You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.

Search for Articles:

Title / Keyword

Author / Affiliation / Email

Journal

Article Type

Advanced Search

Section

Special Issue

Volume

Issue

Number

Page

Logical OperatorOperator

Search Text

Search Type

Next Generation of Electric Vehicles: AI-Driven Approaches for Predictive Maintenance and Battery Management
Building Energy Performance Assessment via BIM and ML Techniques
Advanced Deep Learning Algorithms for Energy Optimization of Smart Cities
Solar Thermochemical Fuel Production: A Novel, Validated Multiphysics Reactor Model for the Reduction–Oxidation of Nonstoichiometric Redox Cycles
Lithium Battery Degradation and Failure Mechanisms

Journal Description

Energies

Energies is a peer-reviewed, open access journal of related scientific research, technology development, engineering policy, and management studies related to the general field of energy, from technologies of energy supply, conversion, dispatch, and final use to the physical and chemical processes behind such technologies. Energies is published semimonthly online by MDPI. The European Biomass Industry Association (EUBIA), Association of European Renewable Energy Research Centres (EUREC), Institute of Energy and Fuel Processing Technology (ITPE), International Society for Porous Media (InterPore), CYTED and others are affiliated with Energies and their members receive a discount on the article processing charges.

Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
High Visibility: indexed within Scopus, SCIE (Web of Science), Ei Compendex, RePEc, Inspec, CAPlus / SciFinder, and other databases.
Journal Rank: CiteScore - Q1 (Control and Optimization)
Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 16.8 days after submission; acceptance to publication is undertaken in 2.9 days (median values for papers published in this journal in the second half of 2024).
Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Sections: published in 41 topical sections.
Testimonials: See what our editors and authors say about Energies.
Companion journals for Energies include: Gases, Nanoenergy Advances, Solar, Wind, Energy Storage and Applications and Bioresources and Bioproducts.

Impact Factor: 3.0 (2023); 5-Year Impact Factor: 3.0 (2023)

Imprint Information Journal Flyer Open Access ISSN: 1996-1073

Latest Articles

20 pages, 6644 KiB

Open AccessArticle

Safe Path for the Transformation of the Polish Energy System Leading to Its Decarbonization and Reliable Operation

by Andrzej Rusin and Adam Wojaczek

Energies 2025, 18(7), 1856; https://doi.org/10.3390/en18071856 (registering DOI) - 7 Apr 2025

The European Union’s energy policy, which aims to achieve climate neutrality by 2050, requires substantial changes in the structure of the energy sources used for power generation. The paper considers the possibilities of increasing the pace of the Polish energy system transformation by [...] Read more.

The European Union’s energy policy, which aims to achieve climate neutrality by 2050, requires substantial changes in the structure of the energy sources used for power generation. The paper considers the possibilities of increasing the pace of the Polish energy system transformation by replacing coal sources with renewable energy sources using energy storage. It is demonstrated that in the analyzed period until 2040 it will be possible to ensure the required level of the system’s energy supply reliability by supporting the system with energy storage. The assessment of the system reliability was carried out based on the LOLE and LOLP indicators, selecting the system structure in such a way that for the hourly energy demand characteristic adopted in the analyzed year, the LOLE was less than 3 h. The required capacity and power of the storage systems depend on the level of the demand for energy and power. The results of the analyses indicate that for the linear trend in the growth in the demand for energy, nuclear power plants with the total power of 8.8 GW have to be installed in the energy system. However, with a significant rise in the power demand and the decommissioning of coal units, balancing the system using other sources with a dominant share of renewable sources will be insufficient. It will therefore be necessary to use the energy storage with a capacity above 11 GWh and a total power above 2 GW. Full article

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

► Show Figures

Figure 1

17 pages, 6330 KiB

Open AccessArticle

A Short-Term Load Forecasting Method Considering Multiple Factors Based on VAR and CEEMDAN-CNN-BILSTM

by Bao Wang, Li Wang, Yanru Ma, Dengshan Hou, Wenwu Sun and Shenghu Li

Energies 2025, 18(7), 1855; https://doi.org/10.3390/en18071855 (registering DOI) - 7 Apr 2025

Short-term load is influenced by multiple external factors and shows strong nonlinearity and volatility, which increases the forecasting difficulty. However, most of existing short-term load forecasting methods rely solely on the original load data or take into account a single external factor, which [...] Read more.

Short-term load is influenced by multiple external factors and shows strong nonlinearity and volatility, which increases the forecasting difficulty. However, most of existing short-term load forecasting methods rely solely on the original load data or take into account a single external factor, which results in significant forecasting errors. To improve the forecasting accuracy, this paper proposes a short-term load forecasting method considering multiple contributing factors based on VAR and CEEMDAN-CNN- BILSTM. Firstly, multiple contributing factors strongly correlated with the short-term load are selected based on the Spearman correlation analysis, the vector autoregressive (VAR) model with multivariate input is derived, and the Levenberg–Marquardt algorithm is introduced to estimate the model parameters. Secondly, the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) algorithm and permutation entropy (PE) criterion are combined to decompose and reconstruct the original load data into multiple relatively stationary mode components, which are respectively input into the CNN-BILTSM network for forecasting. Finally, the sine–cosine and Cauchy mutation sparrow search algorithm (SCSSA) is used to optimize the parameters of the combinative model to improve the forecasting accuracy. The actual simulation results utilizing the Australian data validate the forecasting accuracy of the proposed model, achieving reduction in the root mean square error by 31.21% and 18.04% compared to the VAR and CEEMDAN-CNN-BILSTM, respectively. Full article

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

► Show Figures

Figure 1

19 pages, 2475 KiB

Open AccessArticle

Impact of EU Decarbonization Policy on Polish International Road Freight Competitiveness

by Maciej Matczak and Andrzej S. Grzelakowski

Energies 2025, 18(7), 1854; https://doi.org/10.3390/en18071854 (registering DOI) - 7 Apr 2025

Road freight transport is the key driver of the European economy and society; thus, distortion of its operation would have negative influence on growth and well-being. For that reason, implementation of European policies, including transport decarbonization, should be comprehensively evaluated from an environmental, [...] Read more.

Road freight transport is the key driver of the European economy and society; thus, distortion of its operation would have negative influence on growth and well-being. For that reason, implementation of European policies, including transport decarbonization, should be comprehensively evaluated from an environmental, social and economic perspective. In that case, introduction of electric trucks will create a mutual impact on the market and on haulage companies. The main research problem is to assess the future impact of decarbonization on the international road freight transport market structure on the supply side and the competitiveness of companies operating there. Today, a number of small and medium companies, to a great extent from Eastern Europe, render transportation services, creating a competitive structure with high flexibility, accessibility and low prices. Shifting towards electric trucks, with significantly higher upfront costs, will redefine the market structure, eliminating the small carriers and activating horizontal integration. The key objective of this research is to identify the main factors and challenges related to electric truck implementation and define crucial areas of its impact on future market structure. The research shows that the improvement of environmental performance requires low- or zero-emission trucks, where the battery technology is a leading solution. Thus, fleet renewal needs additional financial support from the public side. Different measures are available in European countries, so the level of support is not equal from a competitiveness perspective. Battery truck selling, as well as sustainable strategies, refer mostly to huge transport companies. On the other hand, the case of Polish truckers shows that the economic viability of SMEs is poor; thus, the introduction of BET would be beyond its reach. The research findings could be treated as recommendations for market regulators (EC), where the tempo of implementation, as well as availability of public support programs, should be rethinking. As a result, the costs of the transition will be covered by citizens, as customers, in the prices of products and transport service, or as taxpayers, in public support programs, mainly consumed by large market stakeholders. Full article

(This article belongs to the Special Issue Economic Strategies for Integrating Energy and Sustainability: Challenges and Opportunities)

► Show Figures

Figure 1

23 pages, 4948 KiB

Open AccessArticle

An Analysis of Structural Integrity and Durability in Determining the Optimal Compaction Parameters for Hemp and Pine

by Kamil Roman, Witold Jan Wardal and Gabriela Maksymiuk

Energies 2025, 18(7), 1853; https://doi.org/10.3390/en18071853 (registering DOI) - 7 Apr 2025

Research on seed hemp and pine was carried out to improve sustainability and energy efficiency. The mechanical properties of different species of lignocellulosic biomass are still undocumented in the context of granulation processes, even though lignocellulosic biomass is widely studied for biofuel production. [...] Read more.

Research on seed hemp and pine was carried out to improve sustainability and energy efficiency. The mechanical properties of different species of lignocellulosic biomass are still undocumented in the context of granulation processes, even though lignocellulosic biomass is widely studied for biofuel production. Hemp and pine have not been thoroughly compared in the granulation process. Under compressive forces pertinent to pelletizing, the study investigated the mechanical properties of lignocellulosic materials, such as hemp and Scots pine. Based on their mechanical properties, microscopic analysis and strength tests were conducted to compare hemp pellets and pine briquettes. In recent years, a significant trend has been towards eco-friendly and innovative biofuel production, motivating research on compaction technologies and material strength enhancement. The study compared hemp (Cannabis sativa L.) with Scots pine (Pinus sylvestris) during compaction. Compared with pine briquettes, hemp pellets exhibit superior mechanical durability (durability factor = 0.98) and compressive strength (average 2.5 kN), demonstrating hemp’s potential as a renewable fuel source. The study results contribute to the development of sustainable biofuel production processes. Full article

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

► Show Figures

Figure 1

27 pages, 9311 KiB

Open AccessArticle

Learning and Characterizing Chaotic Attractors of a Lean Premixed Combustor

by Sara Navarro-Arredondo and Jim B. W. Kok

Energies 2025, 18(7), 1852; https://doi.org/10.3390/en18071852 (registering DOI) - 7 Apr 2025

This paper is about the characteristics of and a method to recognize the onset of limit cycle thermoacoustic oscillations in a gas turbine-like combustor with a premixed turbulent methane/air flame. Information on the measured time series data of the pressure and the OH* [...] Read more.

This paper is about the characteristics of and a method to recognize the onset of limit cycle thermoacoustic oscillations in a gas turbine-like combustor with a premixed turbulent methane/air flame. Information on the measured time series data of the pressure and the OH* chemiluminescence is acquired and postprocessed. This is performed for a combustor with variation in two parameters: fuel/air equivalence ratio and combustor length. It is of prime importance to acknowledge the nonlinear dynamic nature of these instabilities. A method is studied to interpret thermoacoustic instability phenomena and assess quantitatively the transition of the combustor from a stable to an unstable regime. In this method, three-phase portraits are created on the basis of data retrieved from the measured acoustics and flame intensity in the laboratory-scale test combustor. In the path to limit cycle oscillation, the random distribution in the three-phase portrait contracts to an attractor. The phase portraits obtained when changing operating conditions, moving from the stable to the unstable regime and back, are analyzed. Subsequently, the attractor dimension is determined for quantitative analysis. On the basis of the trajectories from the stable to unstable and back in one run, a study is performed of the hysteresis dynamics in bifurcation diagrams. Finally, the onset of the instability is demonstrated to be recognized by the 0-1 criterion for chaos. The method was developed and demonstrated on a low-power atmospheric methane combustor with the aim to apply it subsequently on a high-power pressurized diesel combustor. Full article

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

► Show Figures

Figure 1

25 pages, 2247 KiB

Open AccessArticle

Renewable Energy Consumption and Green Growth in Sub-Saharan Africa

by Brian Tavonga Mazorodze

Energies 2025, 18(7), 1851; https://doi.org/10.3390/en18071851 (registering DOI) - 7 Apr 2025

The debate on renewable energy consumption and green growth is yet to be empirically settled. Motivated by the dearth of literature in sub-Saharan Africa on this subject, this study examines the impact of renewable energy consumption on green growth using a panel of [...] Read more.

The debate on renewable energy consumption and green growth is yet to be empirically settled. Motivated by the dearth of literature in sub-Saharan Africa on this subject, this study examines the impact of renewable energy consumption on green growth using a panel of 22 sub-Saharan countries observed between 1990 and 2019. It criticizes the existing literature for inadequately addressing cross-sectional dependence and inappropriately assuming homogeneity in the way renewable energy consumption affects green growth across countries. A comparison of the commonly applied estimator in the literature which ignores the above two violations, and the preferred estimator suggests that the current state of knowledge could be fundamentally flawed. While the estimator commonly applied in the literature replicates the largely reported positive and direct impact of renewable energy on green growth, the preferred estimator finds the impact insignificant. It instead finds that green growth is primarily driven by gross capital formation, rather than renewable energy consumption. This study additionally examines the effect of renewable energy on several types of environmental damage. Renewable energy is found to significantly reduce CO₂ emissions only. The conclusion is therefore that renewable energy does not have a direct impact on green growth, although it helps reduce CO₂ emissions. Full article

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

► Show Figures

Figure 1

18 pages, 4086 KiB

Open AccessArticle

Piezoelectric Energy Harvesting System to Charge Batteries with the Use of a Portable Musical Organ

by Josué Esaú Vega-Ávila, Guillermo Adolfo Anaya-Ruiz, José Joel Román-Godínez, Gabriela Guadalupe Esquivel-Barajas, Jorge Ortiz-Marín, Rogelio Gudiño-Valdez and Hilda Aguilar-Rodríguez

Energies 2025, 18(7), 1850; https://doi.org/10.3390/en18071850 (registering DOI) - 6 Apr 2025

In recent years, the increase in energy demand has been an incentive to search for new ways to generate energy. An alternative is producing this energy from daily human activities. To do this, piezoelectric devices have been used in different human activities to [...] Read more.

In recent years, the increase in energy demand has been an incentive to search for new ways to generate energy. An alternative is producing this energy from daily human activities. To do this, piezoelectric devices have been used in different human activities to collect energy. Some of these potential activities are transportation, biomedicine, and electronic devices. Harvesting energy from the mechanical force applied by a pianist during their performance is one of these activities that can be used. The implementation of piezoelectric devices under the keys of an electric organ was carried out. A theoretical model was developed to estimate the amount of energy we could recover. The system was characterized by controlled forces. The volume generated by the forces was measured via a Musical Instrument Digital Interface (MIDI) using the open-source music production software “LMMS (Linux MultiMedia Studio) 1.2.2 version”. The electric potential difference was measured as a function of the volume generated by the pianist. The voltages generated for different frequencies of the pianist’s rhythm were studied. The efficiency calculated in the mathematical model agreed with that obtained in the implemented system. The study results indicate that the batteries were recharged, which resulted in 53 s of organ operation. Full article

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

► Show Figures

Figure 1

23 pages, 18453 KiB

Open AccessArticle

Efficient Short-Term Wind Power Prediction Using a Novel Hybrid Machine Learning Model: LOFVT-OVMD-INGO-LSSVR

by Zhouning Wei and Duo Zhao

Energies 2025, 18(7), 1849; https://doi.org/10.3390/en18071849 (registering DOI) - 6 Apr 2025

Accurate wind power forecasting (WPF) is crucial to enhance availability and reap the benefits of integration into power grids. The time lag of wind power generation lags the time of wind speed changes, especially in ultra-short-term forecasting. The prediction model is sensitive to [...] Read more.

Accurate wind power forecasting (WPF) is crucial to enhance availability and reap the benefits of integration into power grids. The time lag of wind power generation lags the time of wind speed changes, especially in ultra-short-term forecasting. The prediction model is sensitive to outliers and sudden changes in input historical meteorological data, which may significantly affect the robustness of the WPF model. To address this issue, this paper proposes a novel hybrid machine learning model for highly accurate forecasting of wind power generation in ultra-short-term forecasting. The raw wind power data were filtered and classified with the local outlier factor (LOF) and the voting tree (VT) model to obtain a subset of inputs with the best relevance. The time-varying properties of the fluctuating sub-signals of the wind power sequences were analyzed with the optimized variational mode decomposition (OVMD) algorithm. The Northern Goshawk optimization (NGO) algorithm was improved by incorporating a logical chaotic initialization strategy and chaotic adaptive inertia weights. The improved NGO algorithm was used to optimize the least squares support vector regression (LSSVR) prediction model to improve the computational speed and prediction results. The proposed model was compared with traditional machine learning models, deep learning models, and other hybrid models. The experimental results show that the proposed model has an average R² of 0.9998. The average MSE, average MAE, and average MAPE are as low as 0.0244, 0.1073, and 0.3587, which displayed the best results in ultra-short-term WPF. Full article

(This article belongs to the Special Issue Intelligent Energy Technical Studies About Automobiles, New Energy Vehicles and Key Systems in the Energy Field)

► Show Figures

Figure 1

36 pages, 2920 KiB

Open AccessReview

Integrated Energy Storage Systems for Enhanced Grid Efficiency: A Comprehensive Review of Technologies and Applications

by Raphael I. Areola, Abayomi A. Adebiyi and Katleho Moloi

Energies 2025, 18(7), 1848; https://doi.org/10.3390/en18071848 (registering DOI) - 6 Apr 2025

The rapid global shift toward renewable energy necessitates innovative solutions to address the intermittency and variability of solar and wind power. This study presents a comprehensive review and framework for deploying Integrated Energy Storage Systems (IESSs) to enhance grid efficiency and stability. By [...] Read more.

The rapid global shift toward renewable energy necessitates innovative solutions to address the intermittency and variability of solar and wind power. This study presents a comprehensive review and framework for deploying Integrated Energy Storage Systems (IESSs) to enhance grid efficiency and stability. By leveraging a Multi-Criteria Decision Analysis (MCDA) framework, this study synthesizes techno-economic optimization, lifecycle emissions, and policy frameworks to evaluate storage technologies such as lithium-ion batteries, pumped hydro storage, and vanadium flow batteries. The framework prioritizes hybrid storage systems (e.g., battery–supercapacitor configurations), demonstrating 15% higher grid stability in high-renewable penetration scenarios, and validates findings through global case studies, including the Hornsdale Power Reserve (90–95% round-trip efficiency) and Kauai Island Utility Cooperative (15,000+ cycles for flow batteries). Regionally tailored strategies, such as Kenya’s fast-track licensing and Germany’s H2Global auctions, reduce deployment timelines by 30–40%, while equity-focused policies like India’s SAUBHAGYA scheme cut energy poverty by 25%. This study emphasizes circular economy principles, advocating for mandates like the EU’s 70% lithium recovery target to reduce raw material costs by 40%. Despite reliance on static cost projections and evolving regulatory landscapes, the MCDA framework’s dynamic adaptation mechanisms, including sensitivity analysis for carbon taxes (USD 100/ton CO₂-eq boosts hydrogen viability by 25%), ensure scalability across diverse grids. This work bridges critical gaps in renewable energy integration, offering actionable insights for policymakers and grid operators to achieve resilient, low-carbon energy systems. Full article

(This article belongs to the Special Issue Advancements in Smart Energy Systems, Energy Storage, and Renewables Integration)

20 pages, 1665 KiB

Open AccessArticle

Enhancing Resiliency in Distribution Power Grids with Distributed Generation Through Application of Visualisation Techniques

by Yasmin Nigar Abdul Rasheed, Ashish P. Agalgaonkar and Kashem Muttaqi

Energies 2025, 18(7), 1847; https://doi.org/10.3390/en18071847 (registering DOI) - 6 Apr 2025

With recent technological advancements, advanced communication technology, sensors and distributed generation (DG), it is an undeniable fact that modern power systems are flooded with massive amounts of data. These vast amount of generated data are difficult to interpret and comprehend, and are slow [...] Read more.

With recent technological advancements, advanced communication technology, sensors and distributed generation (DG), it is an undeniable fact that modern power systems are flooded with massive amounts of data. These vast amount of generated data are difficult to interpret and comprehend, and are slow to sort through and explain. With ever increasing renewable power generation, grid operators should gain insights on identifying the vulnerabilities, behaviour and interactions of various power system components and anticipate challenges to enhance power system resiliency. Visualisation offers a means to reveal patterns, trends and connections in data that speed up and present information to a power system operator in a way that can be well understood topographically and provide an ability to accommodate increasing DG resources. Hence, this paper presents a comprehensive literature review of several visualisation techniques that can be embedded for improving operational efficiency and resiliency in modern power grids embedded with distributed and renewable energy resources. Full article

(This article belongs to the Section F2: Distributed Energy System)

► Show Figures

Figure 1

22 pages, 13573 KiB

Open AccessArticle

Carbon Capture Adsorbents Based on Ash Residues from the Combustion of Coal with Biomass Blended Fuels

by Silviya Boycheva, Boian Mladenov, Ana Borissova, Momtchil Dimitrov, Ivalina Trendafilova, Daniela Kovacheva and Margarita Popova

Energies 2025, 18(7), 1846; https://doi.org/10.3390/en18071846 (registering DOI) - 6 Apr 2025

One of the approaches to limit the negative impact on the environment from the burning of coal in the production of heat and electricity is to limit their use by blending them with biomass. Blended fuel combustion leads to the generation of a [...] Read more.

One of the approaches to limit the negative impact on the environment from the burning of coal in the production of heat and electricity is to limit their use by blending them with biomass. Blended fuel combustion leads to the generation of a solid ash residue differing in composition from coal ash, and opportunities for its utilization have not yet been studied. The present paper provides results on the carbon capture potential of adsorbents developed through the alkaline conversion of ash mixtures from the combustion of lignite and biomass from agricultural plants and wood. The raw materials and the obtained adsorbents were studied with respect to the following: their chemical and phase composition based on Atomic Absorption Spectroscopy with Inductively Coupled Plasma (AAS-ICP) and X-ray powder diffraction (XRD), respectively, morphology based on scanning electron spectroscopy (SEM), thermal properties based on thermal analysis (TG and DTG), surface parameters based on N₂ physisorption, and the type of metal oxides within the adsorbents based on temperature-programmed reduction (TPR) and UV-VIS spectroscopy. The adsorption capacity toward CO₂ was studied in dynamic conditions and the obtained results were compared to those of zeolite-like CO₂ adsorbents developed through the utilization of the raw coal ash. It was observed that the adsorbents based on ash of blended fuel have a comparable carbon capture potential with coal fly ash zeolites despite their lower specific surface areas due to their compositional specifics and that they could be successfully applied as adsorbents in post-combustion carbon capture systems. Full article

(This article belongs to the Special Issue Renewable Fuels and Chemicals)

► Show Figures

Graphical abstract

23 pages, 5386 KiB

Open AccessArticle

Research Trends in Underground Hydrogen Storage: A Bibliometric Approach

by Barbara Uliasz-Misiak, Jacek Misiak and Radosław Tarkowski

Energies 2025, 18(7), 1845; https://doi.org/10.3390/en18071845 (registering DOI) - 5 Apr 2025

This article presents the findings of a bibliometric analysis of scientific publications in journals and materials indexed in the SCOPUS and Web of Science databases, covering the broad topic of underground hydrogen storage (UHS). The use of VOSviewer software for keyword analysis enabled [...] Read more.

This article presents the findings of a bibliometric analysis of scientific publications in journals and materials indexed in the SCOPUS and Web of Science databases, covering the broad topic of underground hydrogen storage (UHS). The use of VOSviewer software for keyword analysis enabled the identification of four key research areas related to UHS. These areas include hydrogen and hydrocarbon reservoir engineering; hydrogen economy and energy transformation; processes in hydrogen storage sites, including lessons from CO₂ sequestration; and the geology, engineering, and geomechanics of underground gas storage. The interdisciplinary nature of UHS research emphasises the synergy of research across diverse fields. A bibliographic analysis allowed for the identification of areas of intensive research and new directions of work related to UHS, key research centres, and the dynamics of the development of research topics related to UHS. This study revealed the chronological dispersion of the research results, their geographical and institutional variability, and the varying contributions of major publishing journals. The research methodology used can serve as an inspiration for the work of other researchers. Full article

(This article belongs to the Special Issue Advanced Studies on Clean Hydrogen Energy Systems of the Future)

► Show Figures

Figure 1

26 pages, 2307 KiB

Open AccessArticle

Solar Panel Waste Management: Challenges, Opportunities, and the Path to a Circular Economy

by Allison Piedrahita, Laura M. Cárdenas and Sebastian Zapata

Energies 2025, 18(7), 1844; https://doi.org/10.3390/en18071844 (registering DOI) - 5 Apr 2025

The swift global proliferation of solar photovoltaic (PV) technology has significantly contributed to the acceleration of the transition to renewable energy. Projections indicate a significant rise in installed capacity by 2050, suggesting that the extensive implementation of solar panels is transforming energy systems [...] Read more.

The swift global proliferation of solar photovoltaic (PV) technology has significantly contributed to the acceleration of the transition to renewable energy. Projections indicate a significant rise in installed capacity by 2050, suggesting that the extensive implementation of solar panels is transforming energy systems while simultaneously highlighting important issues regarding end-of-life waste management and long-term sustainability. The environmental advantages of photovoltaic (PV) systems are overshadowed by the prevalent reliance on landfilling and inadequate recycling practices, revealing a substantial deficiency in sustainable waste management, especially in areas with underdeveloped policy frameworks. This research study examines the solar panel supply chain, highlighting critical stages, sources of waste generation, existing management practices, and potential areas for enhancement. Waste is classified into four categories, solid, hazardous, electronic (WEEE), and environmental, each necessitating specific management strategies. Regions such as Europe exhibit comprehensive legal frameworks and advanced recycling technologies, whereas others, including Latin America and certain areas of Asia, continue to encounter deficits in policy and infrastructure. The research highlights the implementation of the 6R principles—Recycle, Recover, Reduce, Reuse, Repair, and Refine—within a circular economy framework to improve sustainability, optimize resource utilization, and reduce environmental impact. The findings highlight the necessity for coordinated policies, technological innovation, and international collaboration to ensure a sustainable future for solar energy. This study offers important insights for policymakers, industry stakeholders, and researchers focused on enhancing circularity and sustainability within the photovoltaic sector. Full article

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

► Show Figures

Figure 1

20 pages, 3868 KiB

Open AccessArticle

Wind Power Plant Expert System Diagnostic Knowledge Base Creation

by Radosław Duer, Stanisław Duer, Konrad Zajkowski, Marek Woźniak, Dariusz Bernatowicz, Jacek Paś, Marek Stawowy, Atif Iqbal and Marta Harničárová

Energies 2025, 18(7), 1843; https://doi.org/10.3390/en18071843 (registering DOI) - 5 Apr 2025

Under certain weather circumstances, wind farms might lose their operational integrity. The study describes the process for building a WPP (Wind Power Plant) expert knowledge base for the WPPES system. The article presents the creation of an expert knowledge base on wind farm [...] Read more.

Under certain weather circumstances, wind farms might lose their operational integrity. The study describes the process for building a WPP (Wind Power Plant) expert knowledge base for the WPPES system. The article presents the creation of an expert knowledge base on wind farm equipment that is the basis for the functioning of an intelligent expert system. For this purpose, a functional and diagnostic model of wind farm equipment was presented and described. Functional diagnostic models of objects are the basis for obtaining diagnostic information about the study object (set of facts). The operating conditions of the wind farm equipment and their surroundings have been characterized and described. On this basis, admissible and boundary conditions for the functioning of the tested technical object were determined. The above information specifically supplements the diagnostic information set when building the set of facts and rules. An important part of the article is to describe the principles and conditions for developing a set of diagnostic rules for the knowledge base of an expert system diagnosing wind farm equipment. Building expert knowledge bases is an extremely complex process of transforming diagnostic object information sets into the form of knowledge that is required by an expert system. To this end, an analytical relationship was developed and described as the basis for building a set of inference rules for the examined object. The effectiveness of the developed expert knowledge base is presented in the aspect of its introduction to the expert system knowledge module. Full article

(This article belongs to the Section F5: Artificial Intelligence and Smart Energy)

► Show Figures

Figure 1

25 pages, 5804 KiB

Open AccessArticle

Physical Model for the Simulation of an Air Handling Unit Employed in an Automotive Production Process: Calibration Procedure and Potential Energy Saving

by Luca Viscito, Francesco Pelella, Andrea Rega, Federico Magnea, Gerardo Maria Mauro, Alessandro Zanella, Alfonso William Mauro and Nicola Bianco

Energies 2025, 18(7), 1842; https://doi.org/10.3390/en18071842 (registering DOI) - 5 Apr 2025

A meticulous thermo-hygrometric control is essential for various industrial production processes, particularly those involving the painting phases of body-in-white, in which the air temperature and relative humidity in production boots must be limited in strict intervals to ensure the high quality of the [...] Read more.

A meticulous thermo-hygrometric control is essential for various industrial production processes, particularly those involving the painting phases of body-in-white, in which the air temperature and relative humidity in production boots must be limited in strict intervals to ensure the high quality of the final product. However, traditional proportional integrative derivative (PID) controllers may result in non-optimal control strategies, leading to energy wastage due to response delays and unnecessary superheatings. In this regard, predictive models designed for control can significantly aid in achieving all the targets set by the European Union. This paper focuses on the development of a predictive model for the energy consumption of an air handling unit (AHU) used in the paint-shop area of an automotive production process. The model, developed in MATLAB 2024b, is based on mass and energy balances within each component, and phenomenological equations for heat exchangers. It enables the evaluation of thermal powers and water mass flow rates required to process an inlet air flow rate to achieve a target condition for the temperature and relative humidity. The model was calibrated and validated using experimental data of a real case study of an automotive production process, obtaining mean errors of 16% and 31% for the hot and cold heat exchangers, respectively, in predicting the water mass flow rate. Additionally, a control logic based on six regulation thermo-hygrometric zones was developed, which depended on the external conditions of temperature and relative humidity. Finally, as the main outcome, several examples are provided to demonstrate both the applicability of the developed model and its potential in optimizing energy consumption, achieving energy savings of up to 46% compared to the actual baseline control strategy, and external boundary conditions, identifying an optimal trade-off between energy saving and operation feasibility. Full article

(This article belongs to the Section G: Energy and Buildings)

► Show Figures

Figure 1

18 pages, 12292 KiB

Open AccessArticle

Role of -SF₅ Groups in Modulating the Stability and Energy Characteristics of Fluorinated Molecules

by Jelena Tamuliene and Jonas Sarlauskas

Energies 2025, 18(7), 1841; https://doi.org/10.3390/en18071841 (registering DOI) - 5 Apr 2025

In this paper, we present our investigations into the detonation performance and stability variations caused by replacing the -CF₃ or -OCF₃ group with -SF₅. The widely applied DFT B3LYP/cc-pVTZ approach was employed to evaluate the HOMO–LUMO gap, cohesive energy, [...] Read more.

In this paper, we present our investigations into the detonation performance and stability variations caused by replacing the -CF₃ or -OCF₃ group with -SF₅. The widely applied DFT B3LYP/cc-pVTZ approach was employed to evaluate the HOMO–LUMO gap, cohesive energy, chemical hardness, and electronegativity. Based on these parameters, we predict the changes in chemical and thermal stability resulting from the inclusion of -SF₅ instead of -CF₃ or -OCF₃. Our results indicate that, in some cases, the density of fluorine-containing nitro compounds decreases due to the presence of the pentafluorosulfanyl group. Additionally, machine learning techniques were used to determine the detonation pressure and velocity of fluorine–sulfur-containing compounds. Our findings suggest that fluorine-containing nitro compounds exhibit better detonation performance and stability than fluorine–sulfur-containing ones. Overall, the pentafluorosulfanyl groups inclusion of aromatic polynitro compounds improved neither the stability nor the detonation properties such as -CF₃ or -OCF₃ groups. Full article

(This article belongs to the Special Issue Advanced Energy Materials: Innovations and Challenges)

► Show Figures

Figure 1

27 pages, 6981 KiB

Open AccessArticle

A Hybrid Blockchain Solution for Electric Vehicle Energy Trading: Balancing Proof of Work and Proof of Stake

by Sid-Ali Amamra

Energies 2025, 18(7), 1840; https://doi.org/10.3390/en18071840 (registering DOI) - 5 Apr 2025

This research presents an innovative blockchain-based solution for the charging and energy trading of electric vehicles (EVs). By combining the strengths of two prominent consensus mechanisms, Proof of Work (PoW) and Proof of Stake (PoS), the proposed system balances security, decentralization, and energy [...] Read more.

This research presents an innovative blockchain-based solution for the charging and energy trading of electric vehicles (EVs). By combining the strengths of two prominent consensus mechanisms, Proof of Work (PoW) and Proof of Stake (PoS), the proposed system balances security, decentralization, and energy efficiency. PoW secures the blockchain, while PoS enhances energy efficiency and scalability, key factors in meeting the growing demand for EV infrastructure. The system’s decentralized nature allows for EV owners, charging stations, and stakeholders to interact and transact transparently, without relying on centralized entities. The research conducts a comprehensive simulation to assess the performance of the proposed hybrid blockchain model, demonstrating significant improvements in cost-effectiveness, scalability, and energy management. Additionally, dynamic pricing mechanisms within the blockchain enable real-time energy trading, optimizing charging times and balancing grid demand efficiently. Through the use of smart contracts, automated pricing adjustments, and incentive-driven user behaviors, the proposed system paves the way for more sustainable, cost-effective, and efficient energy solutions in the future. Full article

(This article belongs to the Special Issue Challenges and Future Trends of Energy Management Systems for Electric Vehicles)

► Show Figures

Figure 1

27 pages, 6612 KiB

Open AccessArticle

Integrated Atmospheric Water Generators for Building Sustainability: A Simulation-Based Approach

by Lucia Cattani, Roberto Figoni, Paolo Cattani and Anna Magrini

Energies 2025, 18(7), 1839; https://doi.org/10.3390/en18071839 (registering DOI) - 5 Apr 2025

This paper presents the first results of a broader study aimed at considering atmospheric water generation as a viable option within sustainable building design strategies. In particular, the focus is on integrated systems in which atmospheric water generator (AWG) machines, in addition to [...] Read more.

This paper presents the first results of a broader study aimed at considering atmospheric water generation as a viable option within sustainable building design strategies. In particular, the focus is on integrated systems in which atmospheric water generator (AWG) machines, in addition to producing water, support HVAC systems. The research focuses on the combined use of two different simulation tools: a commercial tool designed to study the energy balance of buildings and a custom-developed software for AWG modelling. This is the first step of a more complex procedure of software integration that is aimed to provide designers with a method to implement AWGs in the design process of buildings, both residential or industrial. This preliminary procedure is applied to a case study concerning the link between an advanced integrated AWG and a building housing inverters and transformers that belong to a photovoltaic field. The scope of the integration consists in enhancing the energy sustainability of atmospheric water intended for hydrogen production and panel washing by means of the dry and cold air flux that comes from the cycle of vapour condensation. The results highlight the potentialities of the integrated design, which includes AWGs, to enhance the final efficiency of sustainable housing. In particular, the joint action of the simulation tools used in this study provides insights about the possibility to reduce the size of traditional chiller that serve the building by an order of magnitude, and to achieve an energy saving of 29.8 MWh a year. Full article

(This article belongs to the Special Issue Carbon Neutrality Through Green Innovations—the Role of the Renewable Energy: 3rd Edition)

► Show Figures

Figure 1

23 pages, 4424 KiB

Open AccessArticle

Operational Conditions for an Internal Combustion Engine in a SOFC-ICE Hybrid Power Generation System

by Victor A. Reyes-Flores, Zachary Swartwout, Shane Garland, Daniel B. Olsen, Bret Windom, Robert Braun and Todd Bandhauer

Energies 2025, 18(7), 1838; https://doi.org/10.3390/en18071838 (registering DOI) - 5 Apr 2025

Hybrid power generation systems utilizing pressurized Solid Oxide Fuel Cells (SOFCs) have gained considerable attention recently as an effective solution to the increasing demand for cleaner electricity sources. Among the various hybridization options, gas turbines (GT) and internal combustion engines (ICE) running on [...] Read more.

Hybrid power generation systems utilizing pressurized Solid Oxide Fuel Cells (SOFCs) have gained considerable attention recently as an effective solution to the increasing demand for cleaner electricity sources. Among the various hybridization options, gas turbines (GT) and internal combustion engines (ICE) running on SOFC tail gas have been prominent. Although spark ignition (SI) tail gas engines have received less focus, they show significant potential for stationary power generation, particularly due to their ability to control combustion. This research experimentally characterized an SI engine fueled by simulated SOFC anode gas for five blends, which correspond to overall system power level and loads. The study aimed to optimize the engine operating conditions for each fuel blend and establish operational conditions that would sustain maximum performance. The results showed efficiencies as high as 31.4% at 1600 RPM, with a 17:1 compression ratio, equivalence ratio (φ) of 0.75, and a boost pressure of 165 kPa with low NOx emissions. The study also emphasizes the benefits of optimizing boost supply to minimize parasitic loads and improve brake thermal efficiency. Additionally, installing a catalytic oxidizer would enable the system to comply with new engine emission regulations. A proposed control scheme for automation includes regulating engine power by controlling the boost of the supercharger at a fixed throttle position. The results of this study help to promote the development of this SOFC-based clean energy technology. Full article

(This article belongs to the Special Issue Engine Combustion Characteristics, Performance, and Emission)

► Show Figures

Figure 1

19 pages, 953 KiB

Open AccessReview

A Review of Smart Grid Evolution and Reinforcement Learning: Applications, Challenges and Future Directions

by Na Xu, Zhuo Tang, Chenyi Si, Jinshan Bian and Chaoxu Mu

Energies 2025, 18(7), 1837; https://doi.org/10.3390/en18071837 (registering DOI) - 5 Apr 2025

In the face of the rapid development of smart grid technologies, it is increasingly difficult for traditional power system management methods to support the increasingly complex operation of modern power grids. This study systematically reviews new challenges and research trends in the field [...] Read more.

In the face of the rapid development of smart grid technologies, it is increasingly difficult for traditional power system management methods to support the increasingly complex operation of modern power grids. This study systematically reviews new challenges and research trends in the field of smart grid optimization, focusing on key issues such as power flow optimization, load scheduling, and reactive power compensation. By analyzing the application of reinforcement learning in the smart grid, the impact of distributed new energy’s high penetration on the stability of the system is thoroughly discussed, and the advantages and disadvantages of the existing control strategies are systematically reviewed. This study compares the applicability, advantages, and limitations of different reinforcement learning algorithms in practical scenarios, and reveals core challenges such as state space complexity, learning stability, and computational efficiency. On this basis, a multi-agent cooperation optimization direction based on the two-layer reinforcement learning framework is proposed to improve the dynamic coordination ability of the power grid. This study provides a theoretical reference for smart grid optimization through multi-dimensional analysis and research, advancing the application of deep reinforcement learning technology in this field. Full article

(This article belongs to the Special Issue Advanced Machine Learning and Big Data Technologies for Smart Cities and Grids)

► Show Figures

Figure 1

More Articles...

Submit to Energies Review for Energies

Journal Menu

Journal Browser

► Journal Browser

Highly Accessed Articles

View More...

Latest Books

More Books and Reprints...

E-Mail Alert

News

2 April 2025
MDPI INSIGHTS: The CEO's Letter #21 - Annual Report, Swiss Consortium, IWD, ICARS, Serbia

31 March 2025
Energies | Highly Cited Papers in 2024 in the Section “Sustainable Energy”

21 March 2025
World Water Day—“Glacier Preservation”, 22 March 2025

More News & Announcements...

Topics

Propose a Topic

Topic in Energies, Processes, Electronics, Applied Sciences, WEVJ

Energy Management and Efficiency in Electric Motors, Drives, Power Converters and Related Systems Topic Editors: Mario Marchesoni, Alfonso Damiano
Deadline: 15 April 2025

Topic in Buildings, Energies, Land, Smart Cities, Sustainability

Sustainable and Smart Building Topic Editors: João Quesado Delgado, Ricardo Forgiarini Rupp
Deadline: 10 May 2025

Topic in Energies, Geosciences, Minerals, Resources

Drilling, Completion and Well Engineering for the Natural Energy Resources Extraction, Storage and Sustainable Management, 2nd Edition Topic Editors: Mofazzal Hossain, Hisham Khaled Ben Mahmud, Md Motiur Rahman
Deadline: 20 May 2025

Topic in Batteries, Designs, Energies, Sustainability, WEVJ

Design Strategies for Battery Energy Storage and Electric Vehicles to Promote Circular Economy Topic Editors: King Jet Tseng, Davy Cheong
Deadline: 31 May 2025

More Topics

Conferences

Announce Your Conference

29 July–3 August 2025 The 2nd International Conference on AI Sensors and Transducers

9–10 April 2025 Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD) Conference 2025

8–10 May 2025 WSEEE-2025

More Conferences...

Special Issues

Propose a Special Issue

Special Issue in Energies

Advances in Nuclear Power for Integrated Energy Systems Guest Editors: Tyler Westover, Richard B. Vilim, Rami M. Saeed
Deadline: 8 April 2025

Special Issue in Energies

Energy Data Spaces: Architectures, Concepts and Applications Guest Editor: Aris Dimeas
Deadline: 8 April 2025

Special Issue in Energies

Advances in Hydrogen and Carbon Value Chains in Green Electrification Guest Editors: Ana Cristina Ferreira, José Carlos Fernandes Teixeira
Deadline: 9 April 2025

Special Issue in Energies

Optimization of Building Energy Systems and Energy Grids Guest Editor: Saptarshi Bhattacharya
Deadline: 10 April 2025

More Special Issues

Topical Collections

Topical Collection in Energies

Advanced Technology of Internal Combustion Engines in China Collection Editors: Wenbin Yu, Feiyang Zhao

Topical Collection in Energies

Feature Papers in Advanced Energy Materials Collection Editor: Vassilis Stathopoulos

Topical Collection in Energies

Advances in Heat Transfer Enhancement Collection Editors: Sergio Nardini, Bernardo Buonomo

Topical Collection in Energies

Conference Papers Collection in Electrical Power System Collection Editors: Renato Procopio, Philippe Poure, Alessandro Rosini

More Topical Collections

Back to TopTop