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 (Engineering (miscellaneous))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 16.1 days after submission; acceptance to publication is undertaken in 3.3 days (median values for papers published in this journal in the second half of 2023).
- 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: Fuels, Gases, Nanoenergy Advances and Solar.
Impact Factor:
3.2 (2022);
5-Year Impact Factor:
3.3 (2022)
Latest Articles
Policy Assessment for Energy Transition to Zero- and Low-Emission Technologies in Pickup Trucks: Evidence from Mexico
Energies 2024, 17(10), 2386; https://doi.org/10.3390/en17102386 - 15 May 2024
Abstract
The transport sector is under scrutiny because of its significant greenhouse gas emissions. Essential strategies, particularly the adoption of zero- and low-emission vehicles powered by electricity, are crucial for mitigating emissions in road transport. Pickups, which are integral to Mexico’s fleet, contribute to
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The transport sector is under scrutiny because of its significant greenhouse gas emissions. Essential strategies, particularly the adoption of zero- and low-emission vehicles powered by electricity, are crucial for mitigating emissions in road transport. Pickups, which are integral to Mexico’s fleet, contribute to such emissions. Thus, implementing effective policies targeting pickups is vital for reducing air pollution and aligning with Mexico’s decarbonization objectives. This paper presents a simulation model based on system dynamics to represent the adoption process of zero- and low-emission vehicles, with a focus on pickups and utilizing data from the Mexican case. Three policy evaluation scenarios are proposed based on the simulation model: business as usual; disincentives for zero- and low-emission vehicles; and incentives for unconventional vehicles. One of the most significant findings from this study is that even in a scenario with a greater number of vehicles in circulation, if the technology is fully electric, the environmental impact in terms of emissions is lower. Additionally, a comprehensive sensitivity analysis spanning a wide spectrum is undertaken through an extensive computational process, yielding multiple policy scenarios. The analysis indicates that to achieve a maximal reduction in the country’s emissions, promoting solely hybrid electric vehicles and plug-in hybrid electric vehicles is advisable, whereas internal combustion engines, vehicular natural gas, and battery electric vehicles should be discouraged.
Full article
(This article belongs to the Special Issue Energy Management Systems of Electric Vehicles: New Trends and Dynamic Futures)
Open AccessArticle
Theoretical and Experimental Research on Thermal Dynamic Characteristics of Single-Screw Compressor with a New Composite SLIDE valve
by
Shanwei Liu, Ruiping Zhi, Yuting Wu, Yuanwei Lu, Biao Lei and Chongfang Ma
Energies 2024, 17(10), 2385; https://doi.org/10.3390/en17102385 - 15 May 2024
Abstract
Based on the single-screw compressor (SSC) structure, a new type of composite slide valve (CSV) has been proposed and designed, featuring internal volume ratios of 2.8, 3.9, and 5.6 and operating under a partial load of 35%. The theoretical model describing the dynamic
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Based on the single-screw compressor (SSC) structure, a new type of composite slide valve (CSV) has been proposed and designed, featuring internal volume ratios of 2.8, 3.9, and 5.6 and operating under a partial load of 35%. The theoretical model describing the dynamic features and thermodynamic performance of the SSC with CSV has also been built. The pressure ratio of the experimental system can be adjusted from 3.3 to 7.8, and the experimental results demonstrate the CSV’s effective performance. The deviations between the calculated and measured results for volume ratio and input power are 3.33–9.08% and 0.32–8.03%, and the deviations for heating capacity and adiabatic efficiency range from 0.92–8.73% to 2.09–9.67%, respectively. The introduction of the CSV offers a novel approach to enhancing SSC efficiency. Both the theoretical and experimental findings lay a foundation for future optimization and design improvements in variable load and internal volumetric ratio single-screw compressors.
Full article
(This article belongs to the Section J: Thermal Management)
Open AccessArticle
Optimization of Renewable Energy Hydrogen Production Systems Using Volatility Improved Multi-Objective Particle Swarm Algorithm
by
Hui Wang, Xiaowen Chen, Qianpeng Yang, Bowen Li, Zongyu Yue, Jeffrey Dankwa Ampah, Haifeng Liu and Mingfa Yao
Energies 2024, 17(10), 2384; https://doi.org/10.3390/en17102384 - 15 May 2024
Abstract
Optimizing the energy structure to effectively enhance the integration level of renewable energy is an important pathway for achieving dual carbon goals. This study utilizes an improved multi-objective particle swarm optimization algorithm based on load fluctuation rates to optimize the architecture and unit
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Optimizing the energy structure to effectively enhance the integration level of renewable energy is an important pathway for achieving dual carbon goals. This study utilizes an improved multi-objective particle swarm optimization algorithm based on load fluctuation rates to optimize the architecture and unit capacity of hydrogen production systems. It investigates the optimal configuration methods for the architectural model of new energy hydrogen production systems in Xining City, Qinghai Province, as well as the internal storage battery, ALK hydrogen production equipment, and PEM hydrogen production equipment, aiming at various scenarios of power sources such as wind, solar, wind–solar complementary, and wind–solar–storage complementary, as well as intermittent hydrogen production scenarios such as hydrogen stations, hydrogen metallurgy, and continuous hydrogen production scenarios such as hydrogen methanol production. The results indicate that the fluctuation of hydrogen load scenarios has a significant impact on the installed capacity and initial investment of the system. Compared with the single-channel photovoltaic hydrogen production scheme, the dual-channel hydrogen production scheme still reduces equipment capacity by 6.04% and initial investment by 6.16% in the chemical hydrogen scenario with the least load fluctuation.
Full article
(This article belongs to the Section B: Energy and Environment)
Open AccessArticle
Heat Transfer and Fluid Flow Characteristics in a Micro Heat Exchanger Employing Warm Nanofluids for Cooling of Electronic Components
by
Mahdi Mokrane and Mahmoud Bourouis
Energies 2024, 17(10), 2383; https://doi.org/10.3390/en17102383 - 15 May 2024
Abstract
The heat transfer enhancement and hydrodynamic characteristics of nanofluid use in a micro heat exchanger is investigated for cooling electronic components working in hot climatic conditions. The cooling fluid employed was water and TiO2 nanoparticles at mass concentrations of 1% and 5%,
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The heat transfer enhancement and hydrodynamic characteristics of nanofluid use in a micro heat exchanger is investigated for cooling electronic components working in hot climatic conditions. The cooling fluid employed was water and TiO2 nanoparticles at mass concentrations of 1% and 5%, the Reynolds numbers ranged from 400 to 2000, and the inlet temperatures ranged between 35 °C and 65 °C. At a nanofluid inlet temperature of 55 °C and a nanoparticle concentration of 1%, the Nusselt number increased by 23% up to 54% as the Reynolds number varied between 400 and 2000. At a nanoparticle concentration of 5%, the percentages that correspondingly enhanced the Nusselt number were 32% and 63%. The temperature of the electronic heating component decreased by 4.6–5.2 °C when the nanofluid concentration was increased from 0 to 5% at a Reynolds number of 400 and a nanofluid inlet temperature of 35 °C. Small increments in the pressure drop of about 6% and 13% were observed at nanofluid concentrations of 1% and 5%, respectively. With nanoparticle concentrations of 1% and 5%, a Reynolds number of 2000, and a nanofluid inlet temperature of 35 °C, performance evaluation criterion (PEC) values of 1.36 and 1.45 were obtained. When the nanofluid inlet temperature increased to 65 °C, the PEC parameter decreased to 1.02–1.10 for both concentrations.
Full article
(This article belongs to the Section J1: Heat and Mass Transfer)
Open AccessArticle
Simulation and Experimental Study of Circulatory Flash Evaporation System for High-Salt Wastewater Treatment
by
Hao Feng, Wei Chen, Rui Sun, Zhen Zhang, Wei Li and Bin Zhang
Energies 2024, 17(10), 2382; https://doi.org/10.3390/en17102382 - 15 May 2024
Abstract
Treatment methods for high-salt wastewater mainly consist of physical methods, chemical methods and biological methods. However, there are some problems, such as slow treatment speed, high investment costs and low treatment efficiency. To address NaCl solutions, in this study, a circulatory flash system
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Treatment methods for high-salt wastewater mainly consist of physical methods, chemical methods and biological methods. However, there are some problems, such as slow treatment speed, high investment costs and low treatment efficiency. To address NaCl solutions, in this study, a circulatory flash system was designed based on gas–liquid equilibrium, mass conservation equation and energy conservation equation. A circulatory flash evaporation simulation and a static flash evaporation experiment were conducted on NaCl solutions under various operating conditions to investigate the effects of heating temperature, flash pressure and initial NaCl concentration on the circulatory flash evaporation system. The significance of each factor’s influence on the evaporation fraction and energy consumption was examined through static flash experiments. The simulation results demonstrated that increasing the heating temperature, decreasing the flash pressure and having a higher initial NaCl concentration could enhance the treatment capacity of high-salt wastewater. The flow rate of vapor outlets increased with higher heating temperature but decreased as the flash pressure rose. The experimental results demonstrated that flash evaporation pressure was the primary factor influencing both the evaporation fraction and the energy consumption per unit mass of vapor produced. It was observed that with an increase in heating temperature, the flash pressure decreased and there was a corresponding decrease in energy consumption per unit mass of vapor produced. The optimal experimental conditions were achieved at a heating temperature of 99 °C, a flash pressure of 15 kPa, and an initial NaCl concentration of 20%.
Full article
(This article belongs to the Topic Advanced Heat and Mass Transfer Technologies)
Open AccessArticle
Aspen Simulation Study of Dual-Fluidized Bed Biomass Gasification
by
Jida Zhang and Liguo Yang
Energies 2024, 17(10), 2381; https://doi.org/10.3390/en17102381 - 15 May 2024
Abstract
This article establishes a thermodynamic model of a dual-fluidized bed biomass gasification process based on the Aspen Plus software platform and studies the operational control characteristics of the dual-fluidized bed. Firstly, the reliability of the model is verified by comparing it with the
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This article establishes a thermodynamic model of a dual-fluidized bed biomass gasification process based on the Aspen Plus software platform and studies the operational control characteristics of the dual-fluidized bed. Firstly, the reliability of the model is verified by comparing it with the existing experimental data, and then the influence of different process parameters on the operation and gasification characteristics of the dual-fluidized bed system is investigated. The main parameters studied in the operational process include the fuel feed rate, steam/biomass ratio (S/B), air equivalent ratio (ER), and circulating bed material amount, etc. Their influence on the gasification product composition, reactor temperature, gas heat value (QV), gas production rate (GV), carbon conversion rate (ηc), and gasification efficiency (η) is investigated. The study finds that fuel feed rate and circulating bed material amount are positively correlated with QV, ηc, and η; ER is positively correlated with GV and ηc but negatively correlated with QV and η; S/B is positively correlated with GV, ηc, and η but negatively correlated with QV. The addition of CaO is beneficial for increasing QV. In actual operation, a lower reaction temperature in the gasification bed can be achieved by reducing the circulating bed material amount, and a larger temperature difference between the combustion furnace and the gasification furnace helps to further improve the quality of the gas. At the same time, GV, ηc, and η need to be considered to find the most optimized operating conditions for maximizing the benefits. The model simulation results agree well with the experimental data, providing a reference for the operation and design of dual-fluidized beds and chemical looping technology based on dual-fluidized beds.
Full article
(This article belongs to the Section I3: Energy Chemistry)
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Open AccessCorrection
Correction: Das et al. Comparative Life-Cycle Assessment of Electricity-Generation Technologies: West Texas Case Study. Energies 2024, 17, 992
by
Jani Das, Atta Ur Rehman, Rahul Verma, Gurcan Gulen and Michael H. Young
Energies 2024, 17(10), 2380; https://doi.org/10.3390/en17102380 - 15 May 2024
Abstract
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We discovered a minor mistake in our modeling of the lithium component of the Battery Energy Storage Systems (BESS) that was used in this manuscript [...]
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Open AccessArticle
Sizing Energy Storage Systems to Dispatch Wind Power Plants
by
Bingqing Xia, Mingqi Wu, Wenbin Yang, Qing Chen and Ji Xiang
Energies 2024, 17(10), 2379; https://doi.org/10.3390/en17102379 - 15 May 2024
Abstract
Integrating wind power plants into the electricity grid poses challenges due to the intermittent nature of wind energy generation. Energy storage systems (ESSs) have shown promise in mitigating the intermittent variability associated with wind power. This paper presents a distributionally robust optimization (DRO)
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Integrating wind power plants into the electricity grid poses challenges due to the intermittent nature of wind energy generation. Energy storage systems (ESSs) have shown promise in mitigating the intermittent variability associated with wind power. This paper presents a distributionally robust optimization (DRO) model for sizing energy storage systems to dispatch wind power plants. The variable wind power is formulated as a moment-based ambiguity set. Dispatchability is described by the expected value of the insufficient power of wind power relative to the dispatch command, which is a sum of nonlinear functions and is taken as the optimal index. A deterministic semi-definite positive model is derived to solve the problem effectively. Numerical studies are conducted to demonstrate the effectiveness and advantages of the proposed method.
Full article
(This article belongs to the Section A3: Wind, Wave and Tidal Energy)
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Open AccessArticle
Jerusalem Artichoke as a Raw Material for Manufacturing Alternative Fuels for Gasoline Internal Combustion Engines
by
Michał Bembenek, Vasyl Melnyk, Bolesław Karwat, Mariia Hnyp, Łukasz Kowalski and Yurii Mosora
Energies 2024, 17(10), 2378; https://doi.org/10.3390/en17102378 - 15 May 2024
Abstract
The Jerusalem artichoke (Helianthus tuberosus) is a high-yield crop, and a great source of fermentable sugars, which gives the plant the potential to be used as raw material for economical fuel alcohol production. In this article, the authors focus on the
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The Jerusalem artichoke (Helianthus tuberosus) is a high-yield crop, and a great source of fermentable sugars, which gives the plant the potential to be used as raw material for economical fuel alcohol production. In this article, the authors focus on the technological aspect of the biofuel manufacturing process and its properties. First, the fuel alcohol manufacturing process is described, afterwards assessing its characteristics such as kinematic viscosity, density and octane number. The amount of fuel alcohol obtained from 10 kg of biomass equals to 0.85 L. Afterwards, the mixtures of gasoline and obtained fuel alcohol are prepared and studied. Optimal alcohol and gasoline mixtures are determined to obtain biofuels with octane ratings of 92, 95 and 98. The kinematic viscosity of obtained mixtures does not differ significantly from its values for pure gasoline. The obtained biofuel mixture with 25% alcohol content yielded a decrease of sulfur content by 38%, an increase of vaporized fuel amount by 17.5% at 70 °C and by 10.5% at a temperature of 100 °C, which improves engine startup time and ensures its stable operation in comparison to pure gasoline. The alcohol obtained can be successfully used as a high-octane additive for gasolines.
Full article
(This article belongs to the Special Issue Sustainable Development of Biomass Conversion, Biofuel Production and Biorefinery Processes)
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Open AccessArticle
Thermodynamic Analysis and Optimization of Binary CO2-Organic Rankine Power Cycles for Small Modular Reactors
by
Vladimir Kindra, Igor Maksimov, Daniil Patorkin, Andrey Rogalev and Nikolay Rogalev
Energies 2024, 17(10), 2377; https://doi.org/10.3390/en17102377 - 15 May 2024
Abstract
Small nuclear power plants are a promising direction of research for the development of carbon-free energy in isolated power systems and in remote regions with undeveloped infrastructure. Improving the efficiency of power units integrated with small modular reactors will improve the prospects for
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Small nuclear power plants are a promising direction of research for the development of carbon-free energy in isolated power systems and in remote regions with undeveloped infrastructure. Improving the efficiency of power units integrated with small modular reactors will improve the prospects for the commercialization of such projects. Power cycles based on supercritical carbon dioxide are an effective solution for nuclear power plants that use reactor facilities with an initial coolant temperature above 550 °C. However, the presence of low temperature rejected heat sources in closed Bryton cycles indicates a potential for energy saving. This paper presents a comprehensive thermodynamic analysis of the integration of an additional low-temperature organic Rankine cycle for heat recovery to supercritical carbon dioxide cycles. A scheme for sequential heat recovery from several sources in S-CO2 cycles is proposed. It was found that the use of R134a improved the power of the low-temperature circuit. It was revealed that in the S-CO2 Brayton cycle with a recuperator, the ORC add-on increased the net efficiency by an average of 2.98%, and in the recompression cycle by 1.7–2.2%. With sequential heat recovery in the recuperative cycle from the intercooling of the compressor and the main cooler, the increase in efficiency from the ORC superstructure will be 1.8%.
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(This article belongs to the Section B4: Nuclear Energy)
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Open AccessArticle
Operative Benefits of Residential Battery Storage for Decarbonizing Energy Systems: A German Case Study
by
Natapon Wanapinit, Nils Offermann, Connor Thelen, Christoph Kost and Christian Rehtanz
Energies 2024, 17(10), 2376; https://doi.org/10.3390/en17102376 - 15 May 2024
Abstract
The reduction in PV prices and interest in energy independence accelerate the adoption of residential battery storage. This storage can support various functions of an energy system undergoing decarbonization. In this work, operative benefits of storage from the system perspective, namely, generation cost
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The reduction in PV prices and interest in energy independence accelerate the adoption of residential battery storage. This storage can support various functions of an energy system undergoing decarbonization. In this work, operative benefits of storage from the system perspective, namely, generation cost reduction and congestion mitigation, are investigated. Germany is chosen as a case study due to its strong reliance on variable renewable energy. For the analysis, an economic dispatch model with a high spatial resolution is coupled with a pan-European transmission grid model. It is shown that the system’s generation costs are highest when the assets are used only to maximize PV self-consumption, and the costs are lowest when the storage also reacts to the market dynamics. This amounts to a 6% cost reduction. Both operation strategies result in an equal level of grid congestion and infrastructure loading. This is improved with a strategy that accounts for regional peak reduction as a secondary objective. The high congestion level emphasizes that grid expansion needs to keep pace with the generation and electrification expansion necessary to decarbonize other sectors. Lastly, policymakers should enable multipurpose utilization, e.g., via the introduction of market-oriented retail electricity prices with intervention options for grid operators.
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(This article belongs to the Section D: Energy Storage and Application)
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Open AccessArticle
Consumption-Based Energy Footprints in Iceland: High and Equally Distributed
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Anna Kristín Einarsdóttir, Gereon tho Pesch, Kevin Joseph Dillman, Marta Rós Karlsdóttir and Jukka Heinonen
Energies 2024, 17(10), 2375; https://doi.org/10.3390/en17102375 - 15 May 2024
Abstract
With the urgent global need to limit warming to 2 °C as well as a localized need in our case study to address rising energy demand amid electrical and thermal network limitations, a critical examination of demand-side energy reductions and the concept of
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With the urgent global need to limit warming to 2 °C as well as a localized need in our case study to address rising energy demand amid electrical and thermal network limitations, a critical examination of demand-side energy reductions and the concept of energy sufficiency is needed. This paper contributes to the sparse literature on bottom-up analysis by utilizing Iceland—a leader in renewable energy generation—as a case study to explore the socio-economic factors influencing energy footprints. Our findings reveal significant energy footprints across various consumption domains, particularly housing and mobility, influenced by income levels, urbanization, and lifestyle choices. The study highlights the paradox of a high renewable energy supply leading to potential misconceptions regarding abundant and low-cost energy, resulting in substantial energy consumption-related environmental impacts. Using detailed household consumption survey data, this research provides insights crucial for developing sustainable energy policies that not only target technological advancements but also address the need for a reduction in energy demand and a shift towards energy sufficiency. This work marks a contribution to the literature through the provision of a case study of low income inequality and high energy footprints in a highly renewable energy system context. Further, this work is useful for Icelandic and international policymakers to understand in such high-demand contexts which consumption domains would be most relevant for sufficiency policies. This comprehensive analysis opens pathways for future research to further explore the intersections of energy consumption, socio-economic factors, and well-being, offering a nuanced understanding necessary for crafting sufficiency and demand-side policies aimed at a sustainable energy future.
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(This article belongs to the Collection Feature Papers in Energy, Environment and Well-Being)
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Open AccessArticle
Renewable Energy Investments in Poland: Goals, Socio-Economic Benefits, and Development Directions
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Anna Dębicka, Karolina Olejniczak, Bartosz Radomski, Dariusz Kurz and Dawid Poddubiecki
Energies 2024, 17(10), 2374; https://doi.org/10.3390/en17102374 - 15 May 2024
Abstract
Renewable energy sources (RES) will play a key role in the transition to clean energy. Financial and socio-economic benefits determine the investment management in these energy sources. This article aims to indicate current energy policy goals, present socio-economic benefits resulting from renewable energy
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Renewable energy sources (RES) will play a key role in the transition to clean energy. Financial and socio-economic benefits determine the investment management in these energy sources. This article aims to indicate current energy policy goals, present socio-economic benefits resulting from renewable energy investments, and review further development directions in Poland. The research was carried out using desk research, case studies, and literature review methods to provide a broader economic context for RES investments. The scope of the research included both the Polish and the European Union contexts. The authors examined the Polish objectives of investment in renewable energy contained in strategic, planning, and other legal documents compared to EU targets, reviewed possible investments in renewable energy, and indicated wind farms and photovoltaic investments as the most effective ones from the point of view of further development which aims to meet the EU’s goals by 2030. The authors also demonstrated a wide range of socio-economic benefits based on literature reviews, analysis of policy documents, and regulations regarding the energy sector, and examined a specific example of investment implementation and identified the ecosystem of beneficiaries and their benefits.
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(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
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Experimental Investigation of Parameters Influencing the Formation of Dry Bands and Related Electric Field
by
Marc-Alain Andoh and Christophe Volat
Energies 2024, 17(10), 2373; https://doi.org/10.3390/en17102373 - 15 May 2024
Abstract
This paper presents an experimental investigation conducted to determine the influence of parameters such as the ambient temperature, pollution level, and substrate material on the formation of dry bands on polluted layers. To investigate these parameters, we applied a simplified insulator geometry, developed
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This paper presents an experimental investigation conducted to determine the influence of parameters such as the ambient temperature, pollution level, and substrate material on the formation of dry bands on polluted layers. To investigate these parameters, we applied a simplified insulator geometry, developed in our previous work, to experimentally control the complex process of dry band formation on a polluted surface. The simple geometry of the experimental model enabled the use of Plexiglas, RTV, and glass as construction substrate materials. RTV and glass were used to simulate a composite and ceramic insulator surface, respectively. Moreover, an electrooptic (EO) probe enabled the measurement of the axial E-field evolution at the surface of the dry band during dry band formation. The results indicated that the substrate material, ambient temperature, and pollution level substantially influence dry band formation. The effects of the first two parameters are directly associated with heat transfer phenomena in the substrate material and at the ambient air/substrate interface. The effect of the third parameter is associated with absorption and evaporation of the pollution layer. In addition, the appearance of the dry band can be clearly identified by a rapid increase in both the pollution layer resistance and the axial E-field in the dry band area. The value of the axial E-field is influenced primarily by the width of the dry band and by the pollution layer resistance, which is directly dependent on the humidification duration. Finally, because most of the results obtained herein were in accordance with those in the literature, we conclude that the proposed experimental model may provide an effective and inexpensive testing method for developing new materials and solutions for improving the dielectric performance of insulators used in polluted environments. Similarly, the simple geometry of the experimental model and the ability to easily control the experimental parameters may enable this tool to validate the results of various numerical models in studies of the thermoelectrical behavior of polluted insulators.
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(This article belongs to the Topic High Voltage Engineering)
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Subsidy Policies and Economic Analysis of Photovoltaic Energy Storage Integration in China
by
Wenhui Zhao, Rong Li and Shuan Zhu
Energies 2024, 17(10), 2372; https://doi.org/10.3390/en17102372 - 14 May 2024
Abstract
In the context of China’s new power system, various regions have implemented policies mandating the integration of new energy sources with energy storage, while also introducing subsidies to alleviate project cost pressures. Currently, there is a lack of subsidy analysis for photovoltaic energy
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In the context of China’s new power system, various regions have implemented policies mandating the integration of new energy sources with energy storage, while also introducing subsidies to alleviate project cost pressures. Currently, there is a lack of subsidy analysis for photovoltaic energy storage integration projects. In order to systematically assess the economic viability of photovoltaic energy storage integration projects after considering energy storage subsidies, this paper reviews relevant policies in the Chinese photovoltaic energy storage market. It analyzes the cost and revenue composition of photovoltaic energy storage integration projects, and constructs a system dynamics model for the levelized cost of electricity (LCOE) of such projects. Taking a specific photovoltaic energy storage project as an example, this paper measures the levelized cost of electricity and the investment return rate under different energy storage scenarios. Combining energy storage allocation ratios and internal rate of return indicators, this paper analyzes the net present value of photovoltaic energy storage integration projects under different subsidy standards. The results indicate that, while the current energy storage subsidy policies positively stimulate photovoltaic energy storage integration projects, they exhibit a limited capacity to cover energy storage investment costs, thereby failing to incentivize capital market participation in the construction of such projects. Rational allocation of energy storage capacity and optimization of corresponding subsidy policies are crucial prerequisites for enhancing the economic viability and widespread adoption of photovoltaic energy storage integration projects. This study not only aids in investment decision making for photovoltaic power stations but also contributes to the formulation of energy storage subsidy policies.
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(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
Open AccessArticle
Environmental Impact Evaluation of CO2 Absorption and Desorption Enhancement by Membrane Gas Absorption: A Life Cycle Assessment Study
by
Fuzhao Li, Yuexia Lv, Jinpeng Bi, Hui Zhang, Wei Zhao, Yancai Su, Tingting Du and Junkun Mu
Energies 2024, 17(10), 2371; https://doi.org/10.3390/en17102371 - 14 May 2024
Abstract
Membrane gas absorption technology has been considered a promising approach to mitigate CO2 emissions from power plants. The aim of this study is to evaluate the environmental impacts of CO2 absorption and desorption processes by hollow fiber membrane contactors using a
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Membrane gas absorption technology has been considered a promising approach to mitigate CO2 emissions from power plants. The aim of this study is to evaluate the environmental impacts of CO2 absorption and desorption processes by hollow fiber membrane contactors using a life cycle assessment methodology. On the basis of the ReCipe 2016 Midpoint and the ReCipe 2016 Endpoint methods, the research results show that membrane gas absorption systems exhibit the lowest environmental impacts across the majority of assessed categories in comparison with chemical absorption and membrane gas separation systems. The CO2 capture process via membrane gas absorption has the most significant impact on the METP category, with heat consumption as the primary contributing factor accounting for 55%, followed by electricity consumption accounting for 43.1%. According to the sensitivity analysis, heating by natural gas shows better performance than other heat supply sources in improving overall environmental impacts. In addition, the increasing utilization of renewable energy in electricity supply reduces the global warming potential, fossil resource consumption and ozone formation.
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(This article belongs to the Special Issue Sustainable Technologies for Decarbonising the Energy Sector)
Open AccessArticle
Start of Injection Influence on In-Cylinder Fuel Distribution, Engine Performance and Emission Characteristic in a RCCI Marine Engine
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Alireza Kakoee, Maciej Mikulski, Aneesh Vasudev, Martin Axelsson, Jari Hyvönen, Mohammad Mahdi Salahi and Amin Mahmoudzadeh Andwari
Energies 2024, 17(10), 2370; https://doi.org/10.3390/en17102370 - 14 May 2024
Abstract
Reactivity-controlled compression ignition (RCCI) is a promising new combustion technology for marine applications. It has offered the potential to achieve low NOx emissions and high thermal efficiency, which are both important considerations for marine engines. However, the performance of RCCI engines is
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Reactivity-controlled compression ignition (RCCI) is a promising new combustion technology for marine applications. It has offered the potential to achieve low NOx emissions and high thermal efficiency, which are both important considerations for marine engines. However, the performance of RCCI engines is sensitive to a number of factors, including the start of injection. This study used computational fluid dynamics (CFD) to investigate the effects of start of ignition (SOI) on the performance of a marine RCCI engine. The CFD model was validated against experimental data, and the results showed that the SOI has a significant impact on the combustion process. In particular, the SOI affected the distribution of fuel and air in the combustion chamber, which in turn affected the rate of heat release and the formation of pollutants. Ten different SOIs were implemented on a validated closed-loop CFD model from 96 to 42 CAD bTDC (crank angle degree before top dead center) at six-degree intervals. A chemical kinetic mechanism of 54 species and 269 reactions tuned and used for simulation of in-cylinder combustion. The results show that in early injection, high-reactivity fuel was distributed close to the liner. This distribution was around the center of late injection angles. A homogeneity study was carried out to investigate the local equivalence ratio. It showed a more homogenous mixture in early injection until 66 CAD bTDC, after which point, earlier injection timing had no effect on homogeneity. Maximum indicated mean effective pressure (IMEP) was achieved at SOI 48 CAD bTDC, and minimum amounts of THC (total hydrocarbons) and NOx were observed with middle injection timing angles around 66 CAD bTDC.
Full article
(This article belongs to the Special Issue Renewable Fuels for Internal Combustion Engines: 2nd Edition)
Open AccessArticle
Energy Management of Hydrogen Hybrid Electric Vehicles—Online-Capable Control
by
David Machacek, Nazim Yasar, Fabio Widmer, Thomas Huber and Christopher Onder
Energies 2024, 17(10), 2369; https://doi.org/10.3390/en17102369 - 14 May 2024
Abstract
The results shown in this paper extend our research group’s previous work, which presents the theoretically achievable hydrogen engine-out NO (H -NO ) Pareto front of a hydrogen hybrid electric vehicle (H -HEV).
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The results shown in this paper extend our research group’s previous work, which presents the theoretically achievable hydrogen engine-out NO (H -NO ) Pareto front of a hydrogen hybrid electric vehicle (H -HEV). While the Pareto front is calculated offline, which requires significant computing power and time, this work presents an online-capable algorithm to tackle the energy management of a H -HEV with explicit consideration of the H -NO trade-off. Through the inclusion of realistic predictive data on the upcoming driving mission, a model predictive control algorithm (MPC) is utilized to effectively tackle the conflicting goal of achieving low hydrogen consumption while simultaneously minimizing NO . In a case study, it is shown that MPC is able to satisfy user-defined NO limits over the course of various driving missions. Moreover, a comparison with the optimal Pareto front highlights MPC’s ability to achieve close-to-optimal fuel performance for any desired cumulated NO target on four realistic routes for passenger cars.
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(This article belongs to the Special Issue Sustainable and Low Carbon Development in the Energy Sector)
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Open AccessArticle
The Impact of Energy-Related Uncertainty on Corporate Investment Decisions in China
by
Zhuyun Xie, Hyder Ali, Suresh Kumar, Salma Naz and Umair Ahmed
Energies 2024, 17(10), 2368; https://doi.org/10.3390/en17102368 - 14 May 2024
Abstract
This study investigates the impact of the Energy-related Uncertainty Index (EUI) on corporate investment among Chinese non-financial listed companies, focusing on two aspects: the effect of EUI fluctuations on investment behavior, and its differential impact on energy versus non-energy sectors. Utilizing a dataset
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This study investigates the impact of the Energy-related Uncertainty Index (EUI) on corporate investment among Chinese non-financial listed companies, focusing on two aspects: the effect of EUI fluctuations on investment behavior, and its differential impact on energy versus non-energy sectors. Utilizing a dataset of 2487 firms from 2007 to 2022, encompassing 22,346 firm-year observations, our analysis reveals that a 1% increase in the EUI leads to a 0.045% decrease in overall corporate investment. Notably, this effect is more pronounced in energy-related firms, where a 1% increase in EUI leads to a 0.057% reduction in investment. In comparison, non-energy-related firms exhibit a milder response, with a 1% increase in EUI resulting in a 0.026% decrease in investment. Given the average annual change in EUI over the sample period [2007–2022] of 27.710%, a 0.045% decrease in investment implies a substantial 1.246% per annum change in investment. This highlights the economically significant impact of EUI fluctuations on corporate investment decisions, particularly during periods of heightened uncertainty. These findings, validated through alternative EUI measures and investment metrics, provide crucial insights for understanding investment behavior under energy uncertainty. Conclusively, our study contributes to the literature by highlighting how energy uncertainty uniquely impacts corporate investment, taking into account the specific financial and operational conditions within different sectors. The findings highlight the importance of incorporating energy policy considerations into corporate strategic planning, particularly for energy-intensive industries within transitional economies like China.
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(This article belongs to the Section B: Energy and Environment)
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Open AccessArticle
Real-Time Microgrid Energy Scheduling Using Meta-Reinforcement Learning
by
Huan Shen, Xingfa Shen and Yiming Chen
Energies 2024, 17(10), 2367; https://doi.org/10.3390/en17102367 - 14 May 2024
Abstract
With the rapid development of renewable energy and the increasing maturity of energy storage technology, microgrids are quickly becoming popular worldwide. The stochastic scheduling problem of microgrids can increase operational costs and resource wastage. In order to reduce operational costs and optimize resource
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With the rapid development of renewable energy and the increasing maturity of energy storage technology, microgrids are quickly becoming popular worldwide. The stochastic scheduling problem of microgrids can increase operational costs and resource wastage. In order to reduce operational costs and optimize resource utilization efficiency, the real-time scheduling of microgrids becomes particularly important. After collecting extensive data, reinforcement learning (RL) can provide good strategies. However, it cannot make quick and rational decisions in different environments. As a method with generalization ability, meta-learning can compensate for this deficiency. Therefore, this paper introduces a microgrid scheduling strategy based on RL and meta-learning. This method can quickly adapt to different environments with a small amount of training data, enabling rapid energy scheduling policy generation in the early stages of microgrid operation. This paper first establishes a microgrid model, including components such as energy storage, load, and distributed generation (DG). Then, we use a meta-reinforcement learning framework to train the initial scheduling strategy, considering the various operational constraints of the microgrid. The experimental results show that the MAML-based RL strategy has advantages in improving energy utilization and reducing operational costs in the early stages of microgrid operation. This research provides a new intelligent solution for microgrids’ efficient, stable, and economical operation in their initial stages.
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(This article belongs to the Topic Distributed Generation and Storage in Power Systems)
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