Energies

18 pages, 1536 KiB

Open AccessArticle

Intelligent Fuzzy Multi-Criteria Decision-Making for Energy-Saving Building Designs in Construction

by Pemika Hirankittiwong, Nguyen Van Thanh, Apichart Pattanaporkratana, Nattaporn Chattham, Chawalit Jeenanunta and Vannak Seng

Energies 2025, 18(11), 2726; https://doi.org/10.3390/en18112726 - 23 May 2025

Abstract

The transition toward sustainable construction practices has intensified the demand for intelligent and energy-efficient building components, particularly smart window technologies. While numerous innovations exist, the selection of the most optimal smart window solution is difficult due to the trade-offs among conflicting criteria such [...] Read more.

The transition toward sustainable construction practices has intensified the demand for intelligent and energy-efficient building components, particularly smart window technologies. While numerous innovations exist, the selection of the most optimal smart window solution is difficult due to the trade-offs among conflicting criteria such as energy performance, economic feasibility, environmental impact, and user comfort. This study proposes an integrated Fuzzy Multi-Criteria Decision-Making (FMCDM) framework for selecting smart window technologies. The methodology combines the Fuzzy Analytic Hierarchy Process (FAHP) to determine criterion weights and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to rank alternatives. Nine sustainability-related criteria across the environmental, economic, and social dimensions were evaluated using expert input. The results identify thermochromic smart windows as the optimal choice. This research contributes a structured, adaptable, and scalable FMCDM framework for sustainable technology selection, with broader applicability to green product design and decision-making in the construction and energy sectors. Full article

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

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11 pages, 2362 KiB

Open AccessArticle

Efficiency Testing of Pelton Turbines with Artificial Defects—Part 2: Needles and Seat Rings

by Florian Fahrni, Thomas Staubli and Ernesto Casartelli

Energies 2025, 18(11), 2725; https://doi.org/10.3390/en18112725 - 23 May 2025

Abstract

The erosion of Pelton turbine components in mountainous areas with high sediment input is a major challenge for energy- and cost-efficient operation. Quantitative data on possible efficiency losses associated with local damage are needed. A systematic experimental study was carried out on a [...] Read more.

The erosion of Pelton turbine components in mountainous areas with high sediment input is a major challenge for energy- and cost-efficient operation. Quantitative data on possible efficiency losses associated with local damage are needed. A systematic experimental study was carried out on a model turbine to determine the efficiency losses caused by damaged needles and seat rings. For this purpose, artificial patterns of erosion-like damage were generated on the surfaces of needles and seat rings. These patterns were gradually deepened, and hill charts were measured repeatedly. The combination of needle and seat ring defects was also studied, and the finding is that superimposing the individual efficiency losses of the needle and seat ring resulted in the same efficiency loss measured for both damaged parts. The results of the measurement campaign show that damaged needles should be replaced at an early stage of deterioration, as efficiency losses can quickly add up to several percent and become unacceptable at partial load operations of the turbines. Full article

18 pages, 5887 KiB

Open AccessArticle

Experimental Evaluation of a Radiant Panel System for Enhancing Sleep Thermal Comfort and Energy Efficiency

by Wanfu Xiang, Wenzhi Cui, Yongwei Li and Xiang Wu

Energies 2025, 18(11), 2724; https://doi.org/10.3390/en18112724 - 23 May 2025

Abstract

This study aims to experimentally evaluate a personal comfort system based on a radiant panel (R-PCS) that can regulate the thermal environment of the sleep zone during summer, with a focus on improving both the thermal comfort and energy efficiency of this system. [...] Read more.

This study aims to experimentally evaluate a personal comfort system based on a radiant panel (R-PCS) that can regulate the thermal environment of the sleep zone during summer, with a focus on improving both the thermal comfort and energy efficiency of this system. To investigate thermal comfort under the coupling effect of different covering conditions and operating parameters of the R-PCS, the changing pattern of thermal environment parameters in the berth area and human skin temperature are analyzed. Then, the Predicted Mean Vote (PMV) -Predicted Percent Dissatisfied (PPD) index is employed for assessing the thermal comfort of the human body and energy-saving efficiency of the system. The results show that this system can satisfy the thermal comfort requirements of the human body in the berth area. Meanwhile, the corresponding cooling energy consumption of the R-PCS is significantly lower than that of the traditional HVAC system, indicating that the developed system has significant energy-saving potential in building design. Full article

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13 pages, 419 KiB

Open AccessArticle

The Influential Mechanism of Absorbers and Active Metal on Microwave-Assisted Pyrolysis of Sargassum

by Kai Chen, Qing Xu and Shenwei Zhang

Energies 2025, 18(11), 2723; https://doi.org/10.3390/en18112723 - 23 May 2025

Abstract

Composite catalysts combining absorbers and active metal hold significant potential for improving the efficiency of biomass microwave-assisted pyrolysis (MAP). Compatibility optimization of composite catalysts can be facilitated through comparative analysis for the influential mechanisms of absorbers and catalysts. Therefore, decoupling experiments about the [...] Read more.

Composite catalysts combining absorbers and active metal hold significant potential for improving the efficiency of biomass microwave-assisted pyrolysis (MAP). Compatibility optimization of composite catalysts can be facilitated through comparative analysis for the influential mechanisms of absorbers and catalysts. Therefore, decoupling experiments about the MAP of Sargassum and calculations based on density functional theory (DFT) were conducted in this research, to investigate the influential mechanisms of absorbers and active metal. The results show the introduction of both the absorbers (SiC) and active metal (MgO) increase the yields of high-value components, such as hydrogen and hydrocarbons. However, their influential mechanisms are different. The introduction of SiC enhances the heating rate within the reaction zone, shortening the duration of MAP and inhibiting the condensation of bio-oil and the interaction between bio-oil and bio-char, and thereby increasing the bio-oil yield by 4%. The introduction of MgO lowers the energy barriers for macromolecular decomposition and gas generation, promoting the decomposition of bio-char and bio-oil, and thus leading to a 12% increase in the yield of bio-gas. This research conclusion provides a theoretical basis for the optimization and design of composite catalysts. Full article

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

25 pages, 1595 KiB

Open AccessArticle

From Organizational Readiness to Industry 5.0: An EFQM Model Pathway to Net Zero

by Joanna Martusewicz, Kamil Suchorski, Iwona Chomiak-Orsa, Joanna Usyk, Łukasz Bednarowicz and Marcin Łukaszewicz

Energies 2025, 18(11), 2722; https://doi.org/10.3390/en18112722 - 23 May 2025

Abstract

The automotive industry faces urgent pressures to transition to carbon-neutral operations amid evolving policies, shifting consumer demands, and stringent environmental regulations. This study examines how implementing the EFQM Model 2020 can drive sustainability-oriented transformation in a leading European automotive plant. Over a two-year [...] Read more.

The automotive industry faces urgent pressures to transition to carbon-neutral operations amid evolving policies, shifting consumer demands, and stringent environmental regulations. This study examines how implementing the EFQM Model 2020 can drive sustainability-oriented transformation in a leading European automotive plant. Over a two-year period (November 2021–December 2023), the company reduced CO₂ emissions by 17%, decreased water usage by 9.3%, and elevated recycling rates from 93.3% in FY19 to 98.1% in FY23. Although these improvements demonstrate the EFQM Model’s effectiveness in integrating economic, social, and environmental objectives, further progress toward net zero remains challenging due to diminishing returns on efficiency. Sustaining momentum will require continuous innovation such as passive building designs and on-site renewable energy generation supported by robust stakeholder engagement and compliance with evolving ESG reporting standards. These findings affirm the value of the holistic management framework for operational excellence and environmental stewardship, providing a replicable pathway toward carbon neutrality in resource-intensive industries. Full article

(This article belongs to the Special Issue Environmental Sustainability and Energy Economy)

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17 pages, 439 KiB

Open AccessArticle

Toward Zero-Emission Buildings in Italy: A Holistic Approach to Identify Actions Under Current and Future Climates

by Franz Bianco Mauthe Degerfeld, Mamak P. Tootkaboni, Matteo Piro, Ilaria Ballarini and Vincenzo Corrado

Energies 2025, 18(11), 2721; https://doi.org/10.3390/en18112721 - 23 May 2025

Abstract

The European building sector significantly contributes to the EU’s greenhouse gas reduction goals, with the 2024 Energy Performance of Buildings Directive (EPBD) aiming to achieve a decarbonised building stock by 2050. By focusing on an existing office building representative of the Italian building [...] Read more.

The European building sector significantly contributes to the EU’s greenhouse gas reduction goals, with the 2024 Energy Performance of Buildings Directive (EPBD) aiming to achieve a decarbonised building stock by 2050. By focusing on an existing office building representative of the Italian building stock, this research evaluates various energy efficiency measures and integrates renewable energy systems to transform the building into a Zero-emission Building (ZeB). Moreover, it also utilises future weather data to address the effects of climate change. Results highlight the actions needed for an empirical ZeB transition, offering insights into challenges and key performance indicators across different intervention scenarios. The findings contribute to establishing national ZeB standards, emphasising the importance of the national building renovation plan in compliance with the EPBD recast requirements. Full article

(This article belongs to the Special Issue Performance Analysis of Building Energy Efficiency)

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27 pages, 309 KiB

Open AccessArticle

Progressing Sustainable Development Goal 7 via Energy Access: Results from the 27 EU Member States

by Barbara Fura and Elżbieta Skrzypek

Energies 2025, 18(11), 2720; https://doi.org/10.3390/en18112720 - 23 May 2025

Abstract

Energy plays an undeniable role in socioeconomic development. The energy issue is addressed in Agenda 2030 as one of its 17 goals. The article presents research on the statistical evaluation of the level of implementation of Sustainable Development Goal 7, that is, ‘ensure [...] Read more.

Energy plays an undeniable role in socioeconomic development. The energy issue is addressed in Agenda 2030 as one of its 17 goals. The article presents research on the statistical evaluation of the level of implementation of Sustainable Development Goal 7, that is, ‘ensure access to affordable, reliable, sustainable and modern energy for all’ in the 27 EU member states. Seven indicators measuring different areas of energy accessibility monitored by Eurostat were applied to evaluate the EU countries. A multivariate comparative analysis was used to create a synthetic measure, i.e., the zero unitarisation method. The empirical analysis resulted in a ranking of the 27 EU countries in terms of the level of SDG 7 in 2015–2023. In addition to the ranking, a classification of countries into groups of similar countries in terms of the level of SDG 7 in 2015 and 2023 was presented. Furthermore, countries with the most significant advancement and those with the greatest declines in achieving SDG 7 in 2023 compared to 2015 were proposed. A sensitivity analysis was applied to evaluate a robustness of the composite indicator. Research confirmed a downward differentiation of EU countries in terms of the degree of implementation of SDG 7. Denmark, Romania, and Sweden were the top three countries in 2015, and Denmark, Sweden, and Estonia in 2023. The countries that appeared the weakest in the implementation of SDG 7 were in 2015, Cyprus, Belgium, and Luxembourg, and in 2023, Belgium, Lithuania, Cyprus, and Luxembourg. Luxembourg, Ireland, and Malta made the greatest progress toward SDG 7. At the same time, the largest decline was observed in Spain. The research results highlighted the problems in implementing SDG 7 not only for the less developed countries, mainly in Central, Eastern and Southern Europe, but also for the highly developed Western countries. The applied research procedure may help to identify areas for improvement needed in the effective implementation of SDG 7 in the EU member countries. The procedure, however, has limitations. These include, among others, using a linear approach, taking into account only variables measured by Eurostat or an ambiguous effect of energy consumption indicators on SDG 7 evaluation. Full article

(This article belongs to the Section K: State-of-the-Art Energy Related Technologies)

16 pages, 3237 KiB

Open AccessArticle

Flue Gas Temperature Distribution as a Function of Air Management in a High-Temperature Biomass Burner

by Aleksandra Dzido, Michalina Kurkus-Gruszecka, Marcin Wilczyński and Piotr Krawczyk

Energies 2025, 18(11), 2719; https://doi.org/10.3390/en18112719 - 23 May 2025

Abstract

Nowadays, as a result of the increasing awareness of European societies and new legal regulations, the role of renewable energy sources in individual heating is growing. One of the forms of renewable heat and electricity production is the use of biomass pellet burners [...] Read more.

Nowadays, as a result of the increasing awareness of European societies and new legal regulations, the role of renewable energy sources in individual heating is growing. One of the forms of renewable heat and electricity production is the use of biomass pellet burners coupled with Stirling engines. To ensure high system efficiency, the combustion process of this type of fuel requires an appropriate design of the burners, which can provide high-temperature flue gases. This requirement may be challenging, as the long operation of such a burner may cause the thermal degradation of its components, mainly the upper burner wall. The subject of this analysis was a burner with a nominal power of 10 kW. As the analysis tool, a previously validated CFD model was used. In this work, two ways of thermal degradation prevention are presented. The first one is geometry optimization via secondary air hole distribution. The results show that an appropriate geometrical design of the burner may be an efficient way of shifting the high-temperature zone to the burner axis, which may mitigate the thermal degradation risk. Secondly, the inlet air mass flow is changed to show its impact on the presence and location of the high-temperature zone. Both methods can be treated as interesting ways for solving the challenge of the long-term operation of high-temperature biomass burners by avoiding thermal degradation. Full article

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

26 pages, 15463 KiB

Open AccessArticle

Impact of Passive Modifications on the Efficiency of Darrieus Vertical Axis Wind Turbines Utilizing the Kline-Fogleman Blade Design at the Trailing Edge

by Farzad Ghafoorian and Hui Wan

Energies 2025, 18(11), 2718; https://doi.org/10.3390/en18112718 - 23 May 2025

Abstract

As the utilization of wind energy continues to expand as a prominent renewable energy source, the application of Darrieus Vertical Axis Wind Turbine (VAWT) technology has expanded significantly. Various passive modification methods have been developed to enhance efficiency and optimize the aerodynamic performance [...] Read more.

As the utilization of wind energy continues to expand as a prominent renewable energy source, the application of Darrieus Vertical Axis Wind Turbine (VAWT) technology has expanded significantly. Various passive modification methods have been developed to enhance efficiency and optimize the aerodynamic performance of the rotor through blade modifications. This study presents passive modification method utilizing Kline–Fogleman (KF) blades which incorporate step-like horizontal slats along the trailing edge. Through Computational Fluid Dynamics (CFD) simulations, this study evaluates ten distinct KF blade configurations, varying in step length and depth, with steps positioned on the inner side, outer side, and both sides of the airfoil. The results indicate that the KF blade with a shorter step on inner side, 20%c in length and 2%c in depth, enhances the average power coefficient (C_p) by 19% compared to the rotor with a clean blade. However, when horizontal slats are incorporated on both sides of the blade, with dimensions of 50%c in length and 5%c in depth, C_pdecreases by 33% compared to the clean blade. This reduction occurs across both low and high tip speed ratio (TSR) ranges. It has been observed that the presence of a high-pressure zone of 200 Pa at the trailing edge disrupts the aerodynamic performance when the KF blade is in the upwind region between the azimuth angles of 45° and 135°. Full article

(This article belongs to the Special Issue Wind Turbines and Wind Farms Performance Analysis Through Numerical and Experimental Methods, 2nd Edition)

26 pages, 1031 KiB

Open AccessArticle

Exploring the Role of Digital Economy in Energy Optimization of Manufacturing Industry Under the Constraint of Carbon Reduction? Based on Spatial Panel Threshold Hybrid Model

by Lingyao Wang, Taofeng Wu and Fangrong Ren

Energies 2025, 18(11), 2717; https://doi.org/10.3390/en18112717 - 23 May 2025

Abstract

The development of the digital economy provides important opportunities and conditions for China to achieve the goal of carbon peak and carbon neutrality. Based on panel data from 30 provinces in mainland China from 2016 to 2022, this research investigates the spatial spillover [...] Read more.

The development of the digital economy provides important opportunities and conditions for China to achieve the goal of carbon peak and carbon neutrality. Based on panel data from 30 provinces in mainland China from 2016 to 2022, this research investigates the spatial spillover effect and nonlinear impact of the digital economy on the energy optimization of the manufacturing industry using the spatial econometric and panel threshold model. It is found that both the digital economy and energy optimization of the manufacturing industry have a significant positive spatial correlation. The spatial econometric models under different weights all illustrate that the regional digital economy has not significantly promoted energy optimization of the manufacturing industry in a local region but produced a significant positive influence on the energy optimization of the manufacturing industry in neighboring regions. In addition, the impact of the digital economy on the energy optimization of the manufacturing industry presents a significant single threshold effect. With the improvement of digital economy, energy optimization of manufacturing industry has a U-shaped change trend. This study integrates the digital economy and manufacturing energy optimization into a cohesive analytical framework, elucidating the mechanisms through which the digital economy influences the restructuring of manufacturing energy and enhances energy efficiency while providing innovative pathways and theoretical support for advancing energy efficiency under carbon emission reduction constraints. Full article

(This article belongs to the Special Issue Low-Carbon Development, Energiewende and Digitalization)

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22 pages, 4632 KiB

Open AccessArticle

Efficiency Testing of Pelton Turbines with Artificial Defects—Part 1: Buckets

by Florian Fahrni, Thomas Staubli and Ernesto Casartelli

Energies 2025, 18(11), 2716; https://doi.org/10.3390/en18112716 - 23 May 2025

Abstract

Pelton turbines are susceptible to hydro-abrasive erosion from sediment-laden flows, resulting in a progressive loss of efficiency. Typical defect classes can be derived from the analysis of such damage observed in hydropower plants. A systematic strategy was developed to investigate the effect of [...] Read more.

Pelton turbines are susceptible to hydro-abrasive erosion from sediment-laden flows, resulting in a progressive loss of efficiency. Typical defect classes can be derived from the analysis of such damage observed in hydropower plants. A systematic strategy was developed to investigate the effect of locally damaged Pelton runners on the efficiency in laboratory tests using a model turbine. For this purpose, nine identical runners were fabricated and machined with an increasing size, depth, or number of different artificial defect types, such as splitter, rounded or sharp-edged, defects at the cutout, defects in the bucket base, and added ripples on the bucket sides. The processing steps, the efficiency measurement, and the extracted slopes of the efficiency drops are discussed in detail. The main findings are that the efficiency losses due to the various defects increase in a good approximation linearly with the machining depth and that the individual defect types can be superimposed. Defects at the splitter, bucket base, and bucket side dominate the losses at partial load of the turbine, while those at the cutout dominate at full load. Based on the results of this measurement campaign, power plant operators can estimate the magnitude of efficiency losses in their plant. Full article

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

29 pages, 1522 KiB

Open AccessArticle

Energy and Exergy Analysis of a Photovoltaic-Thermal Geothermal Heat Pump Coupled with Radiant Ceiling and Fresh Air System

by Yaolin Lin, Zhenyan Bu, Wei Yang, Melissa Chan, Lin Tian and Mingqi Dai

Energies 2025, 18(11), 2715; https://doi.org/10.3390/en18112715 - 23 May 2025

Abstract

This paper presents energy and exergy studies on a photovoltaic-thermal solar-assisted geothermal heat pump coupled with a radiant ceiling system. The system utilizes renewable solar and geothermal energy. It has an independent fresh air unit that provides clean air to the space. The [...] Read more.

This paper presents energy and exergy studies on a photovoltaic-thermal solar-assisted geothermal heat pump coupled with a radiant ceiling system. The system utilizes renewable solar and geothermal energy. It has an independent fresh air unit that provides clean air to the space. The computer model of the system was developed under the TRNSYST environment and validated with experimental results from open literature. Distribution of the energy consumption and exergy loss of the system were analyzed. It was found that the heat pump unit consumes the largest amount of energy while the transmission and distribution system has the highest exergy loss. Under optimized operating conditions, i.e., both demand side circulation flow and source side circulation flow are maintained at 65% of the design flow rate (design loop water temperature difference of 7.0 °C), the average exergy efficiency of the whole system was found to be 37.56%, which achieves an accumulative exergy loss reduction of 16.5% compared with 100% design flow rate condition during cooling season. The optimal bearing load ratio of the ground source heat pump vs. photovoltaic-thermal system in the heating season was found to be 67%. Full article

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

28 pages, 5792 KiB

Open AccessArticle

A Numerical Approach to Evaluate the Geothermal Potential of a Flooded Open-Pit Mine: Example from the Carey Canadian Mine (Canada)

by Samuel Lacombe, Félix-Antoine Comeau and Jasmin Raymond

Energies 2025, 18(11), 2714; https://doi.org/10.3390/en18112714 - 23 May 2025

Abstract

Abandoned mines represent an innovative and under-exploited resource to meet current energy challenges, particularly because of their geothermal potential. Flooded open-pits, such as those located in the Thetford Mines region (Eastern Canada), provide large, thermally stable water reservoirs, ideal for the use of [...] Read more.

Abandoned mines represent an innovative and under-exploited resource to meet current energy challenges, particularly because of their geothermal potential. Flooded open-pits, such as those located in the Thetford Mines region (Eastern Canada), provide large, thermally stable water reservoirs, ideal for the use of geothermal cooling systems. Thermal short-circuiting that can impact the system performance affected by both free and forced convective heat transfer is hard to evaluate in these large water reservoirs subject to various heat sink and sources. Thus, this study’s objective was to evaluate the impact of natural heat transfer mechanisms on the performance of an open-loop geothermal system that could be installed in a flooded open-pit mine. Energy needs of an industrial plant using water from the flooded Carey Canadian mine were considered to develop a 3D numerical finite element model to evaluate the thermal impact associated with the operation of the system considering free and forced convection in the flooded open-pit, the natural flow of water into the pit, climatic variations at the surface and the terrestrial heat flux. The results indicate that the configuration of the proposed system meets the plant cooling needs over a period of 50 years and can provide a cooling power of approximately 2.3 MW. The simulations also demonstrated the importance of understanding the hydrological and hydrogeological systems impacting the performance of the geothermal operations expected in a flooded open-pit mine. Full article

(This article belongs to the Section H2: Geothermal)

22 pages, 9593 KiB

Open AccessArticle

Study on Characteristics of Ash Accumulation During Co-Combustion of Salix Biomass and Coal

by Yan Zhang, Chengzhe Shen, Dongxv Wang, Jinbao Zhang, Kai Yang, Haisong Yang, Hailong Liu, Xintong Wen, Yong Zhang, Yunhao Shao, Ruyu Yan, Ningzhu Ye and Lei Deng

Energies 2025, 18(11), 2713; https://doi.org/10.3390/en18112713 - 23 May 2025

Abstract

Co-combustion of coal and biomass for power generation technology could not only realize the effective utilization of biomass energy, but also reduce the emission of greenhouse gases. In this study, a system of a settling furnace with high temperature is applied to study [...] Read more.

Co-combustion of coal and biomass for power generation technology could not only realize the effective utilization of biomass energy, but also reduce the emission of greenhouse gases. In this study, a system of a settling furnace with high temperature is applied to study the ash deposition of the co-combustion of coal and salix. The effects of salix blending ratio, flue gas temperature, and wall temperature on ash deposition are studied. The micro-morphology, elemental content, and compound composition of the ash samples are characterized by scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS) and X-Ray Diffraction (XRD), respectively. The results show that with the biomass blending ratio increasing from 5% to 30%, the content of Ca in ash increases from 8.92% to 20.59%. In particular, when the salix blending ratio exceeds 20%, plenty of the low-melting-point compounds of Ca aggravate the melting adhesion of ash particles, causing serious ash accumulation. Therefore, the salix blending radio is recommended to be limited to no more than 20%. With the increase in flue gas temperature, ash particles melt and stick, forming ash accumulation. Under the condition of flue gas temperature ≥ 1200 °C, a serious ash particle melting flow occurs, and CaO covers the surface of the ash particles, making the ash particles adhere to each other, which makes them difficult to remove. Therefore, controlling the flue gas temperature below 1200 °C is necessary. When the temperature crosses the threshold range of 500–600 °C, the Ca and K contents increase by 35.6% and 41.9%, respectively, while the Si content decreases by 9.7%. The increase in K and Ca content leads to the thickening of the initial layer of the ash deposit, which facilitates the formation of the sintered layer of the deposited ash. Meanwhile, the reduction in Si content leads to the particles’ adhesion, which markedly increases the degree of ash slagging. Once the wall temperature exceeds 600 °C, severe ash slagging becomes a threat to the safe operation of the boiler. Therefore, the wall temperature should not exceed 600 °C. Full article

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

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42 pages, 776 KiB

Open AccessReview

Reinforcement Learning in Energy Finance: A Comprehensive Review

by Spyros Giannelos

Energies 2025, 18(11), 2712; https://doi.org/10.3390/en18112712 - 23 May 2025

Abstract

The accelerating energy transition, coupled with increasing market volatility and computational advances, has created an urgent need for sophisticated decision-making tools that can address the unique challenges of energy finance—a gap that reinforcement learning methodologies are uniquely positioned to fill. This paper provides [...] Read more.

The accelerating energy transition, coupled with increasing market volatility and computational advances, has created an urgent need for sophisticated decision-making tools that can address the unique challenges of energy finance—a gap that reinforcement learning methodologies are uniquely positioned to fill. This paper provides a comprehensive review of the application of reinforcement learning (RL) in energy finance, with a particular focus on option value and risk management. Energy markets present unique challenges due to their complex price dynamics, seasonality patterns, regulatory constraints, and the physical nature of energy commodities. Traditional financial modeling approaches often struggle to capture these intricacies adequately. Reinforcement learning, with its ability to learn optimal decision policies through interaction with complex environments, has emerged as a promising alternative methodology. This review examines the theoretical foundations of RL in financial applications, surveys recent literature on RL implementations in energy markets, and critically analyzes the strengths and limitations of these approaches. We explore applications ranging from electricity price forecasting and optimal trading strategies to option valuation, including real options and products common in energy markets. The paper concludes by identifying current challenges and promising directions for future research in this rapidly evolving field. Full article

(This article belongs to the Special Issue Energy Economics, Finance and Policy Towards Sustainable Energy)

19 pages, 8154 KiB

Open AccessArticle

Energy Consumption Analysis of Fuel Cell Commercial Heavy-Duty Truck with Waste Heat Utilization Under Low-Temperature Environment

by Fujian Liu, Qiao Zhu, Dawei Dong, Zhichao Zhao, Xiuping Zhu, Kunyi Feng, Haifeng Dai and Hao Yuan

Energies 2025, 18(11), 2711; https://doi.org/10.3390/en18112711 - 23 May 2025

Abstract

Waste heat utilization in fuel cell vehicles represents a critical technology for enhancing overall energy utilization efficiency and environmental adaptability, which reduces auxiliary heating consumption, extends driving range, and minimizes thermal management parasitic losses, holding significance for promoting application of fuel cell commercial [...] Read more.

Waste heat utilization in fuel cell vehicles represents a critical technology for enhancing overall energy utilization efficiency and environmental adaptability, which reduces auxiliary heating consumption, extends driving range, and minimizes thermal management parasitic losses, holding significance for promoting application of fuel cell commercial vehicles. This study investigates a 49-ton fuel cell heavy-duty truck equipped with waste heat recovery capability, conducting vehicle energy flow experiments under multiple ambient temperatures (including 7

^{\circ} C

,

- 7

^{\circ} C

and

- 25

^{\circ} C

extreme cold conditions), varying load conditions, and waste heat recovery mode switching, with focused analysis on the energy consumption and temperature response of the waste heat recover critical components, to evaluate the energy utilization of fuel cell waste heat. Experimental results demonstrate the substantial impact of waste heat recovery function on the proportion of the warm air positive temperature coefficient (PTC) energy consumption on total energy consumption, showing that deactivating waste heat recovery increased the PTC energy consumption obviously. Besides, activating the waste heat recovery function contributes to elevated the stack radiator outlet temperature under low-temperature operating conditions. Full article

(This article belongs to the Collection Batteries, Fuel Cells and Supercapacitors Technologies)

27 pages, 1438 KiB

Open AccessArticle

Void Reactivity Coefficient for Hybrid Reactor Cooled Using Liquid Metal

by Andrzej Wojciechowski

Energies 2025, 18(11), 2710; https://doi.org/10.3390/en18112710 - 23 May 2025

Abstract

A negative value of the void reactivity coefficient (α_V) is one of the most important passive safety properties for the operation of nuclear reactor. Herein, are presented calculated values of the void reactivity coefficient for different geometries of reactors cooled by [...] Read more.

A negative value of the void reactivity coefficient (α_V) is one of the most important passive safety properties for the operation of nuclear reactor. Herein, are presented calculated values of the void reactivity coefficient for different geometries of reactors cooled by liquid lead (LFR) and sodium (SFR) with U-238-Pu-239 and Th-232-U-233 fuels. The calculations were carried out for the reactors filled with either one or two types of fuel assemblies. The most interesting results are obtained for reactor filled with two different types of fuel assemblies (hybrid reactor). Hybrid reactors consist of central and peripheral types of fuel assemblies using low enrichment fuel and high enrichment fuel, respectively. Both hybrid reactors based on the uranium cycle (U-cycle) and the thorium cycle (Th-cycle) can maintain a negative void reactivity coefficient value for wide range of reactor parameters. The calculation results of the hybrid reactor matched those from FBR-IME reactor. Full article

(This article belongs to the Special Issue Advanced Multi-physics Modelling and Simulation for Nuclear Technology)

22 pages, 3179 KiB

Open AccessArticle

Lithium-Ion Battery Thermal Runaway Suppression Using Water Spray Cooling

by Eric Huhn, Nicole Braxtan, Shen-En Chen, Anthony Bombik, Tiefu Zhao, Lin Ma, John Sherman and Soroush Roghani

Energies 2025, 18(11), 2709; https://doi.org/10.3390/en18112709 - 23 May 2025

Abstract

Despite the commercial success of lithium-ion batteries (LIBs), the risk of thermal runaway, which can lead to dangerous fires, has become more concerning as LIB usage increases. Research has focused on understanding the causes of thermal runaway and how to prevent or detect [...] Read more.

Despite the commercial success of lithium-ion batteries (LIBs), the risk of thermal runaway, which can lead to dangerous fires, has become more concerning as LIB usage increases. Research has focused on understanding the causes of thermal runaway and how to prevent or detect it. Additionally, novel thermal runaway-resistant materials are being researched, as are different methods of constructing LIBs that better isolate thermal runaway and prevent it from propagating. However, field firefighters are using hundreds of thousands of liters of water to control large runaway thermal emergencies, highlighting the need to merge research with practical observations. To study battery fire, this study utilized a temperature abuse method to increase LIB temperature and investigated whether thermal runaway can be suppressed by applying external cooling during heating. The batteries used were pouch-type ones and subjected to high states of charge (SOC), which primed the thermal runaway during battery temperature increase. A water spray method was then devised and tested to reduce battery temperature. Results showed that, without cooling, a thermal runaway fire occurred every time during the thermal abuse. However, external cooling successfully prevented thermal runaway. This observation shows that using water as a temperature reducer is more effective than using it as a fire suppressant, which can substantially improve battery performance and increase public safety. Full article

(This article belongs to the Special Issue Electrochemical Energy Storage: Batteries, Fuel Cells and Hydrogen Technologies)

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18 pages, 773 KiB

Open AccessArticle

Multi-Level Simulation Framework for Degradation-Aware Operation of a Large-Scale Battery Energy Storage Systems

by Leon Tadayon and Georg Frey

Energies 2025, 18(11), 2708; https://doi.org/10.3390/en18112708 - 23 May 2025

Abstract

The increasing integration of renewable energy sources necessitates efficient energy storage solutions, with large-scale battery energy storage systems (BESS) playing a key role in grid stabilization and time-shifting of energy. This study presents a multi-level simulation framework for optimizing BESS operation across multiple [...] Read more.

The increasing integration of renewable energy sources necessitates efficient energy storage solutions, with large-scale battery energy storage systems (BESS) playing a key role in grid stabilization and time-shifting of energy. This study presents a multi-level simulation framework for optimizing BESS operation across multiple markets while incorporating degradation-aware dispatch strategies. The framework integrates a day-ahead (DA) dispatch level, an intraday (ID) dispatch level, and a high-resolution simulation level to accurately model the impact of operational strategies on state of charge and battery degradation. A case study of BESS operation in the German electricity market is conducted, where frequency containment reserve provision is combined with DA and ID trading. The simulated revenue is validated by a battery revenue index. The study also compares full equivalent cycle (FEC)-based and state-of-health-based degradation models and discusses their application to cost estimation in dispatch optimization. The results emphasize the advantage of using FEC-based degradation costs for dispatch decision-making. Future research will include price forecasting and expanded market participation strategies to further improve and stabilize the profitability of BESS in multi-market environments. Full article

(This article belongs to the Special Issue Advances in Battery Energy Storage Systems)

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21 pages, 4100 KiB

Open AccessArticle

Enhancing Pumped Hydro Storage Regulation Through Adaptive Initial Reservoir Capacity in Multistage Stochastic Coordinated Planning

by Chao Chen, Shan Huang, Yue Yin, Zifan Tang and Qiang Shuai

Energies 2025, 18(11), 2707; https://doi.org/10.3390/en18112707 - 23 May 2025

Abstract

Hybrid pumped hydro storage plants, by integrating pump stations between cascade hydropower stations, have overcome the challenges associated with site selection and construction of pure pumped hydro storage systems, thereby becoming the optimal large-scale energy storage solution for enhancing the absorption of renewable [...] Read more.

Hybrid pumped hydro storage plants, by integrating pump stations between cascade hydropower stations, have overcome the challenges associated with site selection and construction of pure pumped hydro storage systems, thereby becoming the optimal large-scale energy storage solution for enhancing the absorption of renewable energy. However, the multi-energy conversion between pump stations, hydropower, wind power, and photovoltaic plants poses challenges to both their planning schemes and operational performance. This study proposes a multistage stochastic coordinated planning model for cascade hydropower-wind-solar-thermal-pumped hydro storage (CHWS-PHS) systems. First, a Hybrid Pumped Hydro Storage Adaptive Initial Reservoir Capacity (HPHS-AIRC) strategy is developed to enhance the system’s regulation capability by optimizing initial reservoir levels that are synchronized with renewable generation patterns. Then, Non-anticipativity Constraints (NACs) are incorporated into this model to ensure the dynamic adaptation of investment decisions under multi-timescale uncertainties, including inter-annual natural water inflow (NWI) variations and hourly fluctuations in wind and solar power. Simulation results on the IEEE 118-bus system show that the proposed MSSP model reduces total costs by 6% compared with the traditional two-stage approach (TSSP). Moreover, the HPHS-AIRC strategy improves pumped hydro utilization by 33.8%, particularly benefiting scenarios with drought conditions or operational constraints. Full article

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

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16 pages, 2131 KiB

Open AccessArticle

Performance Analysis of a Novel Hybrid Ejector Refrigeration System Driven by Medium- to High-Temperature Industrial Waste Heat

by Fangtian Sun, Chenyang Ma and Zhicheng Wang

Energies 2025, 18(11), 2706; https://doi.org/10.3390/en18112706 - 23 May 2025

Abstract

The thermally driven ejector refrigeration system is generally used to recover industrial waste heat to improve the energy efficiency of industrial processes. However, for conventional single-stage ejector refrigeration systems (ERSs), the higher-pressure steam derived from high-temperature waste heat elevates the primary fluid pressure, [...] Read more.

The thermally driven ejector refrigeration system is generally used to recover industrial waste heat to improve the energy efficiency of industrial processes. However, for conventional single-stage ejector refrigeration systems (ERSs), the higher-pressure steam derived from high-temperature waste heat elevates the primary fluid pressure, resulting in significant pressure mismatch with the secondary fluid, which consequently leads to large irreversible losses and substantial degradation in system performance. To address this issue, a novel hybrid ejector refrigeration system (NHERS) is proposed and analyzed under design and off-design conditions using thermodynamics. The results indicate that under design conditions, compared to the conventional single-stage ejector refrigeration system, the proposed hybrid ejector refrigeration system can achieve increases of about 20.6% in the entrainment ratio, around 15.2% in the coefficient of performance (COP), and about 21.4% in exergetic efficiency. Analyzing its performance under off-design conditions to provide technical solutions for the flexible operation of the hybrid ejector refrigeration system proposed in this paper can broaden its application scenarios. Consequently, the proposed NHERS demonstrates remarkable superiority in energy conversion and transfer processes, showing certain application prospects in the field of medium- to high-temperature industrial waste heat recovery. Full article

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

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16 pages, 5276 KiB

Open AccessArticle

Measurements and Analysis of Electromagnetic Compatibility of Railway Rolling Stock with Train Detection Systems Using Track Circuits

by Adam Garczarek and Dorota Stachowiak

Energies 2025, 18(11), 2705; https://doi.org/10.3390/en18112705 - 23 May 2025

Abstract

One of the main challenges in the operation of electric traction vehicles is ensuring safety and operational reliability. To ensure the safety of railway traffic, vehicles must undergo a series of tests related to the investigation of disturbances generated, among others, in the [...] Read more.

One of the main challenges in the operation of electric traction vehicles is ensuring safety and operational reliability. To ensure the safety of railway traffic, vehicles must undergo a series of tests related to the investigation of disturbances generated, among others, in the return current to the mains. This problem is further complicated by the inability to perform such measurements under laboratory conditions. The implementation of tests under real conditions determines the appearance of additional potential interference sources, from power sources to improper interactions between current collectors and the overhead contact system, and it requires strict compliance with regulatory standards and the implementation of standardized testing procedures. This article presents issues related to the investigation and analysis of the electromagnetic compatibility of rolling stock with train detection systems using track circuits. The aim of these tests is to determine the harmonic components in the traction current in relation to the permissible levels specified in the latest editions of the European Railway Agency—ERA/ERTMS/033281 version 5.0 documents and Annex S-02 to the List of the President of the Office of Rail Transport. The measurement methodology and test procedures are presented in detail with respect to current legal requirements. Full article

(This article belongs to the Special Issue Planning, Operation and Control of Microgrids: 2nd Edition)

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13 pages, 2943 KiB

Open AccessArticle

Magnetron-Sputtered and Rapid-Thermally Annealed NiO:Cu Thin Films on 3D Porous Substrates for Supercapacitor Electrodes

by Seongha Oh, Young-Kil Jun and Nam-Hoon Kim

Energies 2025, 18(11), 2704; https://doi.org/10.3390/en18112704 - 23 May 2025

Abstract

The performance of NiO-based supercapacitor electrodes for energy storage systems was enhanced by doping Cu into NiO thin films (200 nm) using radio-frequency magnetron co-sputtering on 3D porous Ni foam substrates, followed by rapid thermal annealing. The Hall effect measurements demonstrated enhanced electrical [...] Read more.

The performance of NiO-based supercapacitor electrodes for energy storage systems was enhanced by doping Cu into NiO thin films (200 nm) using radio-frequency magnetron co-sputtering on 3D porous Ni foam substrates, followed by rapid thermal annealing. The Hall effect measurements demonstrated enhanced electrical conductivity, with resistivity values of 1.244 × 10⁻⁴ Ω·cm. The 3D porous NiO:Cu electrodes significantly increased the specific capacitance and achieved a value of 1809.2 Fg⁻¹, with the NiO:Cu (10 at% Cu) thin films at a scan rate of 5 mVs⁻¹, which is a 2.67-fold increase compared with the undoped NiO films on a glass substrate. The 3D porous NiO:Cu electrodes significantly improved the electrochemical properties of the NiO-based electrode, which resulted in a higher specific capacitance for enhancing the energy storage performance during grid stabilization. Full article

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

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24 pages, 1277 KiB

Open AccessArticle

Empirical Evidence on Pro-Environmental Activities of Companies in Times of Energy Transformation: A Case Study of Poland

by Beata Bal-Domańska, Elżbieta Stańczyk and Mirosława Szewczyk

Energies 2025, 18(11), 2703; https://doi.org/10.3390/en18112703 - 23 May 2025

Abstract

This article addresses a topic of critical importance globally, particularly in the context of the ongoing energy crisis, climate change, and efforts to transition towards sustainable energy systems. A growing environmental awareness among consumers, along with changing regulations on energy efficiency, forces companies [...] Read more.

This article addresses a topic of critical importance globally, particularly in the context of the ongoing energy crisis, climate change, and efforts to transition towards sustainable energy systems. A growing environmental awareness among consumers, along with changing regulations on energy efficiency, forces companies to adapt their products and services to meet new market demands. Eco-innovations, such as energy-efficient technologies and environmentally friendly materials, can respond to the increasing demand for products with a lower carbon footprint and reduced energy consumption. Using structural equation modelling, our study aimed to evaluate the significance of selected determinants of enterprise activities aimed at innovations that yield environmental benefits. The analysis focused on the scale of the benefits obtained due to these innovations (e.g., reduced material or water use per unit of output, reduced energy use, reduced CO₂ footprint, reduction in pollution, or recycling of waste) and during the consumption or use of goods or services by the end user (e.g., energy savings, facilitated recycling, or extended product life). The empirical data source was a database of anonymised individual data from Statistics Poland. The database comprised 8544 industrial enterprises employing 10 or more people, of which 2714 introduced eco-innovations. To verify the hypothetical relationships between variables, we proposed a structural equation modelling method. The structural model estimates indicated that requirements arising from current and future regulations, pressure from high operational costs and administrative formalities, and reputation and incentives had a positive and statistically significant impact on the scale of benefits obtained due to these eco-innovations. The assessment of the importance of factors determining the introduction of eco-innovations differed slightly between companies of different sizes. For large enterprises, the key determinants were incentives, reputation, and law requirements. For medium-sized enterprises, incentives and reputation were the most influential. For small enterprises, reputation was the primary determinant, followed closely by pressure and incentives at a similar level. Full article

(This article belongs to the Special Issue Economic and Political Determinants of Energy—Contemporary Challenges)

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30 pages, 11506 KiB

Open AccessReview

Research Progress and Future Prospects of Brake-by-Wire Technology for New Energy Vehicles

by Zhengrong Chen, Ruochen Wang, Renkai Ding, Bin Liu, Wei Liu, Dong Sun and Zhongyang Guo

Energies 2025, 18(11), 2702; https://doi.org/10.3390/en18112702 - 23 May 2025

Abstract

The energy crisis and environmental pollution have driven the rapid development of new energy vehicles (NEVs). As a core technology for integrating electrification and intelligence in NEVs, the brake-by-wire (BBW) system has become a research hotspot due to its excellent braking energy recovery [...] Read more.

The energy crisis and environmental pollution have driven the rapid development of new energy vehicles (NEVs). As a core technology for integrating electrification and intelligence in NEVs, the brake-by-wire (BBW) system has become a research hotspot due to its excellent braking energy recovery efficiency and precise active safety control performance. This paper provides a comprehensive review of the research progress in BBW technology for NEVs and provides a forward-looking perspective on its future development. First, the types and structures of the BBW system are introduced, and the development history and representative products are systematically reviewed. Next, this paper focuses on key technologies, such as the design and modeling methods of the BBW system, braking force optimization and distribution strategies, precise actuator control, multi-system coordination, driver operation perception, intelligent decision-making, personalized control, and fault diagnosis and fault-tolerant control. Finally, the main challenges faced in the research of BBW technology for NEVs are analyzed, and future development directions are proposed, providing insights for the optimization designs and industrial application of the BBW system in the future. Full article

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

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21 pages, 4304 KiB

Open AccessArticle

The Optimal Dispatch for a Flexible Distribution Network Equipped with Mobile Energy Storage Systems and Soft Open Points

by Yu Ji, Ying Zhang, Lei Chen, Juan Zuo, Wenbo Wang and Chongxin Xu

Energies 2025, 18(11), 2701; https://doi.org/10.3390/en18112701 - 23 May 2025

Abstract

This paper proposes a flexible distribution network operation optimization strategy considering mobile energy storage system (MESS) integration. With the increasing penetration of renewable energy in power systems, its stochastic and intermittent characteristics pose significant challenges to grid stability. This study introduces an MESS, [...] Read more.

This paper proposes a flexible distribution network operation optimization strategy considering mobile energy storage system (MESS) integration. With the increasing penetration of renewable energy in power systems, its stochastic and intermittent characteristics pose significant challenges to grid stability. This study introduces an MESS, which has both spatial and temporal controllability, and soft open point (SOP) technology to build a co-scheduling framework. The aim is to achieve rational power distribution across spatial and temporal scales. In this paper, a case study uses a regional road network in Chengdu coupled with an IEEE 33-node standard grid, and the model is solved using the non-dominated sorting genetic algorithm III (NSGA-III) algorithm. The simulation results show that the use of the MESS and SOP co-dispatch in the grid not only reduces the net loss and total voltage deviation but also obtains considerable economic benefits. In particular, the net load peak-to-valley difference is reduced by 20.1% and the total voltage deviation is reduced by 52.9%. This demonstrates the effectiveness of the proposed model in improving the stability and economy of the grid. Full article

(This article belongs to the Topic Advances in Power Science and Technology, 2nd Edition)

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11 pages, 2124 KiB

Open AccessArticle

Experimental Study on the Impact of Flow Rate Strategies on the Mass Transfer Impedance of PEM Electrolyzers

by Haoyu Zhang, Jiangong Zhu, Chao Wang, Hao Yuan, Haifeng Dai and Xuezhe Wei

Energies 2025, 18(11), 2700; https://doi.org/10.3390/en18112700 - 23 May 2025

Abstract

The flow rate strategies of deionized water have a significant impact on the mass transfer process of proton exchange membrane (PEM) electrolyzers, which are critical for the efficient and safe operation of hydrogen production systems. Electrochemical impedance spectroscopy is an effective tool for [...] Read more.

The flow rate strategies of deionized water have a significant impact on the mass transfer process of proton exchange membrane (PEM) electrolyzers, which are critical for the efficient and safe operation of hydrogen production systems. Electrochemical impedance spectroscopy is an effective tool for distinguishing different kinetic processes within the electrolyzer. In this study, three different Ti-felt porous transport layers (PTLs) are tested with two flow rate modes, constant flow (50 mL/min) and periodic cycling flow (10 mL/min–50 mL/min–10 mL/min), to investigate the influence of flow rate strategies on the mass transfer impedance of the electrolyzer. The following observations were made: (1) For PTL with better performance, the flow rate of the periodic cycling flow has little effect on its mass transfer impedance, and the mass transfer impedance of the periodic circulation flow mode is not much different from that of the constant flow. (2) For PTL with poorer performance, in the periodic cycling mode, the mass transfer impedance at 10 mL/min is smaller than that at 50 mL/min, but both are higher than the impedance under constant flow. The conclusions of this study provide a theoretical basis for the flow management of PEM electrolytic hydrogen production systems. Full article

(This article belongs to the Section J1: Heat and Mass Transfer)

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21 pages, 5910 KiB

Open AccessArticle

Applying Structure Exchange to Battery Charging to Enhance Light-Load Efficiency

by Kuo-Ing Hwu, Pei-Ching Tseng and Jenn-Jong Shieh

Energies 2025, 18(11), 2699; https://doi.org/10.3390/en18112699 - 23 May 2025

Abstract

A full-bridge DC–DC converter with structure exchange is proposed to simulate battery charging based on an electronic load. The full-bridge phase-shift converter (FBPSC) uses an external resonant inductor and phase-shift control on the primary side to realize zero voltage switching (ZVS) above medium [...] Read more.

A full-bridge DC–DC converter with structure exchange is proposed to simulate battery charging based on an electronic load. The full-bridge phase-shift converter (FBPSC) uses an external resonant inductor and phase-shift control on the primary side to realize zero voltage switching (ZVS) above medium load. However, the energy of the resonant inductor is not enough to carry away the energy of the parasitic capacitance on the switch at light load, leading to the inability of ZVS as well as the circulating current problem due to the long duration of the primary-side circulating current. Consequently, in order to conquer such problems mentioned above, the structure exchange, with only the control strategy changed from the phase-shift control to the two-transistor forward control, is presented to increase the light-load efficiency remarkably. Furthermore, the number of inductors is reduced by using the center-tap structure on the secondary side compared to the current-doubler structure. In addition, the synchronous rectifier on the secondary side is used to further improve the overall efficiency of the converter. Full article

(This article belongs to the Special Issue Energy, Electrical and Power Engineering: 4th Edition)

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15 pages, 5448 KiB

Open AccessArticle

Modeling and Testing of 3D Wound Core Loss of Amorphous Alloy Transformer for Photovoltaic Inverter

by Peng Chen, Jianwei Han, Xinglong Yao, Xiaohui Wang, Yunfei Yan, Zhe Zhao, Lisong Zhang, Zhanyang Yu and Hao Li

Energies 2025, 18(11), 2698; https://doi.org/10.3390/en18112698 - 23 May 2025

Abstract

The harmonic content of transformers used in the field of new energy is significantly higher than that of conventional transformers, leading to an abnormal increase in transformer loss during operation. Therefore, the loss characteristics of amorphous alloy transformers are investigated in this paper. [...] Read more.

The harmonic content of transformers used in the field of new energy is significantly higher than that of conventional transformers, leading to an abnormal increase in transformer loss during operation. Therefore, the loss characteristics of amorphous alloy transformers are investigated in this paper. First, a measurement platform for the magnetic property of transformer cores under sinusoidal excitation is developed. The magnetization characteristics, loss characteristics and loss composition of the amorphous alloy core under sinusoidal excitation are measured and analyzed. On this basis, the traditional Steinmetz loss calculation formula is modified, and the loss calculation formula is further refined by improving its coefficients to accommodate various frequencies. Secondly, using a field-circuit coupling method, a 3D model of the transformer core is established by finite element simulation. The magnetic flux distribution and core losses are computed under both sinusoidal excitation and non-sinusoidal excitation. Finally, the impact of core rotation magnetization on the magnetic flux density is considered, and experimental errors are minimized by applying an empirical formula. The numerical model validity and accuracy are verified by comparing the simulation results with experimental data. Full article

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

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29 pages, 898 KiB

Open AccessArticle

Two-Stage Optimization Strategy for Market-Oriented Lease of Shared Energy Storage in Wind Farm Clusters

by Junlei Liu, Jiekang Wu and Zhen Lei

Energies 2025, 18(11), 2697; https://doi.org/10.3390/en18112697 - 22 May 2025

Abstract

Diversified application scenarios and business models are effective ways to improve the utilization and economic benefits of energy storage systems. In response to the current problems of single application scenarios, high idle rates, and imperfect price formation mechanisms faced by energy storage on [...] Read more.

Diversified application scenarios and business models are effective ways to improve the utilization and economic benefits of energy storage systems. In response to the current problems of single application scenarios, high idle rates, and imperfect price formation mechanisms faced by energy storage on the power generation side, a robust two-stage optimization operation strategy for shared energy storage is proposed, taking into account leasing demand and multiple uncertainties, from the perspective of the sharing concept. A multi-scenario application framework for shared energy storage is established to provide leasing services for wind farm clusters, as well as auxiliary services for participating in the electric energy markets and frequency regulation markets, and the participation sequence is streamlined. Based on the operating and opportunity costs of shared energy storage, a pricing mechanism for leasing services is designed to explore the driving forces of wind farm clusters participating in leasing services from the perspective of cost assessment. Considering the uncertainty of wind power output and market electric prices, as well as the market operational characteristics, an optimized operation model for shared energy storage in the day-ahead and real-time stages is constructed. In the day-ahead stage, a Stackelberg game model is introduced to depict the energy sharing between wind farm clusters and shared energy storage, forming leasing prices, leasing capacities, and energy storage pre-scheduling plans at different time periods. In the real-time stage, the real-time prediction results of wind power output and electric prices are integrated with scheduling decisions, and an improved robust optimization model is used to dynamically regulate the pre-scheduling plan for leasing capacity and shared energy storage. Based on actual data from the electricity market in Guangdong Province, effectiveness verification is conducted, and the results showed that diversified application scenarios improve the utilization rate of shared energy storage in the power generation side by 52.87%, increasing economic benefits by CNY 188,700. The proposed optimized operation strategy has high engineering application value. Full article

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

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Energies, Volume 18, Issue 11 (June-1 2025) – 57 articles

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