With hydrogen becoming an attractive energy carrier, the generation of green hydrogen through electrolysis to decarbonize sectors with high greenhouse gas (GHG) emissions such as the energy generation and transportation sectors has started to gain more traction as an important research focus. Electrolysis, as a process that is not fully efficient, results in the generation of waste heat. The scope of this paper is in increasing the overall efficiency of an electrolyzer system by utilizing the waste heat generated.

This study presents the design, real-time implementation, and full-scale experimental validation of a rule-based Energy Management Strategy (EMS) for a dual-stack Fuel Cell Hybrid Electric Vehicle (FCHEV) developed on a Jeep Wrangler platform. Unlike previous studies, predominantly focused on simulation-based analysis or single-stack architectures, this work provides comprehensive vehicle-level experimental validation of a deterministic real-time EMS applied to a dual fuel cell system in an SUV-class vehicle. The control algorithm, deployed on a National Instruments CompactRIO embedded controller, ensures deterministic real-time energy distribution and stable hybrid operation under dynamic load conditions. Simulation analysis conducted over eight consecutive WLTC cycles shows that both fuel cell stacks operate predominantly within their optimal efficiency range (25–35 kW), achieving an average DC efficiency of 68% and a hydrogen consumption of 1.35 kg/100 km under idealized conditions. Experimental validation on the Wrangler FCHEV demonstrator yields a hydrogen consumption of 1.67 kg/100 km, corresponding to 1.03 kg/100 km·m2 after aerodynamic normalization (Cd·A = 1.624 m2), reflecting real-world operating constraints. The proposed EMS promotes fuel-cell durability by reducing current cycling amplitude and maintaining operation within high-efficiency regions for the majority of the driving cycle. By combining deterministic real-time embedded control with vehicle-level experimental validation, this work strengthens the link between EMS design and practical deployment and provides a scalable reference framework for future hydrogen powertrain control systems.

In this paper, the performance indicators for fuel cell hybrid electric vehicles are evaluated using an energy management strategy based on a new algorithm (named SWA_RTO) proposed here. The analysis is done in comparison with a reference strategy (Static Feed Forward strategy) using performance indicators such as fuel economy, oxygen excess ratio, fuel efficiency, battery state of charge, and electrical efficiency of the fuel cell system. Significant fuel savings were achieved on the main European driving cycles (ECE-15, EUDC and NEDC), highlighting the potential of the new SWA_RTO strategy to choose the best strategy (which offers the lowest fuel consumption) based on the requested power. By controlling the air and hydrogen regulators, the fuel cell system generates a power that follows the requested power profile, so that the batteries operate in a sustained charge mode, increasing their lifespan.

In the last three years, many research papers have been published in the field of Hybrid Energy Systems based on Fuel Cells/Batteries, which highlight that the Zero Emissions objective for transport can be achieved soon, according to the requirements of transport regulations that have been recently revised relative to the proposed objectives for pollutant emissions, carbon footprint, etc. The main objectives of this paper are to analyze the new Hybrid Energy Systems proposed for vehicles, the new Management Systems proposed for these systems, highlighting their advantages and disadvantages compared to previously proposed solutions, emission reduction, etc. compared to previously proposed solutions. The contribution and novelty of the analysis refers to the critical analysis of the new proposed solutions and the presentation of current solutions and challenges for this field.

Carbonic materials functionalized with platinum-iron possess a high chemical activity and are recognized for the possibility of being used as electrocatalytic materials in the fabrication of electrodes for various electrochemical devices such as proton exchange membrane fuel cells (PEMFCs). According to this paper, platinum-iron supported on graphene oxide (Pt-Fe/rGO) was prepared by using a green chemistry synthesis method and evaluated as electrode for PEMFC.

Stable, highly efficient and long-term membrane electrode assemblies (MEAs) for proton exchange membrane fuel cells (PEMFCs) are still the key technologies for space systems using hydrogen and oxygen as reactants. To improve the life and reliability of the next generation of PEMFC stacks for space missions, development of stable and efficient MEAs become critical. This paper addresses two remedies toward these goals: the development of oxidation resistant hydrophilic coatings and oxidation resistant gas diffusion layers.

The development of catalysts with high activity for the ORR is essential to proton exchange membrane fuel cells (PEMFCs), since the majority of activation losses occur at the cathode and it turns into an interesting research area. In the present study, it is investigated the hydrothermal platinum functionalization of the CVD grown three-dimensional graphene foam (3D-GrFoam) using three concentrations of dihydrogen hexachloroplatinate (IV) hydrate [1]. The platinum functionalized graphene foam determined from XPS was 0.2at %, 0.3 at % and 0.4 at %, respectively.The catalytic activity towards ORR was analyzed from linear sweep voltammetry (LSV) plots recorded with a scan rate of 5 mV s-1 in oxygen saturated 0.5 M H2SO4. From the LSV curves and the Koutecky-Levich (K-L) plots for 0.4PtGrFoam as current density (mA-1 cm2 geo) vs. w-1/2 (rad s-1)-1/2), for various rotation speeds (among 250–1500 rpm) and different potentials (0.1 V-0.8 V). From the fitted K-L plots it is noticed a fair linear relationship at all potentials, that confirms the electroreduction of platinum. The number of transferred electrons is between 3.22 to 3.59 indicating the preponderance of the four-electron transfer mechanism in the ORR corresponding to the directly reduction of O2 to H2O. 1. Ion-Ebrasu, R.D. Andrei, S. Enache, S. Caprarescu, C. C. Negrila, C. Jianu, A. Enache, I. Boerasu, E. Carcadea, M. Varlam, B. S. Vasile, J. Ren, Materials 2021, 14, 4952.

In its most concise expression, the economy of hydrogen is synthesized by the use of hydrogen as an energy vector to allow the conversion of variable renewable energy (VRE) into electricity useful for operating various equipment and processes, in the so-called Power to Gas to Power (P2G2P) conversion. The paper deals with a P2G2P system based on solar energy to produce “green” hydrogen to be used as fuel to supply (pure or mixed with natural gas) a gas turbine to generate electricity. Hydrogen is produced by water electrolysis and stored in pressurized tanks in the so-called P2G (power to gas) technology. Its subsequent use for power generation in a G2P (gas to power) system allows the storage of the excess energy produced by the PV (photovoltaic) panels to be used later to compensate the solar energy intermittency. The issues relating to sizing such a P2G2P system supplied by a 5 MW PV panels park, its operating performances and economics are presented. Results are materialized in data regarding the monthly distribution of resources and production, as well as those related to revenues and the expenses involved. Ways to increase system efficiency are also suggested.

The facile and low-time consuming synthesis of an active and stable catalyst based on graphene materials, with the aim of being used in the oxygen reduction reaction (ORR) represents a major challenge that can significantly contribute to the research dedicated to proton exchange membrane fuel cells (PEMFCs). In this work, we present platinum-cobalt-ceria supported on reduced graphene oxide (Pt-Co-CeO 2 /rGO) as a promising electrocatalyst for ORR that can be obtained by a facile one-step process. The synthesized graphene oxide-based nanocomposite was physico-chemically characterized and evaluated as electrode for oxigen reduction reaction by specific electrochemical methods.

A low time consuming and green chemistry synthesis method for preparation of nitrogen-doped graphene oxide (N/rGO) is presented. Through this paper, N/rGO was synthesized by using graphene oxide as carbon source, urea as nitrogen source and ethylene glycol as reduction agent. The effect of the reaction time on the nitrogen content of the doped materials was investigated by specific physical and chemical methods. Based on chemical properties of the prepared materials, it was found that the highest nitrogen concentration (5.86 wt.%) was obtained in mild reaction conditions (60 ° C, 30 min.).

Nitrogen-doped graphene is currently recognized as one of the most promising catalysts for the oxygen reduction reaction (ORR). It has been demonstrated to act as a metal-free electrode with good electrocatalytic activity and long-term operation stability, excellent for the ORR in proton exchange membrane fuel cells (PEMFCs). As a consequence, intensive research has been dedicated to the investigation of this catalyst through varying the methodologies for the synthesis, characterization, and technologies improvement. A simple, scalable, single-step synthesis method for nitrogen-doped graphene oxide preparation was adopted in this paper. The physical and chemical properties of various materials obtained from different precursors have been evaluated and compared, leading to the conclusion that ammonia allows for a higher resulting nitrogen concentration, due to its high vapor pressure, which facilitates the functionalization reaction of graphene oxide. Electrochemical measurements indicated that the presence of nitrogen-doped oxide can effectively enhance the electrocatalytic activity and stability for ORR, making it a viable candidate for practical application as a PEMFC cathode electrode.

The DC microgrids based on renewable energy sources (RES) are simple to be implemented in residential houses and should be possible solution for the energy crisis. This paper presents the preliminary results of the implementation of the power-following strategy in a DC microgrid using a fuel cell / electrolyser unit. The fuel regulators of the fuel cell (FC) system will be controlled by the FC current and the boost DC-DC converter interfacing the FC stack with the DC bus will be controlled using the power-following strategy when the regenerable power are less that the load demand. During the period when the renewable power exceeds the load demand, the excess power will supply the electrolyser unit to operate the battery in charge-sustained mode (with the advantage of a smaller size of the battery pack). The advantages of DC microgrid operation using an energy management strategy based on power following for the hydrogen-based energy generation and storage system are presented.

The field of microgrids based on renewable energy sources (RES) is considered as possible solution for the energy crisis. Different renewable energy alternatives in the solar and wind areas are analyzed in the literature in order to be implemented in buildings (specially on the roofs of the residential houses and buildings of cities), which would create a micro distributed generation on a large scale based on the prediction of data collected, with and without support of a fuel cell system (FC) as back-up energy source. In this paper we analyze three microgrids that exchange energy through the energy market to ensure the operation of the battery in sustained charging mode, with clear advantages in the size of the battery pack and its life. To overcome energy conflicts (such as energy congestion contradiction and energy-related economic and environmental conflicts) and renewable energy uncertainty in order reach an optimal compromise between energy requirements in microgrid, the power-following strategy will be used. The advantages of using hydrogen-based energy storage systems are presented by simulation, but the strategy for connecting to the general distribution network is not discussed here.

Here in, we describe an ultrafast, single-step microwave irradiation route (MW) to prepare graphene supported Pt nanoparticles, during which the small Pt nanoparticles are distributed uniformly on a reduced graphene oxide surface. This route provides evident advantages namely low cost, easiness, low time consuming and high yield in comparison to actual chemical methods to develop efficient Pt/rGO catalyst with Pt content close to state-of-the-art commercial composition. The structure and composition of prepared samples have been studied by specific techniques, while the electrocatalytic stability has been studied using ex-situ and in-situ measurements. High performance and electrochemically stable catalyst for PEM fuel cells was developed using the sample with highest loading and good dispersion. The fabricated Pt-rGO-based MEA was investigated for durability under fuel starvation in comparison with commercial Pt/C-based MEA. The electrocatalytic activity was investigated and the electrochemical response revealed the higher stability during accelerated degradation test under fuel starvation in comparison with commercial Pt/C. This study promotes the applicability of described preparation method to noble or transition metal nanoparticles embedded on graphene-based materials.

In this review are presented 31 hybrid power systems with their energy sources, the used strategy and the main objectives. This paper’s main objective is to highlight the most used strategy for specific systems. The most of the systems are using as main source of energy the fuel cell, photovoltaic panels and wind turbines. The most common strategies are the optimization strategy, the fuzzy logic and the power administration. All the systems are built to provide improved results, respectively better performance, optimal power, extended the renewable grid in the remote area, reduced costs, increased components lifetime, size optimization and so on. The bibliometric maps are highlighting the most important components in the system optimization: “optimization”, “energy management strategy”, “electrolyzer”, “performance”, “system”, “power”, “fuel cell”, “energy”, “strategy”, “cost”, “algorithm”, “solar PV”, “grid”, “battery”, etc. All the selected items are positioned in specific clusters determinate on the co-occurrence process identified in VOSviewer and the number of occurrences, links and the total link strength are mentioned. In conclusion for every system the energy management strategy has to be selected accordingly with the energy source, main objective, geographical positioning and available space.

With the development of technologies in recent decades and the imposition of international standards to reduce greenhouse gas emissions, car manufacturers have turned their attention to new technologies related to electric/hybrid vehicles and electric fuel cell vehicles. This paper focuses on electric fuel cell vehicles, which optimally combine the fuel cell system with hybrid energy storage systems, represented by batteries and ultracapacitors, to meet the dynamic power demand required by the electric motor and auxiliary systems. This paper compares the latest proposed topologies for fuel cell electric vehicles and reveals the new technologies and DC/DC converters involved to generate up-to-date information for researchers and developers interested in this specialized field. From a software point of view, the latest energy management strategies are analyzed and compared with the reference strategies, taking into account performance indicators such as energy efficiency, hydrogen consumption and degradation of the subsystems involved, which is the main challenge for car developers. The advantages and disadvantages of three types of strategies (rule-based strategies, optimization-based strategies and learning-based strategies) are discussed. Thus, future software developers can focus on new control algorithms in the area of artificial intelligence developed to meet the challenges posed by new technologies for autonomous vehicles.

In this paper, the Fueling Optimization (FO) Strategies based on the Power Tracking Control (PTC) required on DC bus from the Fuel Cell (FC) Systems is reviewed. Specific performance indicators are defined to show that a FO strategy is part of a defined class and that they are all part of the PTC-based strategy class. In addition, a linear relationship will be specifically determined between the load demand and the fuel consumption using a FO strategy.

The chapter provides a general overview on the Finite Volume MethodFinite Volume Method (FVM) and on Computational Fluid DynamicComputational Fluid Dynamic (CFD). It introduces the FVM by using a general scalar transport equation and it describes the main steps of a CFD investigation. All these are applied to the mass, momentum, species, energy and potential conservation equations, equations that govern the operation of Proton Exchange Membrane (PEM) fuel cells. The importance of spatial discretizationSpatial discretization and of interpolation schemesInterpolation schemes used in CFD investigations is point out by analysing few parameters with impact on the fuel cellFuel cell operation. Two cases have been considered. First case based on a fuel cell with a simplified configuration, namely a single serpentine channel, revealed the influence of spatial discretization on the accuracy of the simulation results with regards to current density, pressure and temperature. The second case based on a lab-scale fuel cell with two configurations for channels (7 serpentine and 7 parallel) have been used to analyse the effect of three interpolation schemes (first order, second order, QUICK) on the PEM fuel cell operation; therefore, pressure, hydrogen and water mass fraction profiles were considered for comparison. It was found out that besides the differences in the results accuracy due to spatial discretization and interpolation schemes, the design/geometry used in the CFD investigation may or may not emphasize these differences. If for the 7-serpentine channels fuel cell the interpolation scheme did not show much changes in the accuracy of the results not the same conclusion was drawn for the 7-parallel channels fuel cell where the accuracy of the results improved with increasing the order of the interpolation scheme. A mesh-independent solution on a well-posed problem will provide valuable and accurate results only if the numerical methods are appropriate and the interpolation schemes are of high order. The modeling of fuel cells using CFD techniques, as of any other device, can be an important alternative to the experiment, providing information that is critical to design, operation and optimization, the requirement being to use appropriate model, assumptions and boundary conditions and, of course, an adequate numerical method.

Various flow field designs have been numerically investigated to evaluate the effect of pattern and the cross-sectional dimensions of the channel on the performance of a large active area PEM fuel cell. Three types of multiple-serpentine channels (7-channels, 11 channels and 14-channels) have been chosen for the 200 cm2 fuel cell investigated and numerically analysed by varying the width and the land of the channel. The CFD simulations showed that as the channel width decreases, as in the 14-channels serpentine case, the performance improves, especially at high current densities where the concentration losses are dominant. The optimum configuration, i.e. the 14-channels serpentine, has been manufactured and tested experimentally and a very good agreement between the experimental and modelling data was achieved. 4 channel depths have been considered (0.25, 0.4, 0.6 and 0.8 mm) in the CFD study to determine the effects on the pressure drop and water content. Up to 7% increase in the maximum reported current density has been achieved for the smallest depth and this due to the better removal of excess liquid water and better humidification of the membrane. Also, the influence of the air flow rate has been evaluated; the current density at 0.6 V increased by around 25% when air flow rate was increased 4 times; this is attributed to better removal of excess liquid water. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this paper the fuel consumption of the Fuel Cell (FC) Systems using Fueling Optimization (FO) Strategies based on the Power Tracking Control (PTC) is reviewed. The objective is to find for each PTC-FO strategy a linear relationship between the fuel consumption and load. Finally, a generic linear relationship has been proposed for all PCT-FO strategies to estimate the fuel consumption within the allowable errors. This feature implemented on board the FC vehicle will help the driver to choose the preferred hydrogen filling station and also available on the driving route, given the fuel left in the tank.