Pub Date : 2025-04-19DOI: 10.1016/j.apenergy.2025.125859
Guo-Wei Qian , Takeshi Ishihara
A novel full wake model using a double-Gaussian function is derived in this study. Firstly, the full wake characteristics under different inflow and turbine operation conditions are investigated using large eddy simulation. The ambient turbulence intensity and thrust coefficient are found to be the key parameters that determine the wake recovery rate and the distance where double-peak velocity deficits transition to one-peak distribution. A novel double-Gaussian wake model is then proposed to estimate the mean velocity deficit in both the near and far wake region. A linear wake expansion rate and non-linear Gaussian minima are demonstrated and utilized to describe the shape transition of velocity deficit from near-wake to far-wake region. All the parameters in the model are expressed as a function of thrust coefficient and ambient turbulence intensity. Finally, the proposed model is validated using a set of LES results and experimental data. The predicted velocity profiles in the near wake region by the proposed model show good agreement with LES and measurements. Furthermore, the proposed full wake model is applied to Horns Rev. offshore wind farm and provides good accuracy for power prediction in the multiple wakes as well. The applications of this new full wake model include, but are not limited to turbine layout optimization, farm control, and repower of existing wind farms.
{"title":"A novel double-Gaussian full wake model for wind turbines considering dependence on thrust coefficient and ambient turbulence intensity","authors":"Guo-Wei Qian , Takeshi Ishihara","doi":"10.1016/j.apenergy.2025.125859","DOIUrl":"10.1016/j.apenergy.2025.125859","url":null,"abstract":"<div><div>A novel full wake model using a double-Gaussian function is derived in this study. Firstly, the full wake characteristics under different inflow and turbine operation conditions are investigated using large eddy simulation. The ambient turbulence intensity and thrust coefficient are found to be the key parameters that determine the wake recovery rate and the distance where double-peak velocity deficits transition to one-peak distribution. A novel double-Gaussian wake model is then proposed to estimate the mean velocity deficit in both the near and far wake region. A linear wake expansion rate and non-linear Gaussian minima are demonstrated and utilized to describe the shape transition of velocity deficit from near-wake to far-wake region. All the parameters in the model are expressed as a function of thrust coefficient and ambient turbulence intensity. Finally, the proposed model is validated using a set of LES results and experimental data. The predicted velocity profiles in the near wake region by the proposed model show good agreement with LES and measurements. Furthermore, the proposed full wake model is applied to Horns Rev. offshore wind farm and provides good accuracy for power prediction in the multiple wakes as well. The applications of this new full wake model include, but are not limited to turbine layout optimization, farm control, and repower of existing wind farms.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125859"},"PeriodicalIF":10.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-19DOI: 10.1016/j.apenergy.2025.125797
Yue Chen , Soham Chakraborty , Ahmed Zamzam , Jing Wang
This paper introduces an end-to-end microgrid protection framework that offers real-time system monitoring, fault-related decision making, and circuit breaker control. This is achieved through the design of distributed data-driven techniques based on the support vector machine method, where each relay is responsible for distributed data collection, fault detection, fault localization, and fault isolation. Local communication is established among neighboring relays, fostering cooperative fault localization and isolation. This decentralized design not only reduces the computational and communication requirements but also enables the adaptability of each relay under varying operational dynamics. The proposed end-to-end protection framework was validated using MATLAB/Simulink simulations on a renewable microgrid, achieving an accuracy of with response time of 0.0523 s, in protecting against a range of fault scenarios that are characterized by various types, locations, impedances, load conditions, photovoltaic power levels, and microgrid operating modes.
{"title":"End-to-end microgrid protection using distributed data-driven methods","authors":"Yue Chen , Soham Chakraborty , Ahmed Zamzam , Jing Wang","doi":"10.1016/j.apenergy.2025.125797","DOIUrl":"10.1016/j.apenergy.2025.125797","url":null,"abstract":"<div><div>This paper introduces an end-to-end microgrid protection framework that offers real-time system monitoring, fault-related decision making, and circuit breaker control. This is achieved through the design of distributed data-driven techniques based on the support vector machine method, where each relay is responsible for distributed data collection, fault detection, fault localization, and fault isolation. Local communication is established among neighboring relays, fostering cooperative fault localization and isolation. This decentralized design not only reduces the computational and communication requirements but also enables the adaptability of each relay under varying operational dynamics. The proposed end-to-end protection framework was validated using MATLAB/Simulink simulations on a <span><math><mn>100</mn><mspace></mspace><mi>%</mi></math></span> renewable microgrid, achieving an accuracy of <span><math><mn>93.1</mn><mspace></mspace><mi>%</mi></math></span> with response time of 0.0523 s, in protecting against a range of fault scenarios that are characterized by various types, locations, impedances, load conditions, photovoltaic power levels, and microgrid operating modes.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125797"},"PeriodicalIF":10.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-19DOI: 10.1016/j.apenergy.2025.125861
Jianhong Liu , Zhenyu Tian , Mingwei Sun , Xihan Chen , Longbin Qiu , Wenjia Li
The integration of full-spectrum solar energy utilization with solid oxide electrolysis cells (SOECs) offer a promising solution for efficient hydrogen production. However, two significant challenges hinder the development of this technology: firstly, the discrepancy between the supply ratio of heat and electricity from solar energy and the demand ratio of heat and electricity for SOECs, and secondly, the conflict between the fluctuations in solar energy and the limited temperature fluctuation tolerance of SOECs. In this study, an SOEC hydrogen production system with thermal storage module is proposed to address these challenges. Solar energy is divided based on wavelength: shorter-wavelength sunlight is converted into electricity via photovoltaic cells, longer-wavelength sunlight is converted into heat in the reactor. The reactor suppresses temperature fluctuations by storing and releasing solar extra heat. During daylight hours, the system utilizes all the solar electricity and part of the solar heat to produce hydrogen. While at night, the system shifts to rely on grid power and stored solar heat for continued operation, thus recovering the otherwise lost solar heat and avoiding additional power consumption, and enhancing system efficiency. Thermodynamic evaluation shows that the system achieves an efficiency of 54.0 %, considering both grid electricity and solar energy inputs, which is relative 9.8 % higher than the traditional full-spectrum solar hydrogen production system. Additionally, compared to the traditional system, our proposed approach reduces grid power consumption by 26.6 % and increases solar energy utilization efficiency by 18.5 %. These findings underscore the viability and potential of the integrated system in enhancing hydrogen production efficiency while effectively managing solar energy fluctuations.
{"title":"Efficient and adaptive hydrogen production via integrated full-Spectrum solar energy and solid oxide electrolysis cells with thermal storage","authors":"Jianhong Liu , Zhenyu Tian , Mingwei Sun , Xihan Chen , Longbin Qiu , Wenjia Li","doi":"10.1016/j.apenergy.2025.125861","DOIUrl":"10.1016/j.apenergy.2025.125861","url":null,"abstract":"<div><div>The integration of full-spectrum solar energy utilization with solid oxide electrolysis cells (SOECs) offer a promising solution for efficient hydrogen production. However, two significant challenges hinder the development of this technology: firstly, the discrepancy between the supply ratio of heat and electricity from solar energy and the demand ratio of heat and electricity for SOECs, and secondly, the conflict between the fluctuations in solar energy and the limited temperature fluctuation tolerance of SOECs. In this study, an SOEC hydrogen production system with thermal storage module is proposed to address these challenges. Solar energy is divided based on wavelength: shorter-wavelength sunlight is converted into electricity via photovoltaic cells, longer-wavelength sunlight is converted into heat in the reactor. The reactor suppresses temperature fluctuations by storing and releasing solar extra heat. During daylight hours, the system utilizes all the solar electricity and part of the solar heat to produce hydrogen. While at night, the system shifts to rely on grid power and stored solar heat for continued operation, thus recovering the otherwise lost solar heat and avoiding additional power consumption, and enhancing system efficiency. Thermodynamic evaluation shows that the system achieves an efficiency of 54.0 %, considering both grid electricity and solar energy inputs, which is relative 9.8 % higher than the traditional full-spectrum solar hydrogen production system. Additionally, compared to the traditional system, our proposed approach reduces grid power consumption by 26.6 % and increases solar energy utilization efficiency by 18.5 %. These findings underscore the viability and potential of the integrated system in enhancing hydrogen production efficiency while effectively managing solar energy fluctuations.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125861"},"PeriodicalIF":10.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-19DOI: 10.1016/j.apenergy.2025.125826
Tekai Eddine Khalil Zidane , Sebastian Zainali , Yuri Bellone , Mohammed Guezgouz , Arash Khosravi , Silvia Ma Lu , Sultan Tekie , Stefano Amaducci , Pietro Elia Campana
Energy conversion from conventional ground-mounted photovoltaic systems requires a significant amount of land, which can compete with food production. Agrivoltaic systems, which integrate electricity generation and crop production, can help reduce this land competition. The profitability of agrivoltaic systems is expected to be a crucial factor for decision-makers and stakeholders considering their adoption. This work aims to analyze the economic performance of one-axis, vertical and elevated agrivoltaic systems compared to conventional ground-mounted photovoltaic systems across Europe focusing on countries such as Sweden, Denmark, Germany and Italy. By employing a stochastic approach with Monte Carlo simulations, this research makes a significant contribution to forecasting the profitability and cost-effectiveness of agrivoltaic projects in European countries for the next years. Moreover, it identifies the key parameters that significantly impact the net present value and levelized cost of electricity. The economic findings reveal a notable trend: agrivoltaic projects (i.e., one-axis, vertical, and elevated) are likely to be profitable throughout Europe. However, the agricultural profit generated from these systems is minimal for the investigated crop rotations compared to the benefits derived from energy conversion. Among the systems evaluated, one-axis agrivoltaic setups demonstrate higher profitability and cost-effectiveness compared to vertical and elevated setups. They also have a shorter discounted payback period and a lower levelized cost of electricity than conventional ground-mounted photovoltaic systems. These findings are particularly significant for decision-makers and stakeholders involved in developing agrivoltaic policies. This is especially relevant for Sweden which currently lacks agrivoltaic policies, regulations, and definitions, in contrast to Germany and Italy where policies for promoting agrivoltaics have previously been implemented or are in progress.
{"title":"Economic evaluation of one-axis, vertical, and elevated agrivoltaic systems across Europe: a Monte Carlo Analysis","authors":"Tekai Eddine Khalil Zidane , Sebastian Zainali , Yuri Bellone , Mohammed Guezgouz , Arash Khosravi , Silvia Ma Lu , Sultan Tekie , Stefano Amaducci , Pietro Elia Campana","doi":"10.1016/j.apenergy.2025.125826","DOIUrl":"10.1016/j.apenergy.2025.125826","url":null,"abstract":"<div><div>Energy conversion from conventional ground-mounted photovoltaic systems requires a significant amount of land, which can compete with food production. Agrivoltaic systems, which integrate electricity generation and crop production, can help reduce this land competition. The profitability of agrivoltaic systems is expected to be a crucial factor for decision-makers and stakeholders considering their adoption. This work aims to analyze the economic performance of one-axis, vertical and elevated agrivoltaic systems compared to conventional ground-mounted photovoltaic systems across Europe focusing on countries such as Sweden, Denmark, Germany and Italy. By employing a stochastic approach with Monte Carlo simulations, this research makes a significant contribution to forecasting the profitability and cost-effectiveness of agrivoltaic projects in European countries for the next years. Moreover, it identifies the key parameters that significantly impact the net present value and levelized cost of electricity. The economic findings reveal a notable trend: agrivoltaic projects (i.e., one-axis, vertical, and elevated) are likely to be profitable throughout Europe. However, the agricultural profit generated from these systems is minimal for the investigated crop rotations compared to the benefits derived from energy conversion. Among the systems evaluated, one-axis agrivoltaic setups demonstrate higher profitability and cost-effectiveness compared to vertical and elevated setups. They also have a shorter discounted payback period and a lower levelized cost of electricity than conventional ground-mounted photovoltaic systems. These findings are particularly significant for decision-makers and stakeholders involved in developing agrivoltaic policies. This is especially relevant for Sweden which currently lacks agrivoltaic policies, regulations, and definitions, in contrast to Germany and Italy where policies for promoting agrivoltaics have previously been implemented or are in progress.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125826"},"PeriodicalIF":10.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125954
Nabanita Ghosh , Abu Mustafa Khan , Gopinath Halder
The growing concerns over global warming and the finite nature of fossil fuel resources have spurred interest in biodiesel as promising alternative towards carbon-neutral economy. Substituting petro-diesel with biodiesel could trigger to a remarkable decline in environmental pollution. Amidst several customary processes, transesterification is ascertained to be a globally well-adopted cost-competent and scalable method of biodiesel manufacturing. Nevertheless, transesterification faces many challenges particularly with homogeneous catalysis, such as catalyst separation and formation of wastewater. Calcium oxide (CaO) as a heterogeneous catalysts have gained momentum of interest. However, it has still some bottlenecks in scaling-up.
The current review delves into the use of CaO-based catalyst in biodiesel synthesis over the previous fifteen years addressing a critical need for improvement in catalytic activity through regeneration of reused catalyst to promote sustainable development goals (SDG7) of the United Nations. It also digs deeper into exploring possible mechanisms that cause catalyst deactivation to enable designing catalyst synthesis and ensure resistance to leaching and deactivation; advocating the need of kinetic and thermodynamic analysis, which have impact on the reaction process; evaluating the life cycle assessment (LCA), and the practical applications of the findings. The review also underscores the paucity of sufficient data for comparing the environmental impacts of biodiesel production using CaO-mediated catalysts. There is still a remarkable lacuna in the literature pertaining to the CaO-based cost analysis to make biodiesel production economical. Furthermore, it suggests that future research should focus on developing catalysts that can efficiently regenerate themselves in a single step.
{"title":"Advances in calcium oxide mediated catalytic biodiesel production: A paradigm shift in complying with UN's SDG7","authors":"Nabanita Ghosh , Abu Mustafa Khan , Gopinath Halder","doi":"10.1016/j.apenergy.2025.125954","DOIUrl":"10.1016/j.apenergy.2025.125954","url":null,"abstract":"<div><div>The growing concerns over global warming and the finite nature of fossil fuel resources have spurred interest in biodiesel as promising alternative towards carbon-neutral economy. Substituting petro-diesel with biodiesel could trigger to a remarkable decline in environmental pollution. Amidst several customary processes, transesterification is ascertained to be a globally well-adopted cost-competent and scalable method of biodiesel manufacturing. Nevertheless, transesterification faces many challenges particularly with homogeneous catalysis, such as catalyst separation and formation of wastewater. Calcium oxide (CaO) as a heterogeneous catalysts have gained momentum of interest. However, it has still some bottlenecks in scaling-up.</div><div>The current review delves into the use of CaO-based catalyst in biodiesel synthesis over the previous fifteen years addressing a critical need for improvement in catalytic activity through regeneration of reused catalyst to promote sustainable development goals (SDG7) of the United Nations. It also digs deeper into exploring possible mechanisms that cause catalyst deactivation to enable designing catalyst synthesis and ensure resistance to leaching and deactivation; advocating the need of kinetic and thermodynamic analysis, which have impact on the reaction process; evaluating the life cycle assessment (LCA), and the practical applications of the findings. The review also underscores the paucity of sufficient data for comparing the environmental impacts of biodiesel production using CaO-mediated catalysts. There is still a remarkable lacuna in the literature pertaining to the CaO-based cost analysis to make biodiesel production economical. Furthermore, it suggests that future research should focus on developing catalysts that can efficiently regenerate themselves in a single step.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125954"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125811
Luke W. Yerbury , Ricardo J.G.B. Campello , G.C. Livingston Jr , Mark Goldsworthy , Lachlan O’Neil
The widespread adoption of smart meters for monitoring energy consumption has generated vast quantities of high-resolution time series data which remain underutilised. While clustering has emerged as a fundamental tool for mining smart meter time series (SMTS) data, selecting appropriate clustering methods remains challenging despite numerous comparative studies. These studies often rely on problematic methodologies and consider a limited scope of methods, frequently overlooking compelling methods from the broader time series clustering literature. Consequently, they struggle to provide dependable guidance for practitioners designing their own clustering approaches.
This paper presents a comprehensive comparative framework for SMTS clustering methods using expert-informed synthetic datasets that emphasise peak consumption behaviours as fundamental cluster concepts. Using a phased methodology, we first evaluated 31 distance measures and 8 representation methods using leave-one-out classification, then examined the better-suited methods in combination with 11 clustering algorithms. We further assessed the robustness of these combinations to systematic changes in key dataset properties that affect clustering performance on real-world datasets, including cluster balance, noise, and the presence of outliers.
Our results revealed that methods accommodating local temporal shifts while maintaining amplitude sensitivity, particularly Dynamic Time Warping and -sliding distance, consistently outperformed traditional approaches. Among other key findings, we identified that when combined with -medoids or hierarchical clustering using Ward’s linkage, these methods exhibited consistent robustness across varying dataset characteristics without careful parameter tuning. These and other findings inform actionable recommendations for practitioners, and validation with real-world data demonstrates that our findings translate effectively to practical SMTS clustering tasks. Finally, our datasets and code are publicly available to support the development, evaluation, and comparison of both novel and overlooked methods.
{"title":"Comparing clustering approaches for smart meter time series: Investigating the influence of dataset properties on performance","authors":"Luke W. Yerbury , Ricardo J.G.B. Campello , G.C. Livingston Jr , Mark Goldsworthy , Lachlan O’Neil","doi":"10.1016/j.apenergy.2025.125811","DOIUrl":"10.1016/j.apenergy.2025.125811","url":null,"abstract":"<div><div>The widespread adoption of smart meters for monitoring energy consumption has generated vast quantities of high-resolution time series data which remain underutilised. While clustering has emerged as a fundamental tool for mining smart meter time series (SMTS) data, selecting appropriate clustering methods remains challenging despite numerous comparative studies. These studies often rely on problematic methodologies and consider a limited scope of methods, frequently overlooking compelling methods from the broader time series clustering literature. Consequently, they struggle to provide dependable guidance for practitioners designing their own clustering approaches.</div><div>This paper presents a comprehensive comparative framework for SMTS clustering methods using expert-informed synthetic datasets that emphasise peak consumption behaviours as fundamental cluster concepts. Using a phased methodology, we first evaluated 31 distance measures and 8 representation methods using leave-one-out classification, then examined the better-suited methods in combination with 11 clustering algorithms. We further assessed the robustness of these combinations to systematic changes in key dataset properties that affect clustering performance on real-world datasets, including cluster balance, noise, and the presence of outliers.</div><div>Our results revealed that methods accommodating local temporal shifts while maintaining amplitude sensitivity, particularly Dynamic Time Warping and <span><math><mi>k</mi></math></span>-sliding distance, consistently outperformed traditional approaches. Among other key findings, we identified that when combined with <span><math><mi>k</mi></math></span>-medoids or hierarchical clustering using Ward’s linkage, these methods exhibited consistent robustness across varying dataset characteristics without careful parameter tuning. These and other findings inform actionable recommendations for practitioners, and validation with real-world data demonstrates that our findings translate effectively to practical SMTS clustering tasks. Finally, our datasets and code are publicly available to support the development, evaluation, and comparison of both novel and overlooked methods.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125811"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125911
Alexander Wimmer , Markus Kordel , Marc Linder , Inga Bürger
Refueling fuel cell electric vehicles (FCEVs) needs energy for the compressor at the refueling station that is afterwards stored inside the high-pressure tank on board of the vehicle. On the one side, the State of the Art does not allow to recover this energy which results in a negative impact on the efficiency chain of a FECV. On the other side, air-conditioning systems in vehicles consume significant amounts of energy, further reducing the limited driving range and increasing the operation costs. This problem can be addressed by the open metal hydride cooling system (MHCS) arranged between the pressure tank and fuel cell, that converts the available potential energy into a heat pump effect. The challenges of the MHCS is its thermal performance referred to the amount of metal hydride (MH) that is required. This study presents a reactor design that significantly increases the specific cooling power of previous MHCS. The new reactor features MH-graphite composites and micro fluid channels for heat transport enhancement as well as an additive-manufactured lightweight structure of aluminum to reduce sensible losses. Experimental characterization at a pressure ratio of 7, a cold side temperature of 20 °C and hot side temperature of 30 °C show a specific cooling power of 522 W kgMH−1, that is nearly twice as high as the best value reported in the literature. Furthermore, not only cooling efficiencies above 60 % could be maintained on higher specific power, but also the performance at an elevated temperature lift of 20 K is improved in comparison to previous systems. The experimentally proven high performance verifies the good heat and mass transport properties with a low structural heat capacity at the same time. This significantly improved reactor allows to meet the demanding requirements in terms of weight, space and cost for the applications in the mobile application such as a FCEV.
{"title":"High performance reactor of a metal hydride based cooling system for air-conditioning of fuel cell electric vehicles","authors":"Alexander Wimmer , Markus Kordel , Marc Linder , Inga Bürger","doi":"10.1016/j.apenergy.2025.125911","DOIUrl":"10.1016/j.apenergy.2025.125911","url":null,"abstract":"<div><div>Refueling fuel cell electric vehicles (FCEVs) needs energy for the compressor at the refueling station that is afterwards stored inside the high-pressure tank on board of the vehicle. On the one side, the State of the Art does not allow to recover this energy which results in a negative impact on the efficiency chain of a FECV. On the other side, air-conditioning systems in vehicles consume significant amounts of energy, further reducing the limited driving range and increasing the operation costs. This problem can be addressed by the open metal hydride cooling system (MHCS) arranged between the pressure tank and fuel cell, that converts the available potential energy into a heat pump effect. The challenges of the MHCS is its thermal performance referred to the amount of metal hydride (MH) that is required. This study presents a reactor design that significantly increases the specific cooling power of previous MHCS. The new reactor features MH-graphite composites and micro fluid channels for heat transport enhancement as well as an additive-manufactured lightweight structure of aluminum to reduce sensible losses. Experimental characterization at a pressure ratio of 7, a cold side temperature of 20 °C and hot side temperature of 30 °C show a specific cooling power of 522 W kg<sub>MH</sub><sup>−1</sup>, that is nearly twice as high as the best value reported in the literature. Furthermore, not only cooling efficiencies above 60 % could be maintained on higher specific power, but also the performance at an elevated temperature lift of 20 K is improved in comparison to previous systems. The experimentally proven high performance verifies the good heat and mass transport properties with a low structural heat capacity at the same time. This significantly improved reactor allows to meet the demanding requirements in terms of weight, space and cost for the applications in the mobile application such as a FCEV.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125911"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125897
Jiafeng Lin , Jing Qiu , Yi Yang , Xianzhuo Sun , Xin Lu , Zhe Yuan
With the rapid integration of distributed energy resources (DERs), power systems are becoming increasingly vulnerable to cyberattacks, particularly data integrity attacks (DIAs), due to extensive information exchange. Market participants might engage in economic-driven attacks to gain competitive edge and strategic advantages over competitors. Emerging infrastructures, such as Electric Vehicle Charging Management Centres (EVCMCs), have caught increasing attention from attackers, where successful manipulations could lead to significant financial gains or disruptions to the power grid. This paper presents a novel fuzzy-Bayesian attack-resilience mechanism that incorporates a detailed non-ideal Li-ion EV battery model to enhance cybersecurity. A fuzzy inference system (FIS)-based approach is proposed to quantitively evaluate the vulnerability of EVCMCs, and a Bayesian reputation index is introduced to identify and isolate compromised controllers. This scheme more accurately captures real-world battery behaviors, identifies the most vulnerable EVCMCs, and recovers power dispatch against DIAs. According to the simulation results: 1) Compared with traditional methods, the vulnerability of EVCMCs can be assessed quantitatively based on distinct features of each EVCMC. 2) Attackers can achieve greater financial gains and simultaneously diminish competitors' earnings without violating power system operation constraints by exploiting non-ideal battery characteristics. 3) The proposed attack-resilience scheme effectively verifies shared information among neighbors, isolates compromised controllers and recovers optimal power dispatch in the presence of DIAs.
{"title":"Data integrity attack resilience for electric vehicle charging management centers in distributed optimal power flow with non-ideal Li-ion battery models","authors":"Jiafeng Lin , Jing Qiu , Yi Yang , Xianzhuo Sun , Xin Lu , Zhe Yuan","doi":"10.1016/j.apenergy.2025.125897","DOIUrl":"10.1016/j.apenergy.2025.125897","url":null,"abstract":"<div><div>With the rapid integration of distributed energy resources (DERs), power systems are becoming increasingly vulnerable to cyberattacks, particularly data integrity attacks (DIAs), due to extensive information exchange. Market participants might engage in economic-driven attacks to gain competitive edge and strategic advantages over competitors. Emerging infrastructures, such as Electric Vehicle Charging Management Centres (EVCMCs), have caught increasing attention from attackers, where successful manipulations could lead to significant financial gains or disruptions to the power grid. This paper presents a novel fuzzy-Bayesian attack-resilience mechanism that incorporates a detailed non-ideal Li-ion EV battery model to enhance cybersecurity. A fuzzy inference system (FIS)-based approach is proposed to quantitively evaluate the vulnerability of EVCMCs, and a Bayesian reputation index is introduced to identify and isolate compromised controllers. This scheme more accurately captures real-world battery behaviors, identifies the most vulnerable EVCMCs, and recovers power dispatch against DIAs. According to the simulation results: 1) Compared with traditional methods, the vulnerability of EVCMCs can be assessed quantitatively based on distinct features of each EVCMC. 2) Attackers can achieve greater financial gains and simultaneously diminish competitors' earnings without violating power system operation constraints by exploiting non-ideal battery characteristics. 3) The proposed attack-resilience scheme effectively verifies shared information among neighbors, isolates compromised controllers and recovers optimal power dispatch in the presence of DIAs.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125897"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125876
Marco Ficili, Paolo Colbertaldo, Stefano Campanari, Giulio Guandalini
Solid oxide cells are promising electrochemical devices capable of operating in both electrolysis and fuel cell modes with high electrical efficiency. This work investigates the design and partial-load operation of a reversible solid oxide cell (rSOC) system for steam electrolysis and hydrogen-based power generation, when adopting a unified balance of plant for both modes and molten salt thermal energy storage for thermal integration. Different configurations are compared with the aim of widening the part-load window, taking into account the electrochemical behavior as well as the changes in heat exchange properties. The definition of system efficiency losses with respect to the stack efficiency is proposed, helping in identifying the main causes of efficiency degradation throughout the part-load window. Results show that pre- or post-stack heaters are required when switching from exothermic to endothermic conditions. Moreover, they prove essential in keeping the rSOC in thermal balance also when the reaction is slightly exothermic. The use of electric heaters and hydrogen combustors is compared, and electric heaters appear to have the least impact on system efficiency at lower loads. For all configurations, the highest efficiency is obtained close to the thermoneutral point, which optimizes the trade-off between stack efficiency and system efficiency losses. Heat recovery in fuel cell mode is prominent at nominal load and could be beneficial in facilitating thermal integration between the two operational modes. However, the magnitude of its reduction at partial load is greater than the corresponding reduction in heat demand in electrolysis mode, leading to increased thermal imbalances between fuel cell and electrolysis modes.
{"title":"Investigating the partial load of reversible solid oxide cell systems: A focus on balance of plant and thermal integration","authors":"Marco Ficili, Paolo Colbertaldo, Stefano Campanari, Giulio Guandalini","doi":"10.1016/j.apenergy.2025.125876","DOIUrl":"10.1016/j.apenergy.2025.125876","url":null,"abstract":"<div><div>Solid oxide cells are promising electrochemical devices capable of operating in both electrolysis and fuel cell modes with high electrical efficiency. This work investigates the design and partial-load operation of a reversible solid oxide cell (rSOC) system for steam electrolysis and hydrogen-based power generation, when adopting a unified balance of plant for both modes and molten salt thermal energy storage for thermal integration. Different configurations are compared with the aim of widening the part-load window, taking into account the electrochemical behavior as well as the changes in heat exchange properties. The definition of system efficiency losses with respect to the stack efficiency is proposed, helping in identifying the main causes of efficiency degradation throughout the part-load window. Results show that pre- or post-stack heaters are required when switching from exothermic to endothermic conditions. Moreover, they prove essential in keeping the rSOC in thermal balance also when the reaction is slightly exothermic. The use of electric heaters and hydrogen combustors is compared, and electric heaters appear to have the least impact on system efficiency at lower loads. For all configurations, the highest efficiency is obtained close to the thermoneutral point, which optimizes the trade-off between stack efficiency and system efficiency losses. Heat recovery in fuel cell mode is prominent at nominal load and could be beneficial in facilitating thermal integration between the two operational modes. However, the magnitude of its reduction at partial load is greater than the corresponding reduction in heat demand in electrolysis mode, leading to increased thermal imbalances between fuel cell and electrolysis modes.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125876"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.apenergy.2025.125896
Changlan Liu , Zhongbing Liu , Yaling Wu , Benjia Li , Ruimiao Liu
The utilization of a combination of renewable energy and battery energy storage system (BESS) in energy sharing communities can alleviate load pressure on the grid and reduce the overall cost of electricity by improving the efficiency of energy utilization. However, most designs of the BESS in communities neglect the effects of energy-sharing potential, resulting in more energy exchanges between community and the grid and oversized capacity of the BESS. Therefore, this paper proposed a distributed group shared optimization design for grid-connected PV-BESS in a hybrid industrial community, aimed at enhancing energy-sharing potential while minimizing the required storage capacity. Firstly, the buildings in community were divided into four groups to minimize annual operating cost. Then, to reduce the yearly total cost and transmission loss, the capacity of each group was optimized by the genetic algorithm (GA). The results showed that compared to the distributed non-grouping optimization design, the proposed design leveraged the energy-sharing potential of the industrial community, with a 20.7 % reduction of the total battery capacity and a 16.1 % decrease of the total annual cost. The mismatch between PV generation and electricity demand was the main factor affecting grouping and battery capacity allocation. Differences in peak-to-valley tariff ratios have no effect on grouping or battery capacity allocation. When the PV array area increases and the differences in peak-to-valley tariff ratios decrease, the corresponding total optimal battery capacity and annual cost decrease, but transmission loss is increased. This study provides guidance for the shared BESS design and application of community.
{"title":"A group-based optimization design for PV-BESS in energy-sharing hybrid communities","authors":"Changlan Liu , Zhongbing Liu , Yaling Wu , Benjia Li , Ruimiao Liu","doi":"10.1016/j.apenergy.2025.125896","DOIUrl":"10.1016/j.apenergy.2025.125896","url":null,"abstract":"<div><div>The utilization of a combination of renewable energy and battery energy storage system (BESS) in energy sharing communities can alleviate load pressure on the grid and reduce the overall cost of electricity by improving the efficiency of energy utilization. However, most designs of the BESS in communities neglect the effects of energy-sharing potential, resulting in more energy exchanges between community and the grid and oversized capacity of the BESS. Therefore, this paper proposed a distributed group shared optimization design for grid-connected PV-BESS in a hybrid industrial community, aimed at enhancing energy-sharing potential while minimizing the required storage capacity. Firstly, the buildings in community were divided into four groups to minimize annual operating cost. Then, to reduce the yearly total cost and transmission loss, the capacity of each group was optimized by the genetic algorithm (GA). The results showed that compared to the distributed non-grouping optimization design, the proposed design leveraged the energy-sharing potential of the industrial community, with a 20.7 % reduction of the total battery capacity and a 16.1 % decrease of the total annual cost. The mismatch between PV generation and electricity demand was the main factor affecting grouping and battery capacity allocation. Differences in peak-to-valley tariff ratios have no effect on grouping or battery capacity allocation. When the PV array area increases and the differences in peak-to-valley tariff ratios decrease, the corresponding total optimal battery capacity and annual cost decrease, but transmission loss is increased. This study provides guidance for the shared BESS design and application of community.</div></div>","PeriodicalId":246,"journal":{"name":"Applied Energy","volume":"391 ","pages":"Article 125896"},"PeriodicalIF":10.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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