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Topic Review Peer Reviewed
Reactive Transport Processes in Proton Exchange Membrane Fuel Cells
Proton exchange membrane fuel cells are devices that directly convert chemical energy to electricity. A hydrogen oxidation reaction takes place on the anode side, generating protons and electrons. In the cathode, oxygen reduction reaction involving oxygen, proton and electron occurs, producing water and heat. The water content in PEMFCs should be maintained at a reasonable amount to avoid water flooding or membrane dehydration. The thermal management and water management of PEMFCs are important for an efficient and stable operation of PEMFCs. Inside the multiscale spaces of PEMFCs, multiphase flow with a phase change, heat and mass transfer, proton and electron conduction, and electrochemical reaction simultaneously take place, which play important roles in the performance, lifetime and cost of PEMFCs. These processes should be well understood for better designing PEMFCs and improving the thermal management and water management.
  • 1.3K
  • 13 May 2025
Topic Review Video
Cryogenic Treatments in Energy Sector
Cryogenic treatment (CT) is one of the possible solutions for an environmentally friendly, sustainable, and cost-effective technology for tailoring the properties of different metallic materials.
  • 1.3K
  • 01 Nov 2023
Topic Review
Sustainable Energy Development
The global COVID-19 pandemic has had strong impacts on national and international freight, construction and tourism industry, supply chains, and has resulted in a rapid decline in the demand for traditional energy sources. In fact, research has outlined that urban areas depend on global supply chains for their day-to-day basic functions, including energy supplies, food and safe access to potable water. The disruption of global supply chains can leave many urban areas in a very vulnerable position, in which their citizens may struggle to obtain their basic supplies, as the COVID-19 crisis has recently shown. Therefore, solutions aiming to enhance local food, water and energy production systems, even in urban environments, have to be pursued. The COVID-19 crisis has also highlighted in the scientific community the problem of people’s exposure to outdoor and indoor pollution, confirmed as a key element for the increase both in the transmission and severity of the contagion, on top of involving health risks on their own. In this context, most nations are going to adopt new preferential policies to stimulate the development of relevant sustainable energy industries, based on the electrification of the systems supplied by renewable energy sources as confirmed by the International Energy Agency (IEA). Thus, while there is ongoing research focusing on a COVID 19 vaccine, there is also a need for researchers to work cooperatively on novel strategies for world economic recovery incorporating renewable energy policy, technology and management. In this framework, the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference provides a good platform for researchers and other experts to exchange their academic thoughts, promoting the development and improvements on the renewable energy technologies as well as their role in systems and in the transition towards sustainable energy systems. The 14th SDEWES Conference was held in Dubrovnik, Croatia. It brought together around 570 researchers from 55 countries in the field of sustainable development. The present Special Issue of Energies,
  • 1.3K
  • 02 Nov 2020
Topic Review
100% Renewable Energy: Concepts and Progresses
Some advanced countries’ rapid population, economic growth, and energy consumption expansion contribute significantly to global CO2 emissions. And while developed countries have achieved 100% universal access to electricity, mainly from non-renewable sources, many developing countries still lack it. This presents challenges and opportunities for achieving the United Nations’ Sustainable Development Goals (SDGs) 7 and 13 of generating all energy from cleaner or low-carbon sources to reduce CO2 emissions in all countries and combating climate change consequences. Renewable energies have been widely acknowledged to greatly advance this endeavour, resulting in many studies and about 30 countries already with over 70% of their national electricity mix from RE. It has birthed a new paradigm and an emerging field of 100% RE for all purposes, receiving much attention from academia and in public discourse. 
  • 1.3K
  • 20 Sep 2023
Topic Review
Biodiesel Sector
As Earth’s fossil energy resources are limited, there is a growing need for renewable resources such as biodiesel. That is the reason why the social, economic and environmental impacts of biofuels became an important research topic in the last decade. Depleted stocks of crude oil and the significant level of environmental pollution encourage researchers and professionals to seek and find solutions. The study aims to analyze the economic and sustainability issues of biodiesel production by a systematic literature review. During this process, 53 relevant studies were analyzed out of 13,069 identified articles. Every study agrees that there are several concerns about the first generation technology; however, further generations cannot be price-competitive at this moment due to the immature technology and high production costs. However, there are promising alternatives, such as wastewater-based microalgae with up to 70% oil content, fat, oils and grease (FOG), when production cost is below 799 USD/gallon, and municipal solid waste-volatile fatty acids technology, where the raw material is free. Proper management of the co-products (mainly glycerol) is essential, especially at the currently low petroleum prices (0.29 USD/L), which can only be handled by the biorefineries. Sustainability is sometimes translated as cost efficiency, but the complex interpretation is becoming more common. Common elements of sustainability are environmental and social, as well as economic, issues.
  • 1.3K
  • 18 Feb 2021
Topic Review
Thermochemical Recycling of Waste Tyres
Utilising pyrolysis as a waste tyre processing technology has various economic and social advantages, along with the fact that it is an effective conversion method. Despite extensive research and a notable likelihood of success, this technology has not yet seen implementation in industrial and commercial settings. In this review, over 100 recent publications are reviewed and summarised to give attention to the current state of global tyre waste management, pyrolysis technology, and plastic waste conversion into liquid fuel. The study also investigated the suitability of pyrolysis oil for use in diesel engines and provided the results on diesel engine performance and emission characteristics. Most studies show that discarded tyres can yield 40–60% liquid oil with a calorific value of more than 40 MJ/kg, indicating that they are appropriate for direct use as boiler and furnace fuel. It has a low cetane index, as well as high viscosity, density, and aromatic content. According to diesel engine performance and emission studies, the power output and combustion efficiency of tyre pyrolysis oil are equivalent to diesel fuel, but engine emissions (NOX, CO, CO, SOX, and HC) are significantly greater in most circumstances. These findings indicate that tyre pyrolysis oil is not suitable for direct use in commercial automobile engines, but it can be utilised as a fuel additive or combined with other fuels. 
  • 1.3K
  • 23 Jan 2022
Topic Review
Sustainable Transport in Poland
Road transport is one of the key elements of economic development that helps build social and territorial cohesion. The economic development that has taken place in Poland over the last three decades has led to an improvement in road infrastructure throughout the country. Construction of new roads and improvement of existing ones promotes economic development. However, as the number of cars increases, so does the level of air emissions. In reducing pollutant emissions, the analysis of the technological possibilities used and the improvement of their efficiency with the simultaneous minimization of generated pollution is also of particular importance. The purpose of the publication is to present development trends in road transport in Poland and the possibility of reducing emissions in this respect. The method of analysing strategic documents and statistical data was used to achieve this goal. Moreover, the article shows perspectives for reducing the level of emissions from road transport and refers to the assumptions related to the modernization of the transport sector and reducing its share in carbon emissions and its sustainable development in cities.
  • 1.3K
  • 23 Sep 2021
Topic Review
Tubular Reactor Technologies for Acceleration of Biodiesel Production
The need to arrest the continued environmental contamination and degradation associated with the consumption of fossil-based fuels has continued to serve as an impetus for the increased utilization of renewable fuels. The demand for biodiesel has continued to escalate in the past few decades due to urbanization, industrialization, and stringent government policies in favor of renewable fuels for diverse applications. One of the strategies for ensuring the intensification, commercialization, and increased utilization of biodiesel is the adaptation of reactor technologies, especially tubular reactors. 
  • 1.3K
  • 18 Aug 2022
Topic Review
Physics and Technology of ITER
Like many of its fission counterparts, a fusion reactor will employ light water (i.e., H2O) to transfer heat from the Tokamak (i.e., plasma) to a boiler to produce the steam that will then drive conventional steam turbines to produce electrical power. ITER (“the way” in Latin) is not designed to produce electricity on a commercial scale; instead, it is intended to demonstrate sustained plasma burn and hence the feasibility of fusion power. Like most fission reactors, it too will be cooled by light water. The water will spend a certain time in the plasma radiation zone, in which the water will be subjected to intense, high-energy n and γ ionizing radiation. In the tritium breeding blanket containing LiOH, α radiation and tritons will be produced via the reaction 6Li3(1n0, 4He2)3H1, and these high Linear Energy Transfer (LET) radiation forms must be included in the source term for the radiolytically-generated species.
  • 1.3K
  • 21 Sep 2022
Topic Review
Photocatalytic Desulfurization
Desulfurization of fuels such as diesel, gasoline, kerosene, and jet fuel has been a challenging operation and remains critical to the petrochemical industry. The main naturally occurring sulfur-containing organic compounds (SCCs) are sulfides, disulfides, mercaptans, thiophene (Th) and its derivatives (benzothiophene (BT), dibenzothiophenes (DBTs), 4-methylbenzothiophene (4-MBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), 3,7-dimethyldibenzothiophene (3,7-DMDBT), and 2,8-dimethyldibenzothiophene (2,8-DMDBT)). The presence of these SCCs in fuels is undesirable since they create problems during refining, namely deactivation of some catalysts and corrosion of equipment. Moreover, sulfur compounds release toxic SOx and cause severe environmental problems: water and air pollution, global warming, ecological instability, as well as the harmful impact on living organisms. Many countries (USA, European Union, Japan, China and so on) have introduced strict standards to limit the content of sulfur in fuels to 10 ppm.
  • 1.3K
  • 23 Sep 2022
Topic Review
Biodiesel
Biodiesel (mono alkyl esters) is the most attractive alternative fuel to diesel, with numerous environmental advantages over petroleum-based fuel. The most practicable method for converting triglycerides to biodiesel with viscosities comparable to diesel fuel is transesterification.
  • 1.3K
  • 28 Oct 2021
Topic Review
Low/Medium Voltage Direct Current Microgrids
Direct current (DC) microgrids (MG) constitute a research field that has gained great attention over the past few years, challenging the well-established dominance of their alternating current (AC) counterparts in Low Voltage (LV) (up to 1.5 kV) as well as Medium Voltage (MV) applications (up to 50 kV). 
  • 1.3K
  • 22 Sep 2021
Topic Review
Replacement of Incineration by Steam-Gasification
       High temperature processing of waste is usually performed by oxidation of the waste components with atmospheric oxygen. It may be aimed to recovery of energy or / and recovery of materials. We would like show that the atmospheric oxygen may be successfully replaced by steam in incineration of a fraction of MSW.
  • 1.3K
  • 12 Oct 2020
Topic Review
Fault Detection and Classification of Wind Turbines
Wind turbines are widely used worldwide to generate clean, renewable energy. The biggest issue with a wind turbine is reducing failures and downtime, which lowers costs associated with operations and maintenance. Wind turbines’ consistency and timely maintenance can enhance their performance and dependability.
  • 1.3K
  • 27 Sep 2022
Topic Review
Selecting Suitable Battery Technologies for Untethered Robots
Energy storage is one of the major barriers to achieve long-duration autonomy in robots. This entry evaluates the capabilities of relevant battery technologies, taking into consideration the requirements of different applications in robotics. We also discuss additional technologies that can be used to overcome the inherent limitations of the most common battery chemistries.
  • 1.3K
  • 10 Jul 2023
Topic Review
Wireless Power Transfer Systems (WPTSs)1
Wireless power transfer systems (WPTSs) are considered as a promising technology to increase the acceptance of electric vehicles (EVs) . Compared to conductive charging, WPTSs offer vehicle charging without user intervention. This means that no cable handling and plugging are required. Thus, WPTSs provide a low-maintenance charging technology for EVs with high comfort and safety.The working principle of WPTSs for electric vehicles is based on the electromagnetic interaction of an offboard ground pad module (GPM) and an onboard car pad module (CPM). The GPM typically comprises four main elements: a rectifier circuit, an inverter, a matching network and a transmitter coil. The CPM consists of a receiver coil, a matching network, a rectifier and, if necessary, a DC/DC converter. 
  • 1.3K
  • 08 Oct 2021
Topic Review
Subtractive Shading Envelope's Computational Workflow
This study proposes a voxel-based design approach based on the subtractive mechanism of shading envelopes and attributes information of point cloud data in tropical climates. In particular, the proposed method evaluates a volumetric sample of new buildings based on predefined shading performance criteria. With the support of geometric and radiometric information stored in point cloud such as position (XYZ), color (RGB), and reflection intensity (I), an integrated computational workflow between passive design strategy and 3D scanning technology is developed. It aims not only to compensate for some pertinent aspects of the current 3D site modelling such as vegetation and surrounding buildings but also to investigate surface characteristics of existing contexts such as visible sun vectors and material properties. These aspects are relevant for conducting a comprehensively environmental simulation while averting negative microclimatic impacts when locating the new building into the existing context. Ultimately, this study may support architects for taking decision-making in conceptual design stage based on the real contextual conditions.
  • 1.3K
  • 18 Aug 2020
Topic Review
Wave Energy Resource
Advanced assessment of the wave energy resource is fundamental to guarantee the implementation of energy converters in the marine environment, thus capturing the available power with maximum efficiency, reduced costs, and minimum environmental impacts. We review here the most recent resource characterizations encompassing a panel of approaches and techniques applied to available observations (in situ and satellite), hindcast and reanalysis archives, and refined numerical simulations specifically dedicated to wave power assessments. After a description of formulations adopted to characterize the wave energy flux, the review exhibits a series of energy metrics and selection indexes considered to refine the analysis. Benefits, limitations and potential of the different methods were discussed with respect to different applications in the most energetic locations around the world.
  • 1.3K
  • 24 Apr 2021
Topic Review
Operative Forecasting of Electric Energy Consumption
Balancing the production and consumption of electricity is an urgent task. Its implementation largely depends on the means and methods of planning electricity production. Forecasting is one of the planning tools since the availability of an accurate forecast is a mechanism for increasing the validity of management decisions. Both classical and modern forecasting methods have been identified when forecasting electric energy consumption. Classical forecasting methods are based on the theory of regression and statistical analysis (regression, autoregressive models); probabilistic forecasting methods and modern forecasting methods use classical and deep-machine-learning algorithms, rank analysis methodology, fuzzy set theory, singular spectral analysis, wavelet transformations, Gray models, etc. Operational forecasting is the research subject of many scientists; it touches upon the issues of operational management of the operating modes of power facilities.
  • 1.3K
  • 30 Nov 2022
Topic Review
Battery Life Prediction Methods Based on Electrochemical Models
Remaining useful life prediction is of great significance for battery safety and maintenance. The remaining useful life prediction method, based on a physical model, has wide applicability and high prediction accuracy, which is the research hotspot of the next generation battery life prediction method. An electrochemical model is a model built by simulating the electrochemical reaction process of a battery. It describes the laws of the cell from the point of view of internal physical and chemical processes including kinetic parameters, mass conversion processes, thermodynamic properties, mechanical, thermal, and electrical properties of materials.
  • 1.3K
  • 10 May 2023
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