Publications

The ongoing energy transition and decarbonization efforts have prompted the development of Hybrid Renewable Energy Systems (HRES) capable of integrating multiple generation and storage technologies to enhance energy autonomy. Among the available options hydrogen has emerged as a versatile energy carrier yet most studies have focused either on stationary applications or on mobility seldom addressing their integration withing a single framework. In particular the potential of Metal Hydride (MH) tanks remains largely underexplored in the context of sector coupling where the same storage unit can simultaneously sustain household demand and provide in-house refueling for lightduty fuel-cell vehicles. This study presents the design and analysis of a residential-scale HRES that combines photovoltaic generation a PEM electrolyzer a lithium-ion battery and MH storage intended for direct integration with a fuel-cell electric microcar. A fully dynamic numerical model was developed to evaluate system interactions and quantify the conditions under which low-pressure MH tanks can be effectively integrated into HRES with particular attention to thermal management and seasonal variability. Two simulation campaigns were carried out to provide both component-level and system-level insights. The first focused on thermal management during hydrogen absorption in the MH tank comparing passive and active cooling strategies. Forced convection reduced absorption time by 44% compared to natural convection while avoiding the additional energy demand associated with thermostatic baths. The second campaign assessed seasonal operation: even under winter irradiance conditions the system ensured continuous household supply and enabled full recharge of two MH tanks every six days in line with the hydrogen requirements of the light vehicle daily commuting profile. Battery support further reduced grid reliance achieving a Grid Dependency Factor as low as 28.8% and enhancing system autonomy during cold periods.

Global demand for clean energy carriers like hydrogen (H2) is rising under carbon-reduction policies. While domestic H2 projects are progressing international trade presents significant opportunities for countries with abundant renewables or advanced production capabilities. Yet establishing H2 as a viable global commodity requires overcoming supply chain challenges in flexibility efficiency and cost. This review examines hydrogen supply chain network design (HSCND) studies and highlights key research gaps in export-oriented systems. Current work often focuses on transport technologies but lacks integrated analyses combining technical economic and policy dimensions. Notable gaps include limited research on retrofitting infrastructure for H2 derivatives underexplored roles of ports as export hubs and insufficient evaluation of regulatory frameworks and financial risks. This review proposes a methodological approach to guide HSCND for export supporting data collection and strategic planning. Future research should integrate technical geopolitical and social factors into models backed by methodological innovation and empirical evidence.

Developing cleaner processes via newer technologies will accelerate advancement toward more sustainable energy systems. Hydrogen is an energy carrier and an intermediate molecule in chemical processes. This research investigates an innovative hydrogen production process utilizing a non-thermal Cold Atmospheric Pressure Plasma-based Reformer (CAPR). Exploring environmentally friendly and economically viable pathways for hydrogen production is crucial for addressing climate change and reducing the carbon footprint of industrial processes. The study investigates the conversion of natural gas to hydrogen at ambient temperature and pressure highlighting the ability of plasma-based technology to operate without direct CO2 emissions.<br/>Initially through experimental studies natural gas was passed through the CAPR where the plasma's energetic discharges initiate the reforming process. Subsequently the produced hydrogen along with other light hydrocarbons enters the separation system for producing purified hydrogen. The research focuses on techno-economic analyses and sensitivity assessments to determine the levelized cost of producing hydrogen via a nanosecond plasma-based refining plant and benchmark technologies. Sensitivity analyses identify two primary factors that significantly affect the levelized cost of hydrogen production in a plasma-based reforming system.<br/>The research suggests that instead of producing carbon dioxide and capturing the emitted CO2 utilize processes that do not emit direct CO2. CAPR shows potential for cost competitiveness with conventional hydrogen production methods including steam methane reforming (SMR) and electrolysis. The findings underscore the need for further research to optimize the system's performance and cost-effectiveness positioning CAPR as a potentially transformative technology for the chemical process industry.

Solid oxide electrolysis cells (SOECs) have emerged as a promising technology for efficient energy storage and CO2 utilization via H2O–CO2 co-electrolysis. While most previous studies focused on planar or tubular configurations this work investigated a novel flat tubular SOEC design using a comprehensive 3D multi-physics model developed in COMSOL Multiphysics 5.6. This model integrates charge transfer gas flow heat transfer chemical/electrochemical reactions and structural mechanics to analyze operational behavior and thermo-mechanical stress under different voltages and pressures. Simulation results indicate that increasing operating voltage leads to significant temperature and current density inhomogeneity. Furthermore elevated pressure improves electrochemical performance possibly due to increased reactant concentrations and reduced mass transfer limitations; however it also increases temperature gradients and the maximum first principal stress. These findings underscore that the design and optimization of flat tubular SOECs in H2O–CO2 co-electrolysis should take the trade-off between performance and durability into consideration.

Hydrogen production from natural gas or biogas at different purity levels has emerged as an important technology with continuous development and improvement in order to stand for sustainable and clean energy. Regarding biogas which can be obtained from multiple sources hydrogen production through the steam reforming of methane is one of the most important methods for its energy use. In that sense the role of catalysts to make the process more efficient is crucial normally contributing to a higher hydrogen yield under milder reaction conditions in the final product. The aim of this review is to cover the main points related to these catalysts as every aspect counts and has an influence on the use of these catalysts during this specific process (from the feedstocks used for biogas production or the biodigestion process to the purification of the hydrogen produced). Thus a thorough review of hydrogen production through biogas steam reforming was carried out with a special emphasis on the influence of different variables on its catalytic performance. Also the most common catalysts used in this process as well as the main deactivation mechanisms and their possible solutions are included supported by the most recent studies about these subjects.

The transition to sustainable and smart urban energy systems requires combustion technologies that combine high efficiency with near-zero emissions. Moderate or intense low-oxygen dilution (MILD) combustion has emerged as a promising solution offering volumetric heat release reduced peak temperatures and strong NOX suppression ideal for integrating green hydrogen carriers such as ammonia and ammonia–hydrogen blends into stationary energy systems. While MILD combustion is well-studied for hydrocarbons its application to carbon-free fuels presents challenges including high ignition temperatures low reactivity and potential NOX formation. This review examines the behavior of ammonia-based fuels under MILD conditions mapping combustion regimes across reactor types and operating parameters. To address ignition and stability issues the review also explores plasma-assisted MILD combustion (PAMC). Non-equilibrium plasma (NEP) discharges promote radical generation reduce ignition delay times and enhance flame stability under lean highly diluted conditions. Recent experimental and numerical studies demonstrate that plasma activation can reduce ignition delay times by up to an order of magnitude lower flame lift-off heights by over 30 % in certain configurations and enhance OH radical concentrations and heat release intensity. The extent of these improvements depends on factors such as plasma energy input fuel type and dilution level. This review synthesizes key findings identifies technical gaps and highlights the potential of MILD and PAMC as clean flexible and scalable solutions for low-emission stationary energy generation in smart city environments.

With the rapid development of alternative fuel vehicles (AFVs) and renewable energy sources the increasing coordination between electric vehicles (EVs) and hydrogen vehicles (HVs) in urban coupled powertransportation networks (CPTNs) fosters optimized energy scheduling and enhanced system performance. This study proposes a two-level Stackelberg-Nash game framework for AFV-integrated microgrids in a CPTN to enhance the economic efficiency of microgrid. This framework employs a Stackelberg game model to define the leader-follower relationship between the microgrid operator and the vehicle-to-grid (V2G) aggregator. Nash equilibrium games are established to capture competitive interactions among charging stations (CSs) and among hydrogen refueling stations (HRSs). Furthermore an optimal scheduling model is proposed to minimize microgrid operation costs considering the spatiotemporal dynamics and user preferences of EVs and HVs supported by the proposed dynamic choice model. A game-theoretic pricing and incentive mechanism promotes AFV participation in V2G services enhancing the profitability of CSs and HRSs. Afterward a momentum-enhanced Stackelberg-Nash equilibrium algorithm is developed to address the bi-level optimization problem. Finally numerical simulations validate the effectiveness of the proposed method in improving economic efficiency and reducing operation costs. The proposed approach offers an effective solution for integrating large-scale AFV fleets into sustainable urban energy and transportation systems.

In recent years there has been an increasingly larger fraction of intermittent energy sources. In the northern parts of Europe the main source of intermittent power is wind power. This source of power is low inertia inconsistent and will always fluctuate with different magnitudes leaving a need for balancing. One source of balancing is to have the widespread non-zero inertia combined heat and power stations work as back-up sources. One way to boost the capability of these power sources is by adding an oxyfuel internal hydrogen combustor. To study the effects of this the steam generator was tested in four different positions within the power plant to test different possibilities with different levels of retrofits. The first was in the high- and lowpressure crossover the second was a reheat at a higher pressure the third was a superheat of the admission steam and finally the fourth was a superheat using the overload valves. The final results showed that the configurations of crossover reheat and superheat of admission steam were the best in terms of retrofit while the reheat at higher pressure was deemed the best in terms of backup capacity reaching a gain in power of 9.5 MW at a fuel efficiency of 30.93 %. The highest fuel efficiencies were shown by the latter two amounting to 45.19 % and 51.58 % in district heating mode respectively. There is great potential to be made from these power plants due to the possibility of increased capacity all across Sweden.

This study presents the conceptual design and evaluation of an HRS for light-duty FCEVs. The proposed system integrates wind turbines a water electrolyzer three-stage hydrogen compressor heat recovery and storage a two-stage Organic Rankine Cycle (TS-ORC) hydrogen storage tanks a Vapor Compression Refrigeration Cycle (VCRC) and a hydrogen dispenser. Waste heat from the hydrogen compression process is harnessed to power the TS-ORC where the first stage drives the VCRC and the second stage generates additional electricity. A comprehensive assessment of the system confirmed the system's compliance with the principles of thermodynamics. The results indicate an overall system efficiency of 25.4% and the wind turbines alone achieve 46.21% efficiency. The overall exergy destruction rate of the system is computed to be 2120 kW and the main exergy destruction occurs in wind turbines and water electrolyzer. The first and second stages of the ORC exhibit efficiencies of 14.45% and 6.05% respectively while the VCRC yields a Coefficient of Performance (COP) of 1.24. The specific energy consumption for electrolytic hydrogen production compression and pre-cooling are calculated as 58.83 1.99 and 0.29 kWh/kg respectively. The hydrogen dispenser fills an onboard hydrogen storage tank with a 4 kg capacity at 700 bar in 5.5 min.

The rapid development of fuel cell electric vehicles (FCEVs) has highlighted the critical importance of optimizing energy management strategies to improve vehicle performance energy efficiency durability and reduce hydrogen consumption and operational costs. However existing approaches often face limitations in real-time applicability adaptability to varying driving conditions and computational efficiency. This paper aims to provide a comprehensive review of the current state of FCEV energy management strategies systematically classifying methods and evaluating their technical principles advantages and practical limitations. Key techniques including optimization-based methods (dynamic programming model predictive control) and machine learning-based approaches (reinforcement learning deep neural networks) are analyzed and compared in terms of energy distribution efficiency computational demand system complexity and real-time performance. The review also addresses emerging technologies such as artificial intelligence vehicle-to-everything (V2X) communication and multi-energy collaborative control. The outcomes highlight the main bottlenecks in current strategies their engineering applicability and potential for improvement. This study provides theoretical guidance and practical reference for the design implementation and advancement of intelligent and adaptive energy management systems in FCEVs contributing to the broader goal of efficient and low-carbon vehicle operation.