Energies

16 pages, 2152 KiB

Open AccessArticle

An Improved Near-State Pulse-Width Modulation with Low Switching Loss for a Permanent Magnet Synchronous Machine Drive System

by Pei Qing, Ruoyu Chen and Qiang Gao

Energies 2024, 17(13), 3157; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133157 (registering DOI) - 26 Jun 2024

Abstract

Common-mode voltage (CMV) leads to the shaft voltage and shaft current by coupling the capacitor network in the permanent magnet synchronous machine (PMSM), which affects the reliability of the whole motor drive system. Based on the low-CMV modulation strategy for the PMSM drive [...] Read more.

Common-mode voltage (CMV) leads to the shaft voltage and shaft current by coupling the capacitor network in the permanent magnet synchronous machine (PMSM), which affects the reliability of the whole motor drive system. Based on the low-CMV modulation strategy for the PMSM drive system, this paper proposed an improved near-state pulse-width modulation (NSPWM) on switching loss. First, the generation mechanism for the switching signals of NSPWM was analyzed, and it was observed that there exists one phase of switches in an inactive state for every sector. Then, to reduce the switching loss of the NSPWM, this paper proposed an improved NSPWM modulation strategy based on power factor angle to adjust switching action, which ensures the switching tubes that have the biggest conduction current have no switching action. In addition, the switching loss analytic formula of the NSPWM was derived to prove the correctness of the proposed method for optimizing switching loss. Finally, the proposed modulation strategy was carried out in the simulation and experimental platform. Under the premise of good steady and dynamic performance, the results show that the proposed modulation strategy has less switching loss. Full article

(This article belongs to the Topic Advanced Energy and Propulsion Technology for Electric and Intelligent Transportation)

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27 pages, 1933 KiB

Open AccessReview

Solar Radiation Forecasting: A Systematic Meta-Review of Current Methods and Emerging Trends

by Ewa Chodakowska, Joanicjusz Nazarko, Łukasz Nazarko and Hesham S. Rabayah

Energies 2024, 17(13), 3156; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133156 (registering DOI) - 26 Jun 2024

Abstract

Effective solar forecasting has become a critical topic in the scholarly literature in recent years due to the rapid growth of photovoltaic energy production worldwide and the inherent variability of this source of energy. The need to optimise energy systems, ensure power continuity, [...] Read more.

Effective solar forecasting has become a critical topic in the scholarly literature in recent years due to the rapid growth of photovoltaic energy production worldwide and the inherent variability of this source of energy. The need to optimise energy systems, ensure power continuity, and balance energy supply and demand is driving the continuous development of forecasting methods and approaches based on meteorological data or photovoltaic plant characteristics. This article presents the results of a meta-review of the solar forecasting literature, including the current state of knowledge and methodological discussion. It presents a comprehensive set of forecasting methods, evaluates current classifications, and proposes a new synthetic typology. The article emphasises the increasing role of artificial intelligence (AI) and machine learning (ML) techniques in improving forecast accuracy, alongside traditional statistical and physical models. It explores the challenges of hybrid and ensemble models, which combine multiple forecasting approaches to enhance performance. The paper addresses emerging trends in solar forecasting research, such as the integration of big data and advanced computational tools. Additionally, from a methodological perspective, the article outlines a rigorous approach to the meta-review research procedure, addresses the scientific challenges associated with conducting bibliometric research, and highlights best practices and principles. The article’s relevance consists of providing up-to-date knowledge on solar forecasting, along with insights on emerging trends, future research directions, and anticipating implications for theory and practice. Full article

(This article belongs to the Special Issue Simulation Modelling and Analysis of a Renewable Energy System, Volume II)

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36 pages, 6778 KiB

Open AccessArticle

Generalized Quasi-Static Mooring System Modeling with Analytic Jacobians

by Matthew Hall

Energies 2024, 17(13), 3155; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133155 (registering DOI) - 26 Jun 2024

Abstract

This paper presents a generalized and efficient method for quasi-static analysis of mooring systems, including complex scenarios such as when shared mooring lines interconnect multiple floating wind or wave energy devices. While quasi-static mooring models are well established, most published formulations are focused [...] Read more.

This paper presents a generalized and efficient method for quasi-static analysis of mooring systems, including complex scenarios such as when shared mooring lines interconnect multiple floating wind or wave energy devices. While quasi-static mooring models are well established, most published formulations are focused on specific applications, and no publicly available implementations provide efficient handling of large mooring system networks. The present formulation addresses these gaps by: (1) formulating solutions for edge cases not typically supported by quasi-static models; (2) creating a fully generalized model structure such that any combination of mooring lines, point masses, and floating bodies can be assembled; and (3) deriving analytic expressions for the system Jacobians (stiffness matrices) so that systems with many degrees of freedom can be solved efficiently. These techniques form the theory basis of MoorPy, an open-source mooring analysis library. The model is demonstrated on nine scenarios of increasing complexity with features of interest for offshore renewable energy applications. When compared with steady-state results from a lumped-mass dynamic model, the results show that the quasi-static formulation accurately calculates profiles and tensions and that its analytic approach provides more efficient and reliable computation of system stiffness matrices than finite-differencing methods. These results verify the accuracy of the MoorPy model. Full article

(This article belongs to the Collection Modeling and Design of Offshore Renewable Energy Systems)

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17 pages, 3929 KiB

Open AccessArticle

Kinetic Model Implementation of Fluidized Bed Devolatilization

by Armando Vitale, Andrea Di Carlo, Pier Ugo Foscolo and Alessandro Antonio Papa

Energies 2024, 17(13), 3154; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133154 (registering DOI) - 26 Jun 2024

Abstract

Computational modeling is a powerful tool for studying and investigating the behavior of fluidized bed gasifiers and the modeling of the initial devolatilization step is necessary to provide a reliable description of the whole process involving the feedstock decomposition and the subsequent gasification [...] Read more.

Computational modeling is a powerful tool for studying and investigating the behavior of fluidized bed gasifiers and the modeling of the initial devolatilization step is necessary to provide a reliable description of the whole process involving the feedstock decomposition and the subsequent gasification reaction. In this work, a bench-scale fluidized bed reactor was used to examine the devolatilization of different carbonaceous materials within the temperature range from 650 to 850 °C. The experimental test campaign was used to derive the linear correlation factor to describe the devolatilization in terms of product distribution as a function of temperature and highlight the different behavior between lignocellulosic and plastic feedstocks. Furthermore, the experimental data were used to develop concise kinetic expressions able to fit the experimental devolatilization times ranging from 75 in the case of poplar at a lower temperature and 22 s for the Organic Fraction of Municipal Solid Waste (OFMSW) at a higher temperature. The obtained model produces a simple kinetic expression where the size of the particle is enclosed in the kinetic parameters. The kinetic model sided by the application of linear correlations describes the overall thermal decomposition in a fluidized bed, simplifying its modeling in commercial simulation software, even when particles are considered as point-like bodies. Full article

(This article belongs to the Special Issue Advances in Numerical Modeling of Multiphase Flow and Heat Transfer)

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12 pages, 3229 KiB

Open AccessArticle

Evaluation of Growth and Energy Parameters of One-Year-Old Raspberry Shoots, Depending on the Variety

by Grzegorz Maj, Kamil Buczyński, Kamila E. Klimek and Magdalena Kapłan

Energies 2024, 17(13), 3153; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133153 (registering DOI) - 26 Jun 2024

Abstract

The article examines the influence of six varieties of primocane raspberries, Rubus idaeus L., on the growth parameters and energy properties of the biomass. The unique aim of this study was to show the impact of primocane raspberry varieties, grown for a single [...] Read more.

The article examines the influence of six varieties of primocane raspberries, Rubus idaeus L., on the growth parameters and energy properties of the biomass. The unique aim of this study was to show the impact of primocane raspberry varieties, grown for a single harvest, on the growth parameters of the bushes and the energy and emission characteristics of the biomass obtained from the pruned canes. To the best of our knowledge, there is no such analysis connected to varieties of raspberries available in the literature. The following primocane raspberries were assessed: Polana, Polesie, Delniwa, Poemat, Polonez, and Poranek. Among the studied raspberry varieties, Polana was characterized by the highest number of side shoots and the greatest sum of the shoot lengths, while the Polonez variety was characterized by the highest average shoot length and shoot thickness. In the tested raspberry varieties, the weight of the shoots per hectare varied significantly, ranging from 6.06 t in the Poranek variety to 9.05 t in the Delniwa variety. It was shown that the raspberry variety had a significant impact on the higher heating value (HHV) and the lower heating value (LHV). The lowest energy value was found in the Delniwa (HHV—17.32 MJ·kg⁻¹; LHV—16.07 MJ·kg⁻¹) and Polana (HHV—17.33 MJ·kg⁻¹, LHV—16.19 MJ·kg⁻¹) varieties, and the significantly highest value was observed in the Poranek variety (HHV—17.63 MJ·kg⁻¹, LHV—16.39 MJ·kg⁻¹). The assessment of the total volume of exhaust gases showed the highest value of this parameter for the Polesie and Delniwa varieties (6.89 m³·kg⁻¹), with the lowest for the Polana variety (6.69 m³·kg⁻¹). Full article

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

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21 pages, 2112 KiB

Open AccessReview

Advancements and Prospects of Hydrogel Sweat Cooling Technology in Multiphase Heat Transfer Applications: A Review

by Liang Xu, Jiren Li, Lei Xi, Yunlong Li and Jianmin Gao

Energies 2024, 17(13), 3152; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133152 (registering DOI) - 26 Jun 2024

Abstract

Hydrogel sweat cooling is one of the leading areas in the study of multiphase heat transfer. In this study, the principles, applications, current research status, and future trends of hydrogel sweat cooling technology are comprehensively reviewed. By combing through and analyzing the relevant [...] Read more.

Hydrogel sweat cooling is one of the leading areas in the study of multiphase heat transfer. In this study, the principles, applications, current research status, and future trends of hydrogel sweat cooling technology are comprehensively reviewed. By combing through and analyzing the relevant literature, the research progress in hydrogel sweat cooling is presented from the application perspective, including its use in electronic devices, buildings, and clean-energy facilities. The principle of each application is illustrated, the research status is established, and pros and cons are proposed. To provide inspiration for future research, the development trend is set out. Our literature review indicates that research on advanced hydrogels is the most promising research direction, including studies on the effect of environmental and indoor factors on sweat cooling performance through numerical, experimental, and theoretical means. Challenges for future research mainly include conducting hydrogel numerical analysis which can be experimentally verified, developing advanced hydrogels in a green way, and achieving the precise regulation of hydrogel control through intelligent methods. Interdisciplinary integration might be promising as well due to the fact that it can reveal the hydrogel sweat cooling mechanism from a different perspective. This study aims to promote multiphase cooling technology in exploring the application of hydrogels in energy utilization criteria. Full article

(This article belongs to the Special Issue Advances in Numerical Modeling of Multiphase Flow and Heat Transfer)

30 pages, 6274 KiB

Open AccessReview

The Applications and Challenges of Nanofluids as Coolants in Data Centers: A Review

by Le Sun, Jiafeng Geng, Kaijun Dong and Qin Sun

Energies 2024, 17(13), 3151; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133151 (registering DOI) - 26 Jun 2024

Abstract

With the rapid development of artificial intelligence, cloud computing and other technologies, data centers have become vital facilities. In the construction and operation of data centers, how to effectively solve the problem of cooling and energy saving is the key problem. In this [...] Read more.

With the rapid development of artificial intelligence, cloud computing and other technologies, data centers have become vital facilities. In the construction and operation of data centers, how to effectively solve the problem of cooling and energy saving is the key problem. In this review article, a critical review of recent research regarding the application of nanofluids in data center cooling are put forward. Many different aspects of nanofluids such as the classification of nanoparticles, base fluid components, and types and structures of heat exchangers were discussed. Furthermore, some advanced and up-to-date apparatus and theoretical models of utilizing nanofluids as coolants in data centers are reviewed and described in detail. Lastly, but not least, potential research directions in the future and the challenges faced by the researchers and industry in this field are proposed and discussed. In conclusion, nanofluids used as novel heat exchange medium, which has been widely proven in other areas, can also conspicuously improve data center cooling technology in the future. Full article

(This article belongs to the Special Issue Energy Performance of Nanofluids Used for Heat Transfer Applications)

26 pages, 4484 KiB

Open AccessArticle

An Agile Approach for Adopting Sustainable Energy Solutions with Advanced Computational Techniques

by David Abdul Konneh, Harun Or Rashid Howlader, M. H. Elkholy and Tomonobu Senjyu

Energies 2024, 17(13), 3150; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133150 (registering DOI) - 26 Jun 2024

Abstract

In the face of the burgeoning electricity demands and the imperative for sustainable development amidst rapid industrialization, this study introduces a dynamic and adaptable framework suitable for policymakers and renewable energy experts working on integrating and optimizing renewable energy solutions. While using a [...] Read more.

In the face of the burgeoning electricity demands and the imperative for sustainable development amidst rapid industrialization, this study introduces a dynamic and adaptable framework suitable for policymakers and renewable energy experts working on integrating and optimizing renewable energy solutions. While using a case study representative model for Sub-Saharan Africa (SSA) to demonstrate the challenges and opportunities present in introducing optimization methods to bridge power supply deficits and the scalability of the model to other regions, this study presents an agile multi-criteria decision tool that pivots on four key development phases, advancing established methodologies and pioneering refined computational techniques, to select optimal configurations from a set of Policy Decision-Making Metrics (PDM-DPS). Central to this investigation lies a rigorous comparative analysis of variants of three advanced algorithmic approaches: Swarm-Based Multi-objective Particle Swarm Optimization (MOPSO), Decomposition-Based Multi-objective Evolutionary Algorithm (MOEA/D), and Evolutionary-Based Strength Pareto Evolutionary Algorithm (SPEA2). These are applied to a grid-connected hybrid system, evaluated through a comprehensive 8760-hour simulation over a 20-year planning horizon. The evaluation is further enhanced by a set of refined Algorithm Performance Evaluation Metrics (AL-PEM) tailored to the specific constraints. The findings not only underscore the robustness and consistency of the SPEA2 variant over 15 runs of 200 generations each, which ranks first on the AL-PEM scale, but the findings also validate the strategic merit of combining multiple technologies and empowering policymakers with a versatile toolkit for informed decision-making. Full article

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

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26 pages, 1875 KiB

Open AccessArticle

Enhancing Electric Shuttle Bus Efficiency: A Case Study on Timetabling and Scheduling Optimization

by Kayhan Alamatsaz, Frédéric Quesnel and Ursula Eicker

Energies 2024, 17(13), 3149; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133149 (registering DOI) - 26 Jun 2024

Abstract

As transit authorities increasingly adopt electric buses (EBs) to mitigate air quality concerns and greenhouse gas emissions, new challenges arise in bus scheduling and timetabling. Unlike traditional buses, EBs face operational obstacles due to their shorter range and extended charging times. Existing mathematical [...] Read more.

As transit authorities increasingly adopt electric buses (EBs) to mitigate air quality concerns and greenhouse gas emissions, new challenges arise in bus scheduling and timetabling. Unlike traditional buses, EBs face operational obstacles due to their shorter range and extended charging times. Existing mathematical optimization models for operation planning of traditional buses must be revised to address these unique characteristics of EBs. This study introduces a new approach to integrate timetabling and bus scheduling to enhance the level of service and minimize operational costs, using a case study of a University shuttle bus service in Montreal, Canada. The level of service will be enhanced by reducing students waiting time and improving their in-vehicle comfort through seat availability. The scheduling aspect seeks to reduce the total operational costs, which include travel, electricity consumption, and usage costs of EBs. The proposed algorithm calculates the waiting time and seat availability for different headway values and addresses the scheduling problem using a mixed-integer linear programming (MILP) model with an arc-based approach, solved using the Cplex Optimization Studio software version 12.8. A normalized weighted sum technique is then applied to select the optimal headway, balancing waiting time, seat availability, and operational costs. The effectiveness of our approach was tested through a case study of Concordia University’s shuttle bus service. Comparative analysis of the current and proposed schedules shows that our approach significantly improves service quality by decreasing waiting times and increasing seat availability while optimizing cost-effectiveness compared to the existing timetable of the Concordia shuttle bus. The proposed approach ensures a smooth transition to a fully electric transit system for shuttle bus services. Full article

(This article belongs to the Section E: Electric Vehicles)

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17 pages, 1064 KiB

Open AccessArticle

Coordinated Charging Scheduling Approach for Plug-In Hybrid Electric Vehicles Considering Multi-Objective Weighting Control in a Large-Scale Future Smart Grid

by Wei Li, Jiekai Shi and Hanyun Zhou

Energies 2024, 17(13), 3148; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133148 (registering DOI) - 26 Jun 2024

Abstract

The growing popularity of plug-in hybrid electric vehicles (PHEVs) is due to their environmental advantages. But uncoordinated charging of a large number of PHEVs can lead to a significant surge in peak loads and higher charging costs for PHEV owners. To end this, [...] Read more.

The growing popularity of plug-in hybrid electric vehicles (PHEVs) is due to their environmental advantages. But uncoordinated charging of a large number of PHEVs can lead to a significant surge in peak loads and higher charging costs for PHEV owners. To end this, this paper introduces an innovative approach to address the issue by proposing a multi-objective weighting control for coordinated charging of PHEVs in a future smart grid, which aims to find an economically optimal solution while also considering load stabilization with large-scale PHEV penetration. Technical constraints related to the owner’s demand and power limitations are considered. In the proposed approach, the charging behavior of PHEV owners is modeled by a normal distribution. It is observed that owners typically start charging their vehicles when they arrive home and stop charging when they go to their workplace. The charging cost is then calculated based on the tiered electricity price and charging power. By adjusting the cost weighting factor and the load stability weighting factor in the multi-objective function, the grid allows for flexible weight selection between the two objectives. This approach effectively encourages owners to actively participate in coordinated charging scheduling, which sets it apart from existing works. The algorithm offers better robustness and adaptability for large-scale PHEV penetration, making it highly relevant for the future smart grid. Finally, numerical simulations are presented to demonstrate the desirable performance of theory and simulation. Full article

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

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24 pages, 1942 KiB

Open AccessArticle

Cost-Effectiveness of Predictive Maintenance for Offshore Wind Farms: A Case Study

by Rasmus Dovnborg Frederiksen, Grzegorz Bocewicz, Grzegorz Radzki, Zbigniew Banaszak and Peter Nielsen

Energies 2024, 17(13), 3147; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133147 (registering DOI) - 26 Jun 2024

Abstract

The successful implementation of predictive maintenance for offshore wind farms suffers from a poor understanding of the consequential short-term impacts and a lack of research on how to evaluate the cost-efficiency of such efforts. This paper aims to develop a methodology to explore [...] Read more.

The successful implementation of predictive maintenance for offshore wind farms suffers from a poor understanding of the consequential short-term impacts and a lack of research on how to evaluate the cost-efficiency of such efforts. This paper aims to develop a methodology to explore the short-term marginal impacts of predictive maintenance applied to an already existing preventive maintenance strategy. This method will be based on an analysis of the performance of the underlying predictive model and the costs considered under specific maintenance services. To support this analysis, we develop a maintenance efficiency measure able to estimate the efficiency of both the underlying prediction model used for predictive maintenance and the resulting maintenance efficiency. This distinction between the efficiency of the model and the service results will help point out insufficiencies in the predictive maintenance strategy, as well as facilitate calculations on the cost–benefits of the predictive maintenance implementation. This methodology is validated on a realistic case study of an annual service mission for an offshore wind farm and finds that the efficiency metrics described in this paper successfully support cost–benefit estimates. Full article

(This article belongs to the Section A: Sustainable Energy)

24 pages, 7525 KiB

Open AccessArticle

Optimal EMS Design for a 4-MW-Class Hydrogen Tugboat: A Comparative Analysis Using DP-Based Performance Evaluation

by Seonghyeon Hwang, Changhyeong Lee, Juyeol Ryu, Jongwoong Lim, Sohmyung Chung and Sungho Park

Energies 2024, 17(13), 3146; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133146 (registering DOI) - 26 Jun 2024

Abstract

In the current trend of hydrogen fuel cell-powered ships, batteries are used together with fuel cells to overcome the limitations of fuel cell technology. However, performance differences arise depending on fuel cell and battery configurations, load profiles, and energy management system (EMS) algorithms. [...] Read more.

In the current trend of hydrogen fuel cell-powered ships, batteries are used together with fuel cells to overcome the limitations of fuel cell technology. However, performance differences arise depending on fuel cell and battery configurations, load profiles, and energy management system (EMS) algorithms. We designed four hybrid controllers to optimize EMS algorithms for achieving maximum performance based on target profiles and hardware. The selected EMS is based on a State Machine, an Equivalent Consumption Minimization Strategy (ECMS), Economic Model Predictive Control (EMPC), and Dynamic Programming (DP). We used DP to evaluate the optimal design state and fuel efficiency of each controller. To evaluate controller performance, we obtained a 4-MW-class tug load profile as a reference and performed simulations based on Nedstack’s fuel cells and a lithium-ion battery model. The constraints were set according to the description of each equipment manual, and the optimal controller was derived based on the amount of hydrogen consumed by each EMS under the condition of completely tracking the load profile. As a result of simulating the hybrid fuel cell–battery system by applying the load profile of the tugboat, we found that the 4-MW EMPC, which requires more state variables and control inputs, is the most fuel-efficient controller. Full article

(This article belongs to the Special Issue Modeling and Simulation of Electric Vehicle, Hybrid Electric Vehicle, and Intelligent Vehicle Dynamics)

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19 pages, 1117 KiB

Open AccessArticle

Long Short-Term Renewable Energy Sources Prediction for Grid-Management Systems Based on Stacking Ensemble Model

by Wiem Fekih Hassen and Maher Challouf

Energies 2024, 17(13), 3145; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133145 (registering DOI) - 26 Jun 2024

Abstract

The transition towards sustainable energy systems necessitates effective management of renewable energy sources alongside conventional grid infrastructure. This paper presents a comprehensive approach to optimizing grid management by integrating Photovoltaic (PV), wind, and grid energies to minimize costs and enhance sustainability. A key [...] Read more.

The transition towards sustainable energy systems necessitates effective management of renewable energy sources alongside conventional grid infrastructure. This paper presents a comprehensive approach to optimizing grid management by integrating Photovoltaic (PV), wind, and grid energies to minimize costs and enhance sustainability. A key focus lies in developing an accurate scheduling algorithm utilizing Mixed Integer Programming (MIP), enabling dynamic allocation of energy resources to meet demand while minimizing reliance on cost-intensive grid energy. An ensemble learning technique, specifically a stacking algorithm, is employed to construct a robust forecasting pipeline for PV and wind energy generation. The forecasting model achieves remarkable accuracy with a Root Mean Squared Error (RMSE) of less than 0.1 for short-term (15 min and one day ahead) and long-term (one week and one month ahead) predictions. By combining optimization and forecasting methodologies, this research contributes to advancing grid management systems capable of harnessing renewable energy sources efficiently, thus facilitating cost savings and fostering sustainability in the energy sector. Full article

(This article belongs to the Collection Renewable Energy and Energy Storage Systems)

19 pages, 1130 KiB

Open AccessArticle

Optimization of the Joint Operation of an Electricity–Heat–Hydrogen–Gas Multi-Energy System Containing Hybrid Energy Storage and Power-to-Gas–Combined Heat and Power

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

Energies 2024, 17(13), 3144; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133144 (registering DOI) - 26 Jun 2024

Abstract

With the continuous development of hydrogen storage systems, power-to-gas (P2G) and combined heat and power (CHP), the coupling between electricity–heat–hydrogen–gas has been promoted and energy conversion equipment has been transformed from an independent operation with low energy utilization efficiency to a joint operation [...] Read more.

With the continuous development of hydrogen storage systems, power-to-gas (P2G) and combined heat and power (CHP), the coupling between electricity–heat–hydrogen–gas has been promoted and energy conversion equipment has been transformed from an independent operation with low energy utilization efficiency to a joint operation with high efficiency. This study proposes a low-carbon optimization strategy for a multi-energy coupled IES containing hydrogen energy storage operating jointly with a two-stage P2G adjustable thermoelectric ratio CHP. Firstly, the hydrogen energy storage system is analyzed to enhance the wind power consumption ability of the system by dynamically absorbing and releasing energy at the right time through electricity–hydrogen coupling. Then, the two-stage P2G operation process is refined and combined with the CHP operation with an adjustable thermoelectric ratio to further improve the low-carbon and economic performance of the system. Finally, multiple scenarios are set up, and the comparative analysis shows that the addition of a hydrogen storage system can increase the wind power consumption capacity of the system by 4.6%; considering the adjustable thermoelectric ratio CHP and the two-stage P2G, the system emissions reduction can be 5.97% and 23.07%, respectively, and the total cost of operation can be reduced by 7.5% and 14.5%, respectively. Full article

(This article belongs to the Section A: Sustainable Energy)

20 pages, 5581 KiB

Open AccessArticle

A Water–Energy–Carbon–Economy Framework to Assess Resources and Environment Sustainability: A Case Study of the Yangtze River Economic Belt, China

by Hua Zhu, Qing Zhang and Hailin You

Energies 2024, 17(13), 3143; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133143 (registering DOI) - 26 Jun 2024

Abstract

Developing a comprehensive research framework that integrates the water–energy–carbon (WEC) system with economic development is crucial to fostering sustainable development. However, common evaluation indicators for sustainable development fail to cover the most up-to-date climate objectives and policies comprehensively and also lack a decoupling [...] Read more.

Developing a comprehensive research framework that integrates the water–energy–carbon (WEC) system with economic development is crucial to fostering sustainable development. However, common evaluation indicators for sustainable development fail to cover the most up-to-date climate objectives and policies comprehensively and also lack a decoupling analysis between various subsystems and economic development. By incorporating the Tapio model and the coupling coordination degree model (CCDM), we introduce a novel water–energy–carbon–economy (WECE) framework to evaluate the sustainability of regional resources and the environment. Taking the Yangtze River Economic Belt (YREB) as an example, we have constructed a comprehensive water–energy–carbon (WEC) indicator system that aligns with China’s sustainable development objectives and its most recent carbon emission reduction strategies. Employing the indicator system, we conducted an assessment of the sustainable development within the YREB from 2010 to 2019. The results reveal that the YREB has yet to achieve full decoupling between water use, energy consumption, carbon emissions, and economic development, with a prevailing trend towards weak decoupling (WD). The WEC system within the YREB exhibited coordination from 2010 to 2019. Notably, only the WEC system in Sichuan attained good coordination in 2019, indicating the imperative for more extensive initiatives in resource and environmental development to realize sustainable objectives. Finally, we delve into the driving mechanism of the coupling coordination degree (CCD) of the WEC system. Our findings suggest that, from the perspective of system collaborative management, the integrated approach of the WEC system offers superior benefits compared to individual management components. Consequently, it is imperative to bolster collaboration and institute a comprehensive set of policies to ensure sustainable development within the region. Full article

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

22 pages, 8885 KiB

Open AccessArticle

Analysis of the Operational Reliability of Different Types of Switching Substations Using the Monte Carlo Method

by Franjo Pranjić and Peter Virtič

Energies 2024, 17(13), 3142; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133142 (registering DOI) - 26 Jun 2024

Abstract

This study investigates the operational reliability of different types of switching substations within the context of power systems, employing the Monte Carlo method for analysis. The research focuses on evaluating the reliability of high-voltage substations, including single-busbar systems, double-busbar systems, and switchgears with [...] Read more.

This study investigates the operational reliability of different types of switching substations within the context of power systems, employing the Monte Carlo method for analysis. The research focuses on evaluating the reliability of high-voltage substations, including single-busbar systems, double-busbar systems, and switchgears with a ring-type power supply. By conducting simulations and analyzing statistical data on device reliability, the study aims to identify the most reliable implementation of switching substations. The results are presented through graphical representations and comparative tables, highlighting the impact of factors such as the number of switching elements and their connection on operational reliability. The findings indicate that configurations with a greater number of busbars and a parallel connection of switching elements exhibit higher operational reliability. The study provides insights to inform decision-making in the construction of new switching substations, emphasizing the importance of stable operation within power systems. Full article

(This article belongs to the Collection Featured Papers in Electrical Power and Energy System)

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14 pages, 1234 KiB

Open AccessArticle

Comprehensive Power Quality Assessment Based on a Data-Driven Determinant-Valued Extension Hierarchical Analysis Approach

by Jingyi Zhang, Tongtian Sheng, Pan Gu, Miao Yu, Honghao Wu, Jianqun Sun and Jinming Bao

Energies 2024, 17(13), 3141; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133141 (registering DOI) - 26 Jun 2024

Abstract

The increasing demand for power quality in modern power supply facilities and the deepening changes in the power market have led to frequent power quality events, making the assessment of power quality a necessity. In view of the complexity of the model and [...] Read more.

The increasing demand for power quality in modern power supply facilities and the deepening changes in the power market have led to frequent power quality events, making the assessment of power quality a necessity. In view of the complexity of the model and the sensitivity of the parameters of the existing power quality assessment system, as well as the shortcomings of the traditional hierarchical analysis method, this paper proposes a data-driven power quality assessment system based on the improved determinant-valued extension hierarchical analysis, which makes the factors affecting power quality hierarchical, and enhances the conservatism of the matrix while reducing the human subjective factors, so as to analyze the main power quality problems in a clearer and more intuitive way. The evaluation system is validated and analyzed, and the corresponding evaluation result is “excellent”, which proves that the system effectively evaluates the power quality in real scenarios, and has a good prospect in power quality evaluation. Full article

(This article belongs to the Special Issue Intelligent Analysis and Control of Modern Power Systems)

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15 pages, 2084 KiB

Open AccessArticle

Blockchain-Based Joint Auction Model for Distributed Energy in Industrial Park Microgrids

by Li Wang, Zihao Zhang, Jinheng Fan, Shunqi Zeng, Shixian Pan and Haoyong Chen

Energies 2024, 17(13), 3140; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133140 (registering DOI) - 26 Jun 2024

Abstract

To address the centralized trading demand within industrial parks and the scattered peer-to-peer trading demand outside industrial parks, this paper proposes a blockchain-based joint auction architecture for distributed energy in microgrids inside and outside industrial parks. By combining blockchain technology and auction theory, [...] Read more.

To address the centralized trading demand within industrial parks and the scattered peer-to-peer trading demand outside industrial parks, this paper proposes a blockchain-based joint auction architecture for distributed energy in microgrids inside and outside industrial parks. By combining blockchain technology and auction theory, the architecture integrates the physical energy transactions within industrial parks with the distributed transactions in external microgrids to meet the centralized trading demand within industrial parks and the scattered peer-to-peer trading demand outside industrial parks, optimizing resource allocation and improving system resilience. In the microgrid auction mechanism for industrial parks, considering distributed energy providers (sellers) and distributed energy buyers, an auction mechanism with power transmission distance, average electricity price, and enterprise nature as its main attributes was constructed to maximize social welfare, realizing efficient energy flow in a multi-microgrid environment and enabling coordinated mutual benefits for producers and consumers within the region. Finally, a case study was conducted on the joint auction mechanism for microgrids inside and outside industrial parks, including the impacts of market dynamics and user preferences on electricity prices using different trading methods, the computational results using different trading matching methods (comparing single-attribute and multi-attribute methods), and multi-dimensional verification of user satisfaction with peer-to-peer transactions in a blockchain environment. The effectiveness of the joint trading between physical energy transactions within industrial parks and external microgrids was demonstrated, which could efficiently coordinate energy allocation inside and outside the parks and reduce the cost of energy configuration. Full article

(This article belongs to the Section A: Sustainable Energy)

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17 pages, 8337 KiB

Open AccessArticle

Kerr Electro-Optic Effect-Based Methodology for Measuring and Analyzing Electric Field Distribution in Oil-Immersed Capacitors

by Zhaoliang Xing, Hao Ge, Fanqiu Zeng, Shaowei Guo and Chunjia Gao

Energies 2024, 17(13), 3139; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133139 (registering DOI) - 26 Jun 2024

Abstract

In the current design and verification processes of insulation structures for high-voltage oil-immersed capacitors, there is a heavy reliance on electric field simulation calculations using idealized models that lack empirical validation of spatial electric fields. This study employs the Kerr electro-optic effect to [...] Read more.

In the current design and verification processes of insulation structures for high-voltage oil-immersed capacitors, there is a heavy reliance on electric field simulation calculations using idealized models that lack empirical validation of spatial electric fields. This study employs the Kerr electro-optic effect to establish a non-contact optical remote sensing system for measuring the spatial electric field distribution in the insulating liquid dielectric (benzyltoluene) between the capacitor’s element and the case under various temperatures and main insulation distances. The findings reveal that the measured spatial electric field stress can be up to 15% higher than the simulated values. The electric field stress measured in the Y1 direction (up toward the capacitor top) is comparable to that measured in the Y2 direction (down toward the capacitor end). Furthermore, when varying the main insulation distance, the electric field stress consistently shows a negative correlation with increasing measurement distance. Specifically, at a main insulation distance of 1.5 mm, the electric field stress is 1.81 times that at 5.5 mm. As the temperature rises, the spatial electric field stress increases gradually, and the electric field distribution becomes more uneven at higher temperatures. At 80 °C, the field stress is approximately 1.57 times that at 20 °C, with the measured field stress at 80 °C being 19% higher than the simulated value. Finally, this paper undertakes a comprehensive theoretical analysis and experimental validation to elucidate the discrepancies between simulated and measured spatial electric fields. Leveraging these insights, it proposes advanced optimization strategies for the insulation structures of capacitor elements. The outcomes of this study furnish substantial technical and theoretical support, significantly enhancing the design, verification, and optimization processes for insulation in oil-immersed capacitors. Full article

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

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18 pages, 2391 KiB

Open AccessArticle

Hydrodynamic Development and Optimisation of a Retrofittable Dual-Mode Propeller Turbine

by Joylan Rao Erriah, Pengfei Liu and Serkan Turkmen

Energies 2024, 17(13), 3138; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133138 (registering DOI) - 26 Jun 2024

Abstract

Dual-mode propellers, as propulsion and turbine devices, have found widespread application in renewable energy systems for marine vehicles, particularly in sailing boats and yachts. However, the existing dual-mode propellers in these contexts are typically chosen in an off-the-shelf manner, indicating a lack of [...] Read more.

Dual-mode propellers, as propulsion and turbine devices, have found widespread application in renewable energy systems for marine vehicles, particularly in sailing boats and yachts. However, the existing dual-mode propellers in these contexts are typically chosen in an off-the-shelf manner, indicating a lack of hydrodynamic optimisation to enhance both the propulsion and energy generation efficiency in the same rotor. To address this limitation and furnish scientific validation of the design of a dual-mode propeller turbine rotor optimised to achieve a balanced performance in both propulsion and energy generation, rigorous experimentation was conducted using specialised software, Rotorysics 2019, and a case study vessel, the Princess Royale. Utilising prior experimental data for this propeller turbine, code validation was undertaken to ensure accurate prediction of the effects of the pitch, blade count and expanded area ratio on the performance in both modes. With the intention of achieving optimal power generation and propulsion efficiencies in conjunction with a single rotor, the findings reveal that the optimised fixed-pitch propeller exhibits dual functionality. They serve as both propulsion and tidal/current turbines with balanced efficiency. They are particularly suitable for low-speed vessels such as yachts anchored in currents or for sailboats utilising a propeller as a towed turbine. Through thorough testing and analysis, the concept of a dual-mode propeller turbine was feasible. Analysing them separately, in terms of the propulsion, the best geometry found through numerous tests of different expanded area ratios, blade number, pitch and speed was the 3-blade, 0.6 pitch ratio, which achieved a propulsive efficiency of 54.33% (0.5433204) and a power coefficient of 0.291843. Conversely, if the focus was on power generation while maintaining excellent propulsive efficiency, the optimal geometry would be the 5-blade, 0.6 pitch ratio, which offers a power coefficient of 0.348402 and a propulsive efficiency of 48.55% (0.48547). However, when using both power generation and propulsion as the criteria, the 5-blade, 0.6 pitch ratio, with an EAR of 0.387142, is superior, with balanced optimisation, offering a propulsive efficiency of 52.53% (0.52527) and a power coefficient of 0.319718. As expected, this encompasses a higher blade number for increased power generation efficiency and a higher pitch ratio for increased propulsive efficiency. Full article

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

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23 pages, 3802 KiB

Open AccessArticle

Eco-Efficiency of Pellet Production from Dedicated Poplar Plantations

by Giulio Sperandio, Alessandro Suardi, Andrea Acampora and Vincenzo Civitarese

Energies 2024, 17(13), 3137; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133137 (registering DOI) - 26 Jun 2024

Abstract

Biomass, due to its neutrality in terms of greenhouse gas emissions into the atmosphere during its life cycle, is considered an interesting renewable source for energy production as an alternative to the use of more polluting fossil fuels. Among the different wood fuels, [...] Read more.

Biomass, due to its neutrality in terms of greenhouse gas emissions into the atmosphere during its life cycle, is considered an interesting renewable source for energy production as an alternative to the use of more polluting fossil fuels. Among the different wood fuels, pellets are convenient for use in dedicated stoves, and pellet heating systems have a high energy efficiency. The aim of this work was to estimate the economic and global warming potential (GWP100a) generated along the thermal energy supply chain of wood pellets, starting from the production of raw biomass from dedicated poplar cultivations and ending with the use of pellets in stoves by the end-user to produce thermal energy and ash. The Eco-Efficiency Indicator (EEI) was used to link the economic and environmental performance for eight proposed scenarios, obtained by combining different levels of mechanisation for poplar harvesting and wood biomass management before arrival at the pellet plant. For the thermal energy produced by the poplar wood pellet, the GWP100a ranged from 1.5 × 10⁻² to 2.1 × 10⁻² kg CO₂−eq MJ⁻¹ for three-year-old plantations and from 1.9 × 10⁻² to 2.4 × 10⁻² kg CO₂−eq MJ⁻¹, for six-year-old plantations. In terms of eco-efficiency of the baseline scenario (EEIb), the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIb values ranging from 0.31 to 0.60 € kgCO₂−eq⁻¹, compared to from 0.29 to 0.36 € kgCO₂−eq⁻¹ for pellets obtained from biomass produced from six-year-old poplar plantations. In terms of the Global Eco-Efficiency Indicator (EEIg), which also takes into account the positive effect on the reduction of greenhouse gases due to the storage of carbon in the soil by the plantations and the reduction of emissions from avoided fossil fuels, the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIg values that vary in the range of 0.60 ÷ 1.04 € kgCO₂−eq⁻¹, compared to 0.55 ÷ 0.62 € kg CO₂−eq⁻¹ for thermal energy obtained using biomass from six-year-old poplar plantations. Full article

(This article belongs to the Special Issue Renewable and Sustainable Energy in Light of Energy Transition Processes)

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15 pages, 2165 KiB

Open AccessArticle

Optimizing Biomass Supply Chains to Power Plants under Ecological and Social Restrictions: Case Study from Poland

by Jan Banaś, Katarzyna Utnik-Banaś and Stanisław Zięba

Energies 2024, 17(13), 3136; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133136 (registering DOI) - 26 Jun 2024

Abstract

The growing demand for social and regulatory forest ecosystem services can significantly modify the availability and cost of biomass for energy purposes. This article presents a model for optimizing biomass supply chains using a linear programming framework integrated with a geographic information system [...] Read more.

The growing demand for social and regulatory forest ecosystem services can significantly modify the availability and cost of biomass for energy purposes. This article presents a model for optimizing biomass supply chains using a linear programming framework integrated with a geographic information system (GIS). Based on a given type of biomass resource, its calorific value, price, distance from the power plant, and transportation costs, the model identifies the optimal source of biomass, allowing it to cover the demand for the required total energy value with the lowest possible costs. The case study includes the Połaniec power plant in southeastern Poland and potential sources of forest biomass and agricultural straw within 100 km of the plant. The impact of constraints on the availability and cost of biomass was analyzed in the following scenarios: (1) all forest and agriculture biomass is available, (2) forest area in Natura 2000 network is excluded, and (3) firewood and forests with dominated ecological and social function are excluded. Unit costs of biomass varied depending on biomass availability and energy demands. The lowest unit costs of biomass (3.19 EUR/MJ) were for energy demand at the level of 1 TJ yearly for all kinds of biomass and the highest (4.91 EUR/MJ) for ecological and social constraints and energy demand 4 TJ. As energy demand increased, unit costs increased, and the ability to meet this demand with just one type of biomass decreased. The energy biomass sector can utilize the model to benefit both biomass producers and their final buyers. Full article

(This article belongs to the Special Issue Sustainable Biomass Energy Production and Utilization)

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14 pages, 2516 KiB

Open AccessFeature PaperArticle

Using Urban Building Energy Models for the Development of Sustainable Island Energy Systems

by Jaime Cevallos-Sierra, Afonso Pinto Gonçalves and Carlos Santos Silva

Energies 2024, 17(13), 3135; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133135 (registering DOI) - 26 Jun 2024

Abstract

This study evaluates the use of City Energy Analyst, an urban building energy modelling tool, to design zero-carbon energy communities in low-industry isolated island settings. The research aims to test the effectiveness of the software during the development of sustainable energy systems in [...] Read more.

This study evaluates the use of City Energy Analyst, an urban building energy modelling tool, to design zero-carbon energy communities in low-industry isolated island settings. The research aims to test the effectiveness of the software during the development of sustainable energy systems in isolated microgrids and compares it with the widely used tool EnergyPLAN. The goal of the study focused on making a community self-sustainable, considering the rooftop area available in the populated settlements to install photovoltaic systems and distributed storage capacity. With this purpose in mind, the evaluated tool estimated the energy consumption of each building and the respective total annual consumption of Corvo Island, a location that is naturally isolated and dependent on fossil fuels. The results demonstrated that City Energy Analyst is an innovative tool to estimate energy consumption and potential energy generation of photovoltaic systems in a remote location, providing additional features to a traditional model and motivating further development of the associated plug-in. However, it requires initial time-consuming efforts to build a reliable model. As a complement, EnergyPLAN can be used to enhance the design, with the integration of the local existing and potential generation sources and to confirm the stability of the overall energy system. This tool introduced additional wind capacity and centralized storage into the model, testing the balance of the system. Therefore, the study proposes a framework combining the strengths of both tools to measure island energy systems, as they can complement each other, to build a strong analysis model. Full article

(This article belongs to the Collection Feature Paper Collection: Energy and Buildings)

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20 pages, 5791 KiB

Open AccessArticle

The Design and the Control Principle of a Direct Low-Speed PMSM Servo-Drive Operating under a Sign-Changing Load on the Shaft

by Oleksandr Makarchuk and Dariusz Całus

Energies 2024, 17(13), 3134; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133134 (registering DOI) - 26 Jun 2024

Abstract

The paper relates to the development of an algorithm applicable for maintaining the rotational speed of low-speed drives using PMSM motors and operating under a sign-changing load. The moment of inertia of rotating parts does not play the role of a mechanical stabilizer [...] Read more.

The paper relates to the development of an algorithm applicable for maintaining the rotational speed of low-speed drives using PMSM motors and operating under a sign-changing load. The moment of inertia of rotating parts does not play the role of a mechanical stabilizer for the speeds discussed in the article. Simulation studies are presented with the aim of developing a rotational speed control algorithm that utilizes only positional feedback and the previously assumed sign-changing load on the shaft. For the purposes of this research, a mathematical model was developed to calculate transient processes in a PMSM machine operating in the conditions of a sign-changing load on the shaft. This model assumes a deterministic control principle adapted to the known nature of the load change. In this model, the mutual influence occurring between the phase fluxes, the electromagnetic torque, the electric currents and the rotor position angle are established on the basis of FEM analysis of a two-dimensional magnetic field using a quasi-stationary approximation. Principles applicable for controlling a direct low-speed servo drive based on a PMSM machine operating with a known variable shaft load using only positional feedback and a predetermined shaft load change law are defined. The proposed regulation method is verified in an experimental manner. For this purpose, an experimental setup was built, which includes a PMSM with a load imitator on a variable sign shaft, an inverter providing sine-shaped power supply to the machine and a digital dual-processor control system. The discussed rotational speed stabilization algorithm was implemented in the form of a program for a microcontroller, which forms a part of the control system. The results of experimental tests confirm the adequacy of mathematical modeling and the effectiveness of the proposed rotational speed stabilization algorithm. Full article

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

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14 pages, 585 KiB

Open AccessArticle

Performance Evaluation and Working Fluid Screening of Direct Vapor Generation for Solar ORC Using Low-Global Warming Potential (GWP) Working Fluids

by Youtao Jiang, Xunda Zhang, Zhengao Zhang, Lei Hao, Zhaozhi Cao, Shuyang Li, Bowen Guo, Yawen Zheng, Chunhai Dong and Li Zhao

Energies 2024, 17(13), 3133; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133133 - 25 Jun 2024

Abstract

Traditional working fluids used in direct vapor generation for solar organic Rankine cycle (DVG-ORC) systems have a high global warming potential (GWP), making it imperative to find environmentally friendly alternative working fluids for these systems. This paper evaluates the performance of the DVG-ORC [...] Read more.

Traditional working fluids used in direct vapor generation for solar organic Rankine cycle (DVG-ORC) systems have a high global warming potential (GWP), making it imperative to find environmentally friendly alternative working fluids for these systems. This paper evaluates the performance of the DVG-ORC system under different operating conditions. By comparing the results of traditional working fluids with those of low-GWP fluids, the feasibility of using low-GWP fluids as alternative working fluids is explored. Additionally, to screen the working fluids suitable for this system further, the system is optimized with net output power as the objective function. The results show that evaporation temperature has different impacts on system performance. R245ca and R1336mzz(Z) exhibit higher net output power at different evaporation temperatures, with R1336mzz(Z) only reducing it by 3.73–5.26% compared to R245ca. However, an increase in condensation temperature negatively affects system performance, leading to a decrease in net output power and various efficiencies. Net output power increases with an increase in mass flow rate, indicating that higher mass flow rates can enhance system performance. The optimization results show that the net output power of low-GWP working fluid R1336mzz(Z) decreases by only 3.44% compared to R245ca, which achieves the maximum net output power. Moreover, among low-GWP working fluids, R1336mzz(Z) demonstrates the highest ORC efficiency and system efficiency, making it the most suitable working fluid for the DVG-ORC system due to its environmental friendliness and safety. Full article

(This article belongs to the Special Issue Novel Method, Optimization and Applications of Thermodynamic Cycles)

20 pages, 975 KiB

Open AccessArticle

A Wind Power Fluctuation Smoothing Control Strategy for Energy Storage Systems Considering the State of Charge

by Li Peng, Longfu Luo, Jingyu Yang and Wanting Li

Energies 2024, 17(13), 3132; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133132 - 25 Jun 2024

Abstract

With the significant increase in the scale of energy storage configuration in wind farms, improving the smoothing capability and utilization of energy storage has become a key focus. Therefore, a wind power fluctuation smoothing control strategy is proposed for battery energy storage systems [...] Read more.

With the significant increase in the scale of energy storage configuration in wind farms, improving the smoothing capability and utilization of energy storage has become a key focus. Therefore, a wind power fluctuation smoothing control strategy is proposed for battery energy storage systems (BESSs), considering the state of charge (SOC). First, a BESS smoothing wind power fluctuation system model based on model predictive control (MPC) is constructed. The objective function aims to minimize the deviation of grid-connected power from the target power and the deviation of the BESS’s remaining capacity from the ideal value by comprehensively considering the smoothing effect and the SOC. Second, when the wind power’s grid-connected power exceeds the allowable fluctuation value, the weight coefficients in the objective function are adjusted in real time using the first layer of fuzzy control rules combined with SOC partitioning. This approach smooths wind power fluctuations while preventing overcharging and overdischarging of the BESS. When the grid-connected power is within the allowable fluctuation range, the charging and discharging power of the BESS is further refined using a second layer of fuzzy control rules. This enhances the BESS’s capability and utilization for smoothing future wind power fluctuations by preemptively charging and discharging. Finally, the proposed control strategy is simulated using MATLAB R2021b with actual operational data from a wind farm as a case study. Compared to the traditional MPC control method, the simulation results demonstrate that the proposed method effectively controls the SOC within a reasonable range, prevents the SOC from entering the dead zone, and enhances the BESS’s ability to smooth wind power fluctuations. Full article

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

21 pages, 2881 KiB

Open AccessArticle

Biocarbon Production Using Three-Stage Pyrolysis and Its Preliminary Suitability to the Iron and Steel Industry

by Mika Pahnila, Aki Koskela, Petri Sulasalmi and Timo Fabritius

Energies 2024, 17(13), 3131; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133131 - 25 Jun 2024

Viewed by 64

Abstract

There has been a rising interest in the iron and steel industry in replacing fossil-based carbon carriers in their processes because they are the main origin of the anthropogenic carbon emissions within the industry. The use of bio-based carbon carriers could be one [...] Read more.

There has been a rising interest in the iron and steel industry in replacing fossil-based carbon carriers in their processes because they are the main origin of the anthropogenic carbon emissions within the industry. The use of bio-based carbon carriers could be one solution to partly tackle this challenge. Conventionally, biocarbon is produced by pyrolysis with fixed heating rate, pyrolysis temperature, and retention time. Although the mechanisms behind the formation of biocarbon and the decomposition temperatures of the main compounds of biomass-based materials are known, this knowledge is rarely being utilized in the design of commercial pyrolysis reactors, even though the pyrolysis mechanism-based approach increases the biocarbon yield. In this study, the mechanistic pathway of carbonization of lignocellulosic biomass is taken into account to produce biocarbon with higher yield and quality than conventional pyrolysis with the same process time. Results show that when the process time is the same in both methods, segmented pyrolysis increases biocarbon yield up to 5.4% within a pyrolysis temperature range from 300 °C to 900 °C. Also, fixed carbon yield increased 1.5% in this temperature area. When using segmented pyrolysis, the most suitable pyrolysis temperature is 700 °C based on the characteristics of the produced biocarbon. Full article

(This article belongs to the Section A4: Bio-Energy)

21 pages, 1279 KiB

Open AccessArticle

Joint Deployment of Sensors and Chargers in Wireless Rechargeable Sensor Networks

by Jie Lian and Haiqing Yao

Energies 2024, 17(13), 3130; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133130 - 25 Jun 2024

Viewed by 29

Abstract

As a promising technology to achieve the permanent operation of battery-powered wireless sensor devices, wireless rechargeable sensor networks (WRSNs) by radio-frequency radiation have attracted considerable attention in recent years. Determining how to save the deployment cost of WRSNs has been a hot topic. [...] Read more.

As a promising technology to achieve the permanent operation of battery-powered wireless sensor devices, wireless rechargeable sensor networks (WRSNs) by radio-frequency radiation have attracted considerable attention in recent years. Determining how to save the deployment cost of WRSNs has been a hot topic. Previous scholars have mainly studied the cost of deploying chargers, thus ignoring the impact of sensor deployment on the network. Therefore, we consider the new problem of joint deployment of sensors and chargers on a two-dimensional plane, i.e., deploying the minimum number of sensors and chargers used to monitor points of interest (PoIs). Considering the interaction of deployed sensors and chargers, we divide the problem into two stages, P1 and P2. P1 addresses the sensor deployment, while P2 addresses the deployment of chargers. Both P1 and P2 have proved to be NP-hard. Meanwhile, we notice that the aggregation effect of sensors can effectively reduce the number of chargers deployed; therefore, we propose a greedy heuristic approximate solution for deploying sensors by using the aggregation effect (GHDSAE). Then, a greedy heuristic (GH) solution and a particle swarm optimization (PSO) solution are proposed for P2. The time complexity of these solutions is analyzed. Finally, extensive simulation results show that the PSO solution can always reduce the number of chargers deployed based on the GHDSAE solution sensor deployment approach. Therefore, it is more cost-effective to jointly deploy sensors and chargers by using the GHDSAE solution and the PSO solution. Full article

(This article belongs to the Special Issue IoT and Sensor Network Applications for Energy Management and Efficiency)

14 pages, 800 KiB

Open AccessArticle

Modeling of Separation with Drying Processes for Compressed Air Using an Experimental Setup with Separation–Condensation and Throttling Devices

by Oleksandr Liaposhchenko, Dmytro Bondar, Marek Ochowiak, Ivan Pavlenko and Sylwia Włodarczak

Energies 2024, 17(13), 3129; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133129 - 25 Jun 2024

Viewed by 51

Abstract

In modern industrial plants, compressed air is the most commonly used energy source; however, it is a source of condensation, which is not desirable for pneumatic equipment. This article describes a model of compressed air drying based on the principle of a refrigeration [...] Read more.

In modern industrial plants, compressed air is the most commonly used energy source; however, it is a source of condensation, which is not desirable for pneumatic equipment. This article describes a model of compressed air drying based on the principle of a refrigeration dryer. However, instead of gas refrigerants, the method proposed is to use cooled compressed air as a cooling medium with a temperature below 273 K. The main objective is to study the possibility of replacing harmful refrigerant gases with a neutral type of coolant. To carry out this research, a test bench containing a plate heat exchanger and a throttling device was designed and manufactured. This study has yielded the following scientific results. Firstly, the Joule–Thompson effect was used during the experiments, which facilitated a reduction in the temperature of the compressed air to 255 K. Secondly, using the expanded air and a plate heat exchanger, the temperature of the main compressed air stream was reduced to 280 K, which is very close to the temperature provided by standard-refrigeration-type compressed air dryers. This suggests that it is possible to use compressed air energy to cool the main stream of warm compressed air after the compressor. In general, the temperature range ensures the compressed air quality at the level of class 4 in accordance with international standards. Full article

13 pages, 1104 KiB

Open AccessArticle

Discussion on Deep Geothermal Characteristics and Exploration Prospects in the Northern Jiangsu Basin

by Linyou Zhang, Shengtao Li, Wenhao Xu, Junpeng Guan, Jian Song, Yahui Yao, Zhaoxuan Niu and Yang Li

Energies 2024, 17(13), 3128; https://0-doi-org.brum.beds.ac.uk/10.3390/en17133128 - 25 Jun 2024

Viewed by 46

Abstract

The Northern Jiangsu Basin (NJB), located at the northeast edge of the Yangtze block, is not only rich in oil and gas resources but also contains abundant geothermal resources. Nevertheless, the distribution of geothermal resources at medium depth in the NJB is still [...] Read more.

The Northern Jiangsu Basin (NJB), located at the northeast edge of the Yangtze block, is not only rich in oil and gas resources but also contains abundant geothermal resources. Nevertheless, the distribution of geothermal resources at medium depth in the NJB is still unclear due to its complex geological structure and tectonic–thermal evolution process, which restricts its exploitation and utilization. The characteristics of the geothermal field and distribution of geothermal reservoirs within the NJB are preliminarily analyzed based on available temperature measurements and geothermal exploration data. The prospective areas for the exploration of deep geothermal resources are discussed. The analysis results show that (1) Mesozoic–Paleozoic marine carbonate rocks are appropriate for use as principal geothermal reservoirs for the deep geothermal exploration and development within the NJB; (2) the geothermal field is evidently affected by the base fluctuation, and the high-temperature area is mainly concentrated at the junction of the Jianhu uplift and Dongtai depression; (3) the southeast margin of Jinhu sag, Lianbei sag, the east and west slope zone of Gaoyou sag, the low subuplifts within the depression such as Lingtangqiao–Liubao–Zheduo subuplifts, Xiaohai–Yuhua subuplifts and the west of Wubao low subuplift, have good prospects for deep geothermal exploration. Full article

(This article belongs to the Section H2: Geothermal)

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