Energy Conversion and Management最新文献

{"title":"Review of the Lao People’s Democratic Republic energy policies for sustainable development","authors":"Phidsavard Keomeesay ,&nbsp;Na Liu ,&nbsp;Yichen Nie ,&nbsp;Shuaizhe Li ,&nbsp;Wei Zhang ,&nbsp;Ying Liu ,&nbsp;Dona Souliyathai ,&nbsp;Xingyong Li ,&nbsp;Yubao Chen ,&nbsp;Xuebing Zhao ,&nbsp;Longlong Ma ,&nbsp;Shijie Liu","doi":"10.1016/j.enconman.2024.119327","DOIUrl":"10.1016/j.enconman.2024.119327","url":null,"abstract":"<div><div>The Lao People’s Democratic Republic (Lao P.D.R) gets more than 70 % of its energy from conventional sources, which emphasizes the urgent need to switch to renewable energy. This study looks at the supply and demand scenario for energy in the Lao P.D.R. The need to reduce carbon emissions and enhance energy security in a country where over 60 % of the population lacks consistent access to electricity motivates this study. It is predicted that Laos can significantly enhance its energy sustainability by 2030 by implementing a diverse energy mix that includes at least 30 % renewable sources. A mixed-methods approach was used to evaluate the viability of different renewable technologies, including hydropower, solar electricity, and biomass, through the analysis of current energy policy, stakeholder interviews, and modeling scenarios. Findings indicate that switching to renewable energy could cut carbon emissions by up to 40 % and increase electrification rates by 80 % by 2030, provided that significant obstacles such as funding and technical capability are overcome. A coordinated effort among government, corporate sectors, and local communities is essential to addressing existing impediments, ultimately paving the way for a sustainable and resilient energy future in Laos.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119327"},"PeriodicalIF":9.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745216","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}

{"title":"Development of a comprehensive simulation to explore the energy-saving and daylighting features of a multifunctional window in tropical climates","authors":"Mostafa M. Abdelsamie ,&nbsp;Yue Yang ,&nbsp;Luling Li ,&nbsp;M. Fatouh ,&nbsp;Jianhui Liu ,&nbsp;Mohamed I. Hassan Ali","doi":"10.1016/j.enconman.2024.119325","DOIUrl":"10.1016/j.enconman.2024.119325","url":null,"abstract":"<div><div>Leveraging the entire solar spectrum in building facades is crucial to achieving zero-energy buildings concept. This study presents a novel multifunctional window (MFW) that combines photovoltaic laminates with a selective liquid filter (SLF) in a mono-glazing system. For a comprehensive assessment of the energy and daylight performance of a standard office equipped with MFW, it has been developed an innovative model integrating thermal, electrical, optical, and energy aspects, utilizing both CFD and daylighting analysis tools. The net electricity benefit (NEB) serves as a key metric to evaluate the energy performance of MFWs compared to traditional windows. Additionally, Useful Daylight Illuminance (UDI), Illuminance Uniformity (U_o), and Daylight Glare Probability (DGP) are employed to predict the annual daylight performance of MFW under various Photovoltaic-to-Space Ratios (PVSR). The findings reveal that using MFWs significantly reduces office cooling energy consumption, ranging from 41 % to 73 % in south-oriented buildings compared to standard glazing. Despite increased artificial lighting consumption (ALC) with PVSR, MFWs significantly improve the NEB due to higher energy generation and reduced cooling loads. MFWs with 50 % PVSR also enhance daylight distribution uniformity and minimize potential glare, while balancing PVSR at 50 % optimizes energy generation and ensures ample illumination in office spaces. Further, the levelized cost of electricity generation (LCOE_el) for the MFW ranges from $0.166 to $0.143/kWh_e.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"325 ","pages":"Article 119325"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745154","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}

{"title":"Three-dimensional simulation of high temperature ion-pair PEM fuel cell integrated with agglomerate sub-model of cathode catalyst layer","authors":"Utsav Raj Aryal,&nbsp;Bjorn Hasa,&nbsp;Gaohua Zhu","doi":"10.1016/j.enconman.2024.119289","DOIUrl":"10.1016/j.enconman.2024.119289","url":null,"abstract":"<div><div>A steady-state, isothermal simulation of a 3D high temperature (HT) ion-pair proton exchange membrane fuel cell (PEMFC) model, utilizing a quaternary ammonium biphosphate ion-pair membrane, was conducted in COMSOL Multiphysics for the first time. The performance of the fuel cell was analyzed, in terms of polarization curves, molar gas concentrations, and overpotential breakdown to determine mechanism resulting in loss. Experimental validation was performed for both non-protonated and protonated ion-pair fuel cells. The homogeneous catalyst layer model overestimated the performance at low catalyst loading by up to 32%. Hence, this study utilized an agglomerate sub-model of the cathode catalyst layer, to accurately capture the effect of catalyst loading on fuel cell performance. Additionally, a graded catalyst layer design was proposed to improve the catalyst utilization leading to high fuel cell performance. It was found that a graded catalyst layer with higher loading facing the membrane side improved the performance by 5.5% over uniformly loaded catalyst layer. Furthermore, the influence of operating conditions like temperature and back pressure is highlighted. Overall, this study offers a comprehensive approach to understanding HT ion-pair PEMFC operation and optimizing the catalyst structure.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119289"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745210","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}

{"title":"A review on modeling methods and key parameters control of proton exchange membrane fuel cell based on numerical comparison","authors":"Pei Fu,&nbsp;Zijian Lan,&nbsp;Yisong Chen,&nbsp;Shuo Zhang","doi":"10.1016/j.enconman.2024.119309","DOIUrl":"10.1016/j.enconman.2024.119309","url":null,"abstract":"<div><div>Although numerous studies have investigated semi-mechanistic and semi-empirical modeling methods for proton exchange membrane fuel cell (PEMFC) engine systems, the advantages and disadvantages of these modeling methods have rarely been analyzed and summarized. As a result, it is difficult to identify the most suitable models under different conditions. Moreover, there are opportunities to further develop research on controlling the three most critical parameters of the PEMFC engine system-the oxygen excess ratio (OER), stack temperature, and humidity. Thus, a review is presented to develop systematic guidelines for semi-mechanistic and semi-empirical modeling methods and key parameter control studies related to PEMFC engine systems. This paper summarizes all the authoritative modeling methods for the air compressor used in the PEMFC engine system with output power from 60 to 175 kW, and cathode humidifier in the air supply subsystem, ejector and circulation pump in the hydrogen supply subsystem, flow fluid and voltages in the fuel cell stack subsystem, and water pump and radiator in the thermal management subsystem using scientific equations. The advantages and disadvantages of each modeling method are then discussed through numerical comparisons or authoritative opinions. Subsequently, based on the modeling methods, the development and prospects of key parameter control studies for the PEMFC engine system are proposed based on advanced research in recent years. This paper not only makes it more convenient to identify appropriate modeling methods based on different modeling demands, but also highlights development directions for key parameters control research in the future.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119309"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745218","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}

{"title":"A resilience-oriented approach to integrated energy management systems: Addressing energy conversion unit unavailability and cost efficiency","authors":"Ali Taghavi ,&nbsp;Taher Niknam ,&nbsp;Mohsen Gitizadeh ,&nbsp;Jose Rodriguez ,&nbsp;Morteza sheikh","doi":"10.1016/j.enconman.2024.119291","DOIUrl":"10.1016/j.enconman.2024.119291","url":null,"abstract":"<div><div>As integrated energy systems become increasingly complex, their vulnerability to energy conversion units unavailability poses a considerable threat to system resilience and cost efficiency. This research is motivated by the need to address the growing threat of energy conversion unit unavailability and its significant impact on both system performance and operational costs. The development of a comprehensive vulnerability assessment framework, coupled with the integration of machine learning techniques, is hypothesized to significantly enhance the resilience and cost-efficiency of integrated energy management systems when faced with various unavailability scenarios. A novel methodology is introduced to enhance integrated energy management systems, focusing on the critical role of diverse energy conversion units. The methodology includes a new vulnerability index to quantify the impact of energy conversion unit unavailability on system performance, alongside an energy conversion unavailability attack model from the malicious actor perspective. Results indicate that under worst-case energy conversion unavailability attack scenarios, integrated energy systems operational costs can increase by up to 26.19%. The proposed solution, incorporating a Deep Q-Network into the integrated energy management system, achieves an 85.24% F1-score and a 96.68% reduction in additional costs associated with energy conversion unavailability attacks. This research demonstrates the varied impacts of different energy conversion units on integrated energy systems and proposes an enhanced integrated energy management system framework that improves system resilience and cost efficiency.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"325 ","pages":"Article 119291"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745153","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}

{"title":"Shading type and severity diagnosis in photovoltaic systems via I-V curve imaging and two-stream deep neural network","authors":"Zengxiang He ,&nbsp;Hong Cai Chen ,&nbsp;Shuo Shan ,&nbsp;Yihua Hu ,&nbsp;Kanjian Zhang ,&nbsp;Haikun Wei","doi":"10.1016/j.enconman.2024.119311","DOIUrl":"10.1016/j.enconman.2024.119311","url":null,"abstract":"<div><div>Shading is one of the most common anomalies in photovoltaic (PV) systems, leading to power loss and hotspot phenomenon. Currently, most works can only realize shading detection but cannot further diagnose the type and severity of shading. This paper proposes an effective method for diagnosing shading types combining I-V curve imaging with two-stream deep neural networks (DNN), and estimating severity of five common types of shading in actual operating PV systems. In this method, the I-V curves of PV strings are first resampled and converted to standard test conditions (STC) for eliminating the effects of data scale and environmental factors on shading diagnosis results. Then, a time series imaging method called Gramian angular summation field (GASF) is used to enhance the features of shading. Additionally, a two-stream DNN combining long short-term memory (LSTM) and improved two-dimensional convolutional neural network (2D-CNN) is developed to integrate the characteristic information of I-V curves and 2D images. Furthermore, combining the PV mechanism models and characteristics of I-V curves, this work further estimates the severity of different types of shading in operating PV systems considering the effects of aging loss. The effectiveness and generalization of the proposed method are validated via simulated and experimental data obtained from simulation model and an actual PV platform.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119311"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745215","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}

{"title":"Prediction of offshore wind turbine wake and output power using large eddy simulation and convolutional neural network","authors":"Songyue LIU ,&nbsp;Qiusheng LI ,&nbsp;Bin LU ,&nbsp;Junyi HE","doi":"10.1016/j.enconman.2024.119326","DOIUrl":"10.1016/j.enconman.2024.119326","url":null,"abstract":"<div><div>Predicting offshore wind turbine wake and output power is crucial for optimizing wind farm layouts and maximizing wind energy production. In recent years, several Computational Fluid Dynamics methods have been developed to predict wind turbine wake and output power and demonstrated good performance compared with traditional analytical models. However, Computational Fluid Dynamics often involve high computational costs in offshore wind farm design because a wide range of offshore wind conditions need to be considered for turbines with different inter-turbine spacings. To ensure both the fidelity and efficiency for predicting offshore wind turbine wake and output power, Large Eddy Simulation and Convolutional Neural Network are utilized in this study. The Large Eddy Simulation effectively integrates the Actuator Line Method and Discretizing and Synthesizing Random Flow Generation to generate wake velocity, wake turbulence intensity, and output power for a stand-alone turbine under different incoming wind speeds and turbulence intensities. Using the generated dataset, Convolutional Neural Network effectively captures the relationship between inputs and outputs for the stand-alone turbine. The predicted wake data for the turbine can then act as input to estimate the output power density and wake characteristics of a downstream turbine. This process can be iteratively applied to predict the wake and output power of each subsequent turbine in a wind farm, supporting the identification of optimal inter-turbine spacing. The proposed method is illustrated using a utility-scale 5 MW wind turbine. The results show that the errors of predicted output power for a stand-alone wind turbine and multiple wind turbines are blew 3 %.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119326"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745151","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}

{"title":"Towards decarbonisation or lock-in to natural gas? A bottom-up modelling analysis of the energy transition ambiguity in the residential sector by 2050","authors":"Dimitris Papantonis,&nbsp;Vassilis Stavrakas,&nbsp;Dimitra Tzani,&nbsp;Alexandros Flamos","doi":"10.1016/j.enconman.2024.119235","DOIUrl":"10.1016/j.enconman.2024.119235","url":null,"abstract":"<div><div>While a green transition in the Greek building sector is considered critical towards a secure and resilient energy system by 2050, national policymaking continues to support schemes and investments on the expansion of the natural gas grid in the mainland, viewing natural gas as a transition fuel, especially in the residential sector. In this context, this article uses a bottom-up high-resolution demand-side model to simulate different transition scenarios in the Greek residential sector by 2050, as these are extracted from the current existing policy planning and political decisions, recent amendments currently under public consultation, and relevant national experts’ feedback. Simulation outcomes provide the evolution of the energy mix by 2050, along with the respective economic and environmental implications, for the different scenarios under study. Based on these outcomes, two key findings are derived: first, the existing renovation rate as set by national policymaking is not enough to lead to decarbonisation by 2050. If the goal is to achieve decarbonisation by 2050, then the current annual renovation rate of 1.5% must be updated to 2.5%, while, if a more ambitious goal of achieving decarbonisation by 2040 is to be adopted, the annual renovation rate must be updated to 3.5%. Second, the scenarios that promote electrification and the early phase out of natural gas result in lower costs, at both the national and the household level, and in lower levels of carbon emissions by 2050, implying that the current national reliance on natural gas may result in a missed opportunity of a green and inclusive energy transition, or even worse in a potential lock-in effect. Overall, this study provides critical and actionable insights to inform the development of national planning initiatives and support policymakers in crafting strategies that align with the overarching objectives of decarbonisation, climate neutrality, and energy security.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119235"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745430","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}

{"title":"A novel anode-sharing configuration to enhance the volumetric power density of short stack of proton exchange membrane fuel cells: An experimental and numerical simulation study","authors":"Mingxin Liu ,&nbsp;Tongxi Zheng ,&nbsp;Yang Luan ,&nbsp;Xunkang Su ,&nbsp;Ke Jiang ,&nbsp;Wenxuan Fan ,&nbsp;Taotao Zhao ,&nbsp;Seong Hyuk Lee ,&nbsp;Yuanzhu Xin ,&nbsp;Mi Wang ,&nbsp;Guolong Lu ,&nbsp;Zhenning Liu","doi":"10.1016/j.enconman.2024.119329","DOIUrl":"10.1016/j.enconman.2024.119329","url":null,"abstract":"<div><div>One goal for developing proton exchange membrane fuel cells is to increase the volumetric power density, enabling them to compete with internal combustion engines. Hence, this work proposes a novel anode-sharing configuration for a two-unit short stack of proton exchange membrane fuel cells, which effectively decreases the volume of the stack by utilizing one anode gas channel to supply hydrogen to both units. The feasibility and optimal operating conditions of this novel configuration have been validated by experiments. Three-dimensional numerical simulations reveal that alterations in stack configuration do not influence the distribution of reactants. Yet, the temperature in the anode-sharing short stack is relatively high due to the accumulated heat in the shared anode without cooling, which may cause membrane dehydration and affect overall performance. These negative effects can be offset by increasing relative humidity. Moreover, the thermal management can be significantly improved by enhancing cooling of the cathode when scaling up. A six-unit anode-sharing stack equipped with an enhanced cooling flow field has reduced the volume by 33.3 % and increased the volumetric power density by 40 %. The anode-sharing stack can achieve a volumetric power density up to 7 kW/L, a step closer to that of the internal combustion engines.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119329"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745529","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}

{"title":"A flexible tool for the multi-attribute evaluation of Lithium-ion batteries","authors":"Salvatore Cellura,&nbsp;Andrea Mazza,&nbsp;Ettore Bompard,&nbsp;Stefano Corgnati","doi":"10.1016/j.enconman.2024.119312","DOIUrl":"10.1016/j.enconman.2024.119312","url":null,"abstract":"<div><div>Lithium-ion batteries are among the most advanced electrochemical storage technologies and they are critical to the transition to sustainable energy systems. Despite their maturity, different chemistries are characterized by different technical, economic, environmental, and raw materials supply risks, highlighting the need for a comprehensive assessment. Seven lithium-ion battery chemistries were evaluated according to two domains: the techno-economic domain and the environmental and supply risk domain, and synthesized into an overall index called the Energy Storage Sustainability Index. A flexible multi-attribute evaluation tool, called Sustainable Technology Performance, has been developed based on the Multi-Attribute Value Theory model and the Analytic Hierarchy Process weighting method. The model’s uncertainties are addressed by employing various marginal value functions and scenarios for the weights of the domains in the main simulations, and variation for the input data and a different weighting procedure for the attributes in the five sensitivity analyses conducted. The Lithium Iron Phosphate-Natural Graphite battery emerges as the preferred option, performing better in three out of five scenarios in <em>Simulation 1</em> and four out of five in <em>Simulation 2</em>, with high techno-economic scores (0.88 for <em>Simulation 1</em> and 0.93 for <em>Simulation 2</em>) and good environmental and supply risk scores (0.47 for <em>Simulation 1</em> and 0.6 for <em>Simulation 2</em>). Sensitivity analyses show that changing the weighting procedure from AHP to equal weights increases the contribution of attributes where the Lithium Iron Phosphate-Natural Graphite alternative underperforms, such as energy density and resource depletion. Overall, this alternative is preferred in most of the scenarios analyzed (twenty-six over fifty), highlighting its strengths in the techno-economic dimension.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"324 ","pages":"Article 119312"},"PeriodicalIF":9.9,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}