Energies

22 pages, 3845 KiB

Open AccessArticle

Design of Battery Energy Storage System Torsional Damper for a Microgrid with Wind Generators Using Artificial Neural Network

by Kuei-Yen Lee and Yuan-Yih Hsu

Energies 2024, 17(13), 3208; https://doi.org/10.3390/en17133208 (registering DOI) - 29 Jun 2024

Abstract

Ancillary frequency controllers such as droop controllers are beneficial for frequency regulation of a microgrid with high penetration of wind generators. However, the use of such ancillary frequency controllers may cause torsional oscillation in the doubly fed induction generator (DFIG). In this paper, [...] Read more.

Ancillary frequency controllers such as droop controllers are beneficial for frequency regulation of a microgrid with high penetration of wind generators. However, the use of such ancillary frequency controllers may cause torsional oscillation in the doubly fed induction generator (DFIG). In this paper, a supplementary torsional damper in a battery energy storage system (BESS) is designed to improve the damping ratio for the DFIG torsional mode. Since the optimal damper gain depends on system variables such as the number of diesel generators, the number of wind generators, and BESS droop gain, an artificial neural network (ANN) is trained using these system variables as inputs and the desired BESS damper gain as the output. After the ANN has been trained with the training patterns, it can provide the desired BESS damper gain in an accurate and efficient manner. The effectiveness of the proposed ANN approach for BESS damper design is demonstrated by MATLAB/SIMULINK R2022b simulations. Full article

(This article belongs to the Special Issue Advanced Control Technology of Integrated Wind and Wave Energy Conversion System)

21 pages, 16962 KiB

Open AccessArticle

Variation in Flow Characteristics and Power Performance Due to Axial Distance Optimization in the Design of Counter-Rotating Tidal Turbines

by Haechang Jeong and Changjo Yang

Energies 2024, 17(13), 3207; https://doi.org/10.3390/en17133207 (registering DOI) - 29 Jun 2024

Abstract

Counter-rotating turbines, designed to enhance the performance efficiency of tidal turbines, exhibit variable operational characteristics depending on the axial distance between the front and rear blades. This study encompassed both numerical analyses and performance experiments to establish the optimal design by examining the [...] Read more.

Counter-rotating turbines, designed to enhance the performance efficiency of tidal turbines, exhibit variable operational characteristics depending on the axial distance between the front and rear blades. This study encompassed both numerical analyses and performance experiments to establish the optimal design by examining the relationship between flow field alterations and the performance of a counter-rotating tidal turbine with varied axial distances. The blades of the counter-rotating tidal turbine, based on a 10-kW single turbine, were designed utilizing the Blade Element Momentum technique. The turbine blades were assessed for changes in output performance attributed to flow separation by analyzing the velocity distribution and separation points within the flow, demonstrating a maximum power coefficient of 40.3% at a design Tip Speed Ratio of 3. At y/D = 0.3. The counter-rotating tidal turbine achieved a maximum power coefficient of 47%, with performance enhancements of the rear blades driven by the accelerated wake of the front blades. Furthermore, the pressure coefficients of the blades, influenced by their shape, inflow velocity, and angle, were detailed separately for the suction and pressure sides. The study also explored the correlation between the flow characteristics and the output performance of each blade by analyzing the distribution of pressure coefficients. Full article

(This article belongs to the Section A3: Wind, Wave and Tidal Energy)

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21 pages, 1671 KiB

Open AccessArticle

Frequency-Dependent Grounding Impedance of a Pair of Hemispherical Electrodes: Inductive or Capacitive Behavior?

by José Brandão Faria, João Pereira Fernandes, Vitor Maló Machado and Maria Eduarda Pedro

Energies 2024, 17(13), 3206; https://doi.org/10.3390/en17133206 (registering DOI) - 29 Jun 2024

Abstract

This article is the authors’ last contribution to a trilogy of research papers submitted to Energies’ Special Issue on Electromagnetic Field Computation, aimed at the theoretical analysis and numerical computation of the frequency-dependent complex impedance of hemispherical electrodes. In this work, we consider [...] Read more.

This article is the authors’ last contribution to a trilogy of research papers submitted to Energies’ Special Issue on Electromagnetic Field Computation, aimed at the theoretical analysis and numerical computation of the frequency-dependent complex impedance of hemispherical electrodes. In this work, we consider a pair of distant identical hemispherical electrodes buried in the ground, whose constitutive parameters (conductivity and permittivity) are assigned diverse values. Simulation experiments carried out using a full-wave finite element method, considering different combinations of the earth’s constitutive parameters, reveal that the grounding impedance of the electrode system can exhibit surprisingly varied frequency behavior. For frequencies close to zero, the impedance can start out inductive or capacitive, then go through a number of resonant transitions between inductive and capacitive states, finally tending towards purely resistive behavior. The results are interpreted using theoretical approximations valid for low- and high-frequency regimes. Full article

(This article belongs to the Special Issue Electromagnetic Field Computation for Electrical Engineering Devices)

22 pages, 5269 KiB

Open AccessArticle

Optimization Strategy for Low-Carbon Economy of Integrated Energy System Considering Carbon Capture-Two Stage Power-to-Gas Hydrogen Coupling

by Kangjie He, Linjun Zeng, Jun Yang, Yongguo Gong, Zhenhua Zhang and Kun Chen

Energies 2024, 17(13), 3205; https://doi.org/10.3390/en17133205 (registering DOI) - 29 Jun 2024

Abstract

To further optimize the low-carbon economy of the integrated energy system (IES), this paper establishes a two-stage P2G hydrogen-coupled electricity–heat–hydrogen–gas IES with carbon capture (CCS). First, this paper refines the two stages of P2G and introduces a hydrogen fuel cell (HFC) with a [...] Read more.

To further optimize the low-carbon economy of the integrated energy system (IES), this paper establishes a two-stage P2G hydrogen-coupled electricity–heat–hydrogen–gas IES with carbon capture (CCS). First, this paper refines the two stages of P2G and introduces a hydrogen fuel cell (HFC) with a hydrogen storage device to fully utilize the hydrogen energy in the first stage of power-to-gas (P2G). Then, the ladder carbon trading mechanism is considered and CCS is introduced to further reduce the system’s carbon emissions while coupling with P2G. Finally, the adjustable thermoelectric ratio characteristics of the combined heat and power unit (CHP) and HFC are considered to improve the energy utilization efficiency of the system and to reduce the system operating costs. This paper set up arithmetic examples to analyze from several perspectives, and the results show that the introduction of CCS can reduce carbon emissions by 41.83%. In the CCS-containing case, refining the P2G two-stage and coupling it with HFC and hydrogen storage can lead to a 30% reduction in carbon emissions and a 61% reduction in wind abandonment costs; consideration of CHP and HFC adjustable thermoelectric ratios can result in a 16% reduction in purchased energy costs. Full article

(This article belongs to the Special Issue Low-Carbon Integrated Energy System with Renewable Generations: Characterization, Modelling, and Optimization)

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20 pages, 3813 KiB

Open AccessArticle

Data Augmentation with Generative Adversarial Network for Solar Panel Segmentation from Remote Sensing Images

by Justinas Lekavičius and Valentas Gružauskas

Energies 2024, 17(13), 3204; https://doi.org/10.3390/en17133204 (registering DOI) - 29 Jun 2024

Abstract

With the popularity of solar energy in the electricity market, demand rises for data such as precise locations of solar panels for efficient energy planning and management. However, these data are not easily accessible; information such as precise locations sometimes does not exist. [...] Read more.

With the popularity of solar energy in the electricity market, demand rises for data such as precise locations of solar panels for efficient energy planning and management. However, these data are not easily accessible; information such as precise locations sometimes does not exist. Furthermore, existing datasets for training semantic segmentation models of photovoltaic (PV) installations are limited, and their annotation is time-consuming and labor-intensive. Therefore, for additional remote sensing (RS) data creation, the pix2pix generative adversarial network (GAN) is used, enriching the original resampled training data of varying ground sampling distances (GSDs) without compromising their integrity. Experiments with the DeepLabV3 model, ResNet-50 backbone, and pix2pix GAN architecture were conducted to discover the advantage of using GAN-based data augmentations for a more accurate RS imagery segmentation model. The result is a fine-tuned solar panel semantic segmentation model, trained using transfer learning and an optimal amount—60% of GAN-generated RS imagery for additional training data. The findings demonstrate the benefits of using GAN-generated images as additional training data, addressing the issue of limited datasets, and increasing IoU and F1 metrics by 2% and 1.46%, respectively, compared with classic augmentations. Full article

(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)

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23 pages, 3266 KiB

Open AccessArticle

Thermal Analysis of Power Transformer Using 2D and 3D Finite Element Method

by Mohamed S. Seddik, Jehan Shazly and Magdy B. Eteiba

Energies 2024, 17(13), 3203; https://doi.org/10.3390/en17133203 (registering DOI) - 29 Jun 2024

Abstract

An accurate simulation and computational analysis of temperature distribution in large power transformers used in power plants is crucial during both the design and operational phases. This study introduces a thermal modeling analysis encompassing two- and three-dimensional (2D and 3D) approaches for power [...] Read more.

An accurate simulation and computational analysis of temperature distribution in large power transformers used in power plants is crucial during both the design and operational phases. This study introduces a thermal modeling analysis encompassing two- and three-dimensional (2D and 3D) approaches for power transformers. The mathematical model for heat diffusion follows the Finite Element Method (FEM) approach. Validation of the computed results involves comparing them against measurements from Hyundai’s test report for both 2D and 3D models, aiming to identify the most effective solution. Additionally, the thermal dynamics of power transformers under diverse operational conditions, specifically oil-immersed ones, are examined. The efficacy of this model is confirmed through testing on a step-up transformer at Kureimat station in Egypt, with specifications including three-phase, 50 Hz, 16.5/240 KV, nine taps, and cooling type (ONAN/ONAF1/ONAF2). Full article

(This article belongs to the Section F: Electrical Engineering)

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22 pages, 8458 KiB

Open AccessArticle

Innovation in Methods for Incorporating Magnetite into Biocellulose for Electromagnetic Interference Shielding Effectiveness Applications

by Thaís Cavalcante de Souza, Alexsandro Ramos dos Santos, João Luiz da Silva Pereira Chacon, Ítalo José Batista Durval, Andréa Fernanda de Santana Costa, Eduardo Padrón Hernández, Attilio Converti, Glória Maria Vinhas and Leonie Asfora Sarubbo

Energies 2024, 17(13), 3202; https://doi.org/10.3390/en17133202 (registering DOI) - 29 Jun 2024

Abstract

Materials with magnetic properties are essential in various electric sector technologies. However, the generation of pollutants is of concern, increasing the interest in developing new sustainable, low-cost magnetic materials. These materials have notable applications in protecting against electromagnetic interference (EMI), which can lead [...] Read more.

Materials with magnetic properties are essential in various electric sector technologies. However, the generation of pollutants is of concern, increasing the interest in developing new sustainable, low-cost magnetic materials. These materials have notable applications in protecting against electromagnetic interference (EMI), which can lead to health problems as well as environmental pollution. Therefore, the aims of the present study were to produce a sustainable magnetic polymer using different methods of magnetite incorporation, investigate its magnetic properties, and determine its EMI shielding potential. The magnetic BC materials were obtained via in situ and ex situ magnetic incorporation in processed BC membranes and BC hydrogels. Analyses were carried out using XRD, FTIR, SEM, and VSM, and tests were performed to assess electromagnetic interference shielding effectiveness (EMI SE). The results revealed that the magnetite incorporation method influences the final size of nanoparticles, the arrangement among BC fibers, and the magnetic properties. Materials produced from processed BC had a higher percentage of incorporated magnetite and greater magnetic saturation, whereas those containing nanoparticles with a larger diameter had a stronger coercive field. Although samples did not have high EMI SE, magnetite increased the wave reflection and absorption of the material. This biomaterial can drive important innovations in the energy sector, particularly in efficient and ecological electrical infrastructure. Full article

(This article belongs to the Special Issue Green Technologies for Energy Transition II)

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18 pages, 5116 KiB

Open AccessArticle

The Modeling of Concentrators for Solar Photovoltaic Systems

by Ana Francisca Machado da Costa, Ricardo A. Marques Lameirinhas, Catarina Pinho Correia Valério Bernardo, João Paulo Neto Torres and Marcelino Santos

Energies 2024, 17(13), 3201; https://doi.org/10.3390/en17133201 (registering DOI) - 29 Jun 2024

Abstract

Concentrating photovoltaic (CPV) systems have emerged as a transformative technology that incorporates radiation concentrators into the photovoltaic system to enable radiation to be concentrated onto a receiver—the solar cells. Different concentrator configurations have different impacts on the performance of the solar photovoltaic system. [...] Read more.

Concentrating photovoltaic (CPV) systems have emerged as a transformative technology that incorporates radiation concentrators into the photovoltaic system to enable radiation to be concentrated onto a receiver—the solar cells. Different concentrator configurations have different impacts on the performance of the solar photovoltaic system. This research work aims to analyze the impact of different concentrators, comparing and identifying the most efficient structures for capturing and concentrating solar energy. Aiming at a deep analysis and comparison among concentrators shapes, this research work presents a unique investigation and revision among different structures such as flat, triangular, LFR, and parabolic concentrators. Moreover, since, in the UV–visible–NIR region, metals’ reflectance varies with the incident wavelength, five metals were considered: aluminum, gold, platinum, copper, and silver. Additionally, the research focuses on studying the effects of parameters critical to the quality of the concentration on the power obtained and on the uniformity of the radiation distribution on the surface of the receiver, as well as on the number of solar rays that reach the receiver. The power on the receiver increases proportionally with the number of reflector concentrators in the system and their reflectance. For parabolic geometries, the optical efficiency is affected by the receiver’s shadow on the concentrator and, in the case of the LFR, by a non-ideal alignment of the reflectors in relation to the receiver. However, in parabolic concentrator geometries, uniformity is usually lower, since in these configurations, the radiation is focused on specific areas of the receiver, usually the central zone. Full article

(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)

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15 pages, 478 KiB

Open AccessArticle

A Hybrid Approach for Hierarchical Forecasting of Industrial Electricity Consumption in Brazil

by Marlon Mesquita Lopes Cabreira, Felipe Leite Coelho da Silva, Josiane da Silva Cordeiro, Ronald Miguel Serrano Hernández, Paulo Canas Rodrigues and Javier Linkolk López-Gonzales

Energies 2024, 17(13), 3200; https://doi.org/10.3390/en17133200 (registering DOI) - 29 Jun 2024

Abstract

The Brazilian industrial sector is the largest electricity consumer in the power system. Energy planning in this sector is important mainly due to its economic, social, and environmental impact. In this context, electricity consumption analysis and projections are highly relevant for the decision-making [...] Read more.

The Brazilian industrial sector is the largest electricity consumer in the power system. Energy planning in this sector is important mainly due to its economic, social, and environmental impact. In this context, electricity consumption analysis and projections are highly relevant for the decision-making of the industrial sectorand organizations operating in the energy system. The electricity consumption data from the Brazilian industrial sector can be organized into a hierarchical structure composed of each geographic region (South, Southeast, Midwest, Northeast, and North) and their respective states. This work proposes a hybrid approach that incorporates the projections obtained by the exponential smoothing and Box–Jenkins models to obtain the hierarchical forecasting of electricity consumption in the Brazilian industrial sector. The proposed approach was compared with the bottom-up, top-down, and optimal combination approaches, which are widely used for time series hierarchical forecasting. The performance of the models was evaluated using the mean absolute percentage error (MAPE) and root mean squared error (RMSE) precision measures. The results indicate that the proposed hybrid approach can contribute to the projection and analysis of industrial sector electricity consumption in Brazil. Full article

(This article belongs to the Special Issue Energy Efficiency and Economic Uncertainty in Energy Market)

24 pages, 9268 KiB

Open AccessArticle

Modeling the Drying Process of Onion Slices Using Artificial Neural Networks

by Sławomir Francik, Bogusława Łapczyńska-Kordon, Michał Hajos, Grzegorz Basista, Agnieszka Zawiślak and Renata Francik

Energies 2024, 17(13), 3199; https://doi.org/10.3390/en17133199 (registering DOI) - 29 Jun 2024

Abstract

One of the food preservation technologies is the drying process, which requires heat and is significantly energy-intensive, resulting in high costs. This caused the search for new design solutions for dryers, which requires continuous experimental research and the creation of new decision-supporting models [...] Read more.

One of the food preservation technologies is the drying process, which requires heat and is significantly energy-intensive, resulting in high costs. This caused the search for new design solutions for dryers, which requires continuous experimental research and the creation of new decision-supporting models for the optimization of drying processes. In this work, four models of the kinetics of convective onion drying were developed using Artificial Neural Networks (ANNs), taking into account pre-treatment before drying and the different temperatures of the drying agent. The moisture content in the dried material at a specific moment in time was taken as the dependent variable (ANN output). The following were accepted as independent variables (ANN inputs): drying temperature, initial sample thickness, initial moisture content, initial mass of the sample, time of drying, and material pre-treatment (no pre-treatment—blanching–osmotic dehydration). Four semantic models were formulated, the general Ann1 model taking into account all input variables and three detailed Ann2 models for individual types of pre-treatment. For the best Ann1, the MAPE values were 5.88–7.02% (for different data: Training, Test, Validation). For the detailed Ann2 models, the error values were more than twice lower. The MAPE values ranged from 1.14% to 3.12%. Full article

(This article belongs to the Section B: Energy and Environment)

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15 pages, 1799 KiB

Open AccessArticle

Coordinated Frequency Modulation Control Strategy of Wind Power and Energy Storage Considering Mechanical Load Optimization

by Chaoyu Zhang, Jiabin Li, Shiyi Liu, Peng Hu, Jiangzhe Feng, Haoyang Ren, Ruizhe Zhang and Jiaoxin Jia

Energies 2024, 17(13), 3198; https://doi.org/10.3390/en17133198 (registering DOI) - 28 Jun 2024

Abstract

When a doubly fed induction generator (DFIG) participates in primary frequency modulation by rotor kinetic energy control, the torque of the generator is changed sharply and the mechanical load pressure of the shaft increases rapidly, which aggravates the fatigue damage of shafting. In [...] Read more.

When a doubly fed induction generator (DFIG) participates in primary frequency modulation by rotor kinetic energy control, the torque of the generator is changed sharply and the mechanical load pressure of the shaft increases rapidly, which aggravates the fatigue damage of shafting. In order to alleviate the fatigue load of shafting, energy storage was added in the primary frequency modulation of a wind turbine, and a coordinated frequency modulation control strategy of wind power and energy storage based on fuzzy control was proposed. The wind-storage frequency modulation power command was allocated to reduce the response speed of the wind turbine to alleviate the load pressure on the shafting by the fuzzy controller considering the rotor speed range and the state of energy storage charge, and the remaining demand power was supplemented by energy storage. Finally, the joint simulation model based on GH Bladed–Matlab was used to verify the effectiveness of the proposed control strategy. Compared with the traditional integrated control of virtual inertia, the proposed method can reduce the load pressure and fatigue damage of the shafting while satisfying the requirement of frequency modulation. Full article

(This article belongs to the Special Issue Renewable Energy Systems (Solar, Wind) and Grid Integration)

17 pages, 615 KiB

Open AccessReview

EOR Technology (Patents) and Science (Articles) Assessment of BRICS and nonBRICS with Growth Rates and Specializations within Responsible Global Energy Transition: A Critical Review

by C. M. Quintella, P. D. Rodrigues, J. L. Nicoleti, E. Ramos-de-Souza, E. B. Carvalho and S. A. Hanna

Energies 2024, 17(13), 3197; https://doi.org/10.3390/en17133197 (registering DOI) - 28 Jun 2024

Viewed by 35

Abstract

To achieve a low-carbon energy transition, it is essential to ensure that, as long as fossil fuels are needed, their production is sustainable, minimizing the environmental impact and securing resources for advancing greener technologies, in alignment with SDGs 7, 13, and 14. Enhanced [...] Read more.

To achieve a low-carbon energy transition, it is essential to ensure that, as long as fossil fuels are needed, their production is sustainable, minimizing the environmental impact and securing resources for advancing greener technologies, in alignment with SDGs 7, 13, and 14. Enhanced oil recovery (EOR) increases the recovery rates without new developments. The recent expansion of the BRICS consortium, involving major producers, underscores the need to evaluate their EOR technologies, particularly potential gaps that could hinder global energy transition strategies. We analyzed intermediate levels of technological readiness levels (TRLs) utilizing patents (TRL4-5) and articles (TRL3) for 18 EOR methods between 2002 and 2021. Composite indicators derived from patents including compound annual growth rate, specialization, concentration, diversification, and Gini inequality were employed. Both BRICS and nonBRICS exhibited analogous distributions in the articles (particularly Norway, United Kingdom, Canada) and patents (particularly Russia, China, and Ukraine). The decline in growth rates among BRICS and negative rates in nonBRICS suggest a technological plateau for traditional methods. However, environmentally low-impact EOR methods are experiencing exponential emergence (low salinity water, MEOR, polymers and macromolecular compounds, their associations with surfactants, and WAG). Both groups are self-sufficient in EOR, ensuring a responsible and low-impact energy transition. This ensures energy quality while facilitating the maturation of renewable technologies. Full article

(This article belongs to the Section H3: Fossil)

18 pages, 3277 KiB

Open AccessArticle

Research on the Throttling Performance and Anti-Erosion Structure of Trapezoidal Throttle Orifices

by Jianguo Zhao, Haotian Zheng, Chong Xie and Hanxiu Peng

Energies 2024, 17(13), 3196; https://doi.org/10.3390/en17133196 (registering DOI) - 28 Jun 2024

Viewed by 46

Abstract

The throttling performance of conventional throttle orifice structures of fluid control valves is very low. Therefore, this paper proposes a novel trapezoidal throttle orifice with excellent throttling performance. The effect of the taper of the throttle orifice on the erosion was researched. Firstly, [...] Read more.

The throttling performance of conventional throttle orifice structures of fluid control valves is very low. Therefore, this paper proposes a novel trapezoidal throttle orifice with excellent throttling performance. The effect of the taper of the throttle orifice on the erosion was researched. Firstly, two schemes of trapezoidal throttle orifice were proposed according to the fluid control valve. Secondly, the excellent throttling performance of the trapezoidal throttle orifice was compared and optimized. Finally, a numerical simulation method of the erosion-resistant ability of the trapezoidal throttle orifice was established. It was found that for the same throttling area, the differential pressure of the trapezoidal orifice was higher than that of the conventional rectangular orifice by about 18.6%. The taper had little effect on the gas production, which increased by only 3.3% during the 10° to 30° change. The maximum erosion was firstly reduced and then increased with increases in the angle from 0 to 25°of the taper. Moreover, the minimum was achieved at about a 20° taper angle. The above research methods provide a theoretical basis for optimizing the size and structure of orifices and the sealing reliability of fluid control valves. Full article

12 pages, 1167 KiB

Open AccessArticle

Synthesis and Performance Evaluation of Modified Polyaspartic-Acid-Based Scale Inhibitor

by WenLong Gao, LiWei Sun, Miao Li, XiAn Ye, QingChun Gao, DongLiang Kong, JunPu An, KuoBo Wang and Fan Yang

Energies 2024, 17(13), 3195; https://doi.org/10.3390/en17133195 (registering DOI) - 28 Jun 2024

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Abstract

This paper focuses on the selection and application of scale inhibitor by studying the problem of pipeline scaling in geothermal well development. Adding scale inhibitor can effectively reduce the treatment cost and achieve a good scale resistance effect, but the commonly used polyaspartic [...] Read more.

This paper focuses on the selection and application of scale inhibitor by studying the problem of pipeline scaling in geothermal well development. Adding scale inhibitor can effectively reduce the treatment cost and achieve a good scale resistance effect, but the commonly used polyaspartic acid scale inhibitor has problems such as poor scale inhibition effect and large use limitations. Therefore, a new modified polyaspartic acid scale inhibitor (His-Tyr-SA-PASP) was prepared using polysuccinimide (PSI) as the raw material and histidine (His), tyrosine (Tyr), and sulfonic acid (SA) as the modification reagent. When the dosage of His-Tyr-SA-PASP was 8 mg/L, the scale inhibition rate of CaCO₃ was 94.40%. In addition, the scale inhibition effect of His-Tyr-SA-PASP on CaCO₃ was better than that of PASP. At the same time, under the condition of a static experiment at 75 °C, according to the ion concentration of water samples in different scale zones, this paper also identified the ratio of four composite scale inhibitors. When the dosage of compound scale inhibitor was 100 mg/L, Sodium of Polyaspartic Acid–Diethylene Triamine Penta (Methylene Phosphonic Acid)–2-Phosphonobutane-1,2,4-Tricarboxylic Acid–Amino Trimethylene Phosphonic Acid–Copolymer of Maleic and Acrylic Acid = (10:10:5:1:9), (15:10:5:2.5:2.5), (12.5:5:10:1:6.5), and (15:5:10:4:1) and the scale inhibition rate was more than 95%. Under the condition of a dynamic experiment, the optimized composite scale inhibitor still showed a scale inhibition rate of more than 90%. It provides a useful reference for the practical application of water treatment in geothermal wells and has the prospect of industrial application. Full article

(This article belongs to the Section H: Geo-Energy)

14 pages, 574 KiB

Open AccessArticle

Photovoltaic Capacity Management for Investment Effectiveness

by Tomasz Brzęczek and Łukasz Hadaś

Energies 2024, 17(13), 3194; https://doi.org/10.3390/en17133194 (registering DOI) - 28 Jun 2024

Viewed by 53

Abstract

The production of photovoltaic utility varies within the day/night cycle. At night, photovoltaic cells do not produce anything. However, their day-light production, unconsumed on a current basis and exported to the grid, is compensated for with supply from the grid at night. This [...] Read more.

The production of photovoltaic utility varies within the day/night cycle. At night, photovoltaic cells do not produce anything. However, their day-light production, unconsumed on a current basis and exported to the grid, is compensated for with supply from the grid at night. This scheme of exploitation is called net-metering and is considered herein. Solar energy produced by a prosumer and fed into the grid has to be equal to the electricity supplied from the grid at night; otherwise, a shortage or waste of photovoltaic production occurs. The above finding leads us to the proposition for the optimal solution of photovoltaic capacity. We derived a closed-form capacity solution to the maximized non-linear profit function. It solves harmonic and 2-point production functions that vary symmetrically around the mean production. To verify the solution methodology, harmonic and 2-point models from empirical production data are estimated. Then, the solution is presented together with its return rate and internal return rate. The main finding is that the unit cost of the grid electricity, photovoltaic capacity unit cost and exploitation time all affect the total profit and return rate values while not impacting the optimal capacity of the photovoltaics. The optimal capacity depends on the prosumer’s energy consumption volume and on the natural conditions of production captured here by the technology efficiency coefficient estimated from the production time series. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Renewable Energy Policy and Economics)

19 pages, 4053 KiB

Open AccessArticle

A Grid-Wide Comprehensive Evaluation Method of Power Quality Based on Complex Network Theory

by Yang Xiang, Yan Lin, Yan Zhang, Jinchen Lan, Meimei Hao, Lianhui Wang, Jiang Wang and Liang Qin

Energies 2024, 17(13), 3193; https://doi.org/10.3390/en17133193 (registering DOI) - 28 Jun 2024

Viewed by 45

Abstract

To achieve a hierarchical and quantitative evaluation of grid-wide power quality in the distribution network, reflecting the overall power quality level of the distribution network, a comprehensive evaluation method for power quality in a grid-wide system based on complex network theory is proposed. [...] Read more.

To achieve a hierarchical and quantitative evaluation of grid-wide power quality in the distribution network, reflecting the overall power quality level of the distribution network, a comprehensive evaluation method for power quality in a grid-wide system based on complex network theory is proposed. Firstly, based on the propagation characteristics of power quality disturbances, a power quality evaluation index system is constructed. Secondly, to reflect the constraint effect of the local power quality level of nodes on the overall power quality level of the distribution system, corresponding indices such as improved node degree, improved node electrical betweenness, and node self-healing capability are proposed based on complex network theory, and the power quality influence degree of nodes is calculated. Then, the GRA-ANP (Grey Relational Analysis–Analytic Network Process) subjective weight calculation method is improved by introducing grey relational analysis to address the impact of differences in different decision-making results. Based on power quality monitoring data, the entropy weight method is used for objective weighting. To avoid the partiality of a single weight evaluation result, the game equilibrium algorithm is employed to calculate the comprehensive weight of each power quality index. Subsequently, considering the correlation and dependency among indices, the VIKOR (VIseKriterijumska Optimizacija I Kompromisno Resenje) method is used to obtain the power quality grade of each node. Combining this with the calculation of the power quality influence degree of nodes, the overall power quality grade of the distribution network is determined, achieving a hierarchical and quantitative evaluation of power quality in the entire distribution system. Finally, through a case study analysis of an improved 13-node distribution network, it is verified that the proposed method can fully extract data information and produce comprehensive and accurate power quality assessment results by comparing it with other methods. This provides strong support for the safe and stable operation of the distribution system and the subsequent optimization and management of power quality. Full article

(This article belongs to the Special Issue Power Quality and Disturbances in Modern Distribution Networks)

15 pages, 2844 KiB

Open AccessArticle

Electro-Hydraulic Variable-Speed Drive Network Technology—First Experimental Validation

by Lasse Schmidt and Mikkel van Binsbergen-Galán

Energies 2024, 17(13), 3192; https://doi.org/10.3390/en17133192 (registering DOI) - 28 Jun 2024

Viewed by 57

Abstract

The improvement of the energy efficiency of hydraulic systems remains an essential challenge for industry, and the demand for more sustainable solutions is increasing. A main focus in this endeavor is the ability to eliminate or strongly reduce the use of throttle control [...] Read more.

The improvement of the energy efficiency of hydraulic systems remains an essential challenge for industry, and the demand for more sustainable solutions is increasing. A main focus in this endeavor is the ability to eliminate or strongly reduce the use of throttle control valves which have been the preferred control element in industrial hydraulic systems for decades. Components have been subject to continuous evolution, and current industrial grade hydraulic pumps and motors are both efficient and reliable. Even though few percentages of energy efficiency can still be achieved, the main achievements in terms of efficiency are associated with novel system designs rather than further development of components. An area subject to increasing attention is the field of variable-speed displacement control, allowing to avoid the main control valve throttle losses. Systems using this technology are, however, mainly developed as standalone drive systems, necessitating maximum force, speed, and power installed in each axis, with limited hydraulic power distribution capability compared to valve-controlled systems. An emerging field addressing this challenge is that of so-called electro-hydraulic variable-speed drive networks, which allow to completely eliminate the use of control valves and enable power sharing both electrically and hydraulically, potentially reducing the necessary installed power in many cases. The idea of such a technology was first proposed in 2022, and so far developments reported in the literature have mainly been of a theoretical nature. This article presents the first ever experimental results for a dual-cylinder electro-hydraulic variable-speed drive network prototype. The prototype was developed for an industrial application, but has initially been implemented in a laboratory testbench. Extensive data acquisition has been conducted while subject to the associated industrial motion cycle, under different load conditions. The data obtained are further used in combination with models to predict the total efficiency of the drive network prototype under higher loads than what could be achieved in the laboratory, suggesting a total efficiency from the electric supply to the cylinder pistons of 68%. Re-configuring the prototype to a known standalone drive system structure implies comparable efficiencies. Finally, the drive network is theoretically compared to a valve drive solution, generally suggesting that the prototype drive network can provide efficiency improvements of at least 40% in comparison. Full article

(This article belongs to the Special Issue Energy, Electrical and Power Engineering 2024)

32 pages, 1413 KiB

Open AccessReview

Turning Food Loss and Food Waste into Watts: A Review of Food Waste as an Energy Source

by Florentios Economou, Irene Voukkali, Iliana Papamichael, Valentina Phinikettou, Pantelitsa Loizia, Vincenzo Naddeo, Paolo Sospiro, Marco Ciro Liscio, Christos Zoumides, Diana Mihaela Țîrcă and Antonis A. Zorpas

Energies 2024, 17(13), 3191; https://doi.org/10.3390/en17133191 (registering DOI) - 28 Jun 2024

Viewed by 76

Abstract

Food loss (FL) and food waste (FW) have become severe global problems, contributing to resource inefficiency and environmental degradation. Approximately 6% of greenhouse gas emissions (GHGs) are derived from FW, which is usually discarded in landfills, emitting methane, a gas that is 28 [...] Read more.

Food loss (FL) and food waste (FW) have become severe global problems, contributing to resource inefficiency and environmental degradation. Approximately 6% of greenhouse gas emissions (GHGs) are derived from FW, which is usually discarded in landfills, emitting methane, a gas that is 28 times more harmful than CO₂. Diverting the path of FW towards the energy industry represents a promising avenue to mitigate the environmental impact and save resources while generating energy substitutes. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach was utilized to conduct a systematic literature review on 10 different conversion processes used to convert FL and FW into energy. Anaerobic bioconversion integrated with pyrolysis emerges as a potential eco-friendly and promising solution for FW management, nutrient recovery and energy production in various forms, including biogas, heat, biohydrogen and biochar. Despite its potential, the anaerobic digestion of FW still faces some challenges related to the production of intermediate harmful compounds (VOCs, NH₃, H₂S), which necessitate precise process control and optimization. Nonetheless, converting FW into energy can provide economic and environmental benefits in the context of the circular economy. This review offers insightful information to stakeholders, academics and policymakers who are interested in utilizing FW as a means of producing sustainable energy by summarizing the important findings of ten different waste-to-energy processing methods and their potential for improved energy recovery efficiency. Full article

24 pages, 951 KiB

Open AccessArticle

Operation Optimization of Regional Integrated Energy Systems with Hydrogen by Considering Demand Response and Green Certificate–Carbon Emission Trading Mechanisms

by Ji Li, Lei Xu, Lihua Wang, Yang Kou, Yingli Huo and Weile Liang

Energies 2024, 17(13), 3190; https://doi.org/10.3390/en17133190 (registering DOI) - 28 Jun 2024

Viewed by 93

Abstract

Amidst the growing imperative to address carbon emissions, aiming to improve energy utilization efficiency, optimize equipment operation flexibility, and further reduce costs and carbon emissions of regional integrated energy systems (RIESs), this paper proposes a low-carbon economic operation strategy for RIESs. Firstly, on [...] Read more.

Amidst the growing imperative to address carbon emissions, aiming to improve energy utilization efficiency, optimize equipment operation flexibility, and further reduce costs and carbon emissions of regional integrated energy systems (RIESs), this paper proposes a low-carbon economic operation strategy for RIESs. Firstly, on the energy supply side, energy conversion devices are utilized to enhance multi-energy complementary capabilities. Then, an integrated demand response model is established on the demand side to smooth the load curve. Finally, consideration is given to the RIES’s participation in the green certificate–carbon trading market to reduce system carbon emissions. With the objective of minimizing the sum of system operating costs and green certificate–carbon trading costs, an integrated energy system optimization model that considers electricity, gas, heat, and cold coupling is established, and the CPLEX solver toolbox is used for model solving. The results show that the coordinated optimization of supply and demand sides of regional integrated energy systems while considering multi-energy coupling and complementarity effectively reduces carbon emissions while further enhancing the economic efficiency of system operations. Full article

(This article belongs to the Section A5: Hydrogen Energy)

15 pages, 8734 KiB

Open AccessArticle

Assessment of the Heat Transfer Conditions in the Cavity of a Rotating Circular Saw

by Jan Stegmann, Moritz Baumert, Stephan Kabelac, Christian Menze, Johannes Ramme and Hans-Christian Möhring

Energies 2024, 17(13), 3189; https://doi.org/10.3390/en17133189 (registering DOI) - 28 Jun 2024

Viewed by 80

Abstract

To improve machining processes concerning the usage of lubricants, knowledge of the thermo-mechanical and thermo-fluid interactions at the cutting zone is of great importance. This study focuses on the description of the convective heat transfer which occurs during circular sawing when the lubricant [...] Read more.

To improve machining processes concerning the usage of lubricants, knowledge of the thermo-mechanical and thermo-fluid interactions at the cutting zone is of great importance. This study focuses on the description of the convective heat transfer which occurs during circular sawing when the lubricant is provided via an internal coolant supply. The highly complex flow field inside the cavity of the sawing process is separated into two distinct flow forms, an impingement and a channel flow. With the aid of experimental and numerical studies, the heat transfer characteristics of these two flow forms have been examined for water and a lubricant used in the circular sawing process. Studies have been conducted over a wide range of Reynolds numbers (impingement flow:

2 \times 10^{3} < Re < 17 \times 10^{3}

, channel flow:

1 \times 10^{3} < Re < 30 \times 10^{3}

). Additionally, the variation in the inlet temperature of the fluid, as well as the variation in heating power, has been studied. Overall, the impingement flow yields a significantly higher heat transfer than the channel flow with Nußelt-numbers ranging from 120 to 230, whereas the Nußelt-numbers in the case of the channel flow range from 20 to 160. For both flow forms, the use of the lubricant results in a better heat transfer compared with the usage of water. With the aid of these studies, correlations to describe the heat transfer have been derived. The provided correlations are to be used in a coupled numerical model of the chip formation process which also includes the effects of the heat transfer to the coolant lubricant. Full article

(This article belongs to the Topic Applied Heat Transfer)

27 pages, 5997 KiB

Open AccessArticle

Three-Level Secure Smart Protection for Ring Grid-Connected Distributed Generation

by Mostafa Bakkar, Santiago Bogarra, Felipe Córcoles, Ahmed Aboelhassan, Shuo Wang and Javier Iglesias

Energies 2024, 17(13), 3188; https://doi.org/10.3390/en17133188 (registering DOI) - 28 Jun 2024

Viewed by 76

Abstract

The penetration increase in distributed generators (DGs) into smart grids (SGs) will lead to new challenges, especially in protection systems. In the case of ring grids, the behavior of the short-circuit current is affected by DGs, and the medium voltage (MV) transformer connections [...] Read more.

The penetration increase in distributed generators (DGs) into smart grids (SGs) will lead to new challenges, especially in protection systems. In the case of ring grids, the behavior of the short-circuit current is affected by DGs, and the medium voltage (MV) transformer connections significantly influence the changes; therefore, the protection strategies must be adapted for these scenarios. This study provides a comprehensive protection system for the MV distribution system (DS), including reconfigurable smart ring grids. The proposed protection methods contain three protection algorithms. The first protection algorithm relies on communication among all protective devices (PDs) in the grid, whereas the second protection method uses communication among PDs along the same line. Then, a third algorithm built on the local data of each PD is suggested as a backup to prevent communication issues and offer more reliable protection. MATLABTM SIMULINK simulations and experimental results on a scalable hardware grid were also employed to validate the protection algorithms. Full article

(This article belongs to the Section A1: Smart Grids and Microgrids)

23 pages, 6376 KiB

Open AccessArticle

C-Rate- and Temperature-Dependent State-of-Charge Estimation Method for Li-Ion Batteries in Electric Vehicles

by Eyyup Aslan and Yusuf Yasa

Energies 2024, 17(13), 3187; https://doi.org/10.3390/en17133187 (registering DOI) - 28 Jun 2024

Viewed by 102

Abstract

Li-ion batteries determine the lifespan of an electric vehicle. High power and energy density and extensive service time are crucial parameters in EV batteries. In terms of safe and effective usage, a precise cell model and SoC estimation algorithm are indispensable. To provide [...] Read more.

Li-ion batteries determine the lifespan of an electric vehicle. High power and energy density and extensive service time are crucial parameters in EV batteries. In terms of safe and effective usage, a precise cell model and SoC estimation algorithm are indispensable. To provide an accurate SoC estimation, a current- and temperature-dependent SoC estimation algorithm is proposed in this paper. The proposed SoC estimation algorithm and equivalent circuit model (ECM) of the cells include current and temperature effects to reflect real battery behavior and provide an accurate SoC estimation. For including current and temperature effects in the cell model, lookup tables have been used for each parameter of the model. Based on the proposed ECM, the unscented Kalman filter (UKF) approach is utilized for estimating SoC since this approach is satisfactory for nonlinear systems such as lithium-ion batteries. The experimental results reveal that the proposed approach provides superior accuracy when compared to conventional methods and it is promising in terms of meeting electric vehicle requirements. Full article

35 pages, 2034 KiB

Open AccessReview

Control and Stability of Grid-Forming Inverters: A Comprehensive Review

by Marzie Mirmohammad and Sahar Pirooz Azad

Energies 2024, 17(13), 3186; https://doi.org/10.3390/en17133186 (registering DOI) - 28 Jun 2024

Viewed by 97

Abstract

The large integration of inverter-based resources will significantly alter grid dynamics, leading to pronounced stability challenges due to fundamental disparities between inverter-based and traditional energy systems. While grid-following inverters (GFLIs) dominate current inverter configurations, their increased penetration into the grid can result in [...] Read more.

The large integration of inverter-based resources will significantly alter grid dynamics, leading to pronounced stability challenges due to fundamental disparities between inverter-based and traditional energy systems. While grid-following inverters (GFLIs) dominate current inverter configurations, their increased penetration into the grid can result in major stability issues. In contrast, grid-forming inverters (GFMIs) excel over GFLIs by offering features like standalone operation, frequency support, and adaptability in weak grid scenarios. GFMIs, unlike GFLIs, control the AC voltage and frequency at the common coupling point, impacting the inverter dynamic response to grid disturbances and overall stability. Despite the existing literature highlighting differences between GFLIs and GFMIs and their control strategies, a comprehensive review of GFMIs’ stability and the effects of their control schemes on grid stability is lacking. This paper provides an in-depth evaluation of GFMIs’ stability, considering various control schemes and their dynamics. It also explores different types of power system stability, introduces new stability concepts that correspond to power grids with integrated inverters, i.e., resonance and converter-driven stability, and reviews small-signal and transient stability analyses, which are the main two types of GFMI stability studied in the literature. The paper further assesses existing studies on GFMI stability, pinpointing research gaps for future investigations. Full article

(This article belongs to the Section F: Electrical Engineering)

20 pages, 2476 KiB

Open AccessArticle

Real-Time Implementable Integrated Energy and Cabin Temperature Management for Battery Life Extension in Electric Vehicles

by Mattia Mauro, Atriya Biswas, Carlo Fiorillo, Hao Wang, Ezio Spessa, Federico Miretti, Ryan Ahmed, Angelo Bonfitto and Ali Emadi

Energies 2024, 17(13), 3185; https://doi.org/10.3390/en17133185 (registering DOI) - 28 Jun 2024

Viewed by 127

Abstract

Among many emerging technologies, battery electric vehicles (BEVs) have emerged as a prominent and highly supported solution to stringent emissions regulations. However, despite their increasing popularity, key challenges that might jeopardize their further spread are the lack of charging infrastructure, battery life degradation, [...] Read more.

Among many emerging technologies, battery electric vehicles (BEVs) have emerged as a prominent and highly supported solution to stringent emissions regulations. However, despite their increasing popularity, key challenges that might jeopardize their further spread are the lack of charging infrastructure, battery life degradation, and the discrepancy between the actual and promised all-electric driving range. The primary focus of this paper is to formulate an integrated energy and thermal comfort management (IETM) strategy. This strategy optimally manages the electrical energy required by the heating, ventilation, and air conditioning (HVAC) unit, the most impacting auxiliary in terms of battery load, to minimize battery life degradation over any specific drive cycle while ensuring the actual cabin temperature hovers within the permissible tolerance limit from the reference cabin temperature and the driver-requested traction power is always satisfied. This work incorporates a state-of-health (SOH) estimation model, a high-fidelity cabin thermodynamics model, and an HVAC model into the forward-approach simulation model of a commercially available BEV to showcase the impact and efficacy of the proposed IETM strategy for enhancing battery longevity. The instantaneous optimization problem of IETM is solved by the golden-section search method leveraging the convexity of the objective function. Simulated results under different driving scenarios show that the improvement brought by the proposed ITEM controller can minimize battery health degradation by up to 4.5% and energy consumption by up to 2.8% while maintaining the cabin temperature deviation within permissible limits from the reference temperature. Full article

(This article belongs to the Special Issue Energy Management Systems of Electric Vehicles: New Trends and Dynamic Futures)

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15 pages, 4244 KiB

Open AccessArticle

Study on the Operation Optimization of Medium-Depth U-Type Ground Source Heat Pump Systems

by Chaohui Zhou, Yue Hu, Yuce Liu, Rujie Liu, Yongqiang Luo, Xiao Wang and Huiheng Luo

Energies 2024, 17(13), 3184; https://doi.org/10.3390/en17133184 (registering DOI) - 28 Jun 2024

Viewed by 97

Abstract

Deep geothermal energy is a sustainable and renewable spacing heating source. Although many studies have discussed the design optimization of deep borehole systems, few have accomplished optimization and in-depth analysis of system operation control. In this study, an analytical model of the U-type [...] Read more.

Deep geothermal energy is a sustainable and renewable spacing heating source. Although many studies have discussed the design optimization of deep borehole systems, few have accomplished optimization and in-depth analysis of system operation control. In this study, an analytical model of the U-type deep borehole heat exchanger is proposed, and the average relative error between the simulated outlet temperatures and experimental data is −3.2%. Then, this paper presents an integrated model for the operation optimization study of the U-type deep-borehole ground source heat pump system. The optimal control of flow rate is adopted to match the variation in heating load. Compared with the constant-flow rate (110 m³/h) operation mode, the variable flow rate method reduces the power consumption of the heat pump and circulating pump by 22.1%, from 288,423 kW·h to 224,592 kW·h, during 2112 h of operation. In addition, the system has a larger RHS and COP when the thermal conductivity of the backfill material increases. When the borehole depth increases by 200 m from 2300 m, the energy consumption of the circulating pump will drop from 85,844 kW·h to 56,548 kW·h. The COP of the heat pump unit will decrease approximately linearly as the heating load increases, and the total power consumption will increase accordingly. This work can provide guidance for the design and optimization of U-shaped GSHP systems. Full article

(This article belongs to the Special Issue Ground-Source Heat Pumps and Thermal Energy Storage Systems—Energy for the Future)

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35 pages, 2809 KiB

Open AccessReview

Advancements and Challenges of Ammonia as a Sustainable Fuel for the Maritime Industry

by Antonio Chavando, Valter Silva, João Cardoso and Daniela Eusebio

Energies 2024, 17(13), 3183; https://doi.org/10.3390/en17133183 - 28 Jun 2024

Viewed by 154

Abstract

The maritime industry needs sustainable, low-emission fuels to reduce the environmental impact. Ammonia is one of the most promising alternative fuels because it can be produced from renewable energy, such as wind and solar. Furthermore, ammonia combustion does not emit carbon. This review [...] Read more.

The maritime industry needs sustainable, low-emission fuels to reduce the environmental impact. Ammonia is one of the most promising alternative fuels because it can be produced from renewable energy, such as wind and solar. Furthermore, ammonia combustion does not emit carbon. This review article covers the advantages and disadvantages of using ammonia as a sustainable marine fuel. We start by discussing the regulations and environmental concerns of the shipping sector, which is responsible for around 2% to 3% of global energy-related CO₂ emissions. These emissions may increase as the maritime industry grows at a compound annual growth rate of 4.33%. Next, we analyze the use of ammonia as a fuel in detail, which presents several challenges. These challenges include the high price of ammonia compared to other fossil fuels, the low reactivity and high toxicity of ammonia, NOx, and N₂O emissions resulting from incomplete combustion, an inefficient process, and NH₃ slipping. However, we emphasize how to overcome these challenges. We discuss techniques to reduce NOx and N₂O emissions, co-combustion to improve reactivity, waste heat recovery strategies, the regulatory framework, and safety conditions. Finally, we address the market trends and challenges of using ammonia as a sustainable marine fuel. Full article

(This article belongs to the Special Issue Renewable Fuels for Internal Combustion Engines: 2nd Edition)

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12 pages, 3571 KiB

Open AccessArticle

Life Estimation of HVDC Cables Subjected to Fast and Slow Polarity Reversals

by Bassel Diban, Giovanni Mazzanti, Massimo Marzinotto and Antonio Battaglia

Energies 2024, 17(13), 3182; https://doi.org/10.3390/en17133182 - 28 Jun 2024

Viewed by 141

Abstract

This paper aims at estimating the life of extruded HVDC cable insulation subjected to fast and slow voltage polarity reversals (VPRs). An ad hoc MATLAB code is used for the transient electric field simulation in the cable insulation thickness by solving numerically Gauss, [...] Read more.

This paper aims at estimating the life of extruded HVDC cable insulation subjected to fast and slow voltage polarity reversals (VPRs). An ad hoc MATLAB code is used for the transient electric field simulation in the cable insulation thickness by solving numerically Gauss, ohm, and current continuity equations beside a macroscopic conductivity equation. A transient temperature is also considered during slow VPR transients. The results show a significant localized reduction in the life of the inner insulation, making the life distribution non-monotonous inside the insulation thickness. The results show that fast VPRs are the most stressing transients in this study. The longer the duration of the zero-voltage period in slow VPR, the less stressed the insulation, hence, the longer the local life in the inner insulation of the cable. The latter is justified by the charge relaxation during slow VPRs. Full article

(This article belongs to the Section F1: Electrical Power System)

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21 pages, 1330 KiB

Open AccessReview

Recent Developments in Hydrocyclone Technology for Oil-in-Water Separation from Produced Water

by Okwunna Maryjane Ekechukwu, Taimoor Asim and Haval Kukha Hawez

Energies 2024, 17(13), 3181; https://doi.org/10.3390/en17133181 - 28 Jun 2024

Viewed by 227

Abstract

The treatment of produced water is a major challenge faced by oil and gas industries worldwide. As a result of the increase in industrial activities, the generation of produced water has increased significantly. The most commonly used method for produced water oil–water separation [...] Read more.

The treatment of produced water is a major challenge faced by oil and gas industries worldwide. As a result of the increase in industrial activities, the generation of produced water has increased significantly. The most commonly used method for produced water oil–water separation is de-oiling hydrocyclone technology due to its simple construction, compact design, easy maintenance, and high efficiency. A wide breadth of scientific research studies has been carried out on performance evaluation, design optimisation, geometric parametrisation, external interventions, etc., to enhance the performance of hydrocyclones. These studies mostly rely on either experimental data obtained from the field, in laboratories under a controlled environment, or the application of numerical techniques for oil-in-water separation. Considering the extensive research studies published on hydrocyclone technology, this study aims to provide a comprehensive review of recent technological advancements in hydrocyclone technology in order to identify key areas where scientific research efforts should be concentrated. This will help make well-informed decisions for strategic investments in this wide area of research. Furthermore, it will widen the scope of applicability of hydrocyclones in the industrial sector. Full article

(This article belongs to the Section B: Energy and Environment)

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19 pages, 8392 KiB

Open AccessArticle

Pathways to the Large-Scale Adoption of Residential Photovoltaics in Saudi Arabia

by Abeer Alshehri, Patrick James and AbuBakr Bahaj

Energies 2024, 17(13), 3180; https://doi.org/10.3390/en17133180 - 28 Jun 2024

Viewed by 154

Abstract

This survey of predominantly middle–high-income owner-occupier households in the Kingdom of Saudi Arabia (KSA) assessed household perspectives to residential photovoltaics (PVs) (n = 268). Higher-income households were statistically more likely to (i) accept financial payback times of more than 12 months for the [...] Read more.

This survey of predominantly middle–high-income owner-occupier households in the Kingdom of Saudi Arabia (KSA) assessed household perspectives to residential photovoltaics (PVs) (n = 268). Higher-income households were statistically more likely to (i) accept financial payback times of more than 12 months for the CAPEX cost of a PV system, and (ii) be prepared to contribute up to SAR 10,000 (USD 2666) towards the CAPEX cost of a system. A multiple logistic regression analysis indicated that a high household education level and the dwelling tenure (owner) are key variables that positively influence PV acceptability. Median apartment and villa households in this survey had annual electricity demands of 22,969 kWh and 48,356 kWh, respectively. The available roof area per apartment and villa was assessed, considering parapet shading and roof furniture limitations (the presence of AC units, etc.), at 20 m² and 75 m², respectively. This would accommodate either a 4 kWp apartment system or a 10 kWp villa system mounted horizontally. Time-of-use tariffs or grant subsidies towards the cost of a PV system will be required to enable the surveyed households to meet their stated economic conditions for purchasing a PV system. This indicates that PV policies in KSA will need to be adapted to encourage the uptake of PVs. Full article

(This article belongs to the Special Issue Low-Carbon Integrated Energy System with Renewable Generations: Characterization, Modelling, and Optimization)

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31 pages, 1709 KiB

Open AccessReview

Climate Change and Energy Security: A Comparative Analysis of the Role of Energy Policies in Advancing Environmental Sustainability

by Ahmed Elkhatat and Shaheen Al-Muhtaseb

Energies 2024, 17(13), 3179; https://doi.org/10.3390/en17133179 - 28 Jun 2024

Viewed by 213

Abstract

This review analyzes the complex relationship between climate change and energy security and their joint impact on global development. It emphasizes the need for sustainable energy solutions to tackle increasing global warming effects and energy demands. A thorough literature analysis highlights the link [...] Read more.

This review analyzes the complex relationship between climate change and energy security and their joint impact on global development. It emphasizes the need for sustainable energy solutions to tackle increasing global warming effects and energy demands. A thorough literature analysis highlights the link between energy policies, climate goals, and sustainable development aspirations. Moreover, it examines the effectiveness of energy policies in various national contexts in promoting environmental sustainability and emphasizing regional dynamics, socio-economic factors, and diverse energy planning approaches. The review explains the multifaceted relationship between climate change, energy security, and environmental protection. Key recommendations related to renewable energy transitions are provided as crucial means to address global energy demand and resource constraints while reducing dependence on fossil fuels. The analysis underscores renewable energy’s key role in aligned energy strategies that balance security and sustainability for a low-carbon future. It emphasizes the critical need for coordinated policies, technological innovation, and collaborative action between academia, industry, and policymakers to advance integrated energy systems and thermal storage solutions. Full article

(This article belongs to the Special Issue Sustainable Development, Energetic Policies in the Context of the Global Crisis)

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