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Renewable Energy and Energy Storage Systems

A topical collection in Energies (ISSN 1996-1073). This collection belongs to the section "B: Energy and Environment".

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Editors


grade E-Mail Website
Collection Editor
1. Department of Sustainable and Renewable Energy Engineering, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates
2. Mechanical Engineering and Design, School of Engineering and Applied Science, Aston University, Aston Triangle, Birmingham B4 7ET, UK
Interests: renewable energy; energy storage systems, sustainability; CAD and design; smart materials
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E-Mail Website
Collection Editor
Department of Mechanics, Mathematics & Management, Polytechnical University of Bari, Piazza Umberto I, 1, 70121 Bari BA, Italy
Interests: manufacturing processes; product lifecycle management; sustainable manufacturing; eco-sustainability; industrial and manufacturing engineering; continuous improvement of manufacturing processes; distributed and delocalized production systems; quality management; renewable sources; manufacturing execution systems; cyber-physical systems; smart materials and their manufacturing and applications
Special Issues, Collections and Topics in MDPI journals
William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
Interests: carbon capture utilization and storage (CCUS); gas separation; membrane; polymer; absorption; process modeling; mass transfer; heat transfer; fossil fuel; renewable energy; hydrate; wastewater treatment
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

This Special Issue covers the state of the art of the following renewable energy and energy storage systems topics: solar energy, wind energy, biomass and bioenergy, hydro power, tidal and wave energy, geothermal energy, mechanical energy storage systems, electrochemical storage systems, thermal storage systems, air-compressed storage systems, and all related fields.

Prof. Dr. Abdul-Ghani Olabi
Prof. Ing. Michele Dassisti
Dr. Zhien Zhang
Collection Editors

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Published Papers (72 papers)

2024

Jump to: 2023, 2022, 2021, 2020

12 pages, 1869 KiB  
Article
Comparison of Single-Phase Mathematical Models for Solid-State Packed Beds for Thermal Energy Storage
by Thomas Coates, Law Torres Sevilla, Burhan Saeed and Jovana Radulovic
Energies 2024, 17(8), 1842; https://doi.org/10.3390/en17081842 - 11 Apr 2024
Viewed by 186
Abstract
This article presents an analytical solution for the evaluation of the thermal performance of packed bed sensible heat storage. The numerical model developed was tested for four different solid storage mediums. The thermal energy equation is solved numerically by deploying the finite difference [...] Read more.
This article presents an analytical solution for the evaluation of the thermal performance of packed bed sensible heat storage. The numerical model developed was tested for four different solid storage mediums. The thermal energy equation is solved numerically by deploying the finite difference method. The presented analytical solution is based on a novel mathematical approach. The numerical model was validated using the computer simulation package Comsol Multiphysics v5.3. Our numerical model results are in good agreement with the published experimental data, with an overall difference of ~10%. Hence, the numerical model is an efficient way of evaluating the thermal performance of packed bed thermal energy storage systems compared to other numerical strategies or computer simulation techniques. This proves that the novel analytical model has shown to be a reliable and broadly accurate approach to acquire the thermal performance of sensible heat storage. Full article
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12 pages, 3711 KiB  
Article
Numerical Analysis of New PCM Thermal Storage Systems
by Giampietro Fabbri, Matteo Greppi and Federico Amati
Energies 2024, 17(7), 1772; https://doi.org/10.3390/en17071772 - 08 Apr 2024
Viewed by 249
Abstract
In this paper, a thermal storage system based on a phase change material is proposed and investigated. The system is composed of several tubes that cross a phase change material mass. A fluid flowing in the tubes charges and discharges the heat storage [...] Read more.
In this paper, a thermal storage system based on a phase change material is proposed and investigated. The system is composed of several tubes that cross a phase change material mass. A fluid flowing in the tubes charges and discharges the heat storage system. A mathematical model of the system has been developed, which provides the time and space distribution of velocity, temperature, and liquid phase-changing material concentration in a non-stationary regime. A hybrid solution method based on finite volumes and finite differences techniques has been employed for the model equations in the MATLAB environment. To the tubes, a rectangular cross section has been assigned. The performance of the system in terms of accumulated energy density and accumulated power density has been investigated by varying some geometric parameters. The considered geometric parameters influence the number of tubes per unit of system width, the tube hydraulic resistance, the amount of phase change material around each tube, the heat transfer surface of the tube, and the heat storage velocity. In the parametric analysis, peaks have been evidenced in the investigated performance parameters at different instants after the beginning of the heat storage. Full article
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19 pages, 3386 KiB  
Article
Differences and Causal Mechanisms in the Lithospheric Thermal Structures in the Cratons in East China: Implications for Their Geothermal Resource Potential
by Jinhui Wu, Yibo Wang, Lijuan He, Lijuan Wang, Junpeng Guan, Jun Chen, Zhuting Wang, Yaqi Wang and Shengbiao Hu
Energies 2024, 17(7), 1752; https://doi.org/10.3390/en17071752 - 06 Apr 2024
Viewed by 307
Abstract
The thermal structure of the lithosphere is key to understanding its thickness, properties, evolution, and geothermal resources. Cratons are known for their low heat flow and deep lithospheric roots. However, present-day cratons in East China have geothermal characteristics that are highly complex, with [...] Read more.
The thermal structure of the lithosphere is key to understanding its thickness, properties, evolution, and geothermal resources. Cratons are known for their low heat flow and deep lithospheric roots. However, present-day cratons in East China have geothermal characteristics that are highly complex, with variable heat flow values, diverging from the typical thermal state of cratons. In this study, we conducted a detailed analysis of the geothermal geological background of the cratons in East China, summarizing the thermal state and tectono-thermal processes of different tectonic units, calculating the temperature at various depths, and discussing differences in temperature and thermal reservoirs at different depths. The observed lithospheric thermal thickness within the North Jiangsu Basin and the Bohai Bay Basin is notably reduced in comparison to that of the Jianghan Basin and the Southern North China Basin. The phenomenon of craton destruction during the Late Mesozoic emerges as a pivotal determinant, enhancing the geothermal resource prospects of both the Bohai Bay Basin and the North Jiangsu Basin. Our findings contribute significantly to the augmentation of theoretical frameworks concerning the origins of heat sources in global cratons. Furthermore, they offer invaluable insights for the methodical exploration, evaluation, advancement, and exploitation of geothermal resources. Full article
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16 pages, 20102 KiB  
Article
Joint Estimation of SOC and SOH for Lithium-Ion Batteries Based on Dual Adaptive Central Difference H-Infinity Filter
by Bingyu Sang, Zaijun Wu, Bo Yang, Junjie Wei and Youhong Wan
Energies 2024, 17(7), 1640; https://doi.org/10.3390/en17071640 - 29 Mar 2024
Viewed by 325
Abstract
The accurate estimation of the state-of-charge (SOC) and state-of-health (SOH) of lithium-ion batteries is crucial for the safe and reliable operation of battery systems. In order to overcome the practical problems of low accuracy, slow convergence and insufficient robustness in the existing joint [...] Read more.
The accurate estimation of the state-of-charge (SOC) and state-of-health (SOH) of lithium-ion batteries is crucial for the safe and reliable operation of battery systems. In order to overcome the practical problems of low accuracy, slow convergence and insufficient robustness in the existing joint estimation algorithms of SOC and SOH, a Dual Adaptive Central Difference H-Infinity Filter algorithm is proposed. Firstly, the Forgetting Factor Recursive Least Squares (FFRLS) algorithm is employed for parameter identification, and an inner loop with multiple updates of the parameter estimation vector is added to improve the accuracy of parameter identification. Secondly, the capacity is selected as the characterization of SOH, and the open circuit voltage and capacity are used as the state variables for capacity estimation to improve its convergence speed. Meanwhile, considering the interaction between SOC and SOH, the state space equations of SOC and SOH estimation are established. Moreover, the proposed algorithm introduces a robust discrete H-infinity filter equation to improve the measurement update on the basis of the central differential Kalman filter with good accuracy, and combines the Sage–Husa adaptive filter to achieve the joint estimation of SOC and SOH. Finally, under Urban Dynamometer Driving Schedule (UDDS) and Highway Fuel Economy Test (HWFET) conditions, the SOC estimation errors are 0.5% and 0.63%, and the SOH maximum estimation errors are 0.73% and 0.86%, indicating that the proposed algorithm has higher accuracy compared to the traditional algorithm. The experimental results at different initial values of capacity and SOC demonstrate that the proposed algorithm showcases enhanced convergence speed and robustness. Full article
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20 pages, 65866 KiB  
Article
Classification of Highly Imbalanced Supervisory Control and Data Acquisition Data for Fault Detection of Wind Turbine Generators
by Jorge Maldonado-Correa, Marcelo Valdiviezo-Condolo, Estefanía Artigao, Sergio Martín-Martínez and Emilio Gómez-Lázaro
Energies 2024, 17(7), 1590; https://doi.org/10.3390/en17071590 - 26 Mar 2024
Viewed by 309
Abstract
It is common knowledge that wind energy is a crucial, strategic component of the mix needed to create a green economy. In this regard, optimizing the operations and maintenance (O&M) of wind turbines (WTs) is key, as it will serve to reduce the [...] Read more.
It is common knowledge that wind energy is a crucial, strategic component of the mix needed to create a green economy. In this regard, optimizing the operations and maintenance (O&M) of wind turbines (WTs) is key, as it will serve to reduce the levelized cost of electricity (LCOE) of wind energy. Since most modern WTs are equipped with a Supervisory Control and Data Acquisition (SCADA) system for remote monitoring and control, condition-based maintenance using SCADA data is considered a promising solution, although certain drawbacks still exist. Typically, large amounts of normal-operating SCADA data are generated against small amounts of fault-related data. In this study, we use high-frequency SCADA data from an operating WT with a significant imbalance between normal and fault classes. We implement several resampling techniques to address this challenge and generate synthetic generator fault data. In addition, several machine learning (ML) algorithms are proposed for processing the resampled data and WT generator fault classification. Experimental results show that ADASYN + Random Forest obtained the best performance, providing promising results toward wind farm O&M optimization. Full article
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15 pages, 1254 KiB  
Review
Unlocking Geothermal Energy: A Thorough Literature Review of Lithuanian Geothermal Complexes and Their Production Potential
by Abdul Rashid Memon, Pijus Makauskas, Ieva Kaminskaite-Baranauskiene and Mayur Pal
Energies 2024, 17(7), 1576; https://doi.org/10.3390/en17071576 - 26 Mar 2024
Viewed by 329
Abstract
Lithuania is located on the East of Baltic sedimentary basin and has a geothermal anomaly situated in the southwestern region of the country. There are two primary geothermal complexes within the anomaly, composed of Cambrian and Devonian aquifers. The Cambrian formation is composed [...] Read more.
Lithuania is located on the East of Baltic sedimentary basin and has a geothermal anomaly situated in the southwestern region of the country. There are two primary geothermal complexes within the anomaly, composed of Cambrian and Devonian aquifers. The Cambrian formation is composed of sandstones that have a reservoir temperature reaching up to 96 °C (depth > 2000 m). The Devonian aquifer is composed of unconsolidated sands of Parnu–Kemeri and has a reservoir temperature of up to 46 °C (depth > 1000 m). Historically, both formations have been investigated for geothermal energy production. In this article, we present a detailed literature review of the geothermal work carried out on both formations, including past, present, and some possible future studies. The study presented in this paper highlights the key findings of previous research work, summarizes the research gaps, and then elaborates on the possible applications of emerging technologies to bridge the research gaps and improve our understanding of geothermal complexes in Lithuania. Although it is not the main aim of this article, this article also touches upon the important need to develop 2D/3D numerical models, to quantify uncertainties, in the evaluation of the geothermal potential in Lithuania for commercial development. This study also highlights possibilities of extending geothermal development to depleted hydrocarbon reservoirs through repurposing the high-water-production wells. Moreover, from the literature review, it can be concluded that the Lithuanian geothermal aquifers are hyper-saline in nature and temperature changes lead to the deposition of salts both upstream and downstream of the reservoir. Therefore, there is a need for developing multiphysics thermo-mechanical–chemical (THMC) models for evaluation of reservoir behavior. The literature also describes the potential use and development of the THMC model as a part of future work that must be carried out. Full article
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22 pages, 458 KiB  
Review
A Review of Energy Overconsumption Reduction Methods in the Utilization Stage in Compressed Air Systems
by Dominik Gryboś and Jacek S. Leszczyński
Energies 2024, 17(6), 1495; https://doi.org/10.3390/en17061495 - 21 Mar 2024
Viewed by 378
Abstract
Pneumatic systems use the energy of compressed air to carry out manufacturing automation processes through the implementation of complex handling and motion tasks. However, these systems are energy intensive: it is estimated that pneumatic systems in manufacturing plants consume approximately 10% of all [...] Read more.
Pneumatic systems use the energy of compressed air to carry out manufacturing automation processes through the implementation of complex handling and motion tasks. However, these systems are energy intensive: it is estimated that pneumatic systems in manufacturing plants consume approximately 10% of all electricity consumed in the industrial sector. At the same time, the energy efficiency of the whole pneumatic system is observed to be 6–10%, due to the compression process, oversizing, and overconsumption. There are numerous solutions in the literature focusing on improving efficiency at the compression stage of utilization; however, for the utilization stage, there is a lack of systematization and grouping of these solutions. The following review will summarize current knowledge about the utilization stage and methods for improving oversizing and energy overconsumption. In addition, a method of exergy analysis for pneumatic systems will be presented, which is a very useful tool to assess the efficiency of these systems. Full article
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26 pages, 5153 KiB  
Article
Adaptation of Microinverter Reference Design for Integration with Battery Energy Storage Systems in Microgrids
by Danijel Jolevski, Damir Jakus, Josip Vasilj and Joško Novaković
Energies 2024, 17(6), 1487; https://doi.org/10.3390/en17061487 - 20 Mar 2024
Viewed by 361
Abstract
The paper presents an adaptation of the microinverter platform from Texas Instruments to incorporate a battery energy storage system (BESS) alongside the development of the BESS system itself. Initially designed for unidirectional power flow between PV panels and an electric grid, the platform [...] Read more.
The paper presents an adaptation of the microinverter platform from Texas Instruments to incorporate a battery energy storage system (BESS) alongside the development of the BESS system itself. Initially designed for unidirectional power flow between PV panels and an electric grid, the platform required modifications to accommodate bidirectional energy transfer for BESS integration. These modifications encompass software adjustments and hardware enhancements, which are all detailed within the paper. The electrical configuration includes selecting and deploying components such as DCDC power converters, microcontrollers, measured signals, and actuating signals to facilitate battery connection to the platform’s DC bus. Furthermore, a supervisory control and data acquisition (SCADA) system is devised for supervisory control and monitoring, with its implementation outlined. Control software tailored for the chosen microcontroller of the DCDC converters is described in terms of structure and functionality. A hardware-in-the-loop (HIL) methodology is employed to validate the proposed modifications and microgrid configuration. Utilizing the real-time simulator OPAL-RT, the paper presents experimental results and their analysis within the considered microgrid environment. Full article
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30 pages, 4706 KiB  
Article
Sizing of Battery Energy Storage Systems for Firming PV Power including Aging Analysis
by Juan A. Tejero-Gómez and Ángel A. Bayod-Rújula
Energies 2024, 17(6), 1485; https://doi.org/10.3390/en17061485 - 20 Mar 2024
Viewed by 477
Abstract
The variability of solar radiation presents significant challenges for the integration of solar photovoltaic (PV) energy into the electrical system. Incorporating battery storage technologies ensures energy reliability and promotes sustainable growth. In this work, an energy analysis is carried out to determine the [...] Read more.
The variability of solar radiation presents significant challenges for the integration of solar photovoltaic (PV) energy into the electrical system. Incorporating battery storage technologies ensures energy reliability and promotes sustainable growth. In this work, an energy analysis is carried out to determine the installation size and the operating setpoint with optimal constant monthly power through an iterative calculation process, considering various operating setpoints and system parameters. A degradation model is integrated according to the curves offered by battery manufacturers and the charge–discharge cycles are calculated using the rainflow method to guarantee a reliable analysis of the plant. Through massive data analysis in a long-term simulation, indicators are generated that allow for establishing a relationship between the energy unavailability of the system and the BESS dimensions. Full article
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18 pages, 4409 KiB  
Article
Assessing Geothermal Energy Production Potential of Cambrian Geothermal Complexes in Lithuania
by Pijus Makauskas, Ieva Kaminskaite-Baranauskiene, Abdul Rashid Abdul Nabi Memon and Mayur Pal
Energies 2024, 17(5), 1054; https://doi.org/10.3390/en17051054 - 23 Feb 2024
Cited by 1 | Viewed by 563
Abstract
Lithuania has a geothermal anomaly situated in the southwestern region of the country. This anomaly is comprised of two primary geothermal complexes located in western Lithuania. The first complex is characterized by the Pärnu–Kemeri Devonian sandstone aquifers, which exhibit exceptionally good flow properties. [...] Read more.
Lithuania has a geothermal anomaly situated in the southwestern region of the country. This anomaly is comprised of two primary geothermal complexes located in western Lithuania. The first complex is characterized by the Pärnu–Kemeri Devonian sandstone aquifers, which exhibit exceptionally good flow properties. However, the reservoir temperatures in this complex only reach up to 45 °C. The second complex encompasses Cambrian sandstone reservoirs. Although these Cambrian sandstone reservoirs exhibit high temperatures, with the highest reservoir temperatures reaching up to 96 °C, these Cambrian sandstone reservoirs have less favorable petrophysical properties. This study focuses on the high temperature Cambrian Geothermal sandstone reservoirs. The study aims to conduct a geological screening of the existing and depleted hydrocarbon reservoirs with high water production rates. After initial data gathering, numerical modeling is employed with the help of mechanistic box models to evaluate the geothermal potential of the selected sites for commercial development. Ultimately, the study identifies the top five screened sites, which could be developed further for techno-economical modelling. Full article
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12 pages, 2992 KiB  
Article
Thermal Evolution of NiFe-NO3 LDH and Its Application in Energy Storage Systems
by Marco Fortunato, Andrea Pietro Reverberi, Bruno Fabiano and Anna Maria Cardinale
Energies 2024, 17(5), 1035; https://doi.org/10.3390/en17051035 - 22 Feb 2024
Viewed by 464
Abstract
In this work, the performances of nickel iron layered double hydroxides (LDH) with the nitrate anion at the interlayer (NiFe-NO3) for the manufacture of anodes for lithium-ion batteries have been tested before and after its sintering at different temperatures. After synthesis, [...] Read more.
In this work, the performances of nickel iron layered double hydroxides (LDH) with the nitrate anion at the interlayer (NiFe-NO3) for the manufacture of anodes for lithium-ion batteries have been tested before and after its sintering at different temperatures. After synthesis, the material was thermally analyzed in a range 30–1250 °C, showing a mass loss occurring in three different consecutive steps leading to a total mass decrease of ~30 mass%. Following thermogravimetric analysis (TGA), four samples were prepared by annealing at four different temperatures: one of the four did not undergo a thermal treatment (NiFe-0), while the remaining three were annealed at 250 °C, 360 °C, and 560 °C for 6 h (NiFe-250, NiFe-360, and NiFe-560). All materials where completely characterized via FE-SEM, PXRD, and FT-IR. The pristine LDH material showed some structural and compositional changes for growing temperatures, starting from the typical turbostratic hexagonal structure through a mixture of amorphous metal oxides and finally to the stoichiometric oxides FeNi2O4 and NiO. The as-obtained materials were mixed with carbon black (C65) and sodium alginate and tested as electrodes in Swagelok half cells in LP30 vs. metallic Li to perform CV and GCPL analysis. The electrochemical tests showed that the performances of NiFe-0, both in terms of stability and specific capacity, are not so different from the one of the NiFe-560, even if the Ni mass% in the former is lower than in the NiFe-560. This phenomenon could be explained by assuming a combined mechanism of reaction involving both intercalation and conversion. Full article
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16 pages, 2923 KiB  
Article
Assessing the Performance of Continuous-Flow Microbial Fuel Cells and Membrane Electrode Assembly with Electrodeposited Mn Oxide Catalyst
by Laura Mais, Michele Mascia and Annalisa Vacca
Energies 2024, 17(4), 943; https://doi.org/10.3390/en17040943 - 17 Feb 2024
Viewed by 540
Abstract
Microbial fuel cells (MFCs) are considered promising energy sources whereby chemical energy is converted into electricity via bioelectrochemical reactions utilizing microorganisms. Several factors affect MFC performance, including cathodic reduction of oxygen, electrode materials, cell internal and external resistances, and cell design. This work [...] Read more.
Microbial fuel cells (MFCs) are considered promising energy sources whereby chemical energy is converted into electricity via bioelectrochemical reactions utilizing microorganisms. Several factors affect MFC performance, including cathodic reduction of oxygen, electrode materials, cell internal and external resistances, and cell design. This work describes the effect of the catalyst coating in the air-cathode membrane electrode assembly (MEA) for a microbial fuel cell (MFC) prepared via electrodeposition of manganese oxide. The characterization of the synthesized air-cathode MFC, operating in a continuous mode, was made via electrochemical impedance spectroscopy (EIS) analyses for the determination of the intrinsic properties of the electrode that are crucial for scalability purposes. EIS analysis of the MFCs and of the MEA reveals that the anode and cathode contribute to polarization resistance by about 85% and 15%, respectively, confirming the high catalytic activity of the Mn-based air cathode. The maximum power density of the Mn-based cathode is about 20% higher than that recorded using a Pt/C electrode. Full article
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2023

Jump to: 2024, 2022, 2021, 2020

30 pages, 13117 KiB  
Article
Experimental and Numerical Study of Novel Vortex Bladeless Wind Turbine with an Economic Feasibility Analysis and Investigation of Environmental Benefits
by Hasan Hamdan, Sharul Sham Dol, Abdelrahman Hosny Gomaa, Aghyad Belal Al Tahhan, Ahmad Al Ramahi, Haya Fares Turkmani, Mohammad Alkhedher and Rahaf Ajaj
Energies 2024, 17(1), 214; https://doi.org/10.3390/en17010214 - 30 Dec 2023
Viewed by 1664
Abstract
This study combines experimental and numerical evaluations of Vortex Bladeless Wind Turbines (VBWTs) to understand their potential in renewable energy generation. The methodology employs Two-Way Fluid–Solid Interface (FSI) simulations, alongside real-world data, providing important insights into the turbine’s vibration dynamics and flow interactions [...] Read more.
This study combines experimental and numerical evaluations of Vortex Bladeless Wind Turbines (VBWTs) to understand their potential in renewable energy generation. The methodology employs Two-Way Fluid–Solid Interface (FSI) simulations, alongside real-world data, providing important insights into the turbine’s vibration dynamics and flow interactions during operation. Key findings include identifying optimal vibration frequencies and amplitudes that enhance energy harvesting and a clear advantage in power-generation estimations shown by one of the models used. The study reveals possible applications of VBWT in various settings like airport runways, highways, and buildings, indicating a promising avenue for incorporating such renewable-energy solutions. Discussions on the economic feasibility and environmental benefits of VBWT deployment are also presented, suggesting a need for further research and optimization in this area. A conceptual generator design and business model are introduced as part of a broader discussion on technology integration and energy storage. The research in this study encompasses experimental and numerical analysis, to achieve a broader understanding of the workings of a VBWT, realizing the feasibility of using such systems in lower-wind-speed conditions and upscaling to higher-wind-speed cases. Full article
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17 pages, 4299 KiB  
Perspective
The Role of Education and Science-Driven Tools in Scaling Up Photovoltaic Deployment
by Ana M. Martínez, Christian Thiel, Sandor Szabo, Imen Gherboudj, René van Swaaij, Andreea Tanasa, Arnulf Jäger-Waldau, Nigel Taylor and Arno Smets
Energies 2023, 16(24), 8065; https://doi.org/10.3390/en16248065 - 14 Dec 2023
Viewed by 626
Abstract
Accelerating the deployment of Photovoltaic (PV) systems is a key contributing factor in achieving climate neutrality. Even though solar power is one of the cheapest energy sources and its deployment is growing rapidly around the world, an even faster growth is required to [...] Read more.
Accelerating the deployment of Photovoltaic (PV) systems is a key contributing factor in achieving climate neutrality. Even though solar power is one of the cheapest energy sources and its deployment is growing rapidly around the world, an even faster growth is required to achieve existing climate goals. Besides the role that finance and permitting can play as enablers or barriers to this, the key elements to enable fast PV deployment are the use of education, and science and data-driven tools to empower citizens, installers, and investors to make their decisions based on robust scientific evidence. This perspective article aims to summarize the key concepts presented and discussed during the side event at COP27 on PV resources towards climate neutrality. The article will accomplish this by highlighting two key aspects: (1) the advantages of using solar-related education and data-driven tools, and (2) showcasing the significance of education, improved data and tools, community involvement, and PV mapping in expediting the deployment of PV systems. Full article
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32 pages, 8722 KiB  
Review
Power Generation with Renewable Energy and Advanced Supercritical CO2 Thermodynamic Power Cycles: A Review
by Xinyu Zhang and Yunting Ge
Energies 2023, 16(23), 7781; https://doi.org/10.3390/en16237781 - 26 Nov 2023
Cited by 2 | Viewed by 1197
Abstract
Supercritical CO2 (S-CO2) thermodynamic power cycles have been considerably investigated in the applications of fossil fuel and nuclear power generation systems, considering their superior characteristics such as compactness, sustainability, cost-effectiveness, environmentally friendly working fluid and high thermal efficiency. They can [...] Read more.
Supercritical CO2 (S-CO2) thermodynamic power cycles have been considerably investigated in the applications of fossil fuel and nuclear power generation systems, considering their superior characteristics such as compactness, sustainability, cost-effectiveness, environmentally friendly working fluid and high thermal efficiency. They can be potentially integrated and applied with various renewable energy systems for low-carbon power generation, so extensive studies in these areas have also been conducted substantially. However, there is a shortage of reviews that specifically concentrate on the integrations of S-CO2 with renewable energy, encompassing biomass, solar, geothermal and waste heat. It is thus necessary to provide an update and overview of the development of S-CO2 renewable energy systems and identify technology and integration opportunities for different types of renewable resources. Correspondingly, this paper not only summarizes the advantages of CO2 working fluid, design layouts of S-CO2 cycles and classifications of renewable energies to be integrated but also reviews the recent research activities and studies carried out worldwide on advanced S-CO2 power cycles with renewable energy. Moreover, the performance and development of various systems are well grouped and discussed. Full article
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14 pages, 11097 KiB  
Article
Two-Dimensional Geothermal Model of the Peruvian Andes above the Nazca Ridge Subduction
by Sara Ciattoni, Stefano Mazzoli, Antonella Megna, Matteo Basilici and Stefano Santini
Energies 2023, 16(23), 7697; https://doi.org/10.3390/en16237697 - 21 Nov 2023
Viewed by 680
Abstract
The aseismic Nazca Ridge produces localized flat-slab subduction beneath the South American margin at latitudes 10° to 15° S. The geological evolution and the spatio-temporal pattern of deformation of the upper plate have been strongly influenced by the presence of the flat slab. [...] Read more.
The aseismic Nazca Ridge produces localized flat-slab subduction beneath the South American margin at latitudes 10° to 15° S. The geological evolution and the spatio-temporal pattern of deformation of the upper plate have been strongly influenced by the presence of the flat slab. In this study, we investigated the lithospheric thermal structure of this region by elaborating a 2D geothermal model along a section across the top of the Nazca Ridge, the Peru–Chile trench, the Andean Cordillera, and the Amazonian Basin, for a total length of 1000 km. For the sake of modelling, the crust of the overriding plate was subdivided into two parts, i.e., a sedimentary cover (including the entire lithostratigraphic sequence) and a crystalline basement. Applying an analytical methodology, we calculated geotherms and isotherms by setting (i) thickness, (ii) density, (iii) heat production, and (iv) thermal conductivity for each geological unit and considering (v) heat flux at the Moho, (vi) frictional heating produced by faults, and (vii) plate convergence rate. The resulting model could make a significant advance in our understanding of how flat slab geometry associated with the Nazca Ridge subduction affects the thermal structure and hence the tectonic evolution of the region. Full article
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20 pages, 3555 KiB  
Article
What Is the Impact of the Renewable Energy Power Absorption Guarantee Mechanism on China’s Green Electricity Market?
by Yan Lu, Xuan Liu, Hongjian Li, Haoran Wang, Jiajie Kong, Cheng Zhong, Mingli Cui, Yan Li, Xiaoqi Sun, Jiadong Xuan and Tiantian Feng
Energies 2023, 16(21), 7434; https://doi.org/10.3390/en16217434 - 03 Nov 2023
Cited by 1 | Viewed by 661
Abstract
In order to accelerate the construction of a clean, low-carbon, safe and efficient energy system, China set the provincial weight of responsibility for renewable energy power consumption and established a renewable energy power absorption guarantee mechanism in 2019. As a market incentive policy, [...] Read more.
In order to accelerate the construction of a clean, low-carbon, safe and efficient energy system, China set the provincial weight of responsibility for renewable energy power consumption and established a renewable energy power absorption guarantee mechanism in 2019. As a market incentive policy, it has enduring effect on the low-carbon transformation of the power industry. Firstly, the operation mechanism of the renewable energy consumption guarantee mechanism is analyzed. The general framework, core elements and supporting measures are clarified. Secondly, a stock-flow diagram is constructed based on the system dynamics method. It contains the green electricity market sub-module, the green-certificate market sub-module and the excess power absorption market sub-module. Finally, multiple scenarios are set up to simulate the impact of the green-certificate market and excess power absorption market improvements on the installed capacity and tariff of China’s green power market. The renewable energy guarantee mechanism is an effective means to promote the consumption of green electricity in China. In addition, in the short term the cost of electricity for users has increased, but in the long term the cost of electricity shows a fluctuating downward trend. This study provides theoretical references for the formulation of clean and low-carbon policy objectives in the power industry and the optimization of market mechanisms. Full article
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23 pages, 3551 KiB  
Article
Theoretical and Energy Biomass Potential of Heat and Electricity Production in Kosovo
by Ardit Sertolli, Attila Bai, Zoltán Gabnai, Tamás Mizik and Albiona Pestisha
Energies 2023, 16(20), 7209; https://doi.org/10.3390/en16207209 - 23 Oct 2023
Viewed by 1327
Abstract
The energy use of residues from agriculture, forestry, and solid waste can foster the transition towards a more renewable energy supply. This paper analyzes the energy potential of the above-mentioned sources for energy applications in Kosovo. The analysis is based on statistical data [...] Read more.
The energy use of residues from agriculture, forestry, and solid waste can foster the transition towards a more renewable energy supply. This paper analyzes the energy potential of the above-mentioned sources for energy applications in Kosovo. The analysis is based on statistical data from different studies and reports, analyzing and calculating them to determine the theoretical and energy biomass potential. Kosovo can increase its self-sufficiency by taking advantage of its rich but under-utilized potential of biomass energy sources. This is a novelty study in this area, considering Kosovo lignite-dominated heat energy and electricity consumption and the available special literature. According to our estimates, the theoretical potential is 6.13 million tons/year, while the biomass energy potential should be around 4.57 million tons/year, including approximately 74.6% of biomass, which can be used for energy needs (heating and electricity). Based on the data and calculations, the available and usable potential shows biomass as an energy source with high potential in Kosovo; its share is very low, but it is reasonable to grow for both environmental and economic reasons. Full article
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17 pages, 2791 KiB  
Article
Analysis of Frequency Regulation Capability of Doubly Fed Induction Generator and Supercapacitor Energy Storage Based on Dynamic Power Flow
by Tingting Sun, Hongru Shi, Lei Ren and Jiejie Huang
Energies 2023, 16(20), 7059; https://doi.org/10.3390/en16207059 - 12 Oct 2023
Viewed by 624
Abstract
The grid-integrated doubly fed induction generator (DFIG) is required to participate in the frequency regulation of the power system. The supercapacitor energy storage (SES) is capable of enhancing the frequency regulation capability of the DFIG in a coupled manner. The SES is connected [...] Read more.
The grid-integrated doubly fed induction generator (DFIG) is required to participate in the frequency regulation of the power system. The supercapacitor energy storage (SES) is capable of enhancing the frequency regulation capability of the DFIG in a coupled manner. The SES is connected to the DC capacitor of the DFIG and provides active power response through the droop control. The dynamic power flow (DPF) model is established to quantify the frequency response of the power system when the DFIG-SES system participates in the frequency regulation. The integration of the SES affects the internal power flow distribution of the DFIG; thus, the detailed model of the DFIG is incorporated into the DPF analysis. Considering the different response speeds of the synchronous generator (SG), the SES, and the DFIG to the frequency regulation, the first-order inertia delay in the governor control of the SG is included in the DPF model. The impact of the delay time constant on the continued operation time of the SES is analyzed. With the same deloading percentage, the output power of the DFIG is adjusted based on a variable droop coefficient scheme to fully utilize its active power reserve. The feasibility and effectiveness of the DFIG-SES scheme to participate in the frequency regulation are analyzed based on the DPF and verified through numerical analysis. Full article
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17 pages, 16478 KiB  
Article
Detection of Manufacturing Defects in Lithium-Ion Batteries-Analysis of the Potential of Computed Tomography Imaging
by Daniel Evans, Paul-Martin Luc, Claas Tebruegge and Julia Kowal
Energies 2023, 16(19), 6958; https://doi.org/10.3390/en16196958 - 05 Oct 2023
Viewed by 1961
Abstract
Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in [...] Read more.
Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in performance parameters of LIBs within the same batch. The greater the number and/or intensity of inhomogeneities, the more they need to be avoided. Severe inhomogeneities (defects), such as metal particle contamination, significantly impact the cell’s performance. Besides electrical measurements, image-based measurement methods can be used to identify defects and, thus, ensure the production quality and safety of LIBs. While the applicability of computed tomography (CT) as an image-based measurement method for detecting defects has been proven, the limitations of this method still need to be determined. In this study, a systematic analysis of the capabilities of CT imaging was conducted. A multilayer pouch cell without an electrolyte was reassembled with several defects on one of the middle anodes. To investigate the boundaries of CT, defects such as a partial and complete removal of the coating, a cut, or a kink, as well as particle contaminations of various sizes and materials (aluminium, copper, iron) were chosen. By comparing the CT images of the cell using laser scanning microscope images of the defective anode, it could be proven that all selected defects except the kink were detectable. Full article
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23 pages, 943 KiB  
Article
Application of Circular Thermoeconomics to the Diagnosis of Energy Systems
by Antonio Valero and César Torres
Energies 2023, 16(18), 6751; https://doi.org/10.3390/en16186751 - 21 Sep 2023
Viewed by 638
Abstract
This paper reviews the fundamentals of the thermoeconomic diagnosis theory. Thermoeconomic diagnosis is one of the main applications of the exergy cost theory used to identify the causes of additional resource consumption of a system due to inefficiencies in its components, published in [...] Read more.
This paper reviews the fundamentals of the thermoeconomic diagnosis theory. Thermoeconomic diagnosis is one of the main applications of the exergy cost theory used to identify the causes of additional resource consumption of a system due to inefficiencies in its components, published in the late 1990s. Thermoeconomic diagnosis has usually been applied to diagnose power plants with high consumption of fossil fuels and fixed production. However, it does not consider the final production and waste generation variation. In this paper, Circular Thermoeconomics is applied to analyze in depth the effect of malfunctions on additional waste generation and changes in the final output of the system. This new formulation can be applied to polygeneration systems, where there is a simultaneous variation of final products, and to process integration and industrial symbiosis, where a part of the waste generated by a plant could be reused in other processes or plants. Full article
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33 pages, 2788 KiB  
Review
From Lab to Fab: Development and Deployment of Direct Air Capture of CO2
by Vahid Barahimi, Monica Ho and Eric Croiset
Energies 2023, 16(17), 6385; https://doi.org/10.3390/en16176385 - 03 Sep 2023
Viewed by 3641
Abstract
Direct Air Capture (DAC) is a promising technology to fight climate change by capturing carbon dioxide (CO2) from the air. For DAC to be a negative emissions technology, the captured CO2 must be removed permanently, but can also be used [...] Read more.
Direct Air Capture (DAC) is a promising technology to fight climate change by capturing carbon dioxide (CO2) from the air. For DAC to be a negative emissions technology, the captured CO2 must be removed permanently, but can also be used as a net-zero technology to produce sustainable chemicals, fuels or other materials. This review presents a comprehensive survey of recent advancements, challenges, and potential applications of DAC technology, with an emphasis on the recent rapid increase in the number of DAC developers, the majority of them being founded in the past 4 years. Through pilot projects and recent commercial deployments, several DAC companies have made significant advances and demonstrated their scalability. Cost and energy efficiency remain significant impediments to the wide deployment of DAC. Integration with emission-free energy sources and utilization of waste heat are being researched to boost the total energy efficiency of DAC systems. Further research of electrochemical technologies for regeneration or direct capture are needed, as well as the development of new, modified, or hybrid adsorbents for improved capture efficiencies. Moreover, favorable regulations and financial incentives are crucial for enhancing the viability of DAC projects and will need to substantially increase if Paris Agreement goals are to be achieved. Full article
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30 pages, 1502 KiB  
Article
Evolutionary Analysis of the Solar Photovoltaic Products Trade Network in Belt and Road Initiative Countries from an Economic Perspective
by Liusuo Hu, Jian Hu and Weilung Huang
Energies 2023, 16(17), 6371; https://doi.org/10.3390/en16176371 - 02 Sep 2023
Cited by 2 | Viewed by 1242
Abstract
Against the backdrop of global energy transition and the imperative for sustainable development, the trade dynamics of solar photovoltaic (PV) products among “Belt and Road Initiative (BRI)” countries gained momentum. This study investigates the evolving trade patterns of PV products within BRI nations, [...] Read more.
Against the backdrop of global energy transition and the imperative for sustainable development, the trade dynamics of solar photovoltaic (PV) products among “Belt and Road Initiative (BRI)” countries gained momentum. This study investigates the evolving trade patterns of PV products within BRI nations, alongside the underlying determinants. The paper constructs and analyzes a solar PV product trade network, elucidating evolutionary trends, structural complexities, and clusters. A novel centrality influence model explores influencing factors across five dimensions. Methodologically, trade data, the “Five Connectivity” framework, and socio-economic indicators from 2001 to 2022 across 65 BRI countries underpin the study. Empirical insights reveal a robust PV product trade network with density exceeding 0.4 and reciprocity surpassing 0.38. China’s rising centrality, reflected in a weighted degree surge from 14.38 to 79.37 since 2011, signifies its consolidation within the network. Results show sustained high density and reciprocity in the PV trade network, signaling robust communication among BRI countries. China’s centrality in the network has consistently grown since 2011. Trade cluster analysis reveals isolated segments predominant, depicting emerging economies with limited photovoltaic exchanges, mainly export-focused. The study highlights the pivotal role of “Five Connectivity” dimensions in promoting PV trade, while financial connectivity’s impact remains modest. The emergence of PV product centers challenges traditional energy hubs, prompting the need for new energy trading paradigms and robust financial hubs. Full article
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12 pages, 715 KiB  
Article
The Economic Value of New Sustainable Products: The Case of Photovoltaic Thermal (PVT) Hybrid Solar Collectors
by Jeongbin Lee and Jungwoo Shin
Energies 2023, 16(14), 5473; https://doi.org/10.3390/en16145473 - 19 Jul 2023
Viewed by 874
Abstract
Among green energy technologies, solar power is a promising technology in the net-zero era of the power industry. Conventional solar modules have decreasing efficiency weaknesses as the temperature rises, whereas photovoltaic thermal (PVT) systems do not remove heat from the module or lower [...] Read more.
Among green energy technologies, solar power is a promising technology in the net-zero era of the power industry. Conventional solar modules have decreasing efficiency weaknesses as the temperature rises, whereas photovoltaic thermal (PVT) systems do not remove heat from the module or lower the temperature. However, the profitability of PVT systems has been underestimated. The profitability of new convergence products, such as PVT technology, entering the market for the first time allows for the evaluation of the appropriate starting price and policy requirements to support the product’s market entrance. We used the contingent valuation method (CVM) to solve this problem. The survey derived the respondents’ mean willingness to pay (WTP) and the total amount of social benefits. Among these CVM models, the one-and-one-half-bound (OOHB) spike model was used to distinguish zero WTP. Based on a survey of 300 households, respondents were willing to pay an additional yearly average income tax of KRW 10,608 (USD 7.90), and the total social benefit of PVT technology was calculated to be KRW 145 billion (USD 108 million). This result shows that individuals evaluate the value of PVT as 3.69% of their monthly electricity bill and 2.8% of their monthly gas bill. Several additional factors that influence WTP were analyzed, indicating a high possibility of PVT adoption by individuals who have replaced or are planning to replace photovoltaic (PV) modules. This study is significant because it examines the economic value of PVT and proposes a focus group for the effective market entry of new carbon neutrality products. Full article
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23 pages, 5726 KiB  
Review
A Comprehensive Review of Distributed MPPT for Grid-Tied PV Systems at the Sub-Module Level
by Yousef Alharbi, Ahmed Darwish and Xiandong Ma
Energies 2023, 16(14), 5468; https://doi.org/10.3390/en16145468 - 19 Jul 2023
Cited by 3 | Viewed by 1459
Abstract
Energy crises and the growth of the energy demand have increased the interest in utilizing unconventional power sources. Thus, renewable energy sources have become a topic of interest to mitigate rising energy concerns and cope with increased electricity demand. With remarkable merits including [...] Read more.
Energy crises and the growth of the energy demand have increased the interest in utilizing unconventional power sources. Thus, renewable energy sources have become a topic of interest to mitigate rising energy concerns and cope with increased electricity demand. With remarkable merits including cleanness and abundance, photovoltaic (PV) solar energy systems are a key to solving these issues. The employed inverters should effectively utilize the maximum available power from the PV solar system and transfer this power to the utility grid without posing any further limitations. However, the unequal power generation of different PV systems caused by partial shading (PS) and other PV panel degradation factors leads to a reduction in generation capacity. One of the relatively new solutions to mitigate the mismatch concerns between the PV modules and sub-modules is to extract the maximum power of each sub-module individually. The main objective of this paper is to present a comprehensive review of such PV grid-connected inverters topologies associated with sub-module connection and control. It will classify the PV grid-tied inverters in accordance with the level where the maximum power point tracking (MPPT) system is implemented. A special focus has been placed on sub-module microinverters (MI) in terms of circuit topologies, conversion efficiency, and controller design. This paper provides a comprehensive analysis of employing the distributed MPPT (DMPPT) approach to maximize the power generation of PV systems by mitigating the mismatch issues inside the PV module. The circuit topology, PV system configuration, and MPPT algorithms used for applying DMPPT solutions in PV SMs are discussed in detail in this study. Full article
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17 pages, 3638 KiB  
Article
Optimal Sizing of a Photovoltaic/Battery Energy Storage System to Supply Electric Substation Auxiliary Systems under Contingency
by Ailton Gonçalves, Gustavo O. Cavalcanti, Marcílio A. F. Feitosa, Roberto F. Dias Filho, Alex C. Pereira, Eduardo B. Jatobá, José Bione de Melo Filho, Manoel H. N. Marinho, Attilio Converti and Luis A. Gómez-Malagón
Energies 2023, 16(13), 5165; https://doi.org/10.3390/en16135165 - 05 Jul 2023
Cited by 1 | Viewed by 1535
Abstract
Electric substations (ESS) are important facilities that must operate even under contingency to guarantee the electrical system’s performance. To achieve this goal, the Brazilian national electricity system operator establishes that alternating current (AC) auxiliary systems of ESS must have, at least, two power [...] Read more.
Electric substations (ESS) are important facilities that must operate even under contingency to guarantee the electrical system’s performance. To achieve this goal, the Brazilian national electricity system operator establishes that alternating current (AC) auxiliary systems of ESS must have, at least, two power supplies, and in the case of failure of these sources, an emergency generator (EG) must at least supply energy to the essential loads. In order to improve the availability of auxiliary systems, a microgrid with other sources, such as photovoltaic (PV) systems and Battery Energy Storage Systems (BESS), can be an alternative. In this case, an economical optimization of the PV/BESS system must be addressed considering the costs associated with the installation and maintenance of equipment, and the gains from the credits generated by the photovoltaic system in the net metering scheme. In this paper, the size of the BESS system was determined to supply energy to the load of auxiliary systems of an ESS, as well as a PV system to achieve a null total cost. Furthermore, multi-objective optimization using the genetic algorithm technique was employed to optimize the size of the hybrid PV/BESS to minimize the investment cost and time when the demand was not met. Simulations under different scenarios of contingency were allowed to obtain the Pareto frontier for the optimal sizing of a PV/BESS system to supply energy to AC auxiliary systems in an ESS under contingency. Full article
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22 pages, 4269 KiB  
Article
How to Enhance Energy Services in Informal Settlements? Qualitative Comparison of Renewable Energy Solutions
by Rebekka Besner, Kedar Mehta and Wilfried Zörner
Energies 2023, 16(12), 4687; https://doi.org/10.3390/en16124687 - 13 Jun 2023
Cited by 1 | Viewed by 1366
Abstract
More than half of the urban population of Sub-Saharan Africa lives in informal housing conditions. While urban areas are, in general, characterized by a high electrification rate, residents of informal settlements are still affected by energy poverty, the use of traditional energy sources [...] Read more.
More than half of the urban population of Sub-Saharan Africa lives in informal housing conditions. While urban areas are, in general, characterized by a high electrification rate, residents of informal settlements are still affected by energy poverty, the use of traditional energy sources and unreliable electricity supply. The aim of the study is to give an overview of different renewable-energy-based solutions which are able to improve local energy provision. These are Solar Home Systems, Mini-Grids, and Energy-Hubs. The technologies are compared to another option for improving energy supply, namely Grid Expansion. The analysis is based on 24 Key Performance Indicators, which can be classified into technical, economic, environmental, social, and political dimensions. The selection of indicators is based on the challenges prevalent in informal settlements that impede a comprehensive, sustainable energy supply. The literature-based indices are used to determine which of the four technologies is a suitable solution for minimizing the challenges prevailing in informal settlements. The resulting matrix provides a holistic comparison and serves as a decision aid in selecting the appropriate technology for future projects in informal settlements, depending on local conditions and the needs of the population. The results show that the Energy-Hub is a valid alternative for energy supply improvement in Informal Settlements. Full article
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25 pages, 14664 KiB  
Article
Solar Electric Vehicles as Energy Sources in Disaster Zones: Physical and Social Factors
by Kenji Araki, Yasuyuki Ota, Anju Maeda, Minoru Kumano and Kensuke Nishioka
Energies 2023, 16(8), 3580; https://doi.org/10.3390/en16083580 - 20 Apr 2023
Cited by 4 | Viewed by 3409
Abstract
Electric vehicles (EVs) have the advantage of being resilient to natural disasters. However, users hesitate to donate electricity when they lose the chance to recharge at the utility. Solar electric vehicles (SEVs) save energy through vehicle-integrated photovoltaics (VIPV) and make it possible to [...] Read more.
Electric vehicles (EVs) have the advantage of being resilient to natural disasters. However, users hesitate to donate electricity when they lose the chance to recharge at the utility. Solar electric vehicles (SEVs) save energy through vehicle-integrated photovoltaics (VIPV) and make it possible to voluntarily donate excess energy, thus maintaining facility resilience. Given that the supply of solar energy to VIPV systems is not continuous and is difficult to forecast, the contribution of VIPV to the resilience of the larger energy system has been called into question. This is the first study in which the potential of VIPV to maintain utility resilience is investigated in the context of physical factors, such as irradiance, and social factors. The actual energy yield of a VIPV car was determined using an advanced 3D solar irradiation model under a nonuniform shading distribution, with validation from actual measures of solar irradiance on five orthogonal sides of the car body. The Monte Carlo method was used to model the complex factors in VIPV energy storage and energy donations under different scenarios. Depending on the climate, population density, and shading environment, the voluntary contribution of stored electricity in SEV is sufficient to provide disaster relief support. Full article
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27 pages, 6733 KiB  
Article
Assessing the Economic Impact of Introducing Localised PV Solar Energy Generation and Energy Storage for Fleet Electrification
by Maria Nunez Munoz, Erica E. F. Ballantyne and David A. Stone
Energies 2023, 16(8), 3570; https://doi.org/10.3390/en16083570 - 20 Apr 2023
Viewed by 1148
Abstract
Greenhouse gas (GHG) emissions from the transport sector and their effect on air quality are now a major concern, and the electrification of road freight transport is seen as one potential solution. However, this presents a challenge with the increased electricity demand on [...] Read more.
Greenhouse gas (GHG) emissions from the transport sector and their effect on air quality are now a major concern, and the electrification of road freight transport is seen as one potential solution. However, this presents a challenge with the increased electricity demand on a depot’s grid connection, and increased costs if this has to be upgraded. This study seeks to evaluate the impact on costs of introducing solar (PV) panels and a Battery Energy Storage System (BESS) when a company electrifies its fleet, based on two different priorities. On one hand, avoiding the use of the grid at peak price periods at the expense of upgrading the power connection. On the other hand, avoiding any power connection upgrade at the expense of incurring excess capacity charges. These two priorities aim to represent real-life challenges that logistics and commercial companies are facing when it comes to fleet electrification. The choice of prioritising one over the other may be driven by operational requirements and/or technical constraints. For each approach, a different energy management algorithm is developed using MATLAB and Simulink. The results obtained suggest that there is more flexibility in cost reduction when the upgrade of the power connection is not an obstacle. If the upgrade of the power network is not an option, the installation of PV panels and a BESS must be implemented together with other strategies (i.e., smart charging) to make it an economic option. Full article
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27 pages, 416 KiB  
Review
AI-Based Scheduling Models, Optimization, and Prediction for Hydropower Generation: Opportunities, Issues, and Future Directions
by Yoan Villeneuve, Sara Séguin and Abdellah Chehri
Energies 2023, 16(8), 3335; https://doi.org/10.3390/en16083335 - 09 Apr 2023
Cited by 5 | Viewed by 1768
Abstract
Hydropower is the most prevalent source of renewable energy production worldwide. As the global demand for robust and ecologically sustainable energy production increases, developing and enhancing the current energy production processes is essential. In the past decade, machine learning has contributed significantly to [...] Read more.
Hydropower is the most prevalent source of renewable energy production worldwide. As the global demand for robust and ecologically sustainable energy production increases, developing and enhancing the current energy production processes is essential. In the past decade, machine learning has contributed significantly to various fields, and hydropower is no exception. All three horizons of hydropower models could benefit from machine learning: short-term, medium-term, and long-term. Currently, dynamic programming is used in the majority of hydropower scheduling models. In this paper, we review the present state of the hydropower scheduling problem as well as the development of machine learning as a type of optimization problem and prediction tool. To the best of our knowledge, this is the first survey article that provides a comprehensive overview of machine learning and artificial intelligence applications in the hydroelectric power industry for scheduling, optimization, and prediction. Full article
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24 pages, 3951 KiB  
Article
Learning from Other Community Renewable Energy Projects: Transnational Transfer of Multi-Functional Energy Gardens from the Netherlands to Germany
by Maria Rosaria Di Nucci, Michael Krug, Lucas Schwarz, Vincenzo Gatta and Erik Laes
Energies 2023, 16(7), 3270; https://doi.org/10.3390/en16073270 - 06 Apr 2023
Viewed by 2347
Abstract
Citizen energy in general and renewable energy communities (RECs) in particular are becoming key vehicles for decentralisation, but also for the democratisation of the energy system. These initiatives are now more diverse than ever and are likely to continue to act as incubators [...] Read more.
Citizen energy in general and renewable energy communities (RECs) in particular are becoming key vehicles for decentralisation, but also for the democratisation of the energy system. These initiatives are now more diverse than ever and are likely to continue to act as incubators for significant projects in the transition to a renewable energy system. Beside the legal, regulatory, and financial challenges, there are several socio-economic and regulatory barriers that hinder the implementation of community energy projects. For this reason, policy learning and the dissemination of good/best practices that are transferable also to other contexts are important. This is an aspect that has not yet attracted much investigation, and only a few studies have explored the importance of transfer activities for the implementation of REC initiatives and their motives. This article aimed to address this knowledge gap by focussing on the transfer processes of best practices initiated in a particular region and discusses how these can be adapted and transferred to other contexts. We analysed the transfer case of a community renewable energy initiative, the multifunctional energy gardens, from the Netherlands to the German federal State of Thuringia, and extracted lessons with an overall validity for the transferability of drivers and success factors. We show how examples from other contexts with similar enabling conditions can represent significant foundations on which to build an effective strategy and what framework conditions are necessary to enhance the uptake of pervasive community energy initiatives in regions with low community energy development. Full article
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16 pages, 5181 KiB  
Article
Estimation Model of Agrivoltaic Systems Maximizing for Both Photovoltaic Electricity Generation and Agricultural Production
by Daisuke Yajima, Teruya Toyoda, Masaaki Kirimura, Kenji Araki, Yasuyuki Ota and Kensuke Nishioka
Energies 2023, 16(7), 3261; https://doi.org/10.3390/en16073261 - 05 Apr 2023
Cited by 4 | Viewed by 2757
Abstract
Climate change and increasing food demand are global issues that require immediate attention. The agrivoltaic system, which involves installing solar panels above farmland, can simultaneously solve climate and food issues. However, current systems tend to reduce agricultural production and delay the harvest period [...] Read more.
Climate change and increasing food demand are global issues that require immediate attention. The agrivoltaic system, which involves installing solar panels above farmland, can simultaneously solve climate and food issues. However, current systems tend to reduce agricultural production and delay the harvest period due to shading by the solar panels. A delayed harvest period impacts the income of farmers who wish to sell produce at specific times. Incorporating a model that calculates the amount of electricity generated by solar irradiation, this study establishes a model to estimate the correct start date of cultivation for solar panel covered crops to ensure the correct harvest date and determines the expected income of farmers by calculating agricultural production and power generation. Using taro cultivation in Miyazaki Prefecture as a case study, the model estimated that the start date of cultivation should be brought forward by 23 days to ensure the ideal harvest period and agricultural production. This would prevent an opportunity loss of USD 16,000 per year for a farm area of 10,000 m2. Furthermore, an additional income of USD 142,000 per year can be expected by adjusting shading rates for the cultivation and non-cultivation periods. Full article
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17 pages, 2572 KiB  
Article
Barriers and Prospects for the Development of Renewable Energy Sources in Poland during the Energy Crisis
by Hubert Kryszk, Krystyna Kurowska, Renata Marks-Bielska, Stanisław Bielski and Bartłomiej Eźlakowski
Energies 2023, 16(4), 1724; https://doi.org/10.3390/en16041724 - 09 Feb 2023
Cited by 9 | Viewed by 2558
Abstract
Europe is currently facing the potentially biggest energy crisis in history. There are many reasons for this, and the current geopolitical situation makes it clear that we are being forced to take immediate action to ensure sufficient energy supplies to consumers. Until recently, [...] Read more.
Europe is currently facing the potentially biggest energy crisis in history. There are many reasons for this, and the current geopolitical situation makes it clear that we are being forced to take immediate action to ensure sufficient energy supplies to consumers. Until recently, the European Union was dependent on Russian energy resources (mainly oil and gas). For many years, the EU countries had been shutting down their own production and importing much cheaper raw material from Russia. The threat of a blackout is becoming increasingly possible. European governments are preparing businesses and households for the energy crisis in various ways, but there is also a great deal of mobilization to accelerate the development of renewable energy sources (RES). The aim of this study was to identify the barriers and prospects for RES development in Poland in the current geopolitical conditions. The reasons for insufficient grid HC were analyzed. Additionally, the article aimed to assess the prospects for solar energy development in Poland. Wind power was discussed only in general terms because the development of wind farms is inhibited by the regulatory framework. Particular attention was paid to hosting capacity (HC) and the condition of the power infrastructure as the main determinants of RES development in Poland. Numerous documents developed by power companies and government agencies responsible for implementing and managing energy in Poland were analyzed. Special attention was paid to legal regulations and the need for legislative changes. As a country, Poland has one of the highest growth rates in photovoltaic (PV) installations. The forecasts for increasing HC, as a prerequisite for RES development in Poland, are not promising. Full article
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16 pages, 7339 KiB  
Article
A Novel Approach Using High Charging Voltage for the Restoration of Discarded Lead Acid Batteries
by Chee Hiun Lee, Jianhui Wong and Yun Seng Lim
Energies 2023, 16(4), 1598; https://doi.org/10.3390/en16041598 - 05 Feb 2023
Cited by 1 | Viewed by 2148
Abstract
A lead acid battery is an old renewable battery that is usually discharged to deliver a high surge current to ignite a petrol-based engine. Nowadays, there are different improved versions of lead acid batteries that can deliver high energy densities with low maintenance [...] Read more.
A lead acid battery is an old renewable battery that is usually discharged to deliver a high surge current to ignite a petrol-based engine. Nowadays, there are different improved versions of lead acid batteries that can deliver high energy densities with low maintenance costs. As the batteries are charged and discharged repeatedly over time, the amount of lead sulfate across the electrode plates grows, reducing the total surface areas of the plates and, thus, the rate of ionization between the electrolyte and the plate surfaces. The batteries then eventually come to the end of their service lives. Even with the improved versions, lead acid batteries are usually discarded at their retirement. However, if the retired batteries can be used for other purposes, the circular economy of the batteries can be improved significantly. It is therefore necessary to study the physical characteristics of the retired batteries and explore means of improving their charging and discharging capabilities. This paper presents research on improving the storage capability of retired lead acid batteries by applying different charging voltages across them. The results show that the electrode plates of the retired batteries become porous when a high charging voltage is applied, hence increasing the total surface area of the plate surfaces. The storage capability of the batteries is improved because the accumulated lead sulfate is removed from the electrode plates by the high charging voltage. As a result, the rate of ionization is increased, hence restoring the storing capability of the retired batteries to up to 71–89% of the original capacity rating. Full article
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12 pages, 2236 KiB  
Article
Estimating the Operating Reserve Demand Curve for Efficient Adoption of Renewable Sources in Korea
by Wooyoung Jeon and Jungyoun Mo
Energies 2023, 16(3), 1426; https://doi.org/10.3390/en16031426 - 01 Feb 2023
Cited by 1 | Viewed by 1132
Abstract
As the proportions of variable renewable sources (VRSs) such as solar and wind energy increase rapidly in the power system, their uncertainties inevitably undermine power supply reliability and increase the amount of operating reserve resources required to manage the system. However, because operating [...] Read more.
As the proportions of variable renewable sources (VRSs) such as solar and wind energy increase rapidly in the power system, their uncertainties inevitably undermine power supply reliability and increase the amount of operating reserve resources required to manage the system. However, because operating reserves have the characteristics of a public good and their value is related to the social cost of blackouts, it is difficult to determine their market price efficiently, which leads to inefficiencies in procuring operating reserves. This study estimates the operating reserve demand curve (ORDC) of the Korean power system to provide an effective basis for measuring the proper value and quantity of operating reserves needed to meet the reliability standard. A stochastic dynamic optimization model is applied to incorporate the probabilistic characteristics of VRS and the inter-hour constraint, which is necessary for analyzing load-following reserves. An econometric model and the Monte Carlo simulation method are used to generate the forecast profiles of solar and wind generation. The results indicate that the proper amount of hourly operating reserves needed in 2034 is approximately 4.4 times higher than that in 2020 at the current reserve offer price. The ORDC of 2020 has a price-inelastic shape, whereas the ORDC of 2034 has a price-elastic shape because the reserve requirement varies considerably with its offer price level in the high-VRS penetration case. This variability is due to alternatives, such as VRS curtailment or load shedding, which can replace the reserve requirement. This study also showed that VRS curtailment is an effective balancing resource as an alternative to reserves. Full article
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21 pages, 1535 KiB  
Article
Electricity Production and Sustainable Development: The Role of Renewable Energy Sources and Specific Socioeconomic Factors
by George E. Halkos and Apostolos S. Tsirivis
Energies 2023, 16(2), 721; https://doi.org/10.3390/en16020721 - 07 Jan 2023
Cited by 10 | Viewed by 2406
Abstract
An eco-friendly and sustainable power production system constitutes the cornerstone of every country’s strategic plan to tackle climate change and enhance energy resource autonomy. Carbon dioxide abatement in electricity generation, in addition to being a necessary condition for t “green” energy transition, can [...] Read more.
An eco-friendly and sustainable power production system constitutes the cornerstone of every country’s strategic plan to tackle climate change and enhance energy resource autonomy. Carbon dioxide abatement in electricity generation, in addition to being a necessary condition for t “green” energy transition, can contribute greatly to cleaner industrial production and sustainable development. Emphasizing this key role of the power sector, the present research focuses on shedding light on the impact of renewable energy resources (RES), per capita gross domestic product (GDP), electricity gross fixed capital formation (GFCF) and urbanization in the CO2 intensity, and the sustainability level of electricity production. The analysis is based on a comprehensive dataset of 31 countries including 26 European countries, U.S.A., Japan, Australia, Canada, and New Zealand from 1995 until 2018. The econometric outcomes revealed the strong statistical significance of all variables and a plethora of causality relationships, upon which several policy suggestions are made. Interestingly, GDP per capita beyond a certain level can gradually become an aggravating factor for the electricity carbon footprint. Similarly, the vital role of RES in clean electricity production was confirmed as expected, yet surprisingly, this effect also appears to reverse after a certain percentage of total RES reliance. In contrast to urbanization, the electricity GFCF parameter is estimated to have an adverse effect on electricity CO2 intensity, indicating that the vast amount of new investments in the power sector concerns carbon-intensive technologies. Finally, a dynamic analysis is carried out, revealing to policy makers the necessary time frame after which the implementation of new energy policies can have the full impact on the carbon emissions of electricity generation. Full article
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25 pages, 12223 KiB  
Article
Demand Response with Electrical Heating in Detached Houses in Finland and Comparison with BESS for Increasing PV Self-Consumption
by Juha Koskela and Pertti Järventausta
Energies 2023, 16(1), 497; https://doi.org/10.3390/en16010497 - 02 Jan 2023
Cited by 3 | Viewed by 1382
Abstract
Distributed electric power production by small-scale customers is increasing continuously. Photovoltaic production is a popular method of producing self-energy for customers. Additionally, power systems require more flexibility when weather-dependent renewable energy production increases. Small-scale customers can increase the self-consumption of self-produced energy by [...] Read more.
Distributed electric power production by small-scale customers is increasing continuously. Photovoltaic production is a popular method of producing self-energy for customers. Additionally, power systems require more flexibility when weather-dependent renewable energy production increases. Small-scale customers can increase the self-consumption of self-produced energy by using batteries or a demand response operation. However, batteries require high investment, and demand response operations induce a loss of comfort. Customers who heat their buildings using electric heaters are a good target for demand response operations because their heating can be controlled with limited changes in the indoor temperature. The demand response potential of a building can be defined by simply using customer load profiles and knowledge of the outdoor temperature. Any other information is not required in the proposed novel method. A tolerable variation in indoor temperature corresponds to considerably smaller battery capacity, though it is still a significant amount. With an optimally sized photovoltaic system, it is possible to use both methods simultaneously to increase self-consumption. Maximal benefits can be attained from both methods if the battery system is used as a primary control and the demand response is used as a secondary control. The defined novel method for determining the demand response potential of small-scale customers can also be used when estimating the flexibility of a large customer group. Small-scale customers together can provide significant flexible capacity when their electrical heating is centrally controlled. Full article
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2022

Jump to: 2024, 2023, 2021, 2020

22 pages, 3904 KiB  
Article
Optimal Design and Comparative Analysis of a PV/Mini-Hydropower and a PV/Battery Used for Electricity and Water Supply
by Ruben Zieba Falama, Wojciech Skarka and Serge Yamigno Doka
Energies 2023, 16(1), 307; https://doi.org/10.3390/en16010307 - 27 Dec 2022
Cited by 3 | Viewed by 2001
Abstract
This work proposed an optimal design of PV-system-based water-pumped energy storage for both electricity and water supply. A case study was considered in a rural community in Cameroon. The parameters of the assessment of the system were reliability, represented in the present work [...] Read more.
This work proposed an optimal design of PV-system-based water-pumped energy storage for both electricity and water supply. A case study was considered in a rural community in Cameroon. The parameters of the assessment of the system were reliability, represented in the present work by the system supply deficiency (SSD), and economic accessibility, represented by the levelized cost of energy (LCOE). The obtained results showed that for 0% SSD, the optimal configuration of the system was composed of 438 PV modules of 235 W, an immersed solar motor pump of 35 kW, a hydroelectric turbine of 51.7 kW, an upper reservoir of 2307.1 m3, an inverter of 25.27 kW, and a total dynamic head of 88 m. The corresponding LCOE to this configuration is 0.224 USD/kWh. The economic accessibility of the designed system was evaluated by comparison with a PV-system-based battery energy storage. The optimal design configuration of the studied PV-system-based battery energy storage was a PV generator (120 PV modules of 235 W), solar motor pump (15 kW), upper reservoir (590.4 m3), battery capacity (351.78 kWh), inverter (25.27 kW), and total dynamic head (81 m). The corresponding LCOE to this configuration was 0.1857 USD/kWh. Although the PV-system-based battery storage appeared to be economically more cost-effective than the PV-system-based water-pumped energy storage, the sensitivity analysis revealed that there was the possibility for the PV-system-based water-pumped energy storage to be economically more profitable than the PV-system-based battery energy storage. This economic outperformance occurred when the project lifetime was a multiple of 7.5 years or when the costs of the storage components were reduced from 20% to 60%. Full article
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24 pages, 5778 KiB  
Article
Solar Energy Powered Decentralized Smart-Grid for Sustainable Energy Supply in Low-Income Countries: Analysis Considering Climate Change Influences in Togo
by Kokou Amega, Yendoubé Laré, Ramchandra Bhandari, Yacouba Moumouni, Aklesso Y. G. Egbendewe, Windmanagda Sawadogo and Saidou Madougou
Energies 2022, 15(24), 9532; https://doi.org/10.3390/en15249532 - 15 Dec 2022
Cited by 2 | Viewed by 1637
Abstract
A smart and decentralized electrical system, powered by grid-connected renewable energy (RE) with a reliable storage system, has the potential to change the future socio-economic dynamics. Climate change may, however, affect the potential of RE and its related technologies. This study investigated the [...] Read more.
A smart and decentralized electrical system, powered by grid-connected renewable energy (RE) with a reliable storage system, has the potential to change the future socio-economic dynamics. Climate change may, however, affect the potential of RE and its related technologies. This study investigated the impact of climate change on photovoltaic cells’ temperature response and energy potential under two CO2 emission scenarios, RCP2.6 and 8.5, for the near future (2024–2040) and mid-century (2041–2065) in Togo. An integrated Regional Climate Model version 4 (RegCM4) from the CORDEX-CORE initiative datasets has been used as input. The latter platform recorded various weather variables, such as solar irradiance, air temperature, wind speed and direction, and relative humidity. Results showed that PV cells’ temperature would likely rise over all five regions in the country and may trigger a decline in the PV potential under RCP2.6 and 8.5. However, the magnitude of the induced change, caused by the changing climate, depended on two major factors: (1) the PV technology and (2) geographical position. Results also revealed that these dissimilarities were more pronounced under RCP8.5 with the amorphous technology. It was further found that, nationally, the average cell temperature would have risen by 1 °C and 1.82 °C under RCP2.6 and 8.5, in that order, during the 2024–2065 period for a-Si technology. Finally, the PV potential would likely decrease, on average, by 0.23% for RCP2.6 and 0.4% for RCP8.5 for a-Si technology. Full article
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21 pages, 1903 KiB  
Article
Levelling the Photovoltaic Power Profile with the Integrated Energy Storage System
by Alberto Benato, Francesco De Vanna and Anna Stoppato
Energies 2022, 15(24), 9521; https://doi.org/10.3390/en15249521 - 15 Dec 2022
Cited by 3 | Viewed by 1155
Abstract
The extensive penetration in the energy mix of variable renewable energy sources, such as wind and solar, guarantees boosting of the transition toward a decarbonized and sustainable energy system as well as tackling of climate targets. However, the instability and unpredictability of such [...] Read more.
The extensive penetration in the energy mix of variable renewable energy sources, such as wind and solar, guarantees boosting of the transition toward a decarbonized and sustainable energy system as well as tackling of climate targets. However, the instability and unpredictability of such sources predominantly affect their plant production. Thus, utility-scale energy storage is required to aid in balancing supply and demand and, as a result, to prevent unbalances that might cause issues at different grid levels. In the present study, the authors’ patented energy storage technology, known as Integrated Energy Storage System (I-ESS), is combined with a 10 MWp solar plant. The PV plant and the I-ESS unit function as a Virtual Power Plant (VPP). The selected VPP management strategy attempts to optimize the daily hours during which the plant supplies steady power output. Numerical simulations show that the VPP plant can effectively smooth the PV peak and manage the power supply. In particular, by the definition of a novel metric expressing the ratio between regular hours of power provided to the grid plus the energy stored in the backup unit and the total number of hours in a year, the results show that the VPP regularity is relatively high in terms of PV output, ranging from a low of 50% in December to a high of 87% in August. Thus, the proposed VPP arrangement seems to be a promising technology for pushing toward the carbon-neutral transition. Full article
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26 pages, 4171 KiB  
Review
Vanadium Oxide–Conducting Polymers Composite Cathodes for Aqueous Zinc-Ion Batteries: Interfacial Design and Enhancement of Electrochemical Performance
by Elena G. Tolstopyatova, Mikhail A. Kamenskii and Veniamin V. Kondratiev
Energies 2022, 15(23), 8966; https://doi.org/10.3390/en15238966 - 27 Nov 2022
Cited by 4 | Viewed by 1862
Abstract
Aqueous zinc-ion batteries (AZIBs) are being intensively developed as potential alternative electrochemical power sources, due to their advantages such as low cost, high safety, abundance of natural zinc resources and appropriate energy density. Among currently investigated prospective cathode materials for AZIBs, vanadium oxide-based [...] Read more.
Aqueous zinc-ion batteries (AZIBs) are being intensively developed as potential alternative electrochemical power sources, due to their advantages such as low cost, high safety, abundance of natural zinc resources and appropriate energy density. Among currently investigated prospective cathode materials for AZIBs, vanadium oxide-based composites with intrinsically conducting polymers have shown many advantages, such as high capacity, high power density and long battery life. This review gives a focused view of the design for the boosting of zinc ion storage performance using intrinsically conducting polymers in vanadium oxide-based composites and the mechanism of intercalation processes. The main challenges in interfacial engineering of vanadium oxide-conducting polymers composite structures and the prospects for further development of such cathode materials are summarized and discussed. The review would give rise to a broad interest focusing on the advantageous strategy of the development of vanadium oxide composite cathodes with intrinsically conducting polymers (polyaniline, polypyrrole, poly(3,4-ethylenedioxythiophene)) for AZIBs with improved energy density, high-rate capability and stability. Full article
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21 pages, 2603 KiB  
Article
Optimizing Current Profiles for Efficient Online Estimation of Battery Equivalent Circuit Model Parameters Based on Cramer–Rao Lower Bound
by Prarthana Pillai, Sneha Sundaresan, Krishna R. Pattipati and Balakumar Balasingam
Energies 2022, 15(22), 8441; https://doi.org/10.3390/en15228441 - 11 Nov 2022
Cited by 3 | Viewed by 1306
Abstract
Battery management systems (BMS) are important for ensuring the safety, efficiency and reliability of a battery pack. Estimating the internal equivalent circuit model (ECM) parameters of a battery, such as the internal open circuit voltage, battery resistance and relaxation parameters, is a crucial [...] Read more.
Battery management systems (BMS) are important for ensuring the safety, efficiency and reliability of a battery pack. Estimating the internal equivalent circuit model (ECM) parameters of a battery, such as the internal open circuit voltage, battery resistance and relaxation parameters, is a crucial requirement in BMSs. Numerous approaches to estimating ECM parameters have been reported in the literature. However, existing approaches consider ECM identification as a joint estimation problem that estimates the state of charge together with the ECM parameters. In this paper, an approach is presented to decouple the problem into ECM identification alone. Using the proposed approach, the internal open circuit voltage and the ECM parameters can be estimated without requiring the knowledge of the state of charge of the battery. The proposed approach is applied to estimate the open circuit voltage and internal resistance of a battery. Full article
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35 pages, 32554 KiB  
Article
Experimental Validation of an Enhanced MPPT Algorithm and an Optimal DC–DC Converter Design Powered by Metaheuristic Optimization for PV Systems
by Efrain Mendez-Flores, Alexandro Ortiz, Israel Macias and Arturo Molina
Energies 2022, 15(21), 8043; https://doi.org/10.3390/en15218043 - 29 Oct 2022
Cited by 7 | Viewed by 1461
Abstract
Nowadays, photovoltaic (PV) systems are responsible for over 994 TWH of the worldwide energy supply, which highlights their relevance and also explains why so much research has arisen to enhance their implementation; among this research, different optimization techniques have been widely studied to [...] Read more.
Nowadays, photovoltaic (PV) systems are responsible for over 994 TWH of the worldwide energy supply, which highlights their relevance and also explains why so much research has arisen to enhance their implementation; among this research, different optimization techniques have been widely studied to maximize the energy harvested under different environmental conditions (maximum power point tracking) and to optimize the efficiency of the required power electronics for the implementation of MPPT algorithms. On the one hand, an earthquake optimization algorithm (EA) was introduced as a multi-objective optimization tool for DC–DC converter design, mostly to overcome component shortages by optimal replacement, but it had never been tested (until now) for PV applications. On the other hand, the original EA was also taken as inspiration for a promising EA-based MPPT, which presumably enabled a solution with simple parametric calibration and improved dynamic behavior; yet prior to this research, the EA-MPPT had never been experimentally validated. Hence, this work fills the gap and provides the first implementation of the EA-based MPPT, validating its performance and suitability under real physical conditions, where the experimental testbed was optimized through the EA design methodology for DC–DC converters and implemented for the first time for PV applications. The results present energy waste reduction between 12 and 36% compared to MPPTs based on perturb and observe and particle swarm optimization; meanwhile, the designed converter achieved 7.3% current ripple, which is between 2.7 and 12.7% less than some industrial converters, and it had almost 90% efficiency at nominal operation. Finally, the EA-MPPT proved simple enough to be implemented even through an 8-bit MCU (ATmega328P from Arduino UNO). Full article
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17 pages, 7060 KiB  
Article
A Thermal Model to Estimate PV Electrical Power and Temperature Profile along Panel Thickness
by Francesco Nicoletti, Mario Antonio Cucumo, Vittorio Ferraro, Dimitrios Kaliakatsos and Albino Gigliotti
Energies 2022, 15(20), 7577; https://doi.org/10.3390/en15207577 - 14 Oct 2022
Cited by 6 | Viewed by 1172
Abstract
The production of electricity from photovoltaic panels has experienced significant developments. To manage the energy flows introduced into the electricity grid, it is necessary to estimate the productivity of PV panels under the climatic conditions. In this study, a photovoltaic panel is modelled [...] Read more.
The production of electricity from photovoltaic panels has experienced significant developments. To manage the energy flows introduced into the electricity grid, it is necessary to estimate the productivity of PV panels under the climatic conditions. In this study, a photovoltaic panel is modelled from thermal and electrical points of view to evaluate electrical performance and identify the temperature distribution in the layers. The analysis performed is time dependent and the problem is solved using the finite difference technique. A methodology is introduced to estimate the cloudiness of the sky, which affects radiative heat exchange. The calculation method is validated using experimental data recorded in a laboratory of the University of Calabria. Temperature and electrical power are predicted with RMSE of 1.5–2.0 °C and NRMSE of 1.2–2.1%, respectively. The evaluation of the temperature profile inside the panel is essential to understand how heat is dissipated. The results show that the top surface (glass) is almost always colder than the back of the panel, despite being exposed to radiation. In addition, the upper surface dissipates more heat power than the lower one. Cooling systems, such as spray cooling, work better if they are installed on the back of the panel. Full article
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16 pages, 873 KiB  
Article
Selected Characteristics of Municipalities as Determinants of Enactment in Municipal Spatial Plans for Renewable Energy Sources—The Case of Poland
by Małgorzata Blaszke, Iwona Foryś, Maciej J. Nowak and Bartosz Mickiewicz
Energies 2022, 15(19), 7274; https://doi.org/10.3390/en15197274 - 03 Oct 2022
Cited by 4 | Viewed by 1118
Abstract
The article proposes methods by which an in-depth analysis of the factors determining the planning activity of municipalities for renewable energy sources can be carried out. The article aims to determine the relationship between the number of local spatial plans specifying designation for [...] Read more.
The article proposes methods by which an in-depth analysis of the factors determining the planning activity of municipalities for renewable energy sources can be carried out. The article aims to determine the relationship between the number of local spatial plans specifying designation for renewable energy sources and the municipality’s area, population and planning situation. All local spatial plans in Poland (a total of 104,720 plans) were analysed, distinguishing in each municipality the number of plans with designation for renewable energy sources and micro-installations (a total of 11,338 plans). Then, using quantitative methods, this data was matched with data on the municipalities’ population, area, and planning activity. At the same time, the article provides a literature review of the critical problems concerning the relationship between investments in renewable energy sources and local planning. The barriers encountered are transnational in nature. The discussion section indicates how the proposed research methods can address identified barriers. Further possible research directions are also identified. The study shows a correlation between the planning activity of municipalities in the field of renewable energy sources and both population and population density. The higher the population density (highly urbanised areas), the higher the planning activity as well, and with it, the associated planning activity for renewable energy sources. The results in this respect are spatially differentiated. The main contribution of the research is to identify the relationship between the spatial and demographic characteristics of the municipalities and the way spatial plans are approached. This research identifies how local spatial policies toward renewable energy sources can be assessed. Full article
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30 pages, 7936 KiB  
Article
Utilization of Basalt Dust as Waste Material in Cement Grouts for Geothermal Application
by Krzysztof Seńczuk, Aneta Sapińska-Śliwa and Tomasz Kowalski
Energies 2022, 15(19), 7033; https://doi.org/10.3390/en15197033 - 25 Sep 2022
Cited by 1 | Viewed by 1505
Abstract
Research on the utilization of the Earth’s heat focuses mainly on effective sourcing of energy accumulated in rock mass. One of the most important parameters is thermal conductivity, which can be modified using various compositions of cement grouts. Hardened cement slurry is intended [...] Read more.
Research on the utilization of the Earth’s heat focuses mainly on effective sourcing of energy accumulated in rock mass. One of the most important parameters is thermal conductivity, which can be modified using various compositions of cement grouts. Hardened cement slurry is intended to improve thermal conductivity. It should function as a sort of extension of the rock mass to the outer diameter of heat exchanger tubes. Regardless of the thermal conductivity of the rock, high conductivity of the grout increases the energy efficiency of the BHE. Heat accumulated in the rock mass can be extracted using borehole heat exchangers (BHE), in which high thermal conductivity of cement slurry is wanted over the entire length of the exchanger. Generally, in case of deep borehole heat exchangers (DBHE), it is recommended to use two types of cement slurry, one with reduced thermal conductivity in the upper part of the exchanger and grout with increased thermal conductivity in its lower part. When cementing geothermal wells, cement grout with decreased thermal conductivity along the entire length of the borehole is most commonly used. Geothermal boreholes extract geothermal water which, at the surface, is used for heating, for example. Then, after use, the cooled water is injected through injection holes. In this article, two different basalt dusts are examined. These dusts were obtained by crushing basalt boulders in open-pit mines. They were examined for their effect on thermal conductivity when added to grout. According to the Polish Ordinance of the Minister of Environment dated 9 December 2014 regarding the waste catalogue, they were classified as waste. The materials, named basalt dust A and basalt dust B, were used to create cement slurries with a water–cement ratio of 0.5–0.7 with a wide range of percentage concentration of basalt dust. The test results show that as concentrations in the slurry increase, the values of thermal conductivity and strength decrease. This correlation occurred for both tested additives. Full article
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25 pages, 3270 KiB  
Review
Open-Circuit Voltage Models for Battery Management Systems: A Review
by Prarthana Pillai, Sneha Sundaresan, Pradeep Kumar, Krishna R. Pattipati and Balakumar Balasingam
Energies 2022, 15(18), 6803; https://doi.org/10.3390/en15186803 - 17 Sep 2022
Cited by 25 | Viewed by 3762
Abstract
A battery management system (BMS) plays a crucial role to ensure the safety, efficiency, and reliability of a rechargeable Li-ion battery pack. State of charge (SOC) estimation is an important operation within a BMS. Estimated SOC is required in several BMS operations, such [...] Read more.
A battery management system (BMS) plays a crucial role to ensure the safety, efficiency, and reliability of a rechargeable Li-ion battery pack. State of charge (SOC) estimation is an important operation within a BMS. Estimated SOC is required in several BMS operations, such as remaining power and mileage estimation, battery capacity estimation, charge termination, and cell balancing. The open-circuit voltage (OCV) look-up-based SOC estimation approach is widely used in battery management systems. For OCV lookup, the OCV–SOC characteristic is empirically measured and parameterized a priori. The literature shows numerous OCV–SOC models and approaches to characterize them and use them in SOC estimation. However, the selection of an OCV–SOC model must consider several factors: (i) Modeling errors due to approximations, age/temperature effects, and cell-to-cell variations; (ii) Likelihood and severity of errors when the OCV–SOC parameters are rounded; (iii) Computing system requirements to store and process OCV parameters; and (iv) The required computational complexity of real-time OCV lookup algorithms. This paper presents a review of existing OCV–SOC models and proposes a systematic approach to select a suitable OCV–SOC for implementation based on various constraints faced by a BMS designer in practical application. Full article
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35 pages, 5464 KiB  
Review
Novel Trends in Proton Exchange Membrane Fuel Cells
by Abdul Ghani Olabi, Tabbi Wilberforce, Abdulrahman Alanazi, Parag Vichare, Enas Taha Sayed, Hussein M. Maghrabie, Khaled Elsaid and Mohammad Ali Abdelkareem
Energies 2022, 15(14), 4949; https://doi.org/10.3390/en15144949 - 06 Jul 2022
Cited by 18 | Viewed by 5343
Abstract
Fuel cells (FCs) have received huge attention for development from lab and pilot scales to full commercial scale. This is mainly due to their inherent advantage of direct conversion of chemical energy to electrical energy as a high-quality energy supply and, hence, higher [...] Read more.
Fuel cells (FCs) have received huge attention for development from lab and pilot scales to full commercial scale. This is mainly due to their inherent advantage of direct conversion of chemical energy to electrical energy as a high-quality energy supply and, hence, higher conversion efficiency. Additionally, FCs have been produced at a wide range of capacities with high flexibility due to modularity characteristics. Using the right materials and efficient manufacturing processes is directly proportional to the total production cost. This work explored the different components of proton exchange membrane fuel cells (PEMFCs) and their manufacturing processes. The challenges associated with these manufacturing processes were critically analyzed, and possible mitigation strategies were proposed. The PEMFC is a relatively new and developing technology so there is a need for a thorough analysis to comprehend the current state of fuel cell operational characteristics and discover new areas for development. It is hoped that the view discussed in this paper will be a means for improved fuel cell development. Full article
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18 pages, 5101 KiB  
Article
Impact of Solar Inverter Dynamics during Grid Restoration Period on Protection Schemes Based on Negative-Sequence Components
by Almir Ekic, Di Wu and John N. Jiang
Energies 2022, 15(12), 4360; https://doi.org/10.3390/en15124360 - 15 Jun 2022
Cited by 2 | Viewed by 1741
Abstract
The growing penetration of renewable resources such as wind and solar into the electric power grid through power electronic inverters is challenging grid protection. Due to the advanced inverter control algorithms, the inverter-based resources present fault responses different from conventional generators, which can [...] Read more.
The growing penetration of renewable resources such as wind and solar into the electric power grid through power electronic inverters is challenging grid protection. Due to the advanced inverter control algorithms, the inverter-based resources present fault responses different from conventional generators, which can fundamentally affect the way that the power grid is protected. This paper studied solar inverter dynamics focused on negative-sequence quantities during the restoration period following a grid disturbance by using a real-time digital simulator. It was found that solar inverters can act as negative-sequence sources to inject negative-sequence currents into the grid during the restoration period. The negative-sequence current can be affected by different operating conditions such as the number of inverters in service, grid strength, and grid fault types. Such negative-sequence responses can adversely impact the performance of protection schemes based on negative-sequence components and potentially cause relay maloperations during the grid restoration period, thus making system protection less secure and reliable. Full article
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13 pages, 7230 KiB  
Article
Control Strategies Applied to a Heat Transfer Loop of a Linear Fresnel Collector
by Alaric Christian Montenon and Rowida Meligy
Energies 2022, 15