Energies

23 pages, 4091 KiB

Open AccessReview

Data-Driven Approaches for Energy Theft Detection: A Comprehensive Review

by Soohyun Kim, Youngghyu Sun, Seongwoo Lee, Joonho Seon, Byungsun Hwang, Jeongho Kim, Jinwook Kim, Kyounghun Kim and Jinyoung Kim

Energies 2024, 17(12), 3057; https://doi.org/10.3390/en17123057 - 20 Jun 2024

Cited by 4 | Viewed by 1611

Abstract

The transition to smart grids has served to transform traditional power systems into data-driven power systems. The purpose of this transition is to enable effective energy management and system reliability through an analysis that is centered on energy information. However, energy theft caused [...] Read more.

The transition to smart grids has served to transform traditional power systems into data-driven power systems. The purpose of this transition is to enable effective energy management and system reliability through an analysis that is centered on energy information. However, energy theft caused by vulnerabilities in the data collected from smart meters is emerging as a primary threat to the stability and profitability of power systems. Therefore, various methodologies have been proposed for energy theft detection (ETD), but many of them are challenging to use effectively due to the limitations of energy theft datasets. This paper provides a comprehensive review of ETD methods, highlighting the limitations of current datasets and technical approaches to improve training datasets and the ETD in smart grids. Furthermore, future research directions and open issues from the perspective of generative AI-based ETD are discussed, and the potential of generative AI in addressing dataset limitations and enhancing ETD robustness is emphasized. Full article

(This article belongs to the Special Issue Advances in Machine Learning Applications in Modern Energy System)

► Show Figures

Figure 1

16 pages, 2456 KiB

Open AccessArticle

Technical Feasibility Study of Orange Wood Residues (Citrus sinensis) for Bioenergy Generation

by Luciano C. Dias, Damaris Guimarães, Ananias F. Dias Júnior and Michel P. Oliveira

Energies 2024, 17(12), 3056; https://doi.org/10.3390/en17123056 - 20 Jun 2024

Viewed by 772

Abstract

The production of orange (Citrus sinensis) generates many residues, and the few that are used are usually by-products of the fruit juice processing industry. Among the residues, wood is potentially advantageous for use in bioenergy, but with few records in the [...] Read more.

The production of orange (Citrus sinensis) generates many residues, and the few that are used are usually by-products of the fruit juice processing industry. Among the residues, wood is potentially advantageous for use in bioenergy, but with few records in the literature. In this sense, this study sought to evaluate the feasibility of using orange wood for energy purposes by performing chemical characterization, immediate analysis, FTIR, calorific value, thermogravimetry and bulk and energetic densities for three compositions: 100% trunk (100T), 90% trunk + 10% bark (90T10B) and 100% bark (100B). 100T showed a higher fixed carbon content (16.76%) and equality with 90T10B in lignin, holocellulose, useful calorific value and volatile materials. 100B presented higher extractives and ash contents of 19.67% and 10.35%, respectively. The FTIR spectra and thermogravimetric curves were similar in 100T and 90T10B. 100B showed more stages of degradation and a higher incidence of peaks in the range 780–612 cm⁻¹. The bulk density was equal in 100T and 90T10B, but the energy density was higher in 100T (6.16 Gj.m⁻³). 100T and 90T10B are good options for bioenergy and the chemical composition and thermal degradation of 100B point to new investigations in this composition. Full article

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

► Show Figures

Figure 1

15 pages, 3293 KiB

Open AccessArticle

Improving the Fuel Combustion Quality Control System in Medium Power Boilers

by Sylwia Janta-Lipińska, Alexander Shkarovskiy and Łukasz Chrobak

Energies 2024, 17(12), 3055; https://doi.org/10.3390/en17123055 - 20 Jun 2024

Viewed by 789

Abstract

The constant development of electronic devices and components allows for older systems (which have been well received) with electronic control of combustion processes in municipal thermal energy to be improved to new levels, with significant economic and ecological effects. This article presents details [...] Read more.

The constant development of electronic devices and components allows for older systems (which have been well received) with electronic control of combustion processes in municipal thermal energy to be improved to new levels, with significant economic and ecological effects. This article presents details of the development of an improved natural gas combustion quality control system in the modernized DKVR 6.5-13 steam boiler. This paper presents the results of comparative tests of this boiler obtained for various variants of the system operation. It has been proven that maximum boiler efficiency indicators and minimum toxicity of exhaust gases discharged into the atmosphere can be achieved by using a proposed control system. The system uses the regulated residual chemical underburning method, based on simultaneous control of the oxygen and carbon dioxide content in the exhaust gases. As a result of the use of the proposed method, an increase in boiler efficiency was achieved by 1.5–2.1% compared with standard automatic regulation and an increase by 0.3–0.8% compared with regulation based only on the oxygen content in the exhaust gases. These results were achieved by reducing the excess air coefficient. In addition, nitrogen oxide emissions were reduced by 25–30%, which, with a justified safe carbon monoxide content in exhaust gases of up to 250 ppm, reduced the exhaust gas toxicity index to 20%. Full article

(This article belongs to the Section I2: Energy and Combustion Science)

► Show Figures

Figure 1

23 pages, 1842 KiB

Open AccessEditor’s ChoiceArticle

Multi-Objective Plum Tree Algorithm and Machine Learning for Heating and Cooling Load Prediction

by Adam Slowik and Dorin Moldovan

Energies 2024, 17(12), 3054; https://doi.org/10.3390/en17123054 - 20 Jun 2024

Cited by 1 | Viewed by 1077

Abstract

The prediction of heating and cooling loads using machine learning algorithms has been considered frequently in the research literature. However, many of the studies considered the default values of the hyperparameters. This manuscript addresses both the selection of the best regressor and the [...] Read more.

The prediction of heating and cooling loads using machine learning algorithms has been considered frequently in the research literature. However, many of the studies considered the default values of the hyperparameters. This manuscript addresses both the selection of the best regressor and the tuning of the hyperparameter values using a novel nature-inspired algorithm, namely, the Multi-Objective Plum Tree Algorithm. The two objectives that were optimized were the averages of the heating and cooling predictions. The three algorithms that were compared were the Extra Trees Regressor, the Gradient Boosting Regressor, and the Random Forest Regressor of the sklearn machine learning Python library. We considered five hyperparameters which were configurable for each of the three regressors. The solutions were ranked using the MOORA method. The Multi-Objective Plum Tree Algorithm returned a root mean square error value for heating equal to 0.035719 and a root mean square error for cooling equal to 0.076197. The results are comparable to the ones obtained using standard multi-objective algorithms such as the Multi-Objective Grey Wolf Optimizer, Multi-Objective Particle Swarm Optimization, and NSGA-II. The results are also performant concerning the previous studies, which considered the same experimental dataset. Full article

(This article belongs to the Section J: Thermal Management)

► Show Figures

Figure 1

20 pages, 2791 KiB

Open AccessArticle

Heat Pumps for Germany—Additional Pressure on the Supply–Demand Equilibrium and How to Cope with Hydrogen

by Andreas von Döllen and Stephan Schlüter

Energies 2024, 17(12), 3053; https://doi.org/10.3390/en17123053 - 20 Jun 2024

Cited by 1 | Viewed by 1244

Abstract

In the context of the German Energiewende, the current government intends to install six million heat pumps by 2030. Replacing gas heating by power has significant implications on the infrastructure. One of the biggest advantages of using gas is the existing storage portfolio. [...] Read more.

In the context of the German Energiewende, the current government intends to install six million heat pumps by 2030. Replacing gas heating by power has significant implications on the infrastructure. One of the biggest advantages of using gas is the existing storage portfolio. It has not been clarified yet how power demand should be structured on an annual level—especially since power storage is already a problem and solar power is widely promoted to fuel heat pumps, despite having an inverse profile. In this article, three different solutions, namely, hydrogen, batteries, and carbon capture and storage, are discussed with respect to resources, energy, and financial demand. It shows that relying solely on batteries or hydrogen is not solving the structuring problem. A combination of all existing technologies (including fossil fuels) is required to structure the newly generated electricity demand. Full article

(This article belongs to the Special Issue Economic Analysis and Policies in the Energy Sector)

► Show Figures

Figure 1

18 pages, 911 KiB

Open AccessFeature PaperArticle

Exploring Flexibility Potential of Energy-Intensive Industries in Energy Markets

by Laureana Luciani, Juliana Cruz, Victor Ballestin and Boniface Dominick Mselle

Energies 2024, 17(12), 3052; https://doi.org/10.3390/en17123052 - 20 Jun 2024

Cited by 1 | Viewed by 1149

Abstract

The European Union, in pursuit of the goal of reducing emissions by at least 55% by 2030 and achieving climate neutrality by 2050, is deploying different actions, with industry decarbonization as a key strategy. However, increasing electricity demand requires an intensification of energy [...] Read more.

The European Union, in pursuit of the goal of reducing emissions by at least 55% by 2030 and achieving climate neutrality by 2050, is deploying different actions, with industry decarbonization as a key strategy. However, increasing electricity demand requires an intensification of energy generation from clean technologies, and the energy system’s expansion is hindered by renewable generation’s climatic dependencies and the imperative for substantial electrical infrastructure investments. Although the transmission grid is expected to grow, flexibility mechanisms and innovative technologies need to be applied to avoid an overwhelming growth. In this context, this paper presents a thorough assessment, conducted within the FLEXINDUSTRIES project, of the flexibility potential across seven energy-intensive industries (automotive industry, biofuel production, polymer manufacturing, steel manufacturing, paper mills, pharmaceutical industry, and cement production). The methodology followed during the analysis entails reviewing the state-of-the-art existing flexibility mechanisms, industries’ energy markets engagement, and technical/operational readiness. The results highlight the feasibility of the proposed actions for enabling energy market flexibility through demand-response programs, quantifying energy opportunities, and pinpointing regulatory and technical barriers. Full article

(This article belongs to the Special Issue Sustainable Management of Energy Resources, Energy Strategies and Climate Change—2nd Edition)

► Show Figures

Figure 1

50 pages, 9834 KiB

Open AccessEditor’s ChoiceReview

A Review of Energy-Efficient Technologies and Decarbonating Solutions for Process Heat in the Food Industry

by François Faraldo and Paul Byrne

Energies 2024, 17(12), 3051; https://doi.org/10.3390/en17123051 - 20 Jun 2024

Cited by 2 | Viewed by 2355

Abstract

Heat is involved in many processes in the food industry: drying, dissolving, centrifugation, extraction, cleaning, washing, and cooling. Heat generation encompasses nearly all processes. This review first presents two representative case studies in order to identify which processes rely on the major energy [...] Read more.

Heat is involved in many processes in the food industry: drying, dissolving, centrifugation, extraction, cleaning, washing, and cooling. Heat generation encompasses nearly all processes. This review first presents two representative case studies in order to identify which processes rely on the major energy consumption and greenhouse gas (GHG) emissions. Energy-saving and decarbonating potential solutions are explored through a thorough review of technologies employed in refrigeration, heat generation, waste heat recovery, and thermal energy storage. Information from industrial plants is collected to show their performance under real conditions. The replacement of high-GWP (global warming potential) refrigerants by natural fluids in the refrigeration sector acts to lower GHG emissions. Being the greatest consumers, the heat generation technologies are compared using the levelized cost of heat (LCOH). This analysis shows that absorption heat transformers and high-temperature heat pumps are the most interesting technologies from the economic and decarbonation points of view, while waste heat recovery technologies present the shortest payback periods. In all sectors, energy efficiency improvements on components, storage technologies, polygeneration systems, the concept of smart industry, and the penetration of renewable energy sources appear as valuable pathways. Full article

(This article belongs to the Collection Energy Transition Towards Carbon Neutrality)

► Show Figures

Graphical abstract

13 pages, 4940 KiB

Open AccessArticle

The Degradation Prediction of Proton Exchange Membrane Fuel Cell Performance Based on a Transformer Model

by Xuan Meng, Jian Mei, Xingwang Tang, Jinhai Jiang, Chuanyu Sun and Kai Song

Energies 2024, 17(12), 3050; https://doi.org/10.3390/en17123050 - 20 Jun 2024

Cited by 15 | Viewed by 1755

Abstract

Proton exchange membrane fuel cells have attracted widespread attention due to their cleanliness and high energy density, but the performance degradation during operation greatly limits their commercialization. Therefore, the reliable degradation prediction of fuel cell performance is of great significance. The recovery phenomenon [...] Read more.

Proton exchange membrane fuel cells have attracted widespread attention due to their cleanliness and high energy density, but the performance degradation during operation greatly limits their commercialization. Therefore, the reliable degradation prediction of fuel cell performance is of great significance. The recovery phenomenon of the reversible voltage loss that occurs during the operation of fuel cells has posed great difficulties for model training and prediction. Moreover, the models may easily and erroneously learn the combined trends in the recovery of reversible voltage loss and performance degradation. To address this issue, this paper employs the Transformer model to predict the performance degradation of fuel cells. By utilizing the unique self-attention structure and masking mechanism of the Transformer model, the signal for the recovery of the reversible voltage loss is adopted as the input for the model to avoid interference from information before voltage recovery on subsequent predictions. Experimental results show that the model has the highest prediction accuracy at various prediction starting points. Meanwhile, it can predict the accelerated performance degradation of fuel cells, which has positive implications for health management. Full article

(This article belongs to the Section D2: Electrochem: Batteries, Fuel Cells, Capacitors)

► Show Figures

Figure 1

33 pages, 15440 KiB

Open AccessArticle

An Experimental Performance Assessment of a Passively Controlled Wind Turbine Blade Concept: Part A—Isotropic Materials

by Nikolaos Papadakis and Constantinos Condaxakis

Energies 2024, 17(12), 3049; https://doi.org/10.3390/en17123049 - 20 Jun 2024

Cited by 2 | Viewed by 841

Abstract

This paper is the first part of a two-part series, which presents preliminary findings on a novel flexible curved wind turbine blade designed for passive control, comparing its aerodynamic performance and behavior against a conventional straight blade. Characterized by its ability to twist [...] Read more.

This paper is the first part of a two-part series, which presents preliminary findings on a novel flexible curved wind turbine blade designed for passive control, comparing its aerodynamic performance and behavior against a conventional straight blade. Characterized by its ability to twist around its longitudinal axis under bending loads, the flexible curved blade is engineered to self-regulate in response to varying wind speeds, optimizing power output and enhancing operational safety. This design utilizes inherent elasticity and specific geometric configurations to develop torsional loads, resulting in continuous adjustment of the blade’s pitch angle via twist–bend deformation. The study focuses on a comparative analysis conducted in a wind tunnel, testing both a small-scale model of the conventional blade and the flexible curved blade of equivalent diameter. Results indicate that the flexible curved blade concept successfully moderates its rotational speed and power output at higher wind speeds and demonstrates the capability to start generating power at lower wind speeds and stabilize power effectively, aligning with sustainability goals by potentially reducing reliance on active control systems. Despite promising outcomes, passive control mechanisms did not activate at the designed wind speeds, revealing a misalignment between expected and actual performance and underscoring the need for further refinements in blade design and control settings. Additionally, the power coefficient (Cp) versus tip speed ratio (TSR) comparison showed that flexible curved blades operate within a lower TSR range and exhibit controlled capping of power under high wind conditions, marked by a distinctive ‘hook-like’ feature in C_p behavior. This study confirms the feasibility of designing and manufacturing passively controlled wind turbine blades tailored to specific performance criteria and underscores the potential of such technology. Future work, to be detailed in a subsequent paper, will explore further optimizations and the use of Glass Fiber-Reinforced Polymer (GFPR) composite materials to enhance blade flexibility and performance. Full article

(This article belongs to the Special Issue Optimal Control of Wind and Wave Energy Converters)

► Show Figures

Figure 1

21 pages, 4161 KiB

Open AccessArticle

Thermodynamic Optimization of Trigeneration Power System

by Ladislao Eduardo Méndez-Cruz, Miguel-Ángel Gutiérrez-Limón, Raúl Lugo-Leyte and Mauricio Sales-Cruz

Energies 2024, 17(12), 3048; https://doi.org/10.3390/en17123048 - 20 Jun 2024

Cited by 1 | Viewed by 792

Abstract

Worldwide, the growing demand for energy has been largely met through power cycles utilizing fossil fuels. Combined cycles, which integrate a gas turbine with a steam cycle, prove to be the best alternative due to their power generation capacity and high efficiencies. This [...] Read more.

Worldwide, the growing demand for energy has been largely met through power cycles utilizing fossil fuels. Combined cycles, which integrate a gas turbine with a steam cycle, prove to be the best alternative due to their power generation capacity and high efficiencies. This efficiency is primarily attributed to the ability to harness exhaust gases to generate steam in the heat recovery boiler, allowing additional power generation through the steam turbine. Currently, there is a quest for the integration of low-temperature power cycles to maximize the utilization of residual thermal energy flows for power generation. Therefore, this work conducts an exergetic optimization of a power trigeneration system aimed at maximizing exergetic efficiency. This system includes a gas turbine and a steam cycle coupled with three different configurations of the Organic Rankine Cycle (ORC): a simple ORC, a supercritical ORC, and an ultracritical ORC. The ORC configurations are analyzed using eight organic working fluids, namely R1234yf, R290, R134a, R1234ze, R152a, R600a, R245fa, and R123. The results show that the maximum exergetic efficiency is achieved by using R152a in the ultracritical ORC configuration coupled with the combined cycle, achieving an exergetic efficiency of 55.79%. Furthermore, the maximum power generated is attained by the steam cycle with 85,600.63 kW and 3101.21 kW for the ultracritical ORC. Full article

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

► Show Figures

Figure 1

20 pages, 7300 KiB

Open AccessEditor’s ChoiceArticle

Simulation of Power Generation System with Co-Combustion of Coal and Torrefied Biomass by Flue Gas

by Chunshuo Song, Ning Guo, Fengying Ren and Xiaohan Ren

Energies 2024, 17(12), 3047; https://doi.org/10.3390/en17123047 - 20 Jun 2024

Viewed by 1075

Abstract

At present, there is a global rise in electricity consumption, leading to an accelerated depletion of natural resources due to the reliance on fossil fuels to fulfill this energy demand. Consequently, there exists a worldwide emphasis on enhancing the proportion of renewable energy [...] Read more.

At present, there is a global rise in electricity consumption, leading to an accelerated depletion of natural resources due to the reliance on fossil fuels to fulfill this energy demand. Consequently, there exists a worldwide emphasis on enhancing the proportion of renewable energy sources in electricity generation. Biomass, as a renewable energy source, presents a viable alternative to certain fossil energy sources for combustion in electricity generation. This study focuses on a 660 MW coal-fired power plant as the subject of investigation, employing Aspen Plus simulation software (V11) to replicate the operational dynamics of the plant. A model of the direct mixed combustion biomass system within the coal-fired boiler is constructed, and its accuracy is validated against operational data obtained from the power plant. Moreover, a model elucidating the direct co-combustion of biomass in a coal-fired boiler, augmented by flue gas recirculation, was developed through the integration of biomass pre-treatment and flue gas recirculation technologies. This study explores the impacts of varying biomass blending ratios and flue gas recirculation on parameters, including flue gas volume, power generation efficiency, boiler performance, water vapor content, and emissions of pollutants. These findings indicate an inverse relationship between the mixing ratio and various performance metrics as follows: power generation, boiler efficiency, as well as NO_X and SO₂ content, with larger mixing ratios resulting in diminished values. Furthermore, the incorporation of flue gas recirculation was observed to mitigate furnace temperatures and suppress NO_X emissions. Full article

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

► Show Figures

Figure 1

39 pages, 14819 KiB

Open AccessReview

Application of NH₃ Fuel in Power Equipment and Its Impact on NO_x Emissions

by Jinyi Hu, Yongbao Liu, Xing He, Jianfeng Zhao and Shaojun Xia

Energies 2024, 17(12), 3046; https://doi.org/10.3390/en17123046 - 20 Jun 2024

Viewed by 975

Abstract

Due to high greenhouse gas emissions, countries worldwide are stepping up their emission reduction efforts, and the global demand for new, carbon-free fuels is growing. Ammonia (NH₃) fuels are popular due to their high production volume, high energy efficiency, ease of [...] Read more.

Due to high greenhouse gas emissions, countries worldwide are stepping up their emission reduction efforts, and the global demand for new, carbon-free fuels is growing. Ammonia (NH₃) fuels are popular due to their high production volume, high energy efficiency, ease of storage and transportation, and increased application in power equipment. However, their physical characteristics (e.g., unstable combustion, slow flame speed, and difficult ignition) limit their use in power equipment. Based on the structural properties of the power equipment, NH₃ fuel application and emissions characteristics were analyzed in detail. Combustion of NH₃ fuels and reduction measures for NO_x emissions (spark plug ignition, compression ignition, and gas turbines) were analyzed from various aspects of operating conditions (e.g., mixed fuel, fuel-to-exhaust ratio, and equivalence ratio), structure and strategy (e.g., number of spark plugs, compression ratio (CR), fuel injection, and ignition mode), and auxiliary combustion techniques (e.g., preheating, humidification, exhaust gas recirculation, and secondary air supply). The performance of various NH₃ fuel cell (FC) types was analyzed, with a focus on the maximum power achievable for different electrolyte systems. Additionally, the application and NO_x emissions of indirect NH₃ FCs were evaluated under flame and catalytic combustion conditions. The system efficiency of providing heat sources by burning pure NH₃, anode tail gas, and NH₃ decomposition gas was also compared. Based on a comprehensive literature review, the key factors influencing the performance and emissions of NH₃-powered equipment were identified. The challenges and limitations of NH₃-powered equipment were summarized, and potential strategies for improving efficiency and reducing emissions were proposed. These findings provide valuable insights for the future development and application of NH₃ FCs. Full article

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

► Show Figures

Figure 1

25 pages, 3805 KiB

Open AccessArticle

Development and Implementation of a Smart Charging System for Electric Vehicles Based on the ISO 15118 Standard

by Jóni B. Santos, André M. B. Francisco, Cristiano Cabrita, Jânio Monteiro, André Pacheco and Pedro J. S. Cardoso

Energies 2024, 17(12), 3045; https://doi.org/10.3390/en17123045 - 20 Jun 2024

Cited by 1 | Viewed by 1333

Abstract

There is currently exponential growth in the electric vehicle market, which will require an increase in the electrical grid capacity to meet the associated charging demand. If, on the one hand, the introduction of energy generation from renewable energy sources can be used [...] Read more.

There is currently exponential growth in the electric vehicle market, which will require an increase in the electrical grid capacity to meet the associated charging demand. If, on the one hand, the introduction of energy generation from renewable energy sources can be used to meet that requirement, the intermittent nature of some of these sources will challenge the mandatory real-time equilibrium between generation and consumption. In order to use most of the energy generated via these sources, mechanisms are required to manage the charging of batteries in electric vehicles, according to the levels of generation. An effective smart charging process requires communication and/or control mechanisms between the supply equipment and the electric vehicle, enabling the adjustment of the energy transfer according to the generation levels. At this level, the ISO 15118 standard supports high-level communication mechanisms, far beyond the basic control solutions offered through the IEC 61851-1 specification. It is, thus, relevant to evaluate it in smart charging scenarios. In this context, this paper presents the development of a charge emulation system using the ISO 15118 communication protocol, and it discusses its application for demand response purposes. The system comprises several modules developed at both ends, supply equipment and electric vehicles, and allows the exchange of data during an emulated charging process. The system also includes human interfaces to facilitate interactions with users at both ends. Tests performed using the implemented system have shown that it supports a demand response when integrated with a photovoltaic renewable energy source. The dynamic adjustment to charging parameters, based on real-time energy availability, ensures efficient and sustainable charging processes, reducing the reliance on the grid and promoting the use of renewable energy. Full article

(This article belongs to the Special Issue Advanced Solutions for the Efficient Integration of Electric Vehicles in Electricity Grids)

► Show Figures

Figure 1

21 pages, 1242 KiB

Open AccessArticle

Design of a Stochastic Electricity Market Mechanism with a High Proportion of Renewable Energy

by Yifeng Liu, Meng Chen, Yuhong Fan, Liming Ying, Xue Cui and Xuyue Zou

Energies 2024, 17(12), 3044; https://doi.org/10.3390/en17123044 - 20 Jun 2024

Cited by 2 | Viewed by 758

Abstract

Renewable energy, such as wind power and photovoltaic power, has uncertain and intermittent characteristics and zero marginal cost characteristics. The traditional power market mechanism is difficult to adapt to the new power system with a high proportion of renewable energy, and the original [...] Read more.

Renewable energy, such as wind power and photovoltaic power, has uncertain and intermittent characteristics and zero marginal cost characteristics. The traditional power market mechanism is difficult to adapt to the new power system with a high proportion of renewable energy, and the original market system needs to be reformed. This paper discusses the application of a VCG auction mechanism in the electricity market, proposes a two-stage VCG market-clearing model based on the VCG mechanism, including the day-ahead market and the real-time market, and discusses the nature of the VCG mechanism. In order to address the discrepancy between the actual output of stochastic generator sets in the real-time market and their pre-scheduled output in the day-ahead market due to prediction deviations, a method for calculating punitive costs is proposed. A reallocation method based on market entities’ contributing factors to budget imbalance is proposed to address the issue of budget imbalance under the VCG mechanism, in order to achieve revenue and expenditure balance. Through an example, the incentive compatibility characteristics of the VCG mechanism are verified, the problems of the locational marginal pricing (LMP) mechanism in the stochastic electricity market with a high proportion of renewable energy are analyzed, the electricity prices of the LMP mechanism and the VCG mechanism under different renewable energy proportions are compared, and the redistribution of the budget imbalance of the VCG mechanism is analyzed. Full article

(This article belongs to the Section C: Energy Economics and Policy)

► Show Figures

Figure 1

19 pages, 4587 KiB

Open AccessSystematic Review

Exploring Residential Energy Behaviour of the Younger Generation for Sustainable Living: A Systematic Review

by Yehui Peng, Jacopo Gaspari and Lia Marchi

Energies 2024, 17(12), 3043; https://doi.org/10.3390/en17123043 - 20 Jun 2024

Viewed by 968

Abstract

The global energy crisis has spurred increased investments in energy efficiency and clean energy initiatives; however, the results have fallen short of expected effectiveness. Concurrently, population growth and urbanisation drive a persistent surge in energy demands, especially within the residential sector, significant to [...] Read more.

The global energy crisis has spurred increased investments in energy efficiency and clean energy initiatives; however, the results have fallen short of expected effectiveness. Concurrently, population growth and urbanisation drive a persistent surge in energy demands, especially within the residential sector, significant to overall building energy consumption. Current research focuses on residents’ responses to one-shot investments for energy efficiency or clean sources. The renovation wave, involving a massive number of existing buildings, calls for the mobilisation of huge investments that can be hard to afford in the short run. Sustainable behavioural change is complementarily rising as a key asset for maximising the overall estimated energy saving potential. Despite significant efforts to analyse household energy use and promote behavioural transformations, the literature remains gaping about future users, particularly the younger generation, as future leaders of sustainable development who exhibit a more responsible approach towards climate-related issues but also a strong dependency on digital-based solutions, which may influence energy use patterns and living habits, also impacting relations among peers and overall societal sustainability and energy efficiency. This article proposes a systematic literature review to analyse the variables affecting young people’s energy behaviour at home. The aim is to investigate the engines and gaps between strategies or tools for behaviour change and the expected effects, then find potential methods to address that barrier to identify a more promising approach, encouraging the younger generation to translate towards more sustainable energy behaviours. Full article

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

► Show Figures

Figure 1

24 pages, 6864 KiB

Open AccessArticle

Optimization of Flywheel Rotor Energy and Stability Using Finite Element Modelling

by Daniel Coppede, Fabio da Silva Bortoli, Joao Manoel Losada Moreira, Nadja Simao Magalhaes and Carlos Frajuca

Energies 2024, 17(12), 3042; https://doi.org/10.3390/en17123042 - 20 Jun 2024

Viewed by 816

Abstract

An investigation on a flywheel is presented based on finite element modelling simulations for different geometries. The goal was to optimise the energy density (rotational energy-to-mass ratio) and, at the same time, the rotational energy of a flywheel rotor. The stress behaviour of [...] Read more.

An investigation on a flywheel is presented based on finite element modelling simulations for different geometries. The goal was to optimise the energy density (rotational energy-to-mass ratio) and, at the same time, the rotational energy of a flywheel rotor. The stress behaviour of flywheel rotors under the rotational speed at the maximum stress achievable by the flywheel was analysed. Under this condition, the energy density was obtained for the different geometries, as well as the rotational energy. The best energy density performance due to geometry was achieved with a flywheel rotor presenting a new Gaussian section, which is different from the known Laval disk shape. The best results using a single disk involved a rotational speed of nearly 279,000 rpm and a rotational energy density around 1584 kJ/kg (440 Wh/kg). These values still yielded low total energy; to increase its value, two or three rotors were added to the flywheel, which were analysed in regard to stability. In particular, the triple rotor energy density was ≈ 1550 kJ/kg (431 Wh/kg). As some instability was found in these rotors, a solution using reinforcement was developed to avoid such instabilities. The energy density of such a reinforced double rotor neared 1451 kJ/kg (403 Wh/kg), and the system achieved higher total energy. The material assumed for the devices was carbon fibre Hexcel UHM 12,000, a material kept constant throughout the simulations to allow comparison among the different geometries. Full article

(This article belongs to the Special Issue Development of Electromechanical Systems Integrated in the Renewable Energy Systems)

► Show Figures

Figure 1

29 pages, 3999 KiB

Open AccessArticle

Innovative Multigeneration System with Heat Exchangers for Harnessing Thermal Energy from Cement Kiln Exhaust Gases

by Baby-Jean Robert Mungyeko Bisulandu, Rami Mansouri, Marcel Tsimba Mboko, Lucien Mbozi Mbozi and Adrian Ilinca

Energies 2024, 17(12), 3041; https://doi.org/10.3390/en17123041 - 20 Jun 2024

Viewed by 960

Abstract

This article introduces a novel multiple-cycle generation system for efficient heat recovery at high and low temperatures. The system is modeled and optimized using the M2EP analysis method (mass, energy, exergy, and performance) and the particle swarm optimization algorithm. The multigeneration system produces [...] Read more.

This article introduces a novel multiple-cycle generation system for efficient heat recovery at high and low temperatures. The system is modeled and optimized using the M2EP analysis method (mass, energy, exergy, and performance) and the particle swarm optimization algorithm. The multigeneration system produces electricity, cold, domestic hot water, and biogas by utilizing Kalina cycles, diffusion–absorption refrigeration machines, and high-performance heat exchangers by harnessing waste heat from cement kiln exhaust gases. The Kalina cycle is employed for electricity generation, wherein the H₂O+NH₃ mixture, heated by hot water, circulates through heat exchangers. Downstream of the Kalina cycle, the refrigeration machine generates cold by evaporating the strong solution of the H₂O+NH₃ mixture. Hydrogen circulates in the diffusion–absorption refrigerator (DAR) circuit, facilitating the exchange between the evaporator and the absorber. The domestic hot water and biogas production systems operate at lower temperatures (around 45 °C). The simulation results for the Kalina cycle indicate an electrical energy production of 2565.03 kW, with a release of usable energy (residual gases) estimated at 7368.20 kW and a thermal efficiency of 22.15%. Exergy destruction is highest at heat exchanger 1, accounting for 26% of the total. A coefficient of performance of 0.268 and an evaporator temperature of 10.57 °C were obtained for the DAR cycle. The absorber contributes the most to energy exchanges, comprising 37% of the entire circuit. Summarizing the potential for valorizing waste heat from cement kilns, this article lays the foundation for future research. Full article

(This article belongs to the Special Issue Advanced Thermal Energy Storage Technologies)

► Show Figures

Figure 1

14 pages, 8541 KiB

Open AccessArticle

Optimized Fabrication Process and PD Characteristics of MVDC Multilayer Insulation Cable Systems for Next Generation Wide-Body All-Electric Aircraft

by Md Asifur Rahman, Anoy Saha and Mona Ghassemi

Energies 2024, 17(12), 3040; https://doi.org/10.3390/en17123040 - 20 Jun 2024

Cited by 2 | Viewed by 1173

Abstract

For wide-body all-electric aircraft (AEA), a high-power-delivery, low-system-mass electric power system (EPS) necessitates advanced cable technologies. Increasing voltage levels enhances power density yet poses challenges in aircraft cable design, including managing arc-related risks, partial discharges (PDs), and thermal management. Developing multilayer multifunctional electrical [...] Read more.

For wide-body all-electric aircraft (AEA), a high-power-delivery, low-system-mass electric power system (EPS) necessitates advanced cable technologies. Increasing voltage levels enhances power density yet poses challenges in aircraft cable design, including managing arc-related risks, partial discharges (PDs), and thermal management. Developing multilayer multifunctional electrical insulation (MMEI) systems for aircraft applications is a feasible option to tackle these challenges and reduce the size and mass of cable systems. This approach involves selecting layers of different materials to address specific challenges. Our prior research concentrated on the modeling and simulation-based design of MMEI systems for MVDC power cables. Experimental tests are essential for determining the behavior of PDs under varying pressure conditions. Also, the dielectric strength and time to failure of the designs need to be assessed. In this work, the fabrication process of a down-selected MMEI flat configuration is discussed and analyzed. This paper analyzes the fabrication process of power cables employing MMEI configurations and evaluates the PD characteristics of down-selected ARC-SC-T-MMEI cable samples. This study presents a detailed analysis of the characteristics of PD under atmospheric and low-pressure conditions, which will provide essential insights into the design of MVDC cables for future AEA applications. Full article

(This article belongs to the Special Issue Reliability and Condition Monitoring of Electric Motors and Drives)

► Show Figures

Figure 1

17 pages, 2540 KiB

Open AccessReview

Future Green Energy: A Global Analysis

by Sairoel Amertet Finecomess and Girma Gebresenbet

Energies 2024, 17(12), 3039; https://doi.org/10.3390/en17123039 - 20 Jun 2024

Viewed by 1709

Abstract

The main problem confronting the world is human-caused climate change, which is intrinsically linked to the need for energy both now and in the future. Renewable (green) energy has been proposed as a future solution, and many renewable energy technologies have been developed [...] Read more.

The main problem confronting the world is human-caused climate change, which is intrinsically linked to the need for energy both now and in the future. Renewable (green) energy has been proposed as a future solution, and many renewable energy technologies have been developed for different purposes. However, progress toward net zero carbon emissions by 2050 and the role of renewable energy in 2050 are not well known. This paper reviews different renewable energy technologies developed by different researchers and their potential and challenges to date, and it derives lessons for world and especially African policymakers. According to recent research results, the mean global capabilities for solar, wind, biogas, geothermal, hydrogen, and ocean power are 325 W, 900 W, 300 W, 434 W, 150 W, and 2.75 MWh, respectively, and their capacities for generating electricity are 1.5 KWh, 1182.5 KWh, 1.7 KWh, 1.5 KWh, 1.55 KWh, and 3.6 MWh, respectively. Securing global energy leads to strong hope for meeting the Sustainable Development Goals (SDGs), such as those for hunger, health, education, gender equality, climate change, and sustainable development. Therefore, renewable energy can be a considerable contributor to future fuels. Full article

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

► Show Figures

Figure 1

15 pages, 3403 KiB

Open AccessArticle

Experimental Study on the Heat Pump Performance Combined with Dual-Purpose Solar Collector

by Kwang-Am Moon, Seong-Bhin Kim, Hwi-Ung Choi and Kwang-Hwan Choi

Energies 2024, 17(12), 3038; https://doi.org/10.3390/en17123038 - 20 Jun 2024

Viewed by 699

Abstract

In this study, we proposed and experimentally investigated a novel solar-assisted heat pump (SAHP) system integrated with a dual-purpose solar collector (DPSC). The DPSC is a solar collector designed to produce both heated air and hot water, and the proposed configuration of the [...] Read more.

In this study, we proposed and experimentally investigated a novel solar-assisted heat pump (SAHP) system integrated with a dual-purpose solar collector (DPSC). The DPSC is a solar collector designed to produce both heated air and hot water, and the proposed configuration of the SAHP utilizes both heated air and water simultaneously to improve the performance of the heat pump. The experiment was conducted under natural weather conditions on a clear day. The performance of the proposed system was evaluated and compared to that of a conventional air-type SAHP system. The results showed that the coefficient of performance (COP) of the proposed system, which takes into account the performance of the DPSC, heat pump, and the power consumption of both the blower and pump, was 3.14. In contrast, the system COP of the SAHP operated as conventional air-type SAHP was 2.33. This finding clearly demonstrated that the proposed SAHP performed better than the traditional SAHP mode. Additionally, the results of this research are useful as fundamental data related to SAHP combined with DPSC. Full article

(This article belongs to the Special Issue Recent Developments in Solar Thermal Energy)

► Show Figures

Figure 1

13 pages, 2404 KiB

Open AccessArticle

Evaluation of Thermal Properties of Various Insulating Liquids Used in Power Transformers

by Zbigniew Nadolny

Energies 2024, 17(12), 3037; https://doi.org/10.3390/en17123037 - 20 Jun 2024

Viewed by 938

Abstract

This article is a summary of many years of work by the author, in which the thermal properties of various types of insulating liquids, used in power transformers, were evaluated. Recently, esters have been displacing mineral oil. There is a common view that [...] Read more.

This article is a summary of many years of work by the author, in which the thermal properties of various types of insulating liquids, used in power transformers, were evaluated. Recently, esters have been displacing mineral oil. There is a common view that mineral oil has better thermal properties than esters. This claim is supported by comparative results of tests of both materials as a liquid only filling the remaining volume of the transformer. The effect of the type of liquid on the thermal properties of the paper–oil insulation has not been analyzed so far. On this basis, the conclusions formulated may be incomplete. For this reason, the author has analyzed the influence of the type of liquid on both the thermal properties of the liquid filling the remaining volume of the transformer and the paper–oil insulation. It was proved that the more effective liquid filling the remaining volume of the transformer was indeed mineral oil. On the other hand, a more effective electrical insulating liquid, which is an element of paper–oil insulation, is a natural ester. A comprehensive assessment that takes into account both the paper–oil insulation and the remaining transformer volume showed that the natural ester proved to be a slightly more effective electrical insulating liquid than the other analyzed liquids. Full article

(This article belongs to the Special Issue Design and Optimization of Power Transformer Diagnostics II)

► Show Figures

Figure 1

16 pages, 1391 KiB

Open AccessFeature PaperArticle

On the Necessity of Including the Dissociation Kinetics When Modelling Gas Hydrate Pipeline Plug Dissociation

by Johnbosco Aguguo and Matthew Clarke

Energies 2024, 17(12), 3036; https://doi.org/10.3390/en17123036 - 20 Jun 2024

Viewed by 672

Abstract

Gas hydrate plugs in petroleum fluid pipelines are a major flow assurance problem and thus, it is important for industry to have reliable mathematical models for estimating the time required to dissociate a hydrate pipeline plug. The existing mathematical models for modelling hydrate [...] Read more.

Gas hydrate plugs in petroleum fluid pipelines are a major flow assurance problem and thus, it is important for industry to have reliable mathematical models for estimating the time required to dissociate a hydrate pipeline plug. The existing mathematical models for modelling hydrate plug dissociation treat the problem as a pure heat transfer problem. However, an early study by Jamaluddin et al. speculated that the kinetics of gas hydrate dissociation could become the rate-limiting factor under certain operating conditions. In this short communication, a rigorous 2D model couples the equations of heat transfer and fluid flow with Clarke and Bishnoi’s model for the kinetics of hydrate dissociation. A distinguishing feature of the current work is the ability to predict the shape of the dissociating hydrate–gas interface. The model is used to correlate experimental data for both sI and sII hydrate plug dissociation, via single-sided depressurization and double-sided depressurization. As a preliminary examination on the necessity of including dissociation kinetics, this work is limited to conditions for which hydrate dissociation rate constants are available; kinetic rate constants for hydrate dissociation are available at temperatures above 273.15 K. Over the range of conditions that were investigated, it was found that including the intrinsic kinetics of hydrate dissociation led to only a very small improvement in the accuracy of the predictions of the cumulative gas volumes collected during dissociation. By contrast, a sensitivity study showed that the predictions of hydrate plug dissociation are very sensitive to the value of the porosity. Thus, it is concluded that unless values of the thermophysical properties of a hydrate plug are known, accounting for the dissociation kinetics need not be a priority. Full article

(This article belongs to the Special Issue Recent Advances in Gas Hydrate Research Related to the Flow, Storage and Transport of Gases)

► Show Figures

Figure 1

31 pages, 1934 KiB

Open AccessReview

The Biosynthesis of Liquid Fuels and Other Value-Added Products Based on Waste Glycerol—A Comprehensive Review and Bibliometric Analysis

by Joanna Kazimierowicz, Marcin Dębowski, Marcin Zieliński, Aneta Ignaciuk, Sandra Mlonek and Jordi Cruz Sanchez

Energies 2024, 17(12), 3035; https://doi.org/10.3390/en17123035 - 20 Jun 2024

Viewed by 1698

Abstract

Waste glycerol can be subjected to various processing operations, including purification and refining, to obtain glycerol of an appropriate purity. Alternative methods for utilising waste glycerol are also being sought, e.g., by converting it into other valuable chemical products or biofuels. Therefore, various [...] Read more.

Waste glycerol can be subjected to various processing operations, including purification and refining, to obtain glycerol of an appropriate purity. Alternative methods for utilising waste glycerol are also being sought, e.g., by converting it into other valuable chemical products or biofuels. Therefore, various technologies are being developed to ensure effective and sustainable utilisation of this type of waste. The production of value-added products from waste glycerol strongly determines the improvement of the economic viability of biofuel production and corresponds to the model of a waste-free and emission-free circular economy. This paper characterises the mechanisms and evaluates the efficiency of existing methods for microbiological utilisation of waste glycerol into liquid biofuels, including biodiesel, bioethanol and biobutanol, and identifies further production avenues of value-added products. In addition, it presents the results of a bibliographical analysis of publications related to the production of liquid fuels and economically valuable products from glycerol, assesses the progress of research and application work and, finally, identifies areas for future research. Full article

(This article belongs to the Collection Bio-Energy Reviews)

► Show Figures

Figure 1

12 pages, 2161 KiB

Open AccessFeature PaperArticle

Design and Performance Evaluation of the Energy Subsystem of a Hybrid Light and Wave Energy Harvester

by Marcin Drzewiecki, Piotr Kołodziejek and Jarosław Guziński

Energies 2024, 17(12), 3034; https://doi.org/10.3390/en17123034 - 20 Jun 2024

Viewed by 801

Abstract

This paper presents the design and performance of an energy subsystem (ES) dedicated to hybrid energy harvesters (HEHs): wave energy converters (WECs) combined with photovoltaic panels (PVPs). The considered ES is intended for compact HEHs powering autonomous end-node devices in distributed IoT networks. [...] Read more.

This paper presents the design and performance of an energy subsystem (ES) dedicated to hybrid energy harvesters (HEHs): wave energy converters (WECs) combined with photovoltaic panels (PVPs). The considered ES is intended for compact HEHs powering autonomous end-node devices in distributed IoT networks. The designed ES was tested experimentally and evaluated in relation to the mobile and wireless distributed communication use case. The numerical evaluation was based on the balance of the harvested energy versus the energy consumed in the considered use case. The evaluation results proved that the ES ensured energy surplus over the considered IoT node consumption. It confirmed the proposed solution as convenient to the compact HEHs applied for sustainable IoT devices to power them with renewable energy harvested from light and sea waves. It was found that the proposed ES can provide the energy autonomy of the IoT end node and increase its reliability through a hybrid energy-harvesting approach. Full article

(This article belongs to the Special Issue Dynamic Analysis and Optimization of Wave Energy Devices)

► Show Figures

Figure 1

19 pages, 24979 KiB

Open AccessArticle

Battery Electric Roof Bolter versus Diesel Roof Bolter—Results of Field Trials at a Polish Copper Mine

by Artur Kozłowski and Łukasz Bołoz

Energies 2024, 17(12), 3033; https://doi.org/10.3390/en17123033 - 20 Jun 2024

Viewed by 724

Abstract

Battery-powered electric machines have been replacing classic combustion vehicles for many years in the automotive and heavy industry. This change has a positive impact on the environment and, in the case of working machines, also on the safety and comfort of operators. In [...] Read more.

Battery-powered electric machines have been replacing classic combustion vehicles for many years in the automotive and heavy industry. This change has a positive impact on the environment and, in the case of working machines, also on the safety and comfort of operators. In underground mining plants, due to limited working space and difficult environmental conditions, the use of battery-powered electric vehicles (BEVs) in place of combustion machines with diesel engines brings even greater benefits in terms of the operator’s work conditions. This article presents the results of comprehensive tests of two roof bolters in a BEV and a vehicle with a combustion engine. The tests were performed in underground conditions, during normal operation of the machines. They covered many aspects of machines’ operation, such as availability; traction properties; battery use; cooling system; efficiency; costs; safety; and ergonomics in terms of gas emissions, noise, vibrations, and generally understood work comfort. The research results showed a significant advantage of the battery-powered machine over the one with a combustion engine. The tests in question are unique due to their scope and the fact that they were carried out in underground conditions, during normal operation, both for the internal combustion machine and its battery-powered equivalent. Full article

(This article belongs to the Special Issue Energy Consumption at Production Stages in Mining)

► Show Figures

Figure 1

13 pages, 2170 KiB

Open AccessFeature PaperArticle

Evaluation of Heating Efficiency Increase Using a Simple Heat Recovery Unit

by Beáta Stehlíková, Erika Fecková Škrabuľáková, Gabriela Bogdanovská and Matúš Fecko

Energies 2024, 17(12), 3032; https://doi.org/10.3390/en17123032 - 20 Jun 2024

Viewed by 632

Abstract

Heating in the winter is one of the human activities that consumes the most energy, thereby affecting the environment and leaving a carbon footprint. An increase in heating efficiency results in a reduction in the energy demand of the process and environmental protection. [...] Read more.

Heating in the winter is one of the human activities that consumes the most energy, thereby affecting the environment and leaving a carbon footprint. An increase in heating efficiency results in a reduction in the energy demand of the process and environmental protection. This contribution aimed to determine and experimentally verify the possibility of obtaining and effectively using the heat from the chimney of a gas boiler generated during the heating of a family house. For this purpose, we used a simple heat exchanger and measured the relevant temperatures on an exchange unit for almost five months during the heating season. The air temperatures measured at the inlet and outlet of the exchanger unit together with the outside temperatures were statistically analyzed to determine the effect of using the exchanger unit to obtain additional heat that could be used for other purposes. In addition, this study investigated whether there was a statistically significant difference in the temperature of the air entering the heating system with different outdoor temperature values. In the discussion, these hypotheses are either confirmed or disproved. Finally, the effectiveness of the current household heating system is evaluated. Full article

(This article belongs to the Section J: Thermal Management)

► Show Figures

Figure 1

16 pages, 6214 KiB

Open AccessFeature PaperArticle

The Effect of Carpinus betulus Ash on the Maize as an Energy Crop and the Enzymatic Soil Properties

by Edyta Boros-Lajszner, Jadwiga Wyszkowska and Jan Kucharski

Energies 2024, 17(12), 3031; https://doi.org/10.3390/en17123031 - 20 Jun 2024

Cited by 1 | Viewed by 810

Abstract

Maize can easily adapt to changing weather conditions, has moderate soil requirements, and offers high green mass productivity. The goals of this study were to assess the possibility of using ash from Carpinus betulus aided by soil amendment with compost and HumiAgra in [...] Read more.

Maize can easily adapt to changing weather conditions, has moderate soil requirements, and offers high green mass productivity. The goals of this study were to assess the possibility of using ash from Carpinus betulus aided by soil amendment with compost and HumiAgra in Zea mays cultivation and to determine the energy potential of maize. Wood ash had a relatively minimal effect on the combustion heat and calorific value of maize biomass. It increased the contents of C, H, S, N, O, and ash in the aerial parts of the maize. In addition, it positively affected the contents of organic carbon, total nitrogen, soil pH, sum of exchangeable base cations, total exchangeable capacity of soil, and degree of soil saturation with alkaline cations. In contrast, it strongly decreased the yield of maize, negatively affected the biochemical activity of the soil, and reduced the hydrolytic acidity of the soil. Soil amendment with compost and HumiAgra had positive effects on the heat of combustion; calorific value; the contents of C, H, S, N, O, and ash in the aerial parts of maize; and on the properties of the soil. In addition, they mitigated the adverse effects of wood ash on maize biomass and the enzymatic properties of the soil. Full article

(This article belongs to the Collection Feature Papers in Energy, Environment and Well-Being)

► Show Figures

Figure 1

25 pages, 4304 KiB

Open AccessArticle

Data Analysis of Global Research Cooperation Patterns in the Secondary Battery Industry

by Hojin An and Keuntae Cho

Energies 2024, 17(12), 3030; https://doi.org/10.3390/en17123030 - 20 Jun 2024

Viewed by 1032

Abstract

The purpose of this study is to analyze how global research cooperation patterns in the secondary battery industry have changed over recent years and to identify the evolution in the focus of research. To this end, network analysis was performed using the nationality [...] Read more.

The purpose of this study is to analyze how global research cooperation patterns in the secondary battery industry have changed over recent years and to identify the evolution in the focus of research. To this end, network analysis was performed using the nationality information of the authors of a 10-year multinational joint research paper related to lithium-ion batteries. Furthermore, keyword analysis and topic modeling were performed using the abstract data from the study. The results of this study confirm that some countries that are not well-known in the field, such as Australia, Spain, and France, showed high centrality, compared with the level of cooperation scale. Additionally, six research topics were identified. According to a comparison over the first half of the decade, no difference was observed in the appearance of keywords indicating high energy density and conductivity with lithium, a key mineral. Keyword distribution was high for topics like battery charging and discharging in the first half of the decade, and for next-generation battery materials, such as solid electrolytes, lithium metal anodes, and lithium–sulfur batteries in the second. These results provide insights into the establishment of research and development (R&D) cooperation strategies by countries and pre-planning by companies in the battery industry. Full article

(This article belongs to the Section D2: Electrochem: Batteries, Fuel Cells, Capacitors)

► Show Figures

Figure 1

15 pages, 19532 KiB

Open AccessArticle

Comprehensive Analysis of Factors Underpinning the Superior Performance of Ducted Horizontal-Axis Helical Wind Turbines

by Shaikh Zishan Suheel, Ahmad Fazlizan, Halim Razali, Kok Hoe Wong, Altaf Hossain Molla, Rajkumar Singh Rathore, M. S. Hossain Lipu and Mahidur R. Sarker

Energies 2024, 17(12), 3029; https://doi.org/10.3390/en17123029 - 19 Jun 2024

Viewed by 874

Abstract

The societal and economic reliance on non-renewable energy sources, primarily fossil fuels, has raised concerns about an imminent energy crisis and climate change. The transition towards renewable energy sources faces challenges, notably in understanding turbine shear forces within wind technology. To address this [...] Read more.

The societal and economic reliance on non-renewable energy sources, primarily fossil fuels, has raised concerns about an imminent energy crisis and climate change. The transition towards renewable energy sources faces challenges, notably in understanding turbine shear forces within wind technology. To address this gap, a novel solution emerges in the form of the ducted horizontal-axis helical wind turbine. This innovative design aims to improve airflow dynamics and mitigate adverse forces. Computational fluid dynamics and experimental assessments were employed to evaluate its performance. The results indicate a promising technology, showcasing the turbine’s potential to harness energy from diverse wind sources. The venturi duct aided in the augmentation of the velocity, thereby increasing the maximum energy content of the wind by 179.16%. In addition, 12.16% of the augmented energy was recovered by the turbine. Notably, the integration of a honeycomb structure demonstrated increased revolutions per minute (RPM) by rectifying the flow and reducing the circular wind, suggesting the impact of circular wind components on turbine performance. The absence of the honeycomb structure allows the turbine to encounter more turbulent wind (circular wind), which is the result of the movement of the fan. Strikingly, the downwash velocity of the turbine was observed to be equal to the incoming velocity, suggesting the absence of an axial induction factor and, consequently, no back force on the system. However, limitations persist in the transient modelling and in determining optimal performance across varying wind speeds due to experimental constraints. Despite these challenges, this turbine marks a significant stride in wind technology, highlighting its adaptability and potential for heightened efficiency, particularly at higher speeds. Further refinement and exploration are imperative for broadening the turbine’s application in renewable energy generation. This research emphasizes the turbine’s capacity to adapt to different wind velocities, signaling a promising avenue for more efficient and sustainable energy production. Full article

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

► Show Figures

Figure 1

27 pages, 1703 KiB

Open AccessReview

Exploring Blockchain for Nuclear Material Tracking: A Scoping Review and Innovative Model Proposal

by Irem Nur Ecemis, Fatih Ekinci, Koray Acici, Mehmet Serdar Guzel, Ihsan Tolga Medeni and Tunc Asuroglu

Energies 2024, 17(12), 3028; https://doi.org/10.3390/en17123028 - 19 Jun 2024

Cited by 2 | Viewed by 1272

Abstract

Ensuring safe and transparent tracking of nuclear materials in the modern era is critical for global security and compliance with international regulations. Blockchain technology, a decentralized and immutable ledger, offers a new approach to recording transactions, increasing trust without intermediaries. In this study, [...] Read more.

Ensuring safe and transparent tracking of nuclear materials in the modern era is critical for global security and compliance with international regulations. Blockchain technology, a decentralized and immutable ledger, offers a new approach to recording transactions, increasing trust without intermediaries. In this study, it was investigated whether nuclear material tracking was performed with advanced technology blockchain from past to present; it was seen that there needed to be a study on this subject in the literature, and that there was a gap. Search results proving this are presented. The authors present a model that can enable nuclear material tracking with blockchain technology, which will create a solid structure for recording and verifying every process step in the nuclear supply chain, from the creation of the first product to destruction. This model discusses how nuclear materials, which are very important to track from the beginning until they become waste, can be tracked with blockchain technology, and the contributions they can make nationally and internationally are explained. As a result of the research, it is shown that blockchain technology has the potential to pave the way for more resilient and precise nuclear supply chains by significantly increasing the security and efficiency of nuclear material tracking. Full article

(This article belongs to the Special Issue Blockchain, IoT and Smart Grids Challenges for Energy II)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Energies, Volume 17, Issue 12 (June-2 2024) – 261 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI