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Findings on PEMFC designs grew tremendously in the past decade. Commercially, PEMFCs are usually configured in a stack to achieve higher electrochemical output. However, the two-phase fluid transport in a multiple-cell stack raises the complexity of reactant diffusion towards the porous electrodes than a single-cell stack as the higher current generation naturally increases water and heat production. Ensuring optimum hydration with even thermal distribution is critical in maintaining the MEA durability and overall electrochemical performance. Therefore, this review paper provides a comprehensive discussion of how the inconsistencies in water and thermal distribution impact the electrochemical reactiveness within the cell and electrode layers of a multiple-cell PEMFC stack. Targeting the bipolar plate design is not only essential for uniform fluid distribution but it can also be used to maximise the contact surface area to achieve a greater reactant consumption rate. Hence, the effect of varying manifold, flow field and distribution zone designs towardthe fluid and reaction dynamics per cell of a multiple-cell stack were discussed based on available literature. Although the difference in water and heat saturation between single- and multiple-cell stacks could be highlighted clearly in this paper, more research is needed particularly for novel bipolar plate designs. This would be essential knowledge in generating an optimal bipolar plate design that can enhance the durability and performance of PEMFC stacks. • Water and temperature dispersal in multiple-cell PEMFC stacks differ from single-cell units. • Cell dehydration causes higher performance loss in fuel cells compared to flooding. • The fluid dynamics and electrochemical responses across a single-cell stack differ from a multiple-cell stack. [ABSTRACT FROM AUTHOR]

Microfluidic fuel cell (MFC) is a burgeoning category of micro fuel cell technology based on laminar flow electrolytes. The merits of MFC, such as the absence of membrane electrolyte, flexible reactants selection, and high electrolyte conductivity, have been attracting researchers to explore this frontier area over the past two decades. However, realizing practical applications of MFCs remains a tremendous challenge. Many research works have been done to expedite research progress and obtain results reflecting inner mechanism via computational modeling and simulation, the general procedure of which is introduced in this paper. These studies primarily investigate the effects of various geometrical and operational parameters on diverse cell performance metrics, such as open-circuit voltage, current and power densities, and fuel utilization efficiency. However, contradictory outcomes and conclusions may arise due to disparities in the structural and parametric characteristics among different MFC models. In this regard, this review comprehensively summarizes prior computational modeling studies on MFC technology, with specific emphasis on different cell components including microchannels, inlets and outlets, electrodes, etc., as well as effects of different operational conditions encompassing electrolyte input, cell vibration, gas bubbling, and gravity. In addition, other related studies involving paper-based MFCs, cell stacking, and twin models are also introduced. Lastly, the future research perspective on MFC computational modeling is proposed, including potential structural innovations and modeling methods. This review paper shows the big puzzle of MFC modeling, the missing part of which is worthy of further study in the future. [Display omitted] • A comprehensive review on microfluidic fuel cell modeling is presented. • Governing equations and modeling method for microfluidic fuel cell are introduced. • Studies on different cell configurations and operational conditions are introduced. • Studies on paper-based fuel cell, fuel cell stack and twin model are also presented. • Future research directions for microfluidic fuel cell modeling are proposed finally. [ABSTRACT FROM AUTHOR]

This paper reviewed the recent research advances in the thermal management issues of Proton-Exchange-Membrane-Fuel-Cells (PEMFC) from design and control perspectives. Most of the current research on PEMFC thermal management have focused mainly on two main aspects; the cooling technology and stack cold start. However, PEM fuel cell thermal management involves many other issues such as effective heat-dissipation, temperature-distribution, temperature-control, and parasitic power, which are crucial in the process of thermal management research. The PEMFC temperature control has been weakly explored in the current review papers and thus, it has a potential research gap to be further studied in the area of PEMFC research. In addition, a review of the latest research in fuel cell technology is necessary due to its rapid development, especially with the increasing demand for fuel cell vehicles in recent years. In this paper, the PEMFC heat production, transfer and dissipation, and their related calculation equations are first reviewed. Then, the thermal management of PEMFC is reviewed from two perspectives: (i) the temperature-distribution characteristics inside the PEMFC and the influence of the structural parameters of each component on the heat dissipation and the uniformity of temperature distribution. (ii) The effects of different control strategies on stack temperature-control (Tst) with the evaluation of robustness of each controller. In addition, the coupling relationship between the fan and the pump in the cooling system and parasitic power studies are analyzed. Finally, according to the current research status of the PEMFC thermal management, the directions for further research are proposed. • PEMFC temperature control has been weakly explored in the current review papers • PEMFC heat production, transfer and dissipation with related equations are reviewed • PEMFC thermal management review is focused on temperature distribution and control • The coupling control between the fan and the pump in the cooling system is studied [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells offer a sustainable solution to electrical power generation and combined power and heat applications, even if they still encounter durability and reliability challenges. Prognostics and health management (PHM) is a promising solution to enhance the durability and reliability of fuel cell systems by providing information on fuel cell health status, predicting future performance, and prescribing optimal operational actions. Generally, the PHM technique can be divided into observation, analysis, and action phases. In this review, the state-of-the-art fuel cell PHM studies concerning the three phases of the PHM method are summarized. Hybrid fuel cell systems composed of single and multi-stack are investigated. The paper covers the main degradation mechanisms of fuel cell key components and existing durability datasets in the observation phase. The study of defining a proper health indicator and prediction of future health states of fuel cells, namely, prognostics are reviewed in the analysis phase. The outputs from the previous two phases are intended to be integrated into the action phase for optimizing the operational decisions that are responsible for achieving durable and reliable fuel cell systems. The objective of this review is three-fold: (1) to put together the existing studies of fuel cell durability and reliability-related studies into a PHM cycle and summarize the development status of each phase, (2) to identify the research gaps in existing PHM studies, and (3) to provide future perspectives for fuel cell PHM studies to achieve the ultimate goal of enhancing fuel cell system durability and reliability. [Display omitted] • Review of progress of prognostics and health management (PHM) for PEM fuel cells. • The observation, analysis, and action phases in PHM are examined with a focus on action phase. • Basic, deterioration-aware, and maintenance-based management strategies are investigated. • Perspectives on prognostics, deterioration-aware and maintenance-based EMSs. [ABSTRACT FROM AUTHOR]

Biomass gasification receives attention as a promising method to utilize biomass, a fuel which is carbon neutral. The producer gas/syngas which is an energy carrier obtained through this method finds use in engines, fuel cells, Fischer-Tropsch reactors, methanol synthesis and as an input for chemical industries, after the required quality levels for the above applications are achieved. To use the producer gas/syngas for power generation on a commercial scale, the required gas quality has to be established. Producer gas obtained from biomass gasification has several contaminants like particulate matter, tar and gaseous species like H 2 S, NH 3 . The contaminants present in the producer gas, depending upon their nature and the amount, pose issues to power generation systems. Tar, which is a mixture of varying molecular weight hydrocarbon molecules, generated from the thermo-chemical conversion processes of organic materials, could condense at low temperatures, and lead to clogging or blockage in end-use application devices, filters, and fuel lines. So, it is essential to reduce or transform the tar present in the producer gas to utilize the biomass gasification systems for power generation. This paper attempts to provide a critical assessment of tar generated during biomass gasification, covering the sundry aspects of formation, evaluation, issues and mitigation strategies. The paper gives an introduction to biomass gasification systems, followed by a detailed description of tar, including the definition and the chemistry of formation and destruction. An explanation of the various aspects of tar sampling, characterization and analysis, is presented next. The suitability of different tar analysis approaches is compared from an end-use device perspective. Then the multifarious issues posed by the presence of tar in the syngas on the end-use devices is discussed. The last part of the paper describes several tar mitigation strategies used by researchers. [ABSTRACT FROM AUTHOR]

Plasticisers have been widely used as additives in polymer applications, including pharmaceuticals, food processing, and electrochemical sensing, to improve the mechanical and physicochemical properties of the polymers. Recent developments using alternatives to the conventional phthalate ester plasticisers, such as water, ionic liquids (ILs) and deep eutectic solvents (DES), have opened new avenues for expanding plasticiser use into other potential areas such as ion exchange membranes. Owing to the unique properties of plasticisers that promote a higher amount of amorphous phase within the intermolecular structural of the polymer, combinations of plasticisers and polymers improve a polymeric film's ionic conductivity while maintaining film flexibility and thermal stability. Hence, this review paper intends to provide an insight on the applications of conventional and alternative plasticisers in various areas, as well as to address the working mechanism of plasticisers within polymer films. Most importantly, this paper highlights recent developments incorporating plasticisers in proton exchange membranes and the future potential of these materials. The outlook presented here demonstrates that some of the challenges faced during the fabrication of ion exchange membranes, which are alternatives to Nafion membranes, can be overcome. [ABSTRACT FROM AUTHOR]

Fuel cell technology can be traced back to 1839 when British scientist Sir William Grove discovered that it was possible to generate electricity by the reaction between hydrogen and oxygen gases. However, fuel cell still cannot compete with internal combustion engines although they have many advantages including zero carbon emissions. Fossil fuels are cheaper and present very high volumetric energy densities compared with the hydrogen gas. Furthermore, hydrogen storage as a liquid is still a huge challenge. Another important disadvantage is the lifespan of the fuel cell because of their durability, reliability and maintainability. Prognostics is an emerging technology in sustainability of engineering systems through failure prevention, reliability assessment and remaining useful lifetime estimation. Prognostics and health monitoring can play a critical role in enhancing the durability, reliability and maintainability of the fuel cell system. This paper presents a review on the current state-of-the-art in prognostics and health monitoring of Proton Exchange Membrane Fuel Cell (PEMFC), aiming at identifying research and development opportunities in these fields. This paper also highlights the importance of incorporating prognostics and failure modes, mechanisms and effects analysis (FMMEA) in PEMFC to give them sustainable competitive advantage when compared with other non-clean energy solutions. [ABSTRACT FROM AUTHOR]

Since its first appearance in 2002, microfluidic fuel cell has received great attention in the past two decades, which is mainly targeted at its use in portable electronics. This micro fuel cell technology utilizes microfluidic flows as electrolyte instead of conventional polymer membranes. To date, various fuels have been utilized in it, such as vanadium species, hydrogen, hydrocarbons, hydrogen peroxide, borohydride and nitrogenous materials, each of which has its specific merits and demerits. To optimize its power output and fuel utilization, innovative cell structures and advanced catalysts have been continuously developed for different fuels, with remarkable improvements achieved. The power output can be elevated from several mW cm−2 to several W cm−2 at room temperature, while the fuel utilization per single pass can reach 100% by using 3D flow-through electrodes. Also, investigations in recent years have shown that microfluidic fuel cell stacking increases the working voltage. In addition to cells with plastic channel, novel cell designs based on cellulose paper and fabric materials have also been proposed; apart from being lightweight, they are also free from pumping. These innovative cell designs represent a promising route for achieving real applications in areas such as medical diagnostic, wearable healthcare and smart logistics. As for the conventional plastic cells, they are currently less competitive against batteries and other fuel cells because of the extra pumping requirement, which should be resolved in future by developing passive pumps instead. Alternatively, they can be applied in specific circumstances where the extra pumping loss is tolerable. • Microfluidic fuel cells with different types of fuels are summarized and compared. • Various flow configurations and electrode structures are reviewed in detail. • Stacking efficiency is compared among different microfluidic fuel cell stacks. • Paper-based and fabric-based microfluidic fuel cells without pumping are introduced. • An outlook on their future development and application is provided. [ABSTRACT FROM AUTHOR]

Emerging issues on fuel price and greenhouse gas emissions have attracted attention on the alternative energy sources, especially in transportation sector. The transportation sector accounts for 40% of total fuel consumption. Thus, an increasing number of studies have been conducted on hybrid electric vehicles (HEVs) and their energy management system (EMS). This paper focuses on reviews of EMSs for fuel cell (FC) based HEV in combination with battery and super-capacitor, respectively. Various aspects and classifications of fuel cell–HEV EMS are explained in this paper. Different types of FC–HEV control models and algorithms derived from simulation and experiment are explained in details for an analytical justification for the most optimal control strategy. The performances of the various combinations of FC–HEV system are summarized in the table along with relevant references. This paper provides comprehensive survey of FC–HEV on their source combination, models, energy management system (EMS) etc. developed by various researchers. From the rigorous review, it is observed that the existing technologies more or less are capable to perform well; however, the reliability and the intelligent systems are still not up to the mark. Accordingly, current issues and challenges on the FC–HEV technologies are highlighted with a brief suggestions and discussion for the progress of future FC–HEV vehicle research. This review will hopefully lead to increasing efforts towards the development of economic, longer lifetime, hydrogen viable, efficient electronic interface and well performed EMS for future FC–HEV. [ABSTRACT FROM AUTHOR]

Fuel cells convert the chemical energy of fuels directly into electricity. They are not limited by the Carnot efficiency granting theoretical efficiency of up to 100% as per Gibbs free energy and enthalpy of formation ratio. Direct carbon fuel cells (DCFCs) electrochemically convert the chemical energy of solid carbon-rich fuels directly into electricity with efficiencies approaching 90%. Once coupled with a high-grade solid carbon-producing solar methane cracking reactor, DCFCs would essentially produce a pure CO 2 flue stream that is nearly capture-ready. Unlike most fuel cell types that employ gaseous fuels, DCFCs can utilize high-grade carbon derived from solar methane cracking reactors, allowing for nearly complete fuel utilization with the entropy change. Thus the reversible heat of the cell reaction is practically zero eliminating the need for cooling and heating in steady-state operation. Therefore, they have the potential to leapfrog the technical evolution process towards achieving clean power generation with dramatically higher efficiencies and lower emissions by producing a nearly pure CO 2 flue stream that is practically capture-ready. However, despite their advantages, DCFCs experience a complication with respect to solid carbon fuel impurities and ash content of the feedstock. This paper provides a concise overview of recent advances in DCFC technology and elaborates on the potential of high-grade carbon produced from solar methane cracking for use as a fuel in DCFCs. The paper demonstrates a promising system coupling DCFCs with solar methane cracking reactors and lays out the challenges of the proposed system, including carbon agglomeration, deposition, and solar reactor clogging problems. • Review of recent advances in DCFCs. • Discussion of the potential of solar thermally produced carbon for use in DCFCs. • Review of the production of carbon black via solar methane cracking. • A new cleaning mechanism to reduce carbon deposition and clogging. • A novel hybrid DCFC-solar methane cracking system for clean power generation. [ABSTRACT FROM AUTHOR]

This paper presents a novel comparative study on fuel cells (FCs) technologies, its modeling and effect of important parameters on the performance of various types of fuel cells and power management schemes. Firstly, this paper presents a comprehensive review of various FCs technologies with their working principle, efficiency, operating parameters, advantages/disadvantages and applications. Secondly, the mathematical analysis of various FCs has been investigated, which is required for MATLAB simulation of FCs. The influences of various operating parameters such as temperature, reactant flow pressure and membrane resistance are considered to investigate the dynamic behavior of FCs. Thirdly, various control schemes of power management e.g., current, voltage, power and reactants flow pressure based control schemes are proposed with simple and easy to implement PI controller for a phosphoric acid fuel cell (PAFC) operation in this paper. These control mechanisms can be utilized for power management schemes. The proposed model of PAFC along with these control schemes is realized in the MATLAB/Simulink environment. The performance of a PAFC system along with these proposed control is found to be satisfactory even under dynamic conditions. The study can be broadly helpful to select and set the various parameters for the development of a FC based application. [ABSTRACT FROM AUTHOR]

DC microgrids have recently attracted research interest. A DC microgrid is composed of different dispatchable and non-dispatchable power generators and energy buffers, such as fuel cells and ultracapacitors, which are employed to provide the steady-state and transient power demanded by the load. To interface these generation resources to a common DC bus-bar, different configurations of power electronic converters have been proposed in the literature. For the fuel cell, a unidirectional DC–DC converter is utilised, for the ultracapacitor, however, a bidirectional DC–DC converter is needed to maintain the state-of-the-charge of the ultracapacitor. The overall efficiency of the microgrid will depend on the efficiency of these converters. High efficiency and low cost converters are very important to obtain a cost-effective solution. In addition, the power electronics converters must be chosen in respect to the characteristics of these generation resources. In this regard, this paper introduces an overview on different of DC–DC converter topologies and investigates their applicability for fuel cell and ultracapacitor electricity generators based on the electrical output characteristics of these resources. Thus, the fuel cell and ultracapacitor characteristics and properties are presented in this paper. A number of configurations that can be employed to interface the ultracapacitor with the fuel cell generator forming part of a DC bus microgrid are also presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper provides a comprehensive review of fuel cell science and engineering with a focus on hydrogen fuel cells. The paper provides a concise, up-to-date review of fuel cell fundamentals; history; competing technologies; types; advantages and challenges; portable, stationary, and transportation applications and markets; current status of research-and-development; future targets; design levels; thermodynamic and electrochemical principles; system evaluation factors; and prospects and outlook. The most current data from industry and academia have been used with the relation between fuel cell fundamentals and applications highlighted throughout the manuscript. [Copyright &y& Elsevier]

Abstract: Ionic liquids (ILs) and deep eutectic solvents (DESs) have been applied in various fields such as electrolytes for lithium ion batteries, electrodeposition, electropolishing and even in fuel cells. ILs and molten salts have found some applications in redox flow batteries (RFBs) in the past and recently some metal ion based ILs have been proposed and used by Sandia National Laboratories. In addition, only two papers have very recently reported on the application of DESs for the same. This review gives an overview on DESs and discusses the possibility of employing them in RFBs for renewable energy storage and utility-scale load leveling applications. Commencing with a discussion on energy storage technologies and the RFB, this paper goes on to provide an account on ILs and DESs as well as their applications in electrochemistry and energy conversion. A succinct discussion on the results of Sandia National Laboratories on using ILs as electrolytes for RFBs is provided building onto the feasibility of replacing ILs with DESs in the near future (based upon recent publications on the topic). [Copyright &y& Elsevier]

Abstract: Fuel cells were an important technology that could be used for a variety of power applications. The direct methanol fuel cell (DMFC) was a promising candidate for powering portable electronic devices such as laptops, digital cameras and cell phones. Compared with conventional batteries, DMFCs could provide a higher power density with a longer lifetime and almost instant recharging. However, many issues related to the design, fabrication and operation of miniaturised DMFC power systems remain unsolved. Fuel delivery was a key issue in determining the performance of a DMFC. To achieve the desired performance, an efficient fuel delivery system was required to provide an adequate amount of fuel for consumption and to remove the carbon dioxide generated in the fuel-cell devices. This paper presented a detailed description of various fuel flow-field designs for DMFCs and their respective advantages. This paper also discussed the current approaches and challenges in existing fuel delivery and fuel storage systems, including active and passive DMFCs and micro-fluidic systems. The commercialisation of DMFCs with storage was presented. [Copyright &y& Elsevier]

Abstract: It has become imperative for the power and energy engineers to look out for the renewable energy sources such as sun, wind, geothermal, ocean and biomass as sustainable, cost-effective and environment friendly alternatives for conventional energy sources. However, the non-availability of these renewable energy resources all the time throughout the year has led to research in the area of hybrid renewable energy systems. In the past few years, a lot of research has taken place in the design, optimization, operation and control of the renewable hybrid energy systems. It is indeed evident that this area is still emerging and vast in scope. The main aim of this paper is to review the research on the unit sizing, optimization, energy management and modeling of the hybrid renewable energy system components. Developments in research on modeling of hybrid energy resources (PV systems), backup energy systems (Fuel Cell, Battery, Ultra-capacitor, Diesel Generator), power conditioning units (MPPT converters, Buck/Boost converters, Battery chargers) and techniques for energy flow management have been discussed in detail. In this paper, an attempt has been made to present a comprehensive review of the research in this area in the past one decade. [Copyright &y& Elsevier]

Abstract: Even though direct methanol fuel cells (DMFCs) were developed to support power needs, there are still unresolved drawbacks. The main focus of this research is the membrane electrode assembly (MEA), which is the most important component of the fuel cell. The MEA consists of a combination of the diffusion layer, the electrode layer and a membrane. Several obstacles may interfere with the functioning of the MEA, including its relatively low anode electro-catalytic activity, methanol crossover and mass transport. In this paper, an overview of the layer and engineering challenges associated with the MEA will be presented in detail. This paper will also discuss the materials while focusing on the current problems, structure layers, morphologies and fabrication methods of MEAs in DMFCs. [Copyright &y& Elsevier]

Abstract: Fuel cells generate electricity and heat during electrochemical reaction which happens between the oxygen and hydrogen to form the water. Fuel cell technology is a promising way to provide energy for rural areas where there is no access to the public grid or where there is a huge cost of wiring and transferring electricity. In addition, applications with essential secure electrical energy requirement such as uninterruptible power supplies (UPS), power generation stations and distributed systems can employ fuel cells as their source of energy. The current paper includes a comparative study of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells. In addition, techno-economic features of hydrogen fuel cell vehicles (FCV) and internal combustion engine vehicles (ICEV) are compared. The results indicate that fuel cell systems have simple design, high reliability, noiseless operation, high efficiency and less environmental impact. The aim of this paper is to serve as a convenient reference for fuel cell power generation reviews. [Copyright &y& Elsevier]

Abstract The world energy consumption is greatly influenced by the aviation industry with a total energy consumption ranging between 2.5% and 5%. Currently, liquid fossil fuel, which releases various types of Greenhouse Gas (GHG) emissions, is the main fuel in the aviation industry. As the aviation industry grows rapidly to meet the requirements of the increased world population, the demand for environmentally friendly power technology for various applications in the aviation sector has been increased sharply in recent years. Among the various clean power sources, energy obtained from hydrogen is considered the future for energy generation in the aviation industry due to its cleanness and abundance. This paper aims to give an overview of the potential aviation applications where hydrogen and fuel cell technology can be used. Also, the major challenges that limit the wide adoption of hydrogen technology in aviation are highlighted and future research prospects are identified. Highlights • The use of hydrogen as a propulsion fuel in the aviation industry is reviewed. • Hydrogen production and storage technologies are explored. • The various aerospace and aviation applications of fuel cell technology are identified. • The major challenges that limit the wide adoption of hydrogen technology in the aviation sector are discussed. [ABSTRACT FROM AUTHOR]

Abstract The increasing cost of fossil fuels and the need to reduce harmful emissions have been the main motivations in seeking more efficient and environmentally-friendly methods of power and heat generation. In this paper a comprehensive review of fuel cell-based micro-combined-heat-and-power systems is presented. The aim is to present all past findings and also show the recent progress of the technology, aiming at presenting current trends, limitations and perspectives for future planning and development. The configuration details of a basic system are given, with emphasis on the different fuel cell types, fuel processing methods, heat management and component integration options. Also further integration options are given, including energy storage, refrigeration cycles, micro-gas turbines, and renewable energy sources. System operation is distinguished between operating mode and operating strategy. Different modeling approaches are given, such as: steady-state and dynamic modeling, optimization methods, feasibility studies, and emission studies. A summary of the experimental activities are provided, including system characterization and degradation studies. Also a summary of the recent progress in commercialization activities of the technology is given. Finally, a critical review of the technology is provided, with a discussion on scenarios and future prospects. Highlights • A review of fuel cell-based micro-combined-heat-and-power technology is presented. • Past findings, recent progress, current trends, and bottlenecks are analyzed. • All proposed configuration details of basic and advanced systems are given. • Developed models with key findings, and experimental activities are provided. • Recent commercialization activities and future prospects are discussed. [ABSTRACT FROM AUTHOR]

Abstract: It is a well known fact that eight countries have 81% of all world crude oil reserves, six countries have 70% of all natural gas reserves and eight countries have 89% of all coal reserves. Energy is central to achieving the interrelated economic, social, and environmental aims of sustainable human development. But if we are to realise this important goal, the kinds of energy we produce and the ways we use them will have to change. Otherwise, environmental damage will accelerate, inequity will increase, and global economic growth will be jeopardised. Energy produced and used in ways that support human development in all its social, economic and environmental dimensions is what is meant by sustainable energy. The generation of energy by clean, efficient and environmental-friendly means is now one of the major challenges for engineers and scientists. This paper reviews a proposed energy-related solution to global warming, air pollution mortality, and energy security. It discusses recent topics related directly to energy production such as fuel cells (FCs) which represent a promising clean and efficient energy conversion technology. The paper also focuses on those technologies which, in terms of cost, cleanliness, reliability and availability, have the potential to compete with conventional energy conversion systems and to reach commercialisation phase before 2015. [Copyright &y& Elsevier]

Abstract: The whole world is now concentrating on advancing their pool of renewable energy resources. Immense growth has happened in the field of renewable energy and the energy harvesting methods in the past decade. It is estimated that there is still a huge potential of growth remaining in the field of renewable energy resources in the coming years. Generation of renewable energy at the source end to the transmission of the energy to the utility end is done at various interstates coupled with power electronic equipments and systems. Applications of power electronics are expanding at a high pace in industrial power generation, utility, grid integration, and transmission environments due to the advancements in technology and reduction in cost and size of the components and systems. There are numerous multistage converters and inverters topologies being developed for processing and delivering the gigawatt level of renewable power being produced. This paper highlights the growth of power electronics starting from semiconductor type switching devices to various multistage topologies which will extensively contribute to the development and growth of renewable energy resources around the globe. It is a fact that power electronics is an integral part of renewable energy generation and utilization and its optimization of size, cost, and performance is necessary for the most efficient harvesting. Latest advancements in the various ratings of switching devices and components are discussed in the paper. Proper topology based implementation of power electronics and motor drives in the generation of various renewable energy sources such as solar power, wind power, fuel cells, biomass, and other energy storage elements are discussed in details. Individual sources of renewable energy resources interfaced with multistages of power electronic systems are elaborated in the paper. [Copyright &y& Elsevier]

Abstract A hydrogen fuel cell has many advantages, such as no pollution, high efficiency, low noise and continuous operation. Therefore, it has the potential to be widely applied in both the power propulsion and power supply of a ship. However, the consequent hydrogen safety and leakage issues have attracted much attention and become key issues that need to be resolved urgently. In this paper, based on the component transportation and chemical reaction modules in Fluent software, a ferry is selected as the research object, and a diffusion model of the high pressure hydrogen leakage in a cabin is established. The hydrogen concentration distributions at different leakage positions after the leakage occurs are obtained by making transient numerical calculations of the hydrogen leakage diffusion at the corresponding leakage positions in the cabin. At the same time, the effects of different ventilation conditions on the diffusion trend of hydrogen are analyzed. The simulation results have ascertained the optimal positions for hydrogen sensors and ventilations and it is hoped that these results can provide guidance for the design of a fuel cell ship that uses high pressure gaseous hydrogen. Highlights • The safety of hydrogen fuel cell ship is researched by a CFD simulation. • The corners of fuel cell cabins are the areas with a higher concentration of hydrogen. • Reasonable ventilation is the most effective solution to hydrogen safety in cabin. [ABSTRACT FROM AUTHOR]

Abstract Fuel cells and solar energy are promising candidates for electricity generation. It is forecast that fuel cells and solar power systems will play an important role in reducing the greenhouse gas footprint and replacing fossil fuels. Therefore, the limitations of fuel cells and solar power systems, such as low efficiency, high cost, and low reliability, must be addressed appropriately to enable their full potentials. Metal foam is a new class of material that has gained immense attention due to its excellent properties suitable for a wide range of applications. Its unique characteristics distinguish it from typical solid metals. The properties of metal foam can be modified during the fabrication stage by manipulating its physical structure. The goal of this paper is to review the application of metal foam in fuel cells and solar power systems. Besides, the performance of metal foam in fuel cells and solar systems is also discussed. Metal foam has been applied to the electrodes, gas diffusion layer and flow field of fuel cells to enhance performance, especially in regard to current density and flow distribution. Furthermore, metal foam is a heat exchanger for the solar energy harvesting system to improve its efficiency. Superior performances in experimental testing allows the possibility of commercialization of metal foam products in the renewable energy field. Highlights • This article reviews the past research on metal foam in fuel cell and solar power systems. • Metal foam applications on bipolar plates, electrodes and the gas diffusion layer in a fuel cell. • Metal foam as a thermal management system in solar power systems. • Barriers and future perspectives of metal foam applications in fuel cells and solar power systems. [ABSTRACT FROM AUTHOR]

The widespread use of Proton Exchange Membrane fuel cell for its unique advantages compelled researchers for precise modelling of its characteristics. Since, modelling becomes extremely important for better understanding, simulation, design, analysis and development of high efficiency fuel cell system. However, due to its non-linearity, multivariate and strongly coupled characteristics; mathematical modelling based on empirical equations was widely adopted. But, the shortage of data, complexity in modelling, and number of unknown parameters favored the use of optimization methods. Many optimization methods have been endeavored to model Proton Exchange Membrane fuel cell characteristics. However, no prior attempt has been made to consolidate the contributions. Hence, this paper comprehensively describes and discusses the various Artificial Intelligence/bio inspired methods applied for fuel cell parameter estimation problem. The methods background theory and its application to the problem is elaborated. It is envisioned that, this review will be a one stop solution to the researchers and engineers working in the area of fuel cell systems. [ABSTRACT FROM AUTHOR]

Abstract: The issue of renewable energy is becoming significant due to increasing power demand, instability of the rising oil prices and environmental problems. Among the various renewable energy sources, fuel cell is gaining more popularity due to their higher efficiency, cleanliness and cost-effective supply of power demanded by the consumers. This paper presents a comprehensive review of different fuel cell technologies with their working principle, advantages, disadvantages and suitability of applications for residential/grid-connected system, transportation, industries and commercial applications. Development of mathematical model of fuel cell required for simulation study is discussed. This paper also focuses on the necessity of a suitable power-conditioning unit required to interface the fuel cell system with standalone/grid applications. [Copyright &y& Elsevier]

Proton exchange membrane (PEM) fuel cells are ideal power sources with great potential for automobiles, backup power systems and stationary applications, owing to high efficiency, zero emissions and high power density. For these devices with large power consumption, many unit cells are assembled in series to construct a stack to provide the required voltage and power. However, the assembly process remains a major obstacle to the large-scale deployment of high-power stack. The performance and durability of stacks are greatly affected by the assembly procedures, and the impact mechanism and assembly technique need to be fully understanding. This paper presents an overview of important issues related to the assembly process of fuel cell stacks, providing a basis for engineers and researchers to improve stack performance. It begins with a description of quality evaluation of the stack assembly, followed by assembly methods to clarify the history of the development of stack design. The main contributions to in-situ behavior of stack during the assembly compression and dynamic compression is presented in detail. Numerical methods and optimization techniques are analyzed to guide assembly process. Finally, novel stack designs involving the assembly process are sorted out. A summary of the key points in this area is also provided as a direction for future work. The aim of this paper is to evaluate which factors affect the cell performance during assembly process and how adverse effects should be mitigated via mechanism analysis, quality evaluation, assembly method selection, process optimization and novel stack structure design. • Optimization method should be proposed to balance eight quality evaluation metrics. • Stack adaptability and endplate integration are orientation of assembly methods. • Micro scale model should be improved with the consideration of GDL fiber structure. • Complete stack model combining material features and multiscale dimensions is lack. • Accumulated manufacturing errors cause uneven performance of unit cells. [ABSTRACT FROM AUTHOR]

Abstract: The distributed energy resources (DER) comprise several technologies, such as diesel engines, micro turbines, fuel cells, photovoltaic, small wind turbines, etc. The coordinated operation and control of DER together with controllable loads and storage devices, such as flywheels, energy capacitors and batteries are central to the concept of MicroGrid (MG). MG can operate interconnected to the main distribution grid, or in an islanded mode. This paper reviews the researches and studies on MG technology. The operation of MG and the MG in the market environment are also described in the paper. [Copyright &y& Elsevier]

Abstract: This paper provides a detailed review of renewably driven hydrogen systems and modeling approaches applicable to these systems that have been reported over the last two decades. Several renewable energy technologies, including solar photovoltaic, wind, and hydro, have been considered as the power source in these reports. Storage is an important aspect of hydrogen systems, and options for this are summarized here. Utilization systems include fuel cells as well as a variety of thermal uses. Some of the reported studies have addressed residential applications whereas others were related to commercial scale systems. This paper particularly emphasizes aspects of modeling of the various components for the renewable hydrogen system. Based on the literature on this area, conclusions are provided on the current understanding as well as future work related to this topic. [Copyright &y& Elsevier]

The rapidly depleting fossil fuels, as well as the devastating effects of climate change, have propelled the search for a cleaner and sustainable source of energy. Hydrogen fuel cells generate electricity without the need for combustion, producing only water and heat in the process. To be considered sustainable and a carbon-neutral source of energy, the following conditions must be met: 1) the fuel cells must be fed with hydrogen-rich fuel from renewables; 2) hydrogen production rates must be financially viable; and 3) hydrogen generation costs must be competitive with other sources of hydrogen. This paper provides an overview of the various methods of hydrogen production via biochemical reactions (biohydrogen). It also discusses the challenges encountered in biohydrogen production and offers some solutions to overcome such. The paper ends with a discussion of the potential market for biohydrogen in fuel cells. Finally, this article highlights the potential of biohydrogen as an alternative source for clean hydrogen, while emphasizing the areas that require more intensive research to make the hydrogen economy a viable reality. • Integration of two or more biohydrogen production systems can increase yield and efficiency. • The worldwide interest in hydrogen and hydrogen fuel cells is on the rise. • Biohydrogen is a promising alternative to clean hydrogen production apart from electrolyser-derived hydrogen. [ABSTRACT FROM AUTHOR]

Abstract: Proton exchange membrane fuel cells (PEMFCs) have recently passed the test or demonstration phase and have partially reached the commercialization stage due to the impressive worldwide research effort. Despite the currently promising achievements and the plausible prospects of PEMFCs, there are many challenges remaining that need to be overcome before PEMFCs can successfully and economically substitute for the various traditional energy systems. With the many promising research efforts in overcoming these challenges, the most important tools for the commercialization of PEMFCs will be the technical data and information from a real PEMFC application test. For these reasons, this paper introduces and discusses the remaining challenges and some of the latest research on the application test of PEMFC to real systems such as transportation, residential power generation and portable computers. In addition, this paper describes and summarizes the relative prospects and the competitive force of PEMFCs in these fields. These prospects primarily depend on stable and economical high-purity hydrogen supplies, the scale of application, the existence of more efficient competitive power sources and the social viewpoints such as the health and environment benefits as well as infrastructural aspects associated with traditional power supply and demand. The review shows that PEMFC have the most promising applications to buses, recreation vehicles, and lightweight vehicles. Without doubt, the technology for a stable supply of high-purity hydrogen along with the corresponding infrastructure is essential for the success of PEMFC in various application fields. [Copyright &y& Elsevier]

The growing need to alleviate the environmental impact of fossil fuels demands further technical growth in fuel cell hybrid electric vehicles (FCHEVs). Due to the dynamic nature of electrochemical power resources such as fuel cells (FCs) with auxiliary energy storage systems (ESSs), a variety of power management strategies (PMSs) have been widely developed and analysed for optimal power allocation. In this paper, a comprehensive review of various PMSs is systematically investigated for data acquisition and management regarding the search strategy. Within the data collected, the classification and the performance of PMSs are analysed to determine their characteristics and objectives for optimisation process. Additionally, a thorough examination of various PMSs employed in marine industry provides insights into the research trends and challenges associated with FC and battery hybrid systems and particularly ship propulsion systems. Furthermore, a system-level approach to PMS is explored, highlighting the importance of considering the correlation between component sizing and control as well as a health-conscious management that can enhance cost-effectiveness and life cycle of a FC and battery electric ferry applications. • A comprehensive review of power management system (PMS) in fuel cell electric vehicles. • Detailed analysis of PMS classifications and features. • A review and analysis of PMS in fuel cell ferry. • Discussion of current issues and potential research of PMS in ship propulsion system. [ABSTRACT FROM AUTHOR]

The generation of energy by clean, efficient and environmental-friendly means is now one of the major challenges for engineers and scientists. Fuel cells convert chemical energy of a fuel gas directly into electrical work, and are efficient and environmentally clean, since no combustion is required. Moreover, fuel cells have the potential for development to a sufficient size for applications for commercial electricity generation. This paper outlines the acute global population growth and the growing need and use of energy and its consequent environmental impacts. The existing or emerging fuel cells’ technologies are comprehensively discussed in this paper. In particular, attention is given to the design and operation of Solid Oxide Fuel Cells (SOFCs), noting the restrictions based on materials’ requirements and fuel specifications. Moreover, advantages of SOFCs with respect to the other fuel cell technologies are identified. This paper also reviews the limitations and the benefits of SOFCs in relationship with energy, environment and sustainable development. Few potential applications, as long-term potential actions for sustainable development, and the future of such devices are discussed. [Copyright &y& Elsevier]

In India, electricity use in rural areas accounts only 23% of national total usage. It is necessary to expand the access to electricity in Rural India for sustainable development. Biomass, a viable resource is the most direct and simple way at households and rural areas. Organic waste can be converted into an alternative source for cooking, heating and electricity. Biogas, a biofuel produced from organic waste (food scraps and animal waste) through Anaerobic Digestion. It is mainly composed of methane and carbon dioxide produced through Anaerobic Digestion in either large scale or small scale digesters. Traditionally, biogas has been used for cooking. Based on village level survey, electrical energy is the only commercial form of energy that has been used in villages. Biogas production paves the way to produce electricity at villages through high temperature fuel cell unit like Solid Oxide Fuel Cell; thus it is the best possible way to generate and utilize power close to where people live. The present paper discusses about the rural energy requirement, overview of biogas production and fuel cells, potential and operational challenges for biogas fed Solid oxide fuel cell, technical barriers with Solid oxide fuel cell and issues related to rural electrification using renewable energy. Also, a comparative analysis of SOFC with bio and thermo chemical conversion of biomass has been analyzed with a case study and reported. • Based on village level survey in a village at Dindigul Dt, Tamilnadu, India, electrical energy is the only commercial form of energy that has been used. • Biogas production paves the way to produce electricity at villages through high temperature fuel cell unit like Solid Oxide Fuel Cell; thus it is the best possible way to generate and utilize power close to where people live. • The present paper discusses about the rural energy requirement, potential and operational challenges for biogas fed Solid oxide fuel cell. • A comparative analysis of SOFC with bio and thermo chemical conversion of biomass has been analyzed with a case study and reported. [ABSTRACT FROM AUTHOR]

This paper aims to analyze the costs associated with the initial transition to the use of hydrogen as a fuel for road transportation in Spain from a double perspective: that of the investor in the required infrastructure, and that of the end-user who will have to pay for the fuel. To this end, different types of hydrogen refueling stations are taken into consideration, as are strategies for production and delivery of the gas. Scenarios of distributed production (at the actual hydrogen fueling stations) and centralized production (at medium or large-sized plants that produce hydrogen that is subsequently delivered to different fueling stations) are contemplated. Hydrogen production systems based on the reforming of fuels and also on the electrolysis of water are analyzed; renewable and non-renewable systems are compared. Lastly, the case of a Spanish city is analyzed from both perspectives. This analysis allows estimation of the magnitude of the gap between fuel cell road vehicles and gasoline vehicles in terms of fuel price for this country. [ABSTRACT FROM AUTHOR]

One of the most attractive routes for the production of hydrogen or syngas for use in fuel cell applications is the reforming and partial oxidation of hydrocarbons. The use of hydrocarbons in high temperature fuel cells is achieved through either external or internal reforming. Reforming and partial oxidation catalysis to convert hydrocarbons to hydrogen rich syngas plays an important role in fuel processing technology. The current research in the area of reforming and partial oxidation of methane, methanol and ethanol includes catalysts for reforming and oxidation, methods of catalyst synthesis, and the effective utilization of fuel for both external and internal reforming processes. In this paper the recent progress in these areas of research is reviewed along with the reforming of liquid hydrocarbons, from this an overview of the current best performing catalysts for the reforming and partial oxidizing of hydrocarbons for hydrogen production is summarized. [ABSTRACT FROM AUTHOR]

Nanotechnology is utilized well in the development and improvement of the performance in Solid Oxide Fuel Cells (SOFCs). The high operating temperature of SOFCs (700–900 °C) has resulted in serious demerits regarding their overall performance and durability. Therefore, the operating temperature has been reduced to an intermediate temperature range of approximately 400–700 °C which improved performance and, subsequently, commercialized SOFCs as portable power sources. However, at reduced temperature, challenges such as an increase in internal resistance of the fuel cell components arise. Although, this may not be as serious as problems encountered at high temperature, it still significantly affects the performance of SOFCs. This review paper addresses the work of researchers in the application of nanotechnology in fabricating SOFCs through distinct methods. These methods have successfully omitted or at least reduced the internal resistance and showed considerable improvement in power density of the SOFCs at reduced temperatures. [ABSTRACT FROM AUTHOR]

This paper gives a comprehensive insight into gas microturbine (GMT) as a part of microgeneration systems. The gas microturbine is a highly effective source that can operate on various types of fuel, including a low-percentage methane fuel such as biogas or landfill gas. The microturbine is widely used in an industrial, rural and commercial application that can benefit from combined heat and power production as a prime or backup source. A microgrid is a modern way to support decentralised power production. It can operate in off-grid mode or as a tool to stabilise the grid and help with peak-shaving as well as to supply remote areas with generated power. The combination of gas microturbine as a prime mover for the microgrid is a smart solution that can quickly react and implement renewable and new technologies. The GMT can be coupled with solar photovoltaics, wind turbine, fuel cells or combustion engines. Use of these technologies can create a sophisticated, stable and highly effective power system. Based on the findings, the combination of microgrid and gas microturbine is very viable and favourable in terms of efficiency, controllability, stability and variety of applications. This paper provides a survey in the field of gas microturbine, its operation, industrial applications, software for microturbine integration, microgrid operation, and coupling the microgrids with gas microturbines, as well as possible challenges and perspectives for this area of combined power generation. • Provides novel insight into the coupling of gas microturbine with microgrid for decentralised power generation. • New applications for gas microturbine in microgrids and the industry are described. • Gas microturbine proves to be an excellent source for microgrid operation with various possibilities in an application. [ABSTRACT FROM AUTHOR]

Fuel cell (FC) application in vehicular technology has gained much popularity since the past few years. Typically, fuel Cell Hybrid Electric Vehicle (FCHEV) consists of fuel cell, battery and/or ultracapacitor (UC) as the power sources. The power converter is integrated to the power sources to form the hybrid FC system. This helps to compensate the drawback of individual power sources. Apart from the technical efficiency of power sources itself, the performance of an FCHEV is governed by the efficiency of power electronics and associated controller. In this paper, a state-of-the-art of vehicle classification is reviewed, in which the focus is placed on the deployment of fuel cell, battery, ultracapacitor and flywheel. The configurations used in FCHEV, followed by the updated power converter topologies, are also discussed. The topologies are categorized and discussed according to the power stages and control techniques used in the configurations. Then, multiple stages conversion and single stage topologies are described chronologically. The advantages and disadvantages of each topology, safety standards, current situation and environmental impact of FCHEV are also discussed. In addition, the current development of FCHEV, challenges and future prospects are also elaborated. The rapid growth of FC based research and technology has paved great prospects for FCHEVs in the near future, with the prediction of the competitive cost of hydrogen as compared to gasoline. [ABSTRACT FROM AUTHOR]

This paper examines the benefits and potential of biogas generation and uses in India, with focus on advances made in hydrogen production by catalytic reforming technologies with steam, O 2 , and CO 2 as the oxidants. Utilization of biomass by means of generating biogas is one of the easiest and cost effective methods of harnessing renewable energy. As India is an agricultural country, a tremendous amount of biomass and livestock waste is generated every year. Likewise the large population of India generates much food and municipal solid waste that is not being utilized for biogas generation. Fuel cells are one of the effective means of utilizing biogas, although the synthesis gas or hydrogen generated from biogas can also be used in internal combustion engines. Higher efficiency of fuel cells (45%) compared to internal combustion engines (30%) and even higher with co-generation systems (70%) make them highly desirable for biogas utilization for power generation. Investigations of hydrogen productionfor fuel cell use are in their infancy stage in India. Apart from a few scattered investigations not much work has been undertaken in the area of research. Large scale hydrogen production is achieved by steam reforming of hydrocarbons, in particular natural gas. Although the process is a proven technology it has come under considerable scrutiny due to its environmental impact and the energy intensive nature of the process. Several technical and scientific challenges have to be overcome for assimilation of the technology for hydrogen production from biogas and wide scale application in India. These challenges include development of less energy intensive features, highly active and poisons-resistant catalyst, and fuel cell development for utilization of biogas generated hydrogen. [ABSTRACT FROM AUTHOR]

Electric vehicles require fuel cells with a highly specific energy for the purpose of environmental protection and energy saving. However, proton exchange membrane vehicle fuel cells (PEMFC) face problems in terms of energy conversion efficiency, power density, costs and lifespan. This paper reviews key technical issues regarding the application of vehicle PEMFC especially the integration of nano-electro-catalytic energy system with high-performance electrolyte membranes. It also discusses the relation between vehicle PEMFC membrane structures and electrode performance revealing the nanostructured system model and the membrane electrode interface characterization. Manipulation of vehicle PEMFC electrode structure and quantitative characterization of the nanoscale catalyst interface are summarized aiming at improving Pt utilization efficiency, ionic conductivity and nano membrane electrode performance. [ABSTRACT FROM AUTHOR]

Fuel cells directly convert chemical energy stored in fuels into electrical energy through electrochemical reactions and have been identified as one of the most promising technologies for the clean energy industry of the future. In recent years, fuel cells have been applied in the medical field in both exploratory research and prospective products, as they offer multiple advantages over conventional batteries, including ease of recharging, environmentally friendly character and high security. In this paper, we summarize the up to date progress of this energy system in implantable medical devices which use microorganisms, enzymes and precious metals as catalysts, respectively. Safety is the most concerned issue in this application. In addition, we introduce a variety of applications of fuel cells on the vitro medical equipments (such as blood glucose meter, alcohol tester, wound treatment instrument). The introduction of fuel cells on implementable medical devices is in early stage of research, nonetheless the prospects/potential of this application are grant. Evidently, mankind could come across a new medical revolution upon the successful introduction of fuel cells to the human body. [ABSTRACT FROM AUTHOR]

The “Hydrogen Office building (HO)” presents a wind–hydrogen energy system, located in Fife/Scotland, which has been set-up to demonstrate the role of hydrogen in reducing the impact of wind intermittency in a grid-tied microgrid. The main components of the system are a wind turbine, alkaline electrolyser, hydrogen storage and a PEM fuel cell. The building demand is met by the wind turbine, while the fuel cell provides back-up power to the ground floor when wind power is unable to meet the demand. Accurate modelling of wind–hydrogen systems allows their successful implementation and operation, however, most of the currently available simulation tools do not provide consistent methods to represent the dynamic behaviour of such systems which is essential for their precise design, control, performance optimisation and economic study. Previous research lacks global methodologies for a whole-system scope simulation. Moreover, experimental validation is missing in most of these models and no guidelines are given for parameter estimation, which are essential for replicability. This paper presents a comprehensive methodology for the modelling, simulation and performance evaluation of wind–hydrogen systems, while including experimental validation and guidelines for parameters estimation. The developed model encompasses usability, adaptability, dominant dynamics accuracy and reliability that makes it able to assess different systems prior and after their installation. The proposed model has succeeded to depict the HO dynamic behaviour accurately with an error of less than 2% in average. The model has also been successfully utilised to evaluate the HO system performance. Evaluation criteria includes: average energy production, stand-alone operation and round-trip efficiency among others. Quantitative analysis has showed how this methodology can contribute to improve the design and performance of such systems. [ABSTRACT FROM AUTHOR]

This paper reviews the present scenario of cooking fuel in India. Increasing demand of LPG and its impact on Indian economy has been discussed. In context to the current cooking fuel scenario in India, DME blended LPG has been recognized as a potential fuel substitute for LPG. To analyse the potential of DME as a fuel, the review compares its properties with those of propane, butane and natural gas that are relevant to combustion application. Current status of DME combustion research, related to combustion mechanism, laminar burning velocity and characteristics of premixed and diffused flames of DME has been reviewed in detail. Current status of DME–LPG blend performance has also been reviewed. Based on this current review, bio-DME has been identified as most suitable form of DME production for India. However, need for further optimization of DME–LPG blend ratio, development of reduced mechanism for DME–LPG oxidation, further study of DME diffusion flame and development of DME–LPG blend dedicated burner has been identified as major challenges towards making DME as a substitute blending fuel for LPG. [ABSTRACT FROM AUTHOR]

Fuel cell technology holds the combination of benefits, which are barely offered by any other energy generating technology. Because the fuel used in this technology is found in abundance in nature and can also be renewed/sustained. Pakistan is blessed with renewable energy resources which are suitable for fuel cell technology. Therefore, fuel cell technology offers a great opportunity to meet the demand of energy and for the sustainable development of Pakistan. The energy research group at COMSATS Institute of Information Technology (CIIT), Lahore has made efforts to study the technical aspects of fuel cell technology and its commercial benefits. The research group is interested in finding ways and means of generating and storing the energy produced by using fuel cells. In this paper, the research activities on fuel cell technology in Pakistan have been reviewed and it is also discussed how this technology can resolve the current energy crises in Pakistan and can be the source of sustainable energy. It has been also reviewed that the country would greatly benefit from fuel cells and fuel cell hybrid system (environmental friendly technology), which could be the best solution for electricity production as well for automobile industry. [ABSTRACT FROM AUTHOR]

The biorefinery concept provides a wide perspective of products and uses from the biomass conversion. The drive for cost reductions and the threat of food competition have put residual biomass under the spotlight. Sugarcane is the most produced crop in the world, and its residual bagasse has got the additional feature of abundance. Going beyond its traditional use for electricity and thermal generation, this paper explores the potential alternative uses for the sugarcane bagasse in Brazil. Under an Input-Output perspective, Brazilian production recipes are obtained for six distinct biorefining technologies assuming the use of sugarcane bagasse as feedstock. Also, minimum selling prices are derived for the main products of each technological route assessed, comprising an initial estimative of their cost prices in Brazil. The biomass to ethanol and higher alcohol route presented the higher share (25%) of productive and service sectors into its production recipe. The bioplatform succinic acid route was the only one reaching competitive minimum selling prices (0.57 US$/kg) in comparison to current pricing of the fossil-derived succinic acid. [ABSTRACT FROM AUTHOR]

The world is witnessing a change-over from its present centralized generation to a future with greater share of distributed generation. Hybrid energy systems are inter-connected with wind power, photovoltaic power, fuel cell and micro-turbine generator to generate power to local load and connecting to grid/micro-grids that decrease the dependence on fossil fuels. The hybrid system is a better option for construction of modern electrical grids that includes economic, environmental and social benefits. An overview of different distributed generation technologies has been presented. This paper puts forward a comprehensive review of optimal sizing, energy management, operating and control strategies and integration of different renewable energy sources to constitute a hybrid system. The feasibility of the different controllers such as microcontroller, proportional integral controller, hysteresis controller and fuzzy controller are presented. The controller is a closed loop feedback mechanism used for power regulation which achieves zero steady state error and the output signal generated from the controller produces desired output response. [ABSTRACT FROM AUTHOR]

In this paper, an autonomous isolated hybrid power system (IHPS) consisting of wind turbine generators (WTGs), diesel engine generators and an energy storage system (ESS) is considered. Due to the stochastic nature of wind, electric power generated by WTG is highly erratic and may affect power supply quality. ESSs may play an important role in controlling WTG’s power output and, therefore, enabling an increased penetration of WTG in IHPS. This article deals with several ESSs like flywheel energy storage system, battery energy storage system, superconducting magnetic energy storage (SMES), capacitive energy storage (CES) and fuel cell for IHPS application. All the tunable parameters of the studied IHPS model along with those of ESS are optimized by using quasi-oppositional harmony search algorithm and comparative simulation results between various ESSs application in IHPS model for frequency and power deviation are presented in terms of rise time, settling time and steady state error for sudden changes in load/generation or both. The performance analysis of the system with different ESSs has been also carried out with different performance indices. From the simulation results it is inferred in this study that SMES and CES based IHPS perform neck to neck and these two ESSs outperform the others while controlling both frequency and power deviations. [ABSTRACT FROM AUTHOR]

Fuel cell systems powered by bio-fuels such as ethanol are potential solutions to local, small scale electricity needs, especially in remote, off-grid locations. In recent years, many researchers around the world have studied the on-site autothermal reforming of ethanol to hydrogen, which can then be used in the fuel cell. However, a comprehensive review of those efforts has not been carried out. In this paper, a detailed literature review of experimental and numerical research is presented, with a focus on the catalysts, reactor design, and simulation and modelling efforts that sought to understand interactions among fluid flow, heat and mass transfer and chemical kinetics. Our review indicates that although considerable work has been carried out on the development of catalysts, relatively fewer studies report system level experiments and simulations that are necessary before these systems can be commercially deployed. Thereby, we also identify areas for further research in the area of ethanol autothtermal reforming. [ABSTRACT FROM AUTHOR]

This paper analyses the safe operation of a multi-stack Polymer Electrolyte Membrane Fuel Cell (PEMFC) under normal conditions and partial faults using an innovative power-sharing technique based on Load-Following (LF) control. LF control references are designed based on the power flow balance to track the dynamic load profile. These references control the power flow of DC-DC boost converters connected to PEMFC stacks, performing power sharing and output voltage restoration as a final result. The behavior of multi-stack FC architecture is presented in conditions of partial drying and flooding of PEMFCs. If the transitory faults are short, the controllability of the boost converters is ensured by LF control and multi-stack FC architecture continues to safety operate in degraded-operation mode. • Operation in flood or drying conditions of the Fuel Cell (FC) membrane is considered. • The power-sharing technique ensures FC system controllability under variable load. • A safer control strategy for multi-stack FC system using the load-following (LF) control. • LF control is effective for identical or different FC stacks as output power and voltage. [ABSTRACT FROM AUTHOR]