-emission fuel hydrogen aligns with international regulations such as the IMO’s greenhouse gas reduction strategy the MARPOL Convention and regional policies like the EU’s Emissions Trading System. Despite regulatory support and advancements in hydrogen fuel cell technology challenges remain in hydrogen storage fuel cell integration and operational safety. Currently high-pressure gaseous hydrogen storage is the most viable option but its spatial and safety limitations must be addressed. Alternative storage methods including cryogenic liquid hydrogen organic liquid hydrogen carriers and metal hydride storage hold potential for application but still face technical and integration barriers. Overcoming these challenges requires continued innovation in vessel design fuel cell technology and storage systems supported by comprehensive safety standards and regulations. The successful commercialization of hydrogen-powered vessels will be instrumental in decarbonizing global shipping and achieving climate goals.
Hydrogen UK - Hydrogen to Power Report
Jan 2025
Publication
The UK has set an ambitious target of delivering clean power by 2030. Low carbon dispatchable power generation using hydrogen will play a key role in a clean power system by providing flexibility and other services for system operability and also by providing supply adequacy during extended periods of low renewable output decarbonising the role currently performed by an aging portfolio of unabated natural gas power generation. While some 100% hydrogen to power (H2P) commercial projects are already being deployed globally using multi megawatt fuel cells alongside blending hydrogen into existing gas turbines and new hydrogen ready turbines industrial scale 100% H2P projects face additional challenges of deploying new technology into a nascent system one which requires significant volumes of hydrogen storage with long lead times. To achieve the 2030 clean power system ambition and lay the foundations for a clean resilient and secure power system beyond 2030 it is critical that the new government takes resolute actions now to support H2P at scale. A clear strategic plan should be developed within the first 12 months of the new administration with clarity being given on policy business models and deployment rates for hydrogen to power (H2P) and its enabling infrastructure. This report produced by Hydrogen UK’s Power Generation Working Group explores the role that H2P will play in the decarbonised power system of the future the barriers to deployment and recommendations for overcoming them.
This paper can be found on their website.
This paper can be found on their website.
Low-Carbon Economic Dispatch of Integrated Energy Systems for Electricity, Gas, and Heat Based on Deep Reinforcement Learning
Oct 2025
Publication
Under the background of “dual-carbon” the development of energy internet is an inevitable trend for China’s low-carbon energy transition. This paper proposes a hydrogen-coupled electrothermal integrated energy system (HCEH-IES) operation mode and optimizes the source-side structure of the system from the level of carbon trading policy combined with low-carbon technology taps the carbon reduction potential and improves the renewable energy consumption rate and system decarbonization level; in addition for the operation optimization problem of this electric–gas–heat integrated energy system a flexible energy system based on electric–gas–heat is proposed. Furthermore to address the operation optimization problem of the HCEH-IES a deep reinforcement learning method based on Soft Actor–Critic (SAC) is proposed. This method can adaptively learn control strategies through interactions between the intelligent agent and the energy system enabling continuous action control of the multi-energy flow system while solving the uncertainties associated with source-load fluctuations from wind power photovoltaics and multi-energy loads. Finally historical data are used to train the intelligent body and compare the scheduling strategies obtained by SAC and DDPG algorithms. The results show that the SAC-based algorithm has better economics is close to the CPLEX day-ahead optimal scheduling method and is more suitable for solving the dynamic optimal scheduling problem of integrated energy systems in real scenarios.
Combustion Process Analysis of Secondary Jet-Guided Combustion in Hydrogen Direct-Injection Engines
Oct 2025
Publication
This study investigates the effects of secondary jet-guided combustion on the combustion and emissions of a hydrogen direct-injection engine through numerical simulations. The results show that secondary jet-guided combustion which involves injecting and igniting the hydrogen jet at the end of the compression stroke significantly shortens the delay period improves combustion stability and brings the combustion center closer to the top dead center (TDC) achieving a maximum indicative thermal efficiency (ITE) of 46.55% (λ = 2.4). However this strategy results in higher NOx emissions due to high-temperature combustion. In contrast single and double injections lead to worsened combustion and reduced thermal efficiency under lean-burn conditions but with relatively lower NOx emissions. This study demonstrates that secondary jet-guided combustion can effectively enhance hydrogen engine performance by optimizing mixture stratification and flame propagation providing theoretical support for clean and efficient combustion.
Comparative Risk Assessment of Gaseous and Liquid Hydrogen Fuel Gas Supply Systems for Hydrogen-fueled Vessels
Aug 2025
Publication
This study compares qualitative risk analyses of compressed hydrogen gas (GH2) and liquid hydrogen (LH2) fuel gas supply systems (FGSSs) for eco-friendly marine vessels. Using hazard identification (HAZID) and hazard and operability (HAZOP) methodologies the study systematically identifies and compares the unique risks and safety strategies for GH2 and LH2 FGSS. For GH2-FGSS HAZID identifies 22 hazards with one unacceptable risk related to potential explosions from high-pressure hydrogen accumulation due to ventilation failure. HAZOP identifies 27 hazards all categorized as acceptable or ALARP. Recommended safety measures include pressure protection devices real-time alarms and enhanced piping durability. For LH2-FGSS HAZID identifies 38 hazards without any unacceptable risks though cryogenic icing and overpressure remain significant concerns. HAZOP reveals 43 hazards with one unacceptable risk involving thermal contraction and piping damage from repeated operations posing fire hazards. Suggested mitigations include improved cooling and purge gas procedures along with rigorous insulation management. Primary differences in safety management focus on high explosion risk of GH2-FGSS from high-pressure storage and the piping damage risk of LH2-FGSS from icing and thermal contraction. To enhance risk management for each system future research implements an operational simulation-based quantitative risk assessment. This study provides foundational safety strategies and guidelines for future vessels supporting the adoption of eco-friendly fuels in the maritime industry.
Numerical Investigation of Marine Dual-Fuel Engine Operating with High Shares of Premixed Hydrogen Fuel Using LES
Oct 2025
Publication
Hydrogen fuel presents a promising pathway for achieving long-term decarbonization in the maritime sector. However its use in diesel engines introduces challenges due to high reactivity leading to increased NOx emissions and combustion instability. The aim of this study is to identify settings so that the investigated engine operates with 60% hydrogen energy fraction at high load through CFD modelling. The model is utilized to simulate a four-stroke 10.5 MW marine engine at 90% load incorporating 60% hydrogen injection by energy at the engine intake port. The CFD model is verified using experimental data from diesel operation of the marine engine and hydrogen operation of a light-duty engine. The engine performance was determined and detailed emissions analysis was conducted including NO NO2 HO2 and OH. The findings indicate a substantial rise in NOx emissions as opposed to diesel operation due to elevated combustion temperatures and increased residence time at elevated temperature of the mixture in-cylinder. The presence of HO2 and OH highlights critical zones of combustion which contribute to operational stability. The novelty of this study is supported by the examination of the high hydrogen energy fraction the advanced emissions analysis and the insights into the emissions–performance trade-offs in hydrogen-fueled dual-fuel marine engines. The results offer guidance for the development of sustainable hydrogen-based marine propulsion systems.
Decarbonising European Heavy-duty Transport: A Stakeholder Analysis of Technology Readiness and Future R&I Priorities for Zero-emission Vehicles and Infrastructure
Sep 2025
Publication
This report identifies the critical research and innovation (R&I) priorities for decarbonising Europe's heavy-duty vehicles based on direct feedback from industry stakeholders. The findings reveal a consensus: battery electric technology is the primary pathway forward with significant stakeholder support for R&I focused on its improvement. While battery electric technology is perceived as more mature hydrogen is considered a complementary solution for the most demanding long-haul routes. Large-scale demonstrations are suggested for de-risking operations and evaluating integration with the transport and energy system. The analysis confirms that achieving TCO parity or better compared to diesel is the most important factor for market uptake. This study provides direct evidence-based guidance for EU transport R&I policy helping to chart the road ahead and orient R&I call programming to meet the ambitious CO₂ emission standards for heavy-duty vehicles.
Comparative Electrochemical Performance of Solid Oxide Fuel Cells: Hydrogen vs. Ammonia Fuels—A Mini Review
Apr 2025
Publication
Solid oxide fuel cells (SOFCs) have garnered significant attention as a promising technology for clean and efficient power generation due to their ability to utilise renewable fuels such as hydrogen and ammonia. As carbon-free energy carriers hydrogen and ammonia are expected to play a pivotal role in achieving net-zero emissions. However a critical research question remains: how does the electrochemical performance of SOFCs compare when fuelled by hydrogen vs. ammonia and what are the implications for their practical application in power generation? This mini-review paper is premised on the hypothesis that while hydrogen-fuelled SOFCs currently demonstrate superior stability and performance at low and high temperatures ammonia-fuelled SOFCs offer unique advantages such as higher electrical efficiencies and improved fuel utilisation. These benefits make ammonia a viable alternative fuel source for SOFCs particularly at elevated temperatures. To address this the mini-review paper provides a comprehensive comparative analysis of the electrochemical performance of SOFCs under direct hydrogen and ammonia fuels focusing on key parameters such as open-circuit voltage (OCV) power density electrochemical impedance spectroscopy fuel utilisation stability and electrical efficiency. Recent advances in electrode materials electrolytes fabrication techniques and cell structures are also highlighted. Through an extensive literature survey it is found that hydrogen-fuelled SOFCs exhibit higher stability and are less affected by temperature cycling. In contrast ammonia-fuelled SOFCs achieve higher OCVs (by 7%) and power densities (1880 mW/cm2 vs. 1330 mW/cm2 for hydrogen) at 650 °C along with 6% higher electrical efficiency. Despite these advantages ammonia-fuelled SOFCs face challenges such as NOx emissions nitride formation environmental impact and OCV stabilisation which are discussed alongside potential solutions. This mini review aims to provide insights into the future direction of SOFC research emphasising the need for further exploration of ammonia as a sustainable fuel alternative.
Optimization Scheduling of Hydrogen-Integrated Energy Systems Considering Multi-Timescale Carbon Trading Mechanisms
Mar 2025
Publication
Amidst the escalating global challenges presented by climate change carbon trading mechanisms have become critical tools for driving reductions in carbon emissions and optimizing energy systems. However existing carbon trading models constrained by fixed settlement cycles face difficulties in addressing the scheduling needs of energy systems that operate across multiple time scales. To address this challenge this paper proposes an optimal scheduling methodology for hydrogen-encompassing integrated energy systems that incorporates a multi-time-scale carbon trading mechanism. The proposed approach dynamically optimizes the scheduling and conversion of hydrogen energy electricity thermal energy and other energy forms by flexibly adjusting the carbon trading cycle. It accounts for fluctuations in energy demand and carbon emissions occurring both before and during the operational day. In the day-ahead scheduling phase a tiered carbon transaction cost model is employed to optimize the initial scheduling framework. During the day scheduling phase real-time data are utilized to dynamically adjust carbon quotas and emission ranges further refining the system’s operational strategy. Through the analysis of typical case studies this method demonstrates significant benefits in reducing carbon emission costs enhancing energy efficiency and improving system flexibility.
Fundamentals of Innovative Aircraft Heat Exchanger Integration for Hydrogen–Electric Propulsion
Apr 2025
Publication
The potential of utilizing the rejected heat of a fuel cell system to improve the aircraft propulsive efficiency is discussed for various flight conditions. The thermodynamic background of the process and the connection of power consumption in the fan of the ducted propulsor and fuel cell heat are given and a link between these two components is presented. A concept that goes beyond the known ram heat exchanger is discussed which outlines the potential benefits of integrating a fan upstream of the heat exchanger. The influence of the fan pressure ratio flight speed and altitude as well as the temperature level of the available fuel cell heat on the propulsive efficiency is presented. A correlation between the fan pressure ratio flight speed and exchangeable fuel cell heat is established providing a simplified computational approach for evaluating feasible operating conditions within this process. This paper identifies the challenges of heat exchanger integration at International Standard Atmosphere sea level conditions and its benefits for cruise flight conditions. The results show that for a flight Mach number of 0.8 and a fan pressure ratio of 1.5 at a cruising altitude of 11000 m the propulsion efficiency increases by approximately 8 percentage points compared to a ducted propulsor without heat utilization. Under sealevel conditions the concept does not offer any performance advantages over a ducted propulsor. Instead it exhibits either comparable or reduced propulsive efficiency.
Configuring Hydrogen Lancing to Reduce Carbon and Nitrogen Oxides Emissions from Coal-fire Rotary Kilns
Mar 2025
Publication
Coal replacement with hydrogen is a strategy for reducing carbon emissions from high-temperature industrial processes. Hydrogen lancing is a direct way for introducing hydrogen to existing coal-fired kilns. This work investigates the effects of hydrogen lancing on nitrogen oxides (NOx) emissions and ignition behaviour in a pilotscale furnace that employs a 30 % coal replacement with hydrogen lancing. The investigation encompasses the impacts of lancing distance angling and velocity. Advanced measurement techniques including spectrometry and monochromatic digital cameras characterise the flame and assess emissions. The results indicate that the 30 % coal replacement by hydrogen lancing enhances combustion and reduces the emissions of carbon monoxides (CO). The flame characteristics vary with the location of the hydrogen injection generally becoming more-intense than during coal combustion. NOx emissions during lancing are similar or up to double the emissions observed for pure coal combustion depending on the lancing configuration. Increasing the distance between the hydrogen lance and coal burner increases NOx emissions.
Integrated Design and Construction of a 50 kW Flexible Hybrid Renewable Power Hydrogen System Testbed
Mar 2025
Publication
We report on the first stage of an energy systems integration project to develop hybrid renewable energy generation and storage of hydrogen for subsequent use via research-based low regret system testbeds. This study details the design and construction of a flexible plug-and-play hybrid renewable power and hydrogen system testbed with up to 50 kW capacity aimed at addressing and benchmarking the operational parameters of the system as well as key components when commissioned. The system testbed configuration includes three different solar technologies three different battery technologies two different electrolyser technologies hydrogen storage and a fuel cell for regenerative renewable power. Design constraints include the current limit of an AC microgrid regulations for grid-connected inverters power connection inefficiencies and regulated hazardous area approval. We identify and show the resolution of systems integration challenges encountered during construction that may benefit planning for the emerging pilot or testbed configurations at other sites. These testbed systems offer the opportunity for informed decisions on economic viability for commercial-scale industry applications.
An Investigation into the Ability of a Solar Photovoltaic– Hydrogen System to Meet the Electrical Energy Demand of Houses in Different Cities in Türkiye
Mar 2025
Publication
In this study the annual electricity consumption of nine real houses from different cities in Türkiye was recorded on a monthly basis. The feasibility of meeting the electrical energy needs of houses with hydrogen and supplying the energy required for hydrogen production using solar panels is examined. The annual electricity consumption of the houses was normalized based on house size. The solar panel area for hydrogen production needed for these houses was defined. Additionally it was calculated that the average volumetric amount of hydrogen produced per hour during peak sun hours in the investigated cities was 1 m3/h. This approach reduced the solar panel area for hydrogen production by a factor of 1.7.
The Extractive Industry’s Decarbonization Potential Using Electrification and Hydrogen Technologies
Mar 2025
Publication
The challenge of achieving net-zero CO2 emissions will require a significant scaling up of the production of several raw materials that are critical for decarbonizing the global economy. In contrast metal extraction processes utilize carbon as a reducing agent which is oxidized to CO2 resulting in considerable emissions and having a negative impact on climate change. In order to abate their emissions extractive industries will have to go through a profound transformation including switching to alternative climateneutral energy and feedstock sources. This paper presents the authors’ perspectives for consideration in relation to the H2 potential for direct reduction of oxide and sulfide ores. For each case scenario the reduction of CO2 emissions is analyzed and a breakthrough route for H2S decomposition is presented which is a by-product of the direct reduction of sulfide ores with H2. Electrified indirect-fired metallurgical kiln advantages are also presented a solution that can substitute fossil fuel-based heating technologies which is one of the main backbones of industrial processes currently applied to the extractive industries.
A New Electro-Biomembrane Integrated Renewable-Based System to Produce Power, Fresh Water and Hydrogen for Sustainable Communities
Jan 2025
Publication
As the consequences of global warming become more severe it is more crucial than ever to capitalize on all locally accessible potential renewable energy sources and produce sufficient useable energy outputs to meet community demands while causing the least damage to the ecosystem. Therefore this paper focuses on a unique parabolic trough collector solar systempowered electro-biomembrane unit that combines a heat and power system with fresh water electricity and hydrogen (H2) production. The proposed integrated system contains the following subsystems: a combining parabolic trough collector solar system an organic Rankine cycle a steam Rankine cycle a multi-stage flash desalination system and an electro-biomembrane H2 and freshwater production system. A thorough analysis and parametric research are performed on the multigeneration system to determine how important characteristics affect system performance and evaluate the energy and exergy efficiency and exergy destruction levels for particular system elements. The study results show that solar irradiation is the most critical parameter for improving system performance. The highest freshwater production of 1303333.3 L/day is observed at the solar irradiation of 935768 kWh/day. Furthermore the combined output of three electricity production technologies exceeds 2000000 kWh/day highlighting the ability of the system to harness solar thermal energy effectively. The findings indicate that using solar power and biomass as renewable energy sources the proposed integrated system provided 328.56 kg of biohydrogen per day. Overall the energy and exergy efficiencies of the integrated system are obtained at 34.3 and 29.5 % respectively.
Comprehensive Study on Hydrogen Production for Sustainable Transportation Planning: Strategic, Techno-Economic, and Environmental Impacts
Apr 2025
Publication
Hydrogen energy is essential in the transition to sustainable transportation planning providing a clean and efficient alternative to traditional fossil fuels. As a versatile energy carrier hydrogen facilitates the decarbonization of diverse transportation modes including passenger vehicles heavy-duty trucks trains and maritime vessels. To justify and clarify the role of hydrogen energy in sustainable transportation planning this study conducts a comprehensive techno-economic and environmental assessment of hydrogen production in the USA Europe and China. Utilizing the Shlaer–Mellor method for policy modeling the analysis highlights regional differences and offers actionable insights to inform strategic decisions and policy frameworks for advancing hydrogen adoption. Hydrogen production potential was assessed from solar and biomass resources with results showing that solar-based hydrogen production is significantly more efficient producing 704 tons/yr/km2 compared to 5.7 tons/yr/km2 from biomass. A Monte Carlo simulation was conducted to project emissions and market share for hydrogen and gasoline vehicles from 2024 to 2050. The results indicate that hydrogen vehicles could achieve near-zero emissions and capture approximately 30% of the market by 2050 while gasoline vehicles will decline to a 60% market share with higher emissions. Furthermore hydrogen production using solar energy in the USA yields a per capita output of 330513 kg/yr compared to 6079 kg/yr from biomass. The study concludes that hydrogen particularly from renewable sources holds significant potential for reducing greenhouse gas emissions with policy frameworks in the USA Europe and China focused on addressing energy dependence air pollution and technological development in the transportation sector.
Economic Sizing and Placement of Hydrogen Fueling and Electric Vehicles Charging Stations Powered by Renewable and Battery Systems in Smart Distribution Network
Aug 2025
Publication
This article discusses the planning sizing and placement of a vehicle refueling station supplied by renewable energy systems including photovoltaic wind biomass units and an integrated battery system within a smart distribution network. The proposed station comprises facilities for hydrogen fueling and electric vehicle charging stations structured as a bi-level optimization approach. The upper-level model focuses on the planning phase of the refueling station. Its objective is to minimize annual costs associated with construction maintenance and operation. Key constraints involve operational planning for renewable sources battery systems and vehicle refueling stations while accounting for reactive power management. In contrast the lower-level formulation deals with the eco-scheduling of smart distribution grid. Its goal is to minimize the sum of annual energy losses and operation costs within the grid governed by linearized optimal power flow model. To account for uncertainties in demand energy prices renewable generation output and refueling station performance a stochastic optimization framework is employed. The solution is derived using Benders decomposition algorithm to achieve optimal results. The primary innovation highlighted in this paper includes integrating renewable resources and battery systems to power the refueling station leveraging reactive power control for improved station performance and addressing both operational and economic objectives in the distribution system. Numerical results underscore the advantages of this strategy. Constructing a refueling station without battery and renewable units leads to significant drawbacks an increase in network operation cost by 144.6% and grid energy loss by 167.6%. Voltage levels drop below 0.9 per-unit and distribution lines experience severe loading of up to 34.7%. In contrast the proposed plan enhances network economics by 51.3%-74.5% and operational conditions by 17.7%-148.1% effectively showcasing the benefits of incorporating sustainable technologies and advanced planning methods into refueling station development.
Life Cycle Assessment of Different Powertrain Alternatives for a Clean Urban Bus Across Diverse Weather Conditions
Aug 2025
Publication
At present the decarbonization of the public transport sector plays a key role in international and regional policies. Among the various energy vectors being considered for future clean bus fleets green hydrogen and electricity are gaining significant attention thanks to their minimal carbon footprint. However a comprehensive Life Cycle Assessment (LCA) is essential to compare the most viable solutions for public mobility accounting for variations in weather conditions geographic locations and time horizons. Therefore the present work compares the life cycle environmental impact of different powertrain configurations for urban buses. In particular a series hybrid architecture featuring two possible hydrogenfueled Auxiliary Power Units (APUs) is considered: an H2-Internal Combustion Engine (ICE) and a Fuel Cell (FC). Furthermore a Battery Electric Vehicle (BEV) is considered for the same application. The global warming potential of these powertrains is assessed in comparison to both conventional and hybrid diesel over a typical urban mission profile and in a wide range of external ambient conditions. Given that cabin and battery conditioning significantly influence energy consumption their impact varies considerably between powertrain options. A sensitivity analysis of the BEV battery size is conducted considering the effect of battery preconditioning strategies as well. Furthermore to evaluate the potential of hydrogen and electricity in achieving cleaner public mobility throughout Europe this study examines the effect of different grid carbon intensities on overall emissions based also on a seasonal variability and future projections. Finally the present study demonstrates the strong dependence of the carbon footprint of various technologies on both current and future scenarios identifying a range of boundary conditions suitable for each analysed powertrain option.
Photovoltaic Power System with Electrochemical and Hydrogen Storage for Energy Independence in Student Dormitories
Mar 2025
Publication
This article analyzes the path towards achieving electric energy independence for dormitories. It examines electricity consumption in dormitories to determine the necessary volume for daily electrochemical energy storage systems seasonal hydrogen storage system capacity and photovoltaic (PV) system power. Electricity consumption data from dormitories between 2021 and 2024 were analyzed showing hourly daily and monthly trends. The study developed a mathematical model of hourly electric energy usage and production in Matlab/Simulink to optimize the photovoltaic (PV) system increase self-consumption potential and enhance surplus energy storage. This enabled the selection of capacities for daily and seasonal storage along with PV system power to meet dormitory energy needs particularly in autumn and winter. The software accommodates monthly energy consumption profiles and PV system characteristics allowing for the estimation of electric energy surplus after usage by inhabitants for hydrogen production and storage. The study offers a comprehensive framework for sustainable electric energy management in student housing.
Pressurised Fuel Vessel Mass Estimation for High-Altitude PEM Unmanned Aircraft Systems
Apr 2025
Publication
The power to weight ratio of power plants is an important consideration especially in the design of Unmanned Aircraft System (UAS). In this paper a UAS with an MTOW of 35.3 kg equipped with a fuel cell as a prime power supply to provide electrical power to the propulsion system is considered. A pressure vessel design that can estimate and determine the total size and weight of the combined power plant of a fuel cell stack with hydrogen and air/oxygen vessels and the propulsion system of the UAS for highaltitude operation is proposed. Two scenarios are adopted to determine the size and weight of the pressure vessels required to supply oxygen to the fuel cell stack. Different types of stainless-steel materials are used in the design of the pressure vessel in order to find an appropriate material that provides low size and weight advantages. Also the design of a hydrogen pressure vessel and mass estimation are also considered. The estimated sizes and weights of the hydrogen and oxygen vessels of the power plant and propulsion system in this research offer a maximum of four hours of flying time for the UAS mission; this is based on a Horizon (H-1000) Proton Exchange Membrane (PEM) stack.
Accelerating Thermally Safe Operating Area Assessment of Ignition Coils for Hydrogen Engines via AI-Driven Power Loss Estimation
Aug 2025
Publication
In order to determine thermally safe driving parameters of ignition coils for hydrogen internal combustion engines (ICE) a reliable estimation of internal power losses is essential. These losses include resistive winding losses magnetic core losses due to hysteresis and eddy currents dielectric losses in the insulation and electronic switching losses. Direct experimental assessment is difficult because the components are inaccessible while conventional computer-aided engineering (CAE) approaches face challenges such as the need for accurate input data the need for detailed 3D models long computation times and uncertainties in loss prediction for complex structures. To address these limitations we propose an artificial intelligence (AI)-based framework for estimating internal losses from external temperature measurements. The method relies on an artificial neural network (ANN) trained to capture the relationship between external coil temperatures and internal power losses. The trained model is then employed within an optimization process to identify losses corresponding to experimental temperature values. Validation is performed by introducing the identified power losses into a CAE thermal model to compare predicted and experimental temperatures. The results show excellent agreement with errors below 3% across the −30 ◦C to 125 ◦C range. This demonstrates that the proposed hybrid ANN–CAE approach achieves high accuracy while reducing experimental effort and computational demand. Furthermore the methodology allows for a straightforward determination of the coil safe operating area (SOA). Starting from estimates derived from fitted linear trends the SOA limits can be efficiently refined through iterative verification with the CAE model. Overall the ANN–CAE framework provides a robust and practical tool to accelerate thermal analysis and support coil development for hydrogen ICE applications.
Energy Efficiency of Future Hydrogen-based Fuel Supply Chain Routes for Germany's Maritime Demand
Aug 2025
Publication
The share of renewable electricity generation has been growing steadily over the past few years. However not all sectors can be fully electrified to reach decarbonization goals. The maritime industry which plays a critical role in international trade is such a sector. Therefore there is a need for a global strategic approach towards the production transportation and use of synfuels enabling the maritime energy transition to benefit from economies of scale. There are potential locations around the world for renewable generation such as hydropower in Norway wind turbines in the North Sea and photovoltaics in the Sahara where synfuels can be produced and utilized within the country as well as exported to demand hubs. Given that a country's domestic production may not fully meet its demand a scenario-based analysis is essential to determine the feasibility of supply chains pillaring on the demand and supply for the respective sector of utilization. Our work demonstrates this methodology for the import of hydrogen and derived ammonia and methanol to Germany from Norway Namibia and Algeria in 2030 and 2050 utilizing the pipeline- and ship-based transport scenarios. Thereby the overall supply chain efficiency for maritime applications is analyzed based on the individual supply chain energy consumption from production to bunkering of the fuel to a vessel. The analysis showed that the efficiency of import varies from 44.6% to 53.9% between the analyzed countries. Furthermore a sensitivity analysis for green and blue hydrogen production pathways is presented along with the influence of qualitative factors like port infrastructure geopolitics etc. As an example through these analyses recommendations for supply from Norway Algeria and Namibia at the Port of Wilhelmshaven within a supply chain are examined.
Exploring the Barriers to Hydrogen Fuel Cell Vehicles Adoption in the Gulf-Europe Corridor: A Fuzzy AHP and ISM Analysis
Aug 2025
Publication
The adoption of hydrogen fuel cell vehicles (HFCVs) is essential for achieving sustainable low-carbon transportation but many barriers hinder this transition. Therefore this study aims to identify categorize and prioritize these barriers in the context of the Gulf-Europe corridor also known as the Iraq Development Road Project (DRP). To achieve this we adopt a two-stage methodological framework that integrates the Fuzzy Analytical Hierarchy Process (Fuzzy AHP) to quantify the relative importance of thirty secondary barriers and Interpretive Structural Modeling (ISM) to explore the interdependencies among the top ten. The Fuzzy AHP results highlight technological economic and infrastructure-related barriers as the most critical primary barriers. The ISM analysis further reveals that three barriers lack of hydrogen production hubs limited hydrogen transport options and hydrogen storage and transportation are independent. Six barriers fuel cell efficiency and durability hydrogen production and distribution costs vehicle range and refueling time infrastructure investment refueling station compatibility issues and hydrogen purity requirements are classified as linkage barriers. One barrier high initial vehicle cost is found to be dependent. To accelerate HFCVs adoption we recommend strengthening hydrogen infrastructure fostering technological innovation reducing costs through targeted incentives and enhancing policy coordination among stakeholders and policymakers. This study contributes to literature by offering a comprehensive understanding of the adoption barriers and providing actionable insights to support the development of more effective strategies. Notably it uniquely addresses social logistical and technological barriers alongside geographic barriers that have been largely overlooked in previous studies.
Sustainable Aviation Fuel (SAF) Production through Power-to-Liquid (PtL): A Combined Techno-economic and Life Cycle Assessment
Aug 2023
Publication
The current research critically evaluates the technical economic and environmental performance of a Power-toLiquid (PtL) system for the production of sustainable aviation fuel (SAF). This SAF production system comprises a direct air capture (DAC) unit an off-shore wind farm an alkaline electrolyser and a refinery plant (reverse water gas shift coupled with a Fischer-Tropsch reactor). The calculated carbon conversion efficiency hydrogen conversion efficiency and Power-to-liquids efficiency are 88 % 39.16 % and 25.6 % respectively. The heat integration between the refinery and the DAC unit enhances the system’s energy performance while water integration between the DAC and refinery units and the electrolyser reduces the demand for fresh water. The economic assessment estimates a minimum jet fuel selling price (MJSP) of 5.16 £/kg. The process is OPEX intensive due to the electricity requirements while the CAPEX is dominated by the DAC unit. A Well-to-Wake (WtWa) life cycle assessment (LCA) shows that the global warming potential (GWP) equals 21.43 gCO2eq/ MJSAF and is highly dependent on the upstream emissions of the off-shore wind electricity. Within a 95 % confidence interval a stochastic Monte Carlo LCA reveals that the GWP of the SAF falls below the UK aviation mandate treshold of 50 % emissions reduction compared to fossil jet fuel. Moreover the resulting WtWa water footprint is 0.480 l/MJSAF with the refinery’s cooling water requirements and the electricity’s water footprint to pose as the main contributors. The study concludes with estimating the required monetary value of SAF certificates for different scenarios under the UK SAF mandate guidelines.
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.
Techno-Economic Analysis of Geospatial Green Hydrogen Potential Using Solar Photovoltaic in Niger: Application of PEM and Alkaline Water Electrolyzers
Apr 2025
Publication
This study evaluates the techno-economic feasibility of solar-based green hydrogen potential for off-grid and utility-scale systems in Niger. The geospatial approach is first employed to identify the area available for green hydrogen production based on environmental and socio-technical constraints. Second we evaluate the potential of green hydrogen production using a geographic information system (GIS) tool followed by an economic analysis of the levelized cost of hydrogen (LCOH) for alkaline and proton exchange membrane (PEM) water electrolyzers using fresh and desalinated water. The results show that the electricity generation potential is 311617 TWh/year and 353166 TWh/year for off-grid and utility-scale systems. The hydrogen potential using PEM (alkaline) water electrolyzers is calculated to be 5932 Mt/year and 6723 Mt/year (5694 Mt/year and 6454 Mt/year) for off-grid and utility-scale systems respectively. The LCOH production potential decreases for PEM and alkaline water electrolyzers by 2030 ranging between 4.72–5.99 EUR/kgH2 and 5.05–6.37 EUR/kgH2 for off-grid and 4.09–5.21 EUR/kgH2 and 4.22–5.4 EUR/kgH2 for utility-scale systems.
Bi-Level Sustainability Planning for Integrated Energy Systems Considering Hydrogen Utilization and the Bilateral Response of Supply and Demand
Aug 2025
Publication
Under the background of “double carbon” and sustainable development aimed at the problem of resource capacity planning in the integrated energy system (IES) at improving the economy of system planning operation and renewable energy (RE) consumption and at reducing carbon emissions this paper proposes a multi-objective bi-level sustainability planning method for IES considering the bilateral response of supply and demand and hydrogen utilization. Firstly the multi-energy flow in the IES is analyzed constructing the system energy flow framework studying the support ability of hydrogen utilization and the bilateral response of supply and demand to system energy conservation emission reduction and sustainable development. Secondly a multi-objective bi-level planning model for IES is constructed with the purpose of optimizing economy RE consumption and carbon emission. The non-dominated sorting genetic algorithm II (NSGA-II) and commercial solver Gurobi are used to solve the model and through the simulation verify the model’s effectiveness. Finally the planning results show that after introducing the hydrogen fuel cells hydrogen storage tank and bilateral response the total costs and carbon emissions decreased by 29.17% and 77.12% while the RE consumption rate increased by 16.75%. After introducing the multi-objective planning method considering the system economy RE consumption and carbon emissions the system total cost increased by 0.34% the consumption rate of RE increased by 0.6% and the carbon emissions decreased by 43.61t which effectively provides reference for resource planning and sustainable development of IES.
Techno-Economic Analysis of Hydrogen Transport via Truck Using Liquid Organic Hydrogen Carriers
Apr 2025
Publication
This study presents a techno-economic analysis of hydrogen transportation via liquid organic hydrogen carriers by road comparing this option with compressed hydrogen (350 bar) and liquefied hydrogen. The analysis includes the simulation of hydrogenation and dehydrogenation reactors for the dibenzyltoluene/perhydro-dibenzyltoluene system using ASPEN Plus along with a cost assessment of compression liquefaction and trucking. A sensitivity analysis is also carried out evaluating hydrogen transport at varying daily demand levels (1 2 and 4 t/d) and transport distances (50 150 and 300 km) with varying electricity prices and capital expenditures for hydrogenation and dehydrogenation units. Results indicate that compressed hydrogen is the most cost-effective solution for short distances up to 150 km with a levelized cost of transported hydrogen ranging from 1.10 to 1.61 EUR/kg. However LOHC technology becomes more competitive at longer distances with LCOTH values between 1.49 and 1.90 EUR/kg at 300 km across all demand levels. Liquefied hydrogen remains the least competitive option reaching costs up to 5.35 EUR/kg although it requires fewer annual trips due to higher trailer capacity. Notably at 150 km LOHC transport becomes more cost-effective than compressed hydrogen when electricity prices exceed 0.22 EUR/kWh or when the capital costs for hydrogenation and dehydrogenation units are minimized. From an environmental perspective switching from compressed to liquid hydrogen carriers significantly reduces CO2 emissions—by 56% for LOHCs and 78% for liquid hydrogen—highlighting the potential of these technologies to support the decarbonization of hydrogen logistics.
Mitigating Power Deficits in Lean-Burn Hydrogen Engines with Mild Hybrid Support for Urban Vehicles
Aug 2025
Publication
Hydrogen-fueled internal combustion engines present a promising pathway for reducing carbon emissions in urban transportation by allowing for the reuse of existing vehicle platforms while eliminating carbon dioxide emissions from the exhaust. However operating these engines with lean air–fuel mixtures—necessary to reduce nitrogen oxide emissions and improve thermal efficiency—leads to significant reductions in power output due to the low energy content of hydrogen per unit volume and slower flame propagation. This study investigates whether integrating a mild hybrid electric system operating at 48 volts can mitigate the performance losses associated with lean hydrogen combustion in a small passenger vehicle. A complete simulation was carried out using a validated one-dimensional engine model and a full zero-dimensional vehicle model. A Design of Experiments approach was employed to vary the electric motor size (from 1 to 15 kW) and battery capacity (0.5 to 5 kWh) while maintaining a fixed system voltage optimizing both the component sizing and control strategy. Results showed that the best lean hydrogen hybrid configuration achieved reductions of 18.6% in energy consumption in the New European Driving Cycle and 5.5% in the Worldwide Harmonized Light Vehicles Test Cycle putting its performance on par with the gasoline hybrid benchmark. On average the lean H2 hybrid consumed 41.2 kWh/100 km nearly matching the 41.0 kWh/100 km of the gasoline P0 configuration. Engine usage analysis demonstrated that the mild hybrid system kept the hydrogen engine operating predominantly within its high-efficiency region. These findings confirm that lean hydrogen combustion when supported by appropriately scaled mild hybridization is a viable near-zero-emission solution for urban mobility— delivering competitive efficiency while avoiding tailpipe CO2 and significantly reducing NOx emissions all with reduced reliance on large battery packs.
The Hydrogen Trade-Off: Optimizing Decarbonization Pathways for Urban Integrated Energy Systems
Aug 2025
Publication
Rapid socio-economic development has made energy application and environmental issues increasingly prominent. Hydrogen energy clean eco-friendly and highly synergistic with renewable energy has become a global research focus. This study using the EnergyPLAN model that includes the electricity transportation and industrial sectors takes Jinan City as the research object and explores how hydrogen penetration changes affect the decarbonization path of the urban integrated energy system under four scenarios. It evaluates the four hydrogen scenarios with the entropy weight method and technique placing them in an order of preference according to their similarity to the ideal solution considering comprehensive indicators like cost carbon emissions and sustainability. Results show the China Hydrogen Alliance potential scenario has better CO2 emission reduction potential and unit emission reduction cost reducing them by 7.98% and 29.39% respectively. In a comprehensive evaluation it ranks first with a score of 0.5961 meaning it is closest to the ideal scenario when cost environmental and sustainability indicators are comprehensively considered. The Climate Response Pioneer scenario follows with 0.4039 indicating that higher hydrogen penetration in terminal energy is not necessarily the most ideal solution. Instead appropriate hydrogen penetration scenarios should be selected based on the actual situation of different energy systems.
Energy Equivalent Consumption and Optimization Strategies for Hybrid Hydrogen Fuel Systems in Multirotor Drones
Jan 2025
Publication
This paper presents an improved Equivalent Consumption Minimization Strategy (ECMS) designed to optimize energy management for the hybrid hydrogen fuel power setups in multirotor drones. The proposed strategy aims to reduce hydrogen consumption and enhance the performance of the system consisting of Proton Exchange Membrane Fuel Cells (PEMFCs) and lithium batteries. Multirotor drones experience rapid power fluctuations due to their agile maneuvering but PEMFCs are unable to meet these demands swiftly due to their inherent limitations. To address this lithium batteries supplement peak power requirements and absorb excess energy on the DC bus. However this can lead to energy loss if the batteries are charged when not required. Our improved ECMS considers these inefficiencies and adjusts energy distribution to reduce hydrogen consumption and optimize the system’s performance. The proposed strategy effectively maintains the lithium batteries’ State of Charge (SOC) reduces hydrogen usage and enhances overall system efficiency when compared to traditional ECMS approaches.
Techno-Economic Analysis on Implementing Hydrogen in a Combined Heat and Power Plant in Luxembourg to Reduce Carbon Emissions
Apr 2025
Publication
In 2021 the global electricity and heat sector recorded the highest increase in carbon dioxide (CO2) emissions in comparison with the previous year highlighting the ongoing challenges in reducing emissions within the sector. Therefore combined heat and power (CHP) plants running on renewable fuels can play an important role in the energy transition by decarbonising a process increasing the efficiency and capacity factor. Since 2003 Luxembourgish CHP plants have been transitioning from natural gas to biomass mainly wood pellets. However even though wood pellets are a renewable alternative the market volatility in 2022 highlighted the vulnerability of a system reliant solely on one type of fuel. This study assesses the feasibility of using hydrogen to decarbonise a cogeneration plant powered by a natural gas-fuelled internal combustion engine. Although the technology to use hydrogen as a fuel for such systems already exists a technical and economic analysis of implementing a hydrogen-ready plant is still lacking. Our results show that from a technical perspective retrofitting an existing power plant to operate with hydrogen is feasible either by adapting or replacing the engine to accommodate hydrogen blends from 0 up to 100%. The costs of making the CHP plant hydrogen-ready vary depending on the scenario ranging from a 20% increase for retrofitting to a 60% increase for engine replacement in the best-case scenarios. However these values remain highly variable due to uncertainties associated with the ongoing technology development. From an economic standpoint as of 2024 running the plant on hydrogen remains more expensive due to significant initial investments and higher fuel costs. Nevertheless projections indicate that rising climate concerns CO2 taxes geopolitical factors and the development of the hydrogen framework in the region—through projects such as MosaHYc and HY4Link— could accelerate the competitiveness of hydrogen making it a more viable alternative to fossil-based solutions in the near future.
Optimization of Hydrogen Combustion in Diesel Engines: A CFD-Based Approach for Efficient Hydrogen Mixing and Emission Reduction
Apr 2025
Publication
Hydrogen internal combustion engines (ICEs) have gained significant attention as a promising solution for achieving zero-carbon emissions in the transportation sector. This study investigates the conversion of a 2 L Diesel ICE into a lean hydrogen-powered ICE focusing on key challenges such as hydrogen mixing pre-ignition combustion flame development and NOx emissions. The novelty of this research lies in the specific modifications made to optimize engine performance and reduce emissions while utilizing the existing Diesel engine infrastructure. The study identifies several important design changes for the successful conversion of a Diesel engine to hydrogen including the following: Intake port design: transitioning from a swirl to a tumble design to enhance hydrogen mixing; Injection and spark plug configuration: using a lateral injection system combined with a central spark plug to improve combustion; Piston design: employing a lenticular piston shape with adaptable depth to enhance mixing; Mitigating Coanda effect: preventing hydrogen issues at the spark plug using deflectors or caps; and Head design: maintaining a flat head design for efficient mixing while ensuring adequate cooling to avoid pre-ignition. These findings highlight the importance of specific modifications for converting Diesel engines to hydrogen providing a solid foundation for further research in hydrogen-powered ICEs which could contribute to carbon emission reduction and a more sustainable energy transition.
Research on Energy Management Strategy Based on Adaptive Equivalent Fuel Consumption Minimum for Hydrogen Hybrid Energy Systems
Mar 2025
Publication
Hydrogen has attracted widespread attention due to its zero emissions and high energy density and hydrogen-fueled power systems are gradually emerging. This paper combines the advantages of the high conversion efficiency of fuel cells and strong engine power to propose a hydrogen hybrid energy system architecture based on a mixture of fuel cells and engines in order to improve the conversion efficiency of the energy system and reduce its fuel consumption rate. Firstly according to the topology of the hydrogen hybrid energy system and the circuit model of its core components a state-space model of the hydrogen hybrid energy system is established using the Kirchhoff node current principle laying the foundation for the control and management of hydrogen hybrid energy systems. Then based on the state-space model of the hydrogen hybrid system and Pontryagin’s minimum principle a hydrogen hybrid system management strategy based on adaptive equivalent fuel consumption minimum strategy (A-ECMS) is proposed. Finally a hydrogen hybrid power system model is established using the AVL Cruise simulation platform and a control strategy is developed using matlab 2021b/Simulink to analyze the output power and fuel economy of the hybrid energy system. The results show that compared with the equivalent fuel consumption minimum strategy (ECMS) the overall fuel economy of A-ECMS could improve by 10%. Meanwhile the fuel consumption of the hydrogen hybrid energy system is less than half of that of traditional engines.
Advanced Online Fuel Cell Stack Water Management Strategies for Fuel Cell Stacks in Vehicle Powertrain Control
Sep 2025
Publication
Effective water management is crucial for the optimal performance and durability of proton exchange membrane fuel cells (PEMFCs) in automotive applications. Conventional techniques like electrochemical impedance spectroscopy (EIS) face challenges in accurately measuring high-frequency resistance (HFR) impedance during dynamic vehicle operations. This study proposes a novel stack water management stability control and vehicle energy control method to address these limitations. Simulation and experimental results demonstrate improved system and powertrain efficiency extended stack lifespan and optimized hydrogen consumption. These findings contribute to advancing robust water management strategies supporting the transition toward sustainable zero-emission fuel cell vehicles.
Lifecycle CO2 Analysis for Urban Emission Reduction of Hydrogen-fuelled and Battery Electric Buses in the European Union Current and Future Energetic Scenarios
Apr 2025
Publication
As the need to reduce Greenhouse Gas (GHG) emissions and dependence on fossil fuels grows new vehicle concepts are emerging as sustainable solutions for urban mobility. Beyond evaluating tailpipe emissions indirect emissions associated with energy and hydrogen production as vehicle manufacturing must be accounted offering a holistic Lifecycle Assessment (LCA) perspective. This study compares Battery Electric Vehicles (BEVs) Fuel Cell Vehicles (FCVs) Hydrogen Internal Combustion Engine Vehicles (H2ICEVs) and hybrid H2ICEVs analyzing energy efficiency and GHG emissions in urban environment across the European Union. Future scenarios (2030 2050) are examined as well with evolving energy mixes and manufacturing impacts. Findings show BEVs as the most efficient configuration with the lowest GHG emissions in 2024 while FCVs become the best option in future scenarios due to greener hydrogen production and improved manufacturing. This study emphasizes the need for tailored strategies to achieve sustainable urban mobility providing insights for policymakers and stakeholders.
Techno-Economic Optimal Operation of an On-Site Hydrogen Refueling Station
Oct 2025
Publication
An on-site hydrogen refueling station (HRS) directly supplies hydrogen to vehicles using an on-site hydrogen production method such as electrolysis. For the efficient operation of an on-site HRS it is essential to optimize the entire process from hydrogen production to supply. However most existing approaches focus on the efficiency of hydrogen production. This study proposes an optimal operation model for a renewable-energy-integrated on-site HRS which considers the degradation of electrolyzers and operation of compressors. The proposed model maximizes profit by considering the hydrogen revenue electricity costs and energy storage system degradation. It estimates hydrogen production using a voltage equation models compressor power using a shaft power equation and considers electrolyzer degradation using an empirical voltage model. The effectiveness of the proposed model is evaluated through simulation. Comparison with a conventional control strategy shows an increase of over 56% in the operating revenue.
A GAN‑and‑Transformer‑Assisted Scheduling Approach for Hydrogen‑Based Multi‑Energy Microgrid
Sep 2025
Publication
Against the backdrop of ever‑increasing energy demand and growing awareness of en‑ vironmental protection the research and optimization of hydrogen‑related multi‑energy systems have become a key and hot issue due to their zero‑carbon and clean characteristics. In the scheduling of such multi‑energy systems a typical problem is how to describe and deal with the uncertainties of multiple types of energy. Scenario‑based methods and ro‑ bust optimization methods are the two most widely used methods. The first one combines probability to describe uncertainties with typical scenarios and the second one essentially selects the worst scenario in the uncertainty set to characterize uncertainties. The selection of these scenarios is essentially a trade‑off between the economy and robustness of the so‑ lution. In this paper to achieve a better balance between economy and robustness while avoiding the complex min‑max structure in robust optimization we leverage artificial in‑ telligence (AI) technology to generate enough scenarios from which economic scenarios and feasible scenarios are screened out. While applying a simple single‑layer framework of scenario‑based methods it also achieves both economy and robustness. Specifically first a Transformer architecture is used to predict uncertainty realizations. Then a Gener‑ ative Adversarial Network (GAN) is employed to generate enough uncertainty scenarios satisfying the actual operation. Finally based on the forecast data the economic scenar‑ ios and feasible scenarios are sequentially screened out from the large number of gener‑ ated scenarios and a balance between economy and robustness is maintained. On this ba‑ sis a multi‑energy collaborative optimization method is proposed for a hydrogen‑based multi‑energy microgrid with consideration of the coupling relationships between energy sources. The effectiveness of this method has been fully verified through numerical exper‑ iments. Data show that on the premise of ensuring scheduling feasibility the economic cost of the proposed method is 0.67% higher than that of the method considering only eco‑ nomic scenarios. It not only has a certain degree of robustness but also possesses good economic performance.
Mitigating Urban Pollution: A Comparative Life Cycle Assessment of Hydrogen, Electric, and Diesel Buses for Urban Transportation
Mar 2025
Publication
Urban transportation systems particularly public buses contribute significantly to global pollution creating an urgent need for sustainable solutions. Alternative fuel buses and other disruptive technological advancements in this field are essential to resolve these problems. The absence of studies on the life cycle assessment (LCA) of hydrogen-fueled buses along with comparative analyses of alternative-fueled buses makes this research particularly timely. This study develops a comprehensive LCA framework to measure the economic and environmental impact of using different technologies (i.e. hydrogen-fueled electric and diesel buses). Different fuel production methods were examined considering operational factors such as energy consumption across various routes. This study contributes to enhancing the LCA methodology for public bus operations by using machine learning algorithms to cluster routes and identify optimal demonstration routes for analysis. The results highlight the impact of fuel production methods for hydrogen-fueled buses in the significant pollutant reductions (e.g. CO2 and NO ) despite their high life cycle costs. The proposed framework is validated with real data from Halifax Canada and expanded to assess public bus networks in cities with varying routes topology and population levels. The paper’s analyses consider future technological advances to lower costs aligning them with electric buses over time. This study helps policymakers choose the best public bus alternatives to improve the economic environmental and social sustainability of urban transportation.
Enhancing Renewable Energy Integration via Robust Multi-Energy Dispatch: A Wind–PV–Hydrogen Storage Case Study with Spatiotemporal Uncertainty Quantification
Aug 2025
Publication
This paper addresses the challenge of renewable energy curtailment which stems from the inherent uncertainty and volatility of wind and photovoltaic (PV) generation by developing a robust model predictive control (RMPC)-based scheduling strategy for an integrated wind–PV–hydrogen storage multi-energy flow system. By building a “wind– PV–hydrogen storage–fuel cell” collaborative system the time and space complementarity of wind and PV is used to stabilize fluctuations and the electrolyzer–hydrogen production– gas storage tank–fuel cell chain is used to absorb surplus power. A multi-time scale state-space model (SSM) including power balance equation equipment constraints and opportunity constraints is established. The RMPC scheduling framework is designed taking the wind–PV joint probability scene generated by Copula and improved K-means and SSM state variables as inputs and the improved genetic algorithm is used to solve the min–max robust optimization problem to achieve closed-loop control. Validation using real-world data from Xinjiang demonstrates a 57.83% reduction in grid power fluctuations under extreme conditions and a 58.41% decrease in renewable curtailment rates markedly enhancing the local system’s capacity to utilize wind and solar energy.
Computational Thermo-mechanical Modelling and Design-space Exploration of Cryogenic Hydrogen Tanks for Aviation
Aug 2025
Publication
A tool for parametric finite element modeling and analysis of LH2 tanks for aviation is developed. Passively insulated cryogenic composite sandwich pressure vessels are investigated as they conjugate simplicity effectiveness and lightweight design for aeronautical applications. Several parametric analyses are performed with the aim of gaining both general and case-specific understanding of how particular design choices may impact the tank mechanical and thermal performance. Differently from most of previous studies multiple design choices including tank walls thicknesses constraints for airframe integration strategies as well as the presence position and integration of refuelling cutouts and anti-sloshing bulkheads are considered. The thermo-mechanical analyses are performed considering first a simple reference configuration with the aim of evaluating possible directions for performance enhancement. Results indicate how different design features affect the gravimetric and thermal efficiency of the tank without compromising structural integrity if the walls thicknesses are suitably sized. The effects of different constraints and geometric discontinuities which reflect specific fuselage integration choices must be carefully assessed as they reduce safety margins. Ultimately a vessel model including features necessary for safe operation is presented as it serves as a baseline for further optimization.
Multi-Time-Scale Layered Energy Management Strategy for Integrated Production, Storage, and Supply Hydrogen Refueling Stations Based on Flexible Hydrogen Load Characteristics of Ports
Mar 2025
Publication
Aiming at resolving the problem of stable and efficient operation of integrated green hydrogen production storage and supply hydrogen refueling stations at different time scales this paper proposes a multi-time-scale hierarchical energy management strategy for integrated green hydrogen production storage and supply hydrogen refueling station (HFS). The proposed energy management strategy is divided into two layers. The upper layer uses the hourly time scale to optimize the operating power of HFS equipment with the goal of minimizing the typical daily operating cost and proposes a parameter adaptive particle swarm optimization (PSA-PSO) solution algorithm that introduces Gaussian disturbance and adaptively adjusts the learning factor inertia weight and disturbance step size of the algorithm. Compared with traditional optimization algorithms it can effectively improve the ability to search for the optimal solution. The lower layer uses the minute-level time scale to suppress the randomness of renewable energy power generation and hydrogen load consumption in the operation of HFS. A solution algorithm based on stochastic model predictive control (SMPC) is proposed. The Latin hypercube sampling (LHS) and simultaneous backward reduction methods are used to generate and reduce scenarios to obtain a set of high-probability random variable scenarios and bring them into the MPC to suppress the disturbance of random variables on the system operation. Finally real operation data of a HFS in southern China are used for example analysis. The results show that the proposed energy management strategy has a good control effect in different typical scenarios.
Hydrogen-Containing Fuel Influence on Compression-Ignition Engine Part Wear and Emissions of Toxic Substances
Mar 2025
Publication
Issues related to the components of modern fuel equipment wear processes have been discussed. The fuel injector is one of the key elements of the fuel equipment system because it is a device responsible for distributing and spraying hydrogen-containing fuel in the engine combustion chamber. It is mounted in the modern engine head directly in the combustion chamber. If the fuel injector is faulty it affects the operating parameters and in particular the ecological parameters of the modern engine such as the emission of toxic substances into the environment. Additionally a hydrogen reactor has been installed in the Common Rail (CR) system the task of which is to produce hydrogen. As a result of the temperature prevailing in the operating environment of the injection equipment various types of wear occur inside the system including hydrogen degradation. The types of degradation processes of precision pairs of modern fuel injectors have been analyzed and classified. Microscopic tests were performed to analyze the contamination in the fuel system and to compare the ecological parameters of the engine operating on efficient and worn fuel injectors. The emission of nitrogen oxides carbon monoxide and soot has been analyzed as a key ecological parameter. It has been established that the loss of precision of pairs of elements of a damaged fuel injector significantly affects the size of the injection doses of the fuel mixture containing hydrogen.
Research on Pricing Strategy of Shared Electro-thermal-hydrogen Energy Storage in Integrated Energy Multi-microgrid Based on Hybrid Game
May 2025
Publication
Against the backdrop of high investment costs in distributed energy storage systems this paper proposes a bi-level energy management model based on shared multi-type energy storage to enhance system economics and resource utilization efficiency. First an electricity–heat–hydrogen coupled shared storage architecture is developed incorporating hydrogen-blended gas turbines gas boilers and hydrogen loads to achieve deep coupling between the power grid and natural gas network. Then a bi-level game model is formulated with the upper-level objective of minimizing the storage operator’s cost and the lower-level objective of minimizing the cost of the integrated energy microgrid (IEM) aggregator. A cooperative game mechanism is introduced within the microgrids to support peer-to-peer energy trading. Nash bargaining theory is applied to determine benefit allocation and dynamic pricing strategies among microgrids. The model is solved using a genetic algorithm (GA) and the alternating direction method of multipliers (ADMM). Simulation results validate the proposed strategy’s effectiveness and feasibility in reducing system costs improving overall benefits and achieving fair benefit allocation.
Sustainable Fuel Supply for Very Small Island Transportation: The Potential of Hybrid Renewable Energy and Green Hydrogen
Mar 2025
Publication
The transition to a low-carbon future necessitates innovative approaches to renewable energy deployment particularly in the marine environment where abundant resources remain underutilized. This paper explores the potential of hybrid renewable energy systems and green hydrogen production to address the energy challenges faced by Very Small Islands (VSIs). These islands heavily rely on imported fossil fuels making them vulnerable to global price fluctuations and contributing to economic instability and environmental degradation. Offshore floating platforms present a transformative opportunity by harnessing marine renewable resources integrating wind solar and wave energy to maximize energy production while minimizing land use conflicts. Green hydrogen produced through the electrolysis of seawater powered by these renewable sources offers a sustainable alternative for decarbonizing transportation particularly in the maritime sector. The study aims to assess the feasibility of converting small conventional passenger vessels to hydrogen propulsion and evaluate the technical economic and environmental impacts of deploying offshore platforms for hydrogen production. By examining these aspects this research contributes to the broader discourse on sustainable energy solutions for island communities and provides actionable insights into implementing renewable hydrogen-based maritime transport.
Aviation Research & Innovation Strategy: A Pathway to Competitive and Sustainable Aviation Supporting Europe's Sovereignty
Jun 2025
Publication
Renewing a vision for European aviation: Europe today leads the world in civil aviation and air traffic management (ATM). This success should not be taken for granted particularly as the sector undergoes decarbonisation and digitalisation in today’s challenging geopolitical context. Significant value is at stake and capturing this value – for the sake of Europe’s competitiveness sustainability and sovereignty – is contingent on substantial investment in aviation research and innovation (R&I) and support to market uptake of new technologies to avoid the “valley of death” between technological development and product entry-into-service. Aviation is a major socio-economic contributor to Europe: The aviation industry is a vital component of Europe’s economy contri buting significantly to jobs gross domestic product (GDP) and trade. Overall the European aviation sector supports 15 million jobs and contributes EUR 1.1 trillion to European economic activity. The aviation sector is also critical to the EU single market European integration and global connectivity. It drives innovation and enhances Europe’s global influence and security through its combined focus on sustainability and competitiveness. The importance of aviation in achieving these fundamental goals for Europe is underscored by the findings of the Draghi report.
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