bluuebunny/crossref_metadata_2025 huggingface dataset:
A Unit Commitment Model Considering Feasibility of Operating Reserves under Stochastic Optimization Framework
Authors: Park Heejung
Published: August 2022

Grid integration of renewable resources such as solar and wind energy can significantly raise the level of uncertainty in power systems, making the scheduled operation of generating units difficult. Therefore, the importance of operating reserves is more emphasized to prevent disruption by sudden changes in outputs of generators. In this paper, a stochastic unit commitment (UC) model to reflect uncertainty due to a large amount of renewable resources is proposed, in which upward and downward operating reserves are deployed simultaneously, and feasibility of the reserves is examined to make the deployed reserves supplied reliably. Uncertain parameters considered in the model are wind power availability, solar direct normal irradiance, and electric load. Two-stage stochastic programming is applied to the mathematical formulation, where UC decisions including dispatch are modeled as non-anticipative variables at the first stage, and redispatch decisions to serve realized electric demand are made at the second stage as recourse. By solving the UC problem, feasible and reliable stochastic UC and dispatch solutions can be provided to power system operators.
Design of a Load Frequency Controller Based on an Optimal Neural Network
Authors: Al-Majidi Sadeq D. , Kh. AL-Nussairi Mohammed , Mohammed Ali Jasim , Dakhil Adel Manaa , Abbod Maysam F. , Al-Raweshidy Hamed S.
Published: August 2022

A load frequency controller (LFC) is a crucial part in the distribution of a power system network (PSN) to restore its frequency response when the load demand is changed rapidly. In this paper, an artificial neural network (ANN) technique is utilised to design the optimal LFC. However, the training of the optimal ANN model for a multi-area PSN is a major challenge due to its variations in the load demand. To address this challenge, a particle swarm optimization is used to distribute the nodes of a hidden layer and to optimise the initial neurons of the ANN model, resulting in obtaining the lower mean square error of the ANN model. Hence, the mean square error and the number of epochs of the ANN model are minimised to about 9.3886 × 10−8 and 25, respectively. To assess this proposal, a MATLAB/Simulink model of the PSN is developed for the single-area PSN and multi-area PSN. The results show that the LFC based on the optimal ANN is more effective for adjusting the frequency level and improves the power delivery of the multi-area PSN comparison with the single-area PSN. Moreover, it is the most reliable for avoiding the fault condition whilst achieving the lowest time multiplied absolute error about 3.45 s when compared with the conventional ANN and PID methods.
Air Pollution and Limitations in Health: Identification of Inequalities in the Burdens of the Economies of the “Old” and “New” EU
Authors: Jakubowska Agnieszka , Rabe Marcin
Published: August 2022

The aim of the present research is to assess the scale of the impact of air pollution on the level of burdening EU economies with the consequences of chronic diseases (non-communicable diseases—NCDs) in the context of limiting the potential productivity of human resources. This study attempts to identify inequalities in this area that occur in the territory of the European Union. The scale of the impact of environmental factors, and air pollution in particular, on the level of health limitations in the labor resources of EU countries was measured by the number of the years of healthy life lost (YLL and YLD) as a result of chronic diseases. The verification of the assumption of a persistently high level of dispersion was based on an analysis of the convergence process (β and σ) in the group of EU countries in 1990–2019. The results demonstrate that the level of health restrictions caused by air pollution is diverse in the group of EU-27 countries. The inequalities observed concern, in particular, the relationship between the old and the new EU, indicating a high burden of health consequences for the inhabitants of Central and Eastern Europe (EU-CEE).
Review on Innovative Piezoelectric Materials for Mechanical Energy Harvesting
Authors: Clementi Giacomo , Cottone Francesco , Di Michele Alessandro , Gammaitoni Luca , Mattarelli Maurizio , Perna Gabriele , López-Suárez Miquel , Baglio Salvatore , Trigona Carlo , Neri Igor
Published: August 2022

The huge number of electronic devices called the Internet of Things requires miniaturized, autonomous and ecologically sustainable power sources. A viable way to power these devices is by converting mechanical energy into electrical through electro-active materials. The most promising and widely used electro-active materials for mechanical energy harvesting are piezoelectric materials, where the main one used are toxic or not biocompatible. In this work, we focus our attention on biocompatible and sustainable piezoelectric materials for energy harvesting. The aim of this work is to facilitate and expedite the effort of selecting the best piezoelectric material for a specific mechanical energy harvesting application by comprehensively reviewing and presenting the latest progress in the field. We also identify and discuss the characteristic property of each material for each class to which the material belong to, in terms of piezoelectric constants and achievable power.
Stator Curvature Optimization and Analysis of Axial Hydraulic Vane Pumps
Authors: Sun Yongguo , Xue Dong , Liu Shisheng , Wu Jinghang , Bai Xingyu
Published: August 2022

Aiming at the problem of large vibration of a high-subside stator inner cavity curve vane pump, the force analysis of the vane at the transition curve is carried out, and the functional relationship between the vane turning angle θ, the large arc radius R, the small arc radius r and the sliding friction is established. The particle swarm algorithm is used to optimize the solution of the objective function, and the optimized parameter values are brought into the MATLAB simulation program to obtain the optimized stator curve profile diagram. The dynamic performance of the vane pump before and after optimization is simulated using ADAMS. The results show that: the acceleration of the vane pump slide is significantly reduced; the friction between the slide and the slide groove is significantly reduced; the contact force between the slide and the stator is significantly reduced; the impact vibration of the optimized vane pump is significantly reduced; and the dynamic performance of the vane pump is improved.
Optimization of Micro-CAES and TES Systems for Trigeneration
Authors: Congedo Paolo Maria , Baglivo Cristina , Panico Simone , Mazzeo Domenico , Matera Nicoletta
Published: August 2022

Energy storage makes energy continuously available, programmable, and at power levels different from the original intensity. This study investigates the feasibility of compressed-air energy storage (CAES) systems on a small scale. In addition to the CAES systems, there are two TES (thermal energy storage) systems for the recovery of calories and frigories. The micro-CAES + TES system is designed for a single-family residential building equipped with a photovoltaic system with a nominal power of 3 kW. The system is optimized as a potential alternative to battery storage for a typical domestic photovoltaic system. The multi-objective optimization analysis is carried out with the modeFRONTIER software. Once the best configuration of the micro-CAES + TES system is identified, it is compared with electrochemical storage systems, considering costs, durability, and performance. The efficiency of CAES (8.4%) is almost one-tenth of the efficiency of the most efficient batteries on the market (70–90%). Its discharge times are also extremely short. It is shown that the advantages offered by the application of mechanical accumulation on a small scale are mainly related to the exploitation of the thermal waste of the process and the estimated useful life compared to the batteries currently on the market. The studied system proves to be non-competitive compared to batteries because of its minimal efficiency and high cost.
Lithofacies Characteristics, Depositional Environment and Sequence Stratigraphic Framework in the Saline Lacustrine Basin-A Case Study of the Eocene Low Member of Xingouzui Formation, Jianghan Basin, China
Authors: Fan Xiaojie , Lu Yongchao , Zhang Jingyu , Wu Shiqiang , Zhang Liang , Du Xiaojuan , Cui Qinyu , Wang Hao
Published: August 2022

The Jianghan Basin is a lacustrine basin in central China developing multiple salt bearing deposits in the Eocene with the success of shale oil exploration in the Qianjiang Formation. The lower member of the Xingouzui Formation in the Chentuokou Depression has become another exploration target. However, rapid changes in lithofacies and strong sedimentary heterogeneity limit the exploration progress. This study aimed to explore the sequence division, lithofacies characteristics, and sedimentary environment using sedimentological, X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses. The sequence stratigraphic analysis indicates that the low member of the Xingouzui Formation is divided into two third-order sequences, namely SQ1 and SQ2, and four system tracts, including highstand systems tract (HST), lake expanding system tract (EST), early highstand system tract (EHST), and late highstand system tract (LHST). Moreover, a total of nine major lithofacies and five lithofacies associations (LA1-5) were identified. The organic geochemical data show that the laminated argillaceous dolomite in EST and EHST developed the best oil content with an average TOC of 1.18% and S1 of 3.18 mg/g, The laminated argillaceous dolomite deposited in anoxic conditions with a humid climate, moderate salinity, and stratified deep waterbody is a favorable exploration facies for shale oil.
Flexible Sandwich-Structured Foldable Triboelectric Nanogenerator Based on Paper Substrate for Eco-Friendly Electronic Devices
Authors: Kim Da Eun , Park Jiwon , Kim Youn Tae
Published: August 2022

Recently, as the use of wearable devices and the demand for eco-friendly energy have increased, many studies have been conducted on triboelectric nanogenerators (TENGs), which can economically harvest energy. Paper is considered a promising substrate and frame material that can be used to manufacture self-powered TENGs, owing to its flexibility, low cost, and accessibility. Herein, we present a sandwich-structured foldable paper-based TENG (FP-TENG) that comprises flexible materials and uses paper as a substrate. The FP-TENG can generate up to 572 mW/m2 of power via contact–separation of the triboelectric electrified body at the top and bottom. With more folds of the FP-TENG, the triboelectric cross-sectional area increases, and, thus, the electrical output increases. In addition, the proposed TENG exhibits excellent durability without signal degradation under 5000 cycles of repeated pushing motions. To demonstrate its practicality, the FP-TENG was manufactured in the form of a wristwatch Velcro and connected to an electronic watch panel to supply power. Various deformations are possible with origami, and they can drive wristwatches through external forces. Therefore, the FP-TENG is expected to be utilized as a sustainable and promising eco-friendly energy source for small electronic devices.
A Review on Popular Control Applications in Wind Energy Conversion System Based on Permanent Magnet Generator PMSG
Authors: Majout Btissam , El Alami Houda , Salime Hassna , Zine Laabidine Nada , El Mourabit Youness , Motahhir Saad , Bouderbala Manale , Karim Mohammed , Bossoufi Badre
Published: August 2022

There has always been a high expectation that wind generation systems would capture maximum power and integrate properly with the grid. Utilizing a wind generation system with increased management to meet the growing electricity demand is a clever way of accomplishing this. However, wind power generation systems require a sophisticated, unique, and dependable control mechanism in order to achieve stability and efficiency. To improve the operation of the wind energy conversion method, researchers are continually addressing the obstacles that presently exist. Therefore, it is necessary to know which control can improve the whole system’s performance and ensure its successful integration into the network, despite the variable conductions. This article examines wind turbine control system techniques and controller trends related to the permanent magnet synchronous generator. It presents an overview of the most popular control strategies that have been used to control the PMSG wind power conversion system. Among others, we mention nonlinear sliding mode, direct power, backstepping and predictive currents control. First, a description of each control is presented, followed by a simulation performed in the Matlab/Simulink environment to evaluate the performance of each control in terms of reference tracking, response time, stability and the quality of the signal delivered to the network under variable wind conditions. Finally, to get a clear idea of the effect of each control, this work was concluded with a comparative study of the four controls.
Preliminary Design and Blade Optimization of a Two-Stage Radial Outflow Turbine for a CO2 Power Cycle
Authors: Kim Jun-Seong , Kim You-Taek , Kim Do-Yeop
Published: August 2022

Recently, the CO2 power cycle has attracted attention because of tightening environmental regulations. The turbine is a factor that greatly affects the efficiency of the cycle. The radial outflow turbine is a turbomachine with the various advantages of an axial flow turbine and a radial inflow turbine, but the design theory for the turbine is uncertain. In this study, a preliminary design algorithm for a radial outflow turbine with a multi-stage configuration is presented. To verify the preliminary design algorithm, a preliminary design for a two-stage radial outflow turbine for a CO2 power cycle was carried out, and a computational fluid dynamic analysis was performed. Consequently, values close to the target performance were obtained, but blade optimization was performed to obtain more satisfactory results. The final geometry of the radial outflow turbine was obtained through optimization considering the blade exit angle related to the deviation angle, blade maximum thickness-true chord ratio, and incidence angle. In the final geometry, the error rates of power (W˙), efficiency (ηts), and pressure ratio (PRts) between target performance and computational fluid dynamic results were improved to 5.0%, 4.8%, and 1.8%, respectively. The performance and flow characteristics of the initial and final geometries were analyzed.
FedDP: A Privacy-Protecting Theft Detection Scheme in Smart Grids Using Federated Learning
Authors: Ashraf Muhammad , Waqas Muhammad , Abbas Ghulam , Baker Thar , Abbas Ziaul , Alasmary Hisham
Published: August 2022

In smart grids (SGs), the systematic utilization of consumer energy data while maintaining its privacy is of paramount importance. This research addresses this problem by energy theft detection while preserving the privacy of client data. In particular, this research identifies centralized models as more accurate in predicting energy theft in SGs but with no or significantly less data protection. Current research proposes a novel federated learning (FL) framework, namely FedDP, to tackle this issue. The proposed framework enables various clients to benefit from on-device prediction with very little communication overhead and to learn from the experience of other clients with the help of a central server (CS). Furthermore, for the accurate identification of energy theft, the use of a novel federated voting classifier (FVC) is proposed. FVC uses the majority voting-based consensus of traditional machine learning (ML) classifiers namely, random forests (RF), k-nearest neighbors (KNN), and bagging classifiers (BG). To the best of our knowledge, conventional ML classifiers have never been used in a federated manner for energy theft detection in SGs. Finally, substantial experiments are performed on the real-world energy consumption dataset. Results illustrate that the proposed model can accurately and efficiently detect energy theft in SGs while guaranteeing the security of client data.
A Common-Mode Voltage Suppression Strategy Based on Double Zero-Sequence Injection PWM for Two-Level Six-Phase VSIs
Authors: Zhao Li , Huang Shoudao , Gao Yuan , Zheng Jian
Published: August 2022

A common-mode voltage (CMV) suppression strategy, namely double zero-sequence injection common-mode voltage (DZICMV), is proposed in this paper for an asymmetrical six-phase induction motor fed by two-level dual three-phase voltage source inverters (VSIs). In this strategy, the sinusoidal waveforms injected by double zero-sequence signals are employed as modulation signals, and two opposite triangular waveforms are used as carriers. The fundamental period is divided into 24 sectors. In each sector, the carrier used by the medium amplitude phase is distinct from the carriers used by the other two phases in each set of three-phase windings. Using this method, the zero vectors (000) and (111) in each set of three-phase windings can be eliminated, and the peak values of sub-CMV and total CMV can be reduced from ±Udc/2 to ±Udc/6. The experiment results show that the root mean square (RMS) value of common-mode leakage current in DZICMV can be reduced by 51.83% compared with the double zero-sequence injection PWM (DZIPWM) strategy. It is also found in the other four existing benchmark CMV suppression strategies that the peak values of sub-CMV therein are nearly all ±Udc/2, and only in the low linear modulation region could one of these strategies suppress sub-CMV peak values to ±Udc/6. However, the proposed DZICMV can suppress the sub-CMV peak values to ±Udc/6 in the whole linear modulation range. Moreover, the maximum linear modulation index of the DZICMV is 1.15, which is larger than that of the four benchmark strategies, whose maximum modulation index is 1.
Changes in Energy Consumption and Energy Intensity in EU Countries as a Result of the COVID-19 Pandemic by Sector and Area Economy
Authors: Rokicki Tomasz , Jadczak Radosław , Kucharski Adam , Bórawski Piotr , Bełdycka-Bórawska Aneta , Szeberényi András , Perkowska Aleksandra
Published: August 2022

Energy is vital for the proper functioning of the various sectors of the economy and social life. During the pandemic, there have been some changes in these aspects that need to be investigated. The main objective of this article is to identify the direction of change caused by the COVID-19 pandemic in energy consumption and energy intensity in sectors and economic areas in EU countries. The specific objectives are to identify the importance of energy consumption in sectors and areas of the economy in individual EU countries; to determine the dynamics of change and variability during the pandemic in energy consumption in individual sectors and areas of the economy in EU countries, especially during the COVID-19 pandemic; to determine the changes in energy intensity of individual economic sectors and the differences in energy intensity between individual EU countries, including during the COVID-19 pandemic. Using a purposive selection method, all 27 EU Member States were selected for the study on 31 December 2020. The analysed period covered the years 2005–2020. The sources of material were literature and data from Eurostat. Descriptive, tabular and graphical methods, dynamic indicators with a fixed base and variable base, Gini coefficient, coefficient of variation, Pearson’s linear correlation coefficient, and multi-criteria analysis were used for analysis and presentation. It was found that the structure of energy consumption had remained unchanged for several years, with transport, industry and households dominating. There were no significant differences between countries. The COVID-19 pandemic reduced energy consumption in all sectors of the economy, the largest in transport and services and the smaller in industry. At the same time, household energy consumption increased. As a result of the pandemic, there was an increase in energy intensity in all sectors of the economy, the largest in industry. Western European countries had a lower energy intensity of the economy than Central and Eastern European countries. There was little change over several years. Countries generally maintained their ranking. The pandemic did not change anything in this respect, meaning that it had a similar impact on individual EU countries.
How Much Excess Heat Might Be Used in Buildings? A Spatial Analysis at the Municipal Level in Germany
Authors: Fritz Markus , Aydemir Ali , Schebek Liselotte
Published: August 2022

Excess heat can make an important contribution to reduce greenhouse gas emissions in the heating and cooling sector. Due to the local character of heat, the local excess heat potential is decisive for using excess heat. However, the spatially distributed potential and the subdivision of the potential into different subsectors have not been sufficiently investigated in Germany. Here we analyse the excess heat potential in Germany according to different subsectors and spatially distributed to the municipal level. We use data of more than 115,000 records on exhaust gas and fuel input from over 11,000 industrial sites. We calculate the site-specific excess heat potential and check its plausibility using the fuel input of the respective industrial sites. Finally, we compare the excess heat potential with the residential heat demand at the municipal level. Our results show that the excess heat potential in Germany is about 36.6 TWh/a, and that in 148 municipalities, the annual excess heat potential is greater than 50% of the annual heat demand. In conclusion, there is a large potential for excess heat utilisation in Germany. In some regions, more excess heat is available throughout the year than is needed to provide space heat and hot water.
Displacement Characteristics and Produced Oil Properties in Steam Flood Heavy Oil Process
Authors: Yang Xingchao , Zhao Hongyan , Zhang Bo , Zhao Qinghui , Cheng Yulin , Zhang Yong , Li Yiqiang
Published: August 2022

Thermal recovery is one of the most effective techniques for viscous oil production, which has been widely used in the heavy oilfield development. The mechanisms and percolation characteristics of thermal recovery have attracted a lot of attention. However, the displacement characteristics and produced oil properties in the steam flood heavy oil process are rarely addressed. In this paper, steam flooding experiments with two heavy oil viscosities under the temperatures from 120 to 200 °C and velocities from 1 to 3 mL/min were carried out to examine the oil displacement efficiency and the produced oil properties. The results show that the majority of the oil is produced in the low water cut stage. Temperature increment is helpful for prolonging the water breakthrough time. The high injection velocity of steam contributes to a high recovery factor, even if it enters into the high water cut stage. The rheology of the produced oils severely changes because the SARA composition changes, and emulsification occurs during the steam flooding heavy oil process. With the increasing steam temperature, the relative content of resins in the produced oils decreases, and asphaltenes increase. With the increase in the injection volume and the injection velocity of steam, the content of resins and asphaltenes increases. This leads to an increment in the produced oil viscosities. The effect of injection velocity on the rheology properties of the produced oils increases with temperature increment. The finding of this work will provide the technical support for heavy oilfields development.
A Review on the Progress and Future of TiO2/Graphene Photocatalysts
Authors: Nasir Amara , Khalid Sadia , Yasin Tariq , Mazare Anca
Published: August 2022

TiO2 is seen as a low cost, well-known photocatalyst; nevertheless, its sluggish charge kinetics does limit its applications. To overcome this aspect, one of the recent approaches is the use of its composites with graphene to enhance its photoactivity. Graphene-based materials (nanosheets, quantum dots, etc.) allow for attachment with TiO2 nanostructures, resulting in synergistic properties and thus increasing the functionality of the resulting composite. The current review aims to present the marked progress recently achieved in the use of TiO2/graphene composites in the field of photocatalysis. In this respect, we highlight the progress and insights in TiO2 and graphene composites in photocatalysis, including the basic mechanism of photocatalysis, the possible design strategies of the composites and an overview of how to characterize the graphene in the mixed composites. The use of composites in photocatalysis has also been reviewed, in which the recent literature has opened up more questions related to the reliability, potential, repeatability and connection of photocatalytic mechanisms with the resulting composites. TiO2/graphene-based composites can be a green light in the future of photocatalysis, targeting pollution remediation, energy generation, etc.
Recent Advances on the Valorization of Glycerol into Alcohols
Authors: Smith Louise R. , Douthwaite Mark , Mugford Karl , Dummer Nicholas F. , Willock David J. , Hutchings Graham J. , Taylor Stuart H.
Published: August 2022

Glycerol, a highly functionalised polyol, can be used as a platform molecule to produce a variety of high-value chemicals. As glycerol production is projected to increase over the coming years, it’s critically important that technology and infrastructure are developed to make use of the inevitable surplus. The catalytic production of ‘green’ mono alcohols from glycerol, in the absence of H2, is an emerging area of research that, in recent years, has generated significant industrial interest. Herein, we provide an update on recent advances in this field and discuss challenges which need to be overcome if this approach is to be considered viable industrially. The economic significance of using crude glycerol as a feedstock for glycerol valorisation strategies is also addressed and suggestions for improving the impact of research conducted in this field are proposed.
Effects of Loading Level on the Variation of Flow Losses in Subsonic Axial Compressors
Authors: Wang Ruoyu , Yu Xianjun , Liu Baojie , An Guangfeng
Published: August 2022

The development of the aircraft industry seeks an increase in compressor loading, bringing unique flow phenomena and design problems; thus, insights into the ultrahigh loaded compressor are in great need. To reveal the loss characteristics of the ultrahigh loaded subsonic axial compressors, four well comparable compressor stages are carefully designed with the loading coefficient varying from 0.41 to 0.65. A novel flow-based loss decomposition method is performed to investigate the variation of different kinds of losses (including blade profile loss, tip leakage loss, casing endwall loss, and hub endwall loss) with the change in compressor loading level and operating condition. Results show that the blade profile loss always occupies the largest part of the total loss. In rotor passages, the percentage of the blade profile loss at the design point is increased from 69% to 76% with the increase in the compressor loading. Meanwhile, the proportion of the tip leakage loss decreases as the loading increases. For a specific compressor stage, the total loss of the rotor passage tends to increase with the increase in stage pressure rise coefficient along the operation line, whereas the proportion of the blade profile loss is squeezed by the tip leakage loss. As for stator passages, the proportion of blade profile loss to the total passage loss is nearly constant along the compressor operating line, but increases from 79% to 90% with the increase in the compressor loading level. By correlating the losses with blade solidity, it was found that the increase in flow losses in the highly loaded compressor, i.e., the decrease in efficiency, stems mainly from the high blade solidity.
Bridging Social and Technical Sciences: Introduction of the Societal Embeddedness Level
Authors: Sprenkeling Marit , Geerdink Tara , Slob Adriaan , Geurts Amber
Published: August 2022

The successful and fast development and deployment of renewable energy and greenhouse gas reduction technologies is a continuing and structural challenge. The deployment of these technologies is slowed down and sometimes even stalled due to societal challenges like public resistance, lack of appropriate policy and regulations, unsolid business cases and uncertainty concerning the impact on the environment. In this paper we elaborate on societal aspects that influence technology development and deployment and introduce the societal embeddedness level (SEL) framework. Building upon the technology readiness level (TRL), the SEL framework enables the assessment of the current level of societal embeddedness of energy technologies in order to identify the societal aspects which need to be taken into account to accelerate deployment of energy technologies. The SEL framework takes into account four societal dimensions (impact on the environment, stakeholder involvement, policy and regulations, and market and financial resources) and four stages of technology development (exploration, development, demonstration and deployment) that are linked to the TRL. The SEL framework has been elaborated for CCS technologies and is being applied to the monitoring of geological CO2 storage by the ACT II project DigiMon (Digital Monitoring of CO2 storage projects). DigiMon is an ACT second call project, funded by the national funding agencies in the period September 2019–August 2022.
Techniques of Improving Infrastructure and Energy Resilience in Urban Setting
Authors: Singh Kuljeet , Hachem-Vermette Caroline
Published: August 2022

The work proposes a technique to improve the infrastructure and energy resilience of new developments during the planning stage. Several resilience-related parameters are developed in this paper that can be used to quantify resilience. To apply these parameters, the work assumes various energy outage scenarios varying from less than 24 h to 3 weeks. During these scenarios, a neighborhood population can be relocated to several public buildings promoting better utilization of onsite energy resources. The technique is applied to four representative neighborhoods encompassing various sustainability measures including clean energy. Further, this paper demonstrates an urban scale improvement technique for greater energy and infrastructure resilience. The results indicate a significant improvement in infrastructure resilience by relocating public shelter buildings on the main street intersections so that these can be easily accessible during energy outages or disaster events. Energy resilience can be achieved by the appropriate design of onsite energy resources to eliminate vulnerabilities. For instance, 8.8% to 15.4% of additional land for solar thermal collectors can eliminate thermal energy vulnerabilities. When surplus generation from onsite resources is twice or more as compared to demand during their unavailability, the electrical vulnerability can be eliminated by employing suitable battery banks in various buildings.
Impact of a Connection Structure of Macro Fiber Composite Patches on Energy Storage in Piezoelectric Energy Harvesting from a Rotating Shaft
Authors: Micek Piotr , Grzybek Dariusz
Published: August 2022

Energy collection in a capacitor, which was charged by four connection structures of Macro Fiber Composite (MFC) patches, was the subject of laboratory research. The first structure was the delta circuit created by three MFC patches and connected with a three-phase rectifier; the second structure was the delta circuit created by three MFC patches and connected with a three-phase rectifier; the third structure was the parallel connection of three circuits, each of which consisted of an MFC patch and a full bridge rectifier; and the fourth structure the series connection of three circuits, each of which consisted of an MFC patch and a full bridge rectifier. Laboratory experiments were carried out on a laboratory stand which consisted of a rotating shaft, three MFC patches powering an energy storage system, and a data acquisition system. The star connection generated the highest values of voltage across a capacitor in the long time period. The delta connection produced the highest capacitor-charging power. The shortest time to reach a target voltage on the capacitor equal to a few volts was achieved by use of the delta or parallel connection. The delta connection generated target voltage equal to a few volts across a capacitor in the shortest time at a lower level of stress in the shaft, but the difference between the charging times by the delta circuit and by the parallel connection decreased as the stress in the shaft increased.
Organization and Reliability Testing of a Wind Farm Device in Its Operational Process
Authors: Duer Stanisław , Rokosz Krzysztof , Bernatowicz Dariusz , Ostrowski Arkadiusz , Woźniak Marek , Zajkowski Konrad , Iqbal Atif
Published: August 2022

This article deals with the importance of simulation studies for the reliability of wind farm (WF) equipment during the operation process. Improvements, upgrades, and the introduction of new solutions that change the reliability, quality, and conditions of use and operation of wind farm equipment present a research problem during study. Based on this research, it is possible to continuously evaluate the reliability of WF equipment. The topic of reliability testing of complex technical facilities is constantly being developed in the literature. The article assumes that the operation of wind farm equipment is described and modeled based on Markov processes. This assumption justified the use of Kolmogorov–Chapman equations to describe the developed research model. Based on these equations, an analytical model of the wind farm operation process was created and described. As a result of the simulation analysis, the reliability of the wind farm was determined in the form of a probability function (R0(t)) for the WPPs system.
The Use of Aminated Wheat Straw for Reactive Black 5 Dye Removal from Aqueous Solutions as a Potential Method of Biomass Valorization
Authors: Jóźwiak Tomasz , Filipkowska Urszula , Walczak Paulina
Published: August 2022

Straw is a by-product from cereal cultivation. Using straw surplus as a biofuel is a popular means of its management. However, before being used for fuel purposes, straw can be successfully used as a sorbent. The present study investigated the sorption properties of wheat straw (Triticum aestivum L.) modified with ammonia water and epichlorohydrin against the reactive dye Reactive Black 5 (RB5). The tested sorbents were characterized based on FTIR, elemental analysis (C/N content), and pHPZC. The scope of the research included, among others, research on the effect of pH (pH 2–11) on the RB5 sorption efficiency, research on sorption kinetics, and determination of the maximum sorption capacity of the tested sorbents. The sorption efficiency of RB5 on the tested sorbents was the highest at pH 2–3. The experimental data from the research on the sorption kinetics of RB5 were best described by a pseudo-second-order model. The introduction of primary amine groups to the structure of sorbents significantly increased their sorption capacity towards RB5. The obtained sorption capacity of the aminated straw and the aminated straw pre-activated with epichlorohydrin was 24.12 mg RB5/g and 91.04 mg RB5/g, respectively, and it was higher by 44.3% and 444.5% compared to the unmodified straw.
Component Sizing of an Isolated Networked Hybrid Microgrid Based on Operating Reserve Analysis
Authors: Salehi Navid , Martínez-García Herminio , Velasco-Quesada Guillermo
Published: August 2022

The power-sharing possibility amongst microgrids (MGs) in networked microgrids (NMGs) offers multiple profits to the NMG by employing an applicable energy management system. An efficient energy management system can provide an adequate compromise in terms of the component sizing of NMGs through MG collaboration. This paper proposes a procedure to size the component for an isolated networked hybrid microgrid. The proposed design procedure relies on the optimum operation of individual MGs. The defined Reduced Factor (RF) identifies the possible size reduction for the dispatchable components, such as diesel generators and the energy storage system of each MG. The introduced RF is based on the operating reserve evaluation obtained from the optimal operation of individual MGs and the correlation between load profiles. Eventually, the simulation and practical results of a networked hybrid MG consisting of three MGs are presented to verify the proposed component sizing procedure. The practical results verify the theoretical expectations. The results show that NPC and capital costs are reduced up to 13% and 17%, respectively.
Health Monitoring of Pressure Regulating Stations in Gas Distribution Networks Using Mathematical Models
Authors: Sharma Shivom , Karimi Iftekhar A. , Farooq Shamsuzzaman , Samavedham Lakshminarayanan , Srinivasan Rajagopalan
Published: August 2022

Many cities have extensive distribution networks that supply natural or town gas to domestic, industrial, and power plant consumers. A typical network may have hundreds of pressure regulating stations that are of different types and capacities, but most legacy networks are sparsely instrumented. The reliability of these stations is the first priority for ensuring uninterrupted gas supplies; hence, condition monitoring and prescriptive maintenance are critical. In this study, mathematical models were developed for two types of commonly used regulators: spring-loaded and lever-type regulators. We also considered three faults that are typically of interest: filter choking, valve seat damage, and diaphragm deterioration. The proposed methodologies used the available measured data and mathematical models to diagnose faults, track prognoses, and estimate the remaining useful life of the regulators. The applicability of our proposed methodologies was demonstrated using real data from an existing distribution network. To facilitate industrial use, the methodologies were packaged into a user-friendly dashboard that could act as an interface with the operational database and display the health status of the regulators.
An Optimal Energy Management System (EMS) for Residential and Industrial Microgrids
Authors: Nasir M. Bilal , Hussain Asif , Niazi Kamran Ali Khan , Nasir Mashood
Published: August 2022

This research presents an optimal scheme for the integration of renewable resources with the utility grid to minimize the operational cost of the residential and industrial microgrids. With the changing paradigm of solar photovoltaic in low-voltage distribution networks, utilities have allowed net metering and feed-in tariff (FiT). These incentives encourage residential and industrial consumers to contribute toward energy generation. However, in conventional mode, the system may underperform if resources are not scheduled optimally. To compensate for the price difference during off-peak and on-peak hours, the energy should be taken from the grid when electricity prices are lower and supplied to the grid when the electricity price is higher. The proposed models will therefore allow optimal resource utilization considering intermittent renewable generation as well as a time-varying utility tariff. A complete comparative analysis of on-grid and off-grid models was carried out. The results indicate that the daily average saving is about 32.0% by using the proposed on-grid scheme, where a feed-in tariff is available.
Systematic Review on Impact of Different Irradiance Forecasting Techniques for Solar Energy Prediction
Authors: Sudharshan Konduru , Naveen C. , Vishnuram Pradeep , Krishna Rao Kasagani Damodhara Venkata Siva , Nastasi Benedetto
Published: August 2022

As non-renewable energy sources are in the verge of exhaustion, the entire world turns towards renewable sources to fill its energy demand. In the near future, solar energy will be a major contributor of renewable energy, but the integration of unreliable solar energy sources directly into the grid makes the existing system complex. To reduce the complexity, a microgrid system is a better solution. Solar energy forecasting models improve the reliability of the solar plant in microgrid operations. Uncertainty in solar energy prediction is the challenge in generating reliable energy. Employing, understanding, training, and evaluating several forecasting models with available meteorological data will ensure the selection of an appropriate forecast model for any particular location. New strategies and approaches emerge day by day to increase the model accuracy, with an ultimate objective of minimizing uncertainty in forecasting. Conventional methods include a lot of differential mathematical calculations. Large data availability at solar stations make use of various Artificial Intelligence (AI) techniques for computing, forecasting, and predicting solar radiation energy. The recent evolution of ensemble and hybrid models predicts solar radiation accurately compared to all the models. This paper reviews various models in solar irradiance and power estimation which are tabulated by classification types mentioned.
Heat and Mass Transport Analysis of MHD Rotating Hybrid Nanofluids Conveying Silver and Molybdenum Di-Sulfide Nano-Particles under Effect of Linear and Non-Linear Radiation
Authors: Hassan Ali , Hussain Azad , Arshad Mubashar , Awrejcewicz Jan , Pawlowski Witold , Alharbi Fahad , Karamti Hanen
Published: August 2022

This article is an attempt to explore the heat transfer features of the steady three-dimensional rotating flow of magneto-hydrodynamic hybrid nanofluids under the effect of nonlinear radiation over the bi-directional stretching surface. For this purpose, two different nano-particles, namely silver (Ag) and molybdenum di-sulfide (MoS2), were selected. Three different conventional base fluids were utilized to form desired hybrid nanofluids such as water (H2O), engine oil (EO), and ethylene glycol (EG). We obtained steady three-dimensional highly nonlinear partial differential equations. These highly nonlinear partial differential equations cannot be solved analytically, so these equations were handled in MATLAB with the BVP-4C technique with convergence tolerance at 10−6. The graph depicts the effect of the magnetization effect, thermal radiation, and stretching ratio on rotating hybrid nanofluids. Additionally, the impact of thermal radiation on the heat coefficient of three different hybrid nanofluids is being investigated. The augmentation in magnetization decreases the primary velocity, whereas the increment in radiation enhances the primary velocity. The stretching ratio and the presence of higher magnetic forces increase the temperature profile. The concentration profile was enhanced with an increment in the magnetic field, stretching, and rotation ratio. The maximum Nusselt number was achieved for the Ag-MoS2/EO hybrid nanofluid. It was concluded that augmentation in nonlinear radiation enhances the heat transfer coefficient for the examined cases (I) and (II) of the hybrid nanofluids. The Nusselt number doubled for both the examined cases under nonlinear radiation. Moreover, it was discovered that Ag-MoS2/water produced the best heat transfer results under nonlinear radiation. Therefore, the study recommends more frequent exploration of hybrid nanofluids (Ag-MoS2/water) when employing nonlinear radiation to analyze the heat transfer coefficient.
Critical Success Factors of the Energy Sector Security Strategy: The Case of Poland
Authors: Wisniewski Radoslaw , Daniluk Piotr , Nowakowska-Krystman Aneta , Kownacki Tomasz
Published: August 2022

The aim of this article is to identify important factors that determine the strategy of the energy sector. It has been assumed that the determinants of this strategy are goals related to the energy security of a European Union member state and the reduction of environmental pollution and anthropogenic pressures. Therefore, this article uses the method of the strategic analysis of critical success factors (CSFs), applied to the energy sector. As the name implies, in this method, factors that determine energy strategies, relating to the economic, technological, political, social and ecological spheres, were identified. Poland served as a case study. Research was carried out by experts in the energy sector and people working with this sector in order to determine the significance of the most important CSFs related to the energy security strategy. This approach is based on an evolutionary approach to creating a security strategy. The proposed analysis is a new proposal for a sectorial analysis based on the application of benchmarking, taking into account, in particular, the current conditions for the development of the energy sector. Our findings indicate that: European Union countries have different energy strategies, resulting from an evolutionary approach. The member states of the European Union create individual solutions in the field of energy strategies, which are conditioned by many factors, the most important of which are the geographic and physical location of a country on the European continent, economic and social contexts, and environmental as well as political conditions. According to Polish experts, the key success factors in building an energy strategy stem mainly from the economic and political areas, followed by the technological area, while the environmental and social areas are the least important. The authors hope that the article will serve to popularize the use of CSFs in scientific research, which can then translate into improved government policies for the energy sector.
Trends and Emerging Technologies for the Development of Electric Vehicles
Authors: Mo Tiande , Li Yu , Lau Kin-tak , Poon Chi Kin , Wu Yinghong , Luo Yang
Published: August 2022

In response to severe environmental and energy crises, the world is increasingly focusing on electric vehicles (EVs) and related emerging technologies. Emerging technologies for EVs have great potential to accelerate the development of smart and sustainable transportation and help build future smart cities. This paper reviews new trends and emerging EV technologies, including wireless charging, smart power distribution, vehicle-to-home (V2H) and vehicle-to-grid (V2G) systems, connected vehicles, and autonomous driving. The opportunities, challenges, and prospects for emerging EV technologies are systematically discussed. The successful commercialization development cases of emerging EV technologies worldwide are provided. This review serves as a reference and guide for future technological development and commercialization of EVs and offers perspectives and recommendations on future smart transportation.