Energy Conversion and Management-X最新文献

{"title":"A review of operational factors affecting photovoltaic system performance","authors":"Edgar Hernando Sepúlveda-Oviedo","doi":"10.1016/j.ecmx.2025.100942","DOIUrl":"10.1016/j.ecmx.2025.100942","url":null,"abstract":"<div><div>The reduction in manufacturing costs of photovoltaic (PV) systems has driven significant growth in the PV industry. This expansion has shifted the current challenge from constructing new PV systems to maximizing the performance and longevity of installed PV modules. PV performance is influenced by two major categories of factors: environmental and operational. While environmental factors, such as dust and temperature, have been extensively studied, operational factors — critical for optimizing system efficiency — have not received the same level of attention. This study analyzes 102 articles focusing on operational factors such as PV technology, tilt and orientation angles, surface properties, height, and component aging, while also examining their interaction with environmental factors, particularly dust. In addition, the study compiles a set of standardized metrics aimed at quantifying efficiency losses and enabling consistent comparisons across studies. Finally, this review outlines a roadmap identifying key research gaps and provides recommendations for improving PV system performance. This roadmap offers valuable insights for researchers, engineers, and policymakers to better understand and address the operational factors that influence the efficiency and lifespan of PV systems.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100942"},"PeriodicalIF":7.1,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agricultural tractor electrical propulsion concept","authors":"Tero Lappalainen,&nbsp;Ilya Petrov,&nbsp;Juha Pyrhönen","doi":"10.1016/j.ecmx.2025.100935","DOIUrl":"10.1016/j.ecmx.2025.100935","url":null,"abstract":"<div><div>Although the limited energy density of energy storages currently slows down the electrification of agricultural tractors, the wide rotation speed range and excellent torque of electric machines are of particular interest in propulsion research and development in the field. Modern tractor propulsion systems must be able to comply with a variety of applications from low-speed high-torque to moderate and high-speed applications. Two distinct operating points may be highlighted. Ploughing or cultivating are typically performed at speed less than 10 km/h, whereas transportation takes place at speeds between 50–60 km/h. In both cases, constant high-power operation is demanded. This differentiates a tractor’s electric drive cycle totally from e.g. a passenger car electric drive load. A concept-level examination into the electrical propulsion suitability for an agricultural tractor’s rear axle is presented. Since there are several options for the type of propulsion motor, a rough pre-selection process is first performed. Selected machine types are then studied against the required pulling performance curve by employing applicable ratios for planetary and final drive gear reduction. Machine efficiencies are analytically calculated at operating points and further validated with 2D efficiency maps for the best candidates. Magnetic circuits are subjected to a mechanical quantification and a corresponding cost structure is calculated with publicly available commodity prices. Finally, a candidate for a prototype building and testing phase is proposed.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100935"},"PeriodicalIF":7.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simple simultaneous envelope/system optimization for energy efficiency improvement in near-zero energy buildings","authors":"Martín Muñoz-Salcedo ,&nbsp;José L. Saquinaula-Brito ,&nbsp;Jhonny Ortíz-Mata ,&nbsp;Fernando Peci-López","doi":"10.1016/j.ecmx.2025.100951","DOIUrl":"10.1016/j.ecmx.2025.100951","url":null,"abstract":"<div><div>This study develops a simple yet innovative framework for the simultaneous long-term optimization of building envelope strategies and energy systems in near-zero energy buildings (nZEB). The proposed framework evaluates the energy and economic performance of four envelope strategies—phase change materials (PCM), aerogel insulation, green walls, and awnings—integrated into a distributed generation mix comprising photovoltaic (PV) systems, wind turbines, battery storage, and grid support. The main objective is to analyze the influence of envelope solutions within the distributed generation mix to meet the building’s energy demand. The model is formulated as a mixed-integer disciplined convex program (MIDCP) and solved using the CVXR package in R, minimizing the total cost of envelope and energy systems over a 30-year period. The cost function is based on the CEN EN 15459 standard. Model validation is performed using real experimental data from a building located in Ecuador’s coastal region, characterized by a hot and humid climate. Its robustness is further verified through a sensitivity analysis that explores economic parameter variations and long-term climate change scenarios, combining EnergyPlus simulations with eplusr in R. Results indicate that the awning-based envelope strategy achieves the best performance under current conditions, with energy savings of 12–15 kW/year and a payback period of 8 years. For long-term economic viability, investment cost reductions of 73 %, 60 %, and 71 % are necessary for PCM, aerogel, and green wall solutions, respectively. This integrated optimization model provides a practical decision-making tool for evaluating cost-effectiveness and energy performance under evolving market and climate conditions.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100951"},"PeriodicalIF":7.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative assessment of single axis manual solar PV trackers: A case study for agricultural applications","authors":"Jad Atallah,&nbsp;Pierre Rahme,&nbsp;Jimmy S. Issa","doi":"10.1016/j.ecmx.2025.100927","DOIUrl":"10.1016/j.ecmx.2025.100927","url":null,"abstract":"<div><div>Harnessing solar energy through photovoltaic (PV) systems has become crucial due to the global need for sustainable energy solutions. Agricultural projects are often conducted in remote areas lacking direct access to the power grid. This study evaluates four solar system configurations for irrigation. The first is a fixed-panel system with panels oriented south at an optimized tilt angle. The second and third systems involve manual adjustment, requiring one or two rotations per day to enhance solar tracking. The fourth configuration is a dual-axis tracking system, which continuously tracks the sun in real-time. The case study, conducted over six months (May to October) in northern Lebanon, utilized hourly solar irradiance data from an on-site pyranometer to determine optimal tilt angles for the fixed and manually adjusted systems. Solar irradiation received by each configuration was then calculated and compared. Results show the dual-axis system performed best, capturing 38% more solar energy than the fixed system. Manually adjusted systems also improved efficiency, with one-time daily rotation increasing energy capture by 23% and two-time daily rotation by 28%. Although the dual-axis system achieves maximum performance, manually adjusted systems provide a cost-effective alternative with significant efficiency gains and lower installation and maintenance expenses.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100927"},"PeriodicalIF":7.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of combined electricity generation and cooling load reduction by incorporating roof top photovoltaic module: An approach to energy consumption reduction in a hospital building","authors":"Khaza Shahriar,&nbsp;Md. Hasan Ali,&nbsp;Md.Khaled Mahmud,&nbsp;Mohammad Rezwan Hossain","doi":"10.1016/j.ecmx.2025.100948","DOIUrl":"10.1016/j.ecmx.2025.100948","url":null,"abstract":"<div><div>In this era of renewable energy growth, PV systems are being used in buildings extensively for onsite off-grid electricity generation to reduce dependency on grid energy and hence dependency on fossil fuel. Among various PV systems of buildings, the Rooftop PV system is the most common practice. This system has combined the advantage of energy efficient design and use of renewable energy as rooftop PV system has not only the potential of electricity generation but also potential of cooling load reduction acting as passive cooling device by providing shadow on roof. In this study, performance test and optimization of rooftop solar PV system is studied considering three different PV system mountings: south facing single separate string, south facing multiple string attached system and east–west facing system. A 35.5 kWp PV system was designed considering KUET Medical Center building and was analyzed in terms of tilt angle and height of the panel from roof surface considering optimum row spacing. It was found that multiple string attached system offers the best performance in terms of electricity generation, cooling load reduction and CO₂ reduction with an annual cooling load reduction of 16.6%, generation of 65.6 MWh and CO₂ reduction of 32.55 tons. The optimum tilt angle for single-string, multi-string and east–west system was found 24°, 28° and 2°, respectively. In all cases, generation increases with the increase of height from roof surface. The cost analysis suggests that along with other benefits, multi-string attached system has the lowest LCOE of 6.10 BDT/kWh, shortest payback period and highest ROI compared to the other two systems. Greater generation than the electricity load suggests that incorporating PV system can make the studied building net positive energy building and the surplus electricity can be used in other buildings or supplied to grid. The results suggest that locations with higher solar exposure, benefit the from integrated rooftop PV implementation not only reduces dependence on conventional energy sources but also ensures a sustainable and uninterrupted power supply for healthcare facilities.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100948"},"PeriodicalIF":7.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental life cycle assessment of industrial high-temperature to residential small-size heat Pumps: A critical review","authors":"Jacopo Famiglietti ,&nbsp;Leonardo Acconito ,&nbsp;Cordin Arpagaus ,&nbsp;Tommaso Toppi","doi":"10.1016/j.ecmx.2025.100947","DOIUrl":"10.1016/j.ecmx.2025.100947","url":null,"abstract":"<div><div>The decarbonization process of the industry and the heating sector, underway in Europe, directly involves heating, cooling, ventilation, and air conditioning systems. In this context, heat pump technologies play a key role in having the ability to be powered by decarbonized energy carriers (i.e., electricity from renewables for vapor compression cycle, hydrogen for absorption cycle, etc.), as well as harnessing renewable or waste heat, in different applications (i.e., industry, district heating networks, and civil sector). The European Commission considers the life cycle assessment method one of the leading methodologies for environmental metrics. Many scientific studies related to analyzing the environmental profile of heat pumps have been written using this method. With the aim to investigate the outcomes achieved and modeling approaches applied, this study reviews existing environmental life cycle assessment studies of (i) high-temperature, (ii) large-size (over 300 kW_th), and (iii) medium and small-size heat pumps. In total, 19 articles containing 637 scenarios were found in the literature to be relevant to the research aim. The study analyzes different heat pump technologies (i.e., vapor compression, absorption, and indirect Stirling cycles). The analysis shows that the use phase is the main contributor: (i) average value of 94.6% for the global warming potential, (ii) 69.9% for abiotic depletion potential indicator (metals and minerals). The analysis reveals that life cycle assessment studies apply a rather narrow approach and lack variability in modeling. For future research, it is recommended that the thermodynamic behavior of the heat pumps be properly simulated or monitored. In addition, a stochastic evaluation shall be included in the analysis to reduce and highlight the uncertainty of the results, especially the global sensitivity analysis. Finally, high-temperature heat pumps shall also be investigated using the consequential approach to understand better the environmental consequences of installation in an industrial production process.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100947"},"PeriodicalIF":7.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioethanol as an alternative fuels: A review on production strategies and technique for analysis","authors":"Mona Fatin Syazwanee Mohamed Ghazali ,&nbsp;Muskhazli Mustafa","doi":"10.1016/j.ecmx.2025.100933","DOIUrl":"10.1016/j.ecmx.2025.100933","url":null,"abstract":"<div><div>Bioethanol production represents an alternative source of energy that also helps minimize greenhouse gas effects. Currently, the focus of advanced technologies for bioethanol production is on the conversion of lignocellulosic biomass into renewable energy for transportation as it offers a low cost of investment and non-pollution bioprocesses. However, the utilization of lignocellulosic biomass has several challenges, including the high cost of pretreatment, the recalcitrant nature of the biomass and the requirement for robust microbes to ferment various types of sugars. Informations on the subject were achieved through a literature search using various electronic databases such as Google Scholar, ScienceDirect, Scopus, and others. From literature findings, few strategies such as separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), simultaneous saccharification and co-fermentation (SSCF), and consolidated bioprocessing (CBP); were found established to overcome these challenges, ultimately increasing the effectiveness of the bioconversion process and minimizing the overall cost of production. CBP was found to be the most promising strategy as direct production of ethanol from pretreated corn cob yielded 11.1 g/L ethanol without the addition of external hydrolytic catalyst. Various analytical techniques are commonly used to quantify bioethanol in a sample, and these methods were theoretically analyzed in relation to established theories. Currently, gas chromatography is known to be the most effective approach with limits of detection typically around 0.099 mg/mL, demonstrating excellent linearity and recovery rates between 91% and 109%. This paper aims to highlight the efficiency of every strategy involved in the bioconversion process and provide insights into every suitable analytical technique that can be employed to ensure the sustainability of biofuel by allowing researchers to improve the productivity and quality of bioethanol, thus promoting its role as a feasible alternative fuel.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100933"},"PeriodicalIF":7.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"State-of-the-art Gaidai hypersurface reliability assessment for semi-submersible wind turbines, accounting for memory effects","authors":"Oleg Gaidai ,&nbsp;Fang Wang ,&nbsp;Jinlu Sheng ,&nbsp;Yan Zhu ,&nbsp;Alia Ashraf ,&nbsp;Yu Cao","doi":"10.1016/j.ecmx.2025.100946","DOIUrl":"10.1016/j.ecmx.2025.100946","url":null,"abstract":"<div><div>Nowadays renewable, sustainable green energy generation gaining momentum, as environmental concerns, e.g., climate change making fossil fuel usage less attractive. Resultingly, offshore wave and wind power are gaining popularity, steadily replacing hydrocarbon energy sources. Floating offshore wind turbines (FOWT), being pivotal for contemporary offshore green wind energy generation.</div><div>Accurate structural lifespan prognostics is necessary for safe and resilient technological design, operational safety and economic viability. Non-stationary, multi-modal dynamic environmental wave-wind loads result in accumulated fatigue damage, as well as excessive structural deformations. Presented case study introduces generic, robust multi-modal structural reliability evaluation methodology, based on accurate numerical modelling of in-situ environmental hydro- and aero-dynamic stressors, acting on operating FOWT. Coupled aero-hydro-servo-elastic nonlinear software package OpenFAST was employed for numerical Monte Carlo Simulations (MCS). Investigated 5 MW FOWT is designed to withstand nonlinear, nonstationary, periodically adverse ambient environmental conditions throughout its complete designed service-life. This case study outlines state-of-the-art multi-modal hypersurface risk evaluation and lifetime assessment methodology.</div><div>The primary novelty and practical advantage of the proposed multi-modal Gaidai hypersurface structural risk evaluation approach lie within its robust capacity to evaluate structural damage (hazard/failure) risks for complex dynamic structural systems, with no limitation on the structural Number of Degrees Of Freedom (NDOF), i.e., the number of inter-correlated system dimensions/components.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100946"},"PeriodicalIF":7.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The hybrid attic ventilation technique as a sustainable strategy for thermal comfort improvement and energy saving in tropical residential buildings","authors":"Mahdi Moharrami ,&nbsp;Aidin Nobahar Sadeghifam ,&nbsp;Hamed Golzad ,&nbsp;Eeydzah binti Aminudin ,&nbsp;Seyedeh Sara Miryousefi Ata ,&nbsp;Hesam Kamyab","doi":"10.1016/j.ecmx.2025.100944","DOIUrl":"10.1016/j.ecmx.2025.100944","url":null,"abstract":"<div><div>Thermal comfort in hot-humid tropical climates, such as Malaysia’s, is significantly affected by solar radiation, humidity, and air temperature. Solar radiation heats the roof, warming the enclosed attic space and distributing heat throughout the building’s interior. In tropical regions, the attic is integral to the building, and inadequate ventilation can elevate the overall thermal load. This study investigates the impact of a hybrid attic ventilation technique designed to operate continuously over 24 h on enhancing thermal comfort and increasing energy savings. Field measurements were conducted simultaneously in two typical one-storey terrace houses: one with conventional attic conditions and the other equipped with hybrid attic ventilation. Building Information Modelling (BIM) was used to simulate and analyse energy consumption. The results demonstrated that the hybrid ventilation system improved thermal comfort by reducing indoor temperature by 1 °C and relative humidity by 7%, achieving a 10% reduction in overall building energy consumption. The results showed that this hybrid technique effectively enhances thermal comfort and energy efficiency through continuous operation, showing the benefits of both nighttime and daytime ventilation.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100944"},"PeriodicalIF":7.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic, economic, and carbon emission evaluation of various Organic Rankine cycle configurations for maximizing waste heat recovery potential","authors":"Thepparat Klamrassamee ,&nbsp;Tanatip Kittijungjit ,&nbsp;Yanin Sukjai ,&nbsp;Yossapong Laoonual","doi":"10.1016/j.ecmx.2025.100943","DOIUrl":"10.1016/j.ecmx.2025.100943","url":null,"abstract":"<div><div>Waste heat recovery using the Organic Rankine Cycle (ORC) enhances energy efficiency, lowers emissions, and reduces costs. This study evaluates ORC systems for high-temperature waste heat recovery (515.14 °C) using DWSIM software. Various ORC configurations, including simple ORC (sORC), series ORC (S-ORC), single-stage regenerative ORC (SR-ORC), double-stage regenerative ORC (DR-ORC), and multi-evaporating pressure ORC (ME-ORC), were analyzed with different working fluids, including Toluene, Dodecane, Benzene, and Cyclopentane. Toluene was identified as the best working fluid, achieving a thermal efficiency of 24.33 % and a net power output of 1,839.66 kW in the sORC. The S-ORC demonstrated superior performance, delivering 3,679.32 kW of net power at the same efficiency. A parametric study examined the effects of operating pressure, exhaust gas temperature, and mass flow rate on efficiency. Results showed thermal efficiency peaked at 40.08 bar, with optimal performance at an exhaust gas temperature of 520 °C and a mass flow rate of 44.5 kg/s. Exergy analysis identified the evaporator as the main source of inefficiency, highlighting opportunities for improvement to boost overall system efficiency. Economically, the S-ORC achieved a Net Present Value (NPV) of 3.98 million EUR, a payback period of 5.75 years, and an Internal Rate of Return (IRR) of 12.66 %. It also reduced CO₂ emissions by 12,971.36 metric tons annually, translating to 1.04 million EUR in revenue through carbon credit trading under the EU ETS. In summary, the S-ORC configuration offers the best balance of thermodynamic, economic, and environmental benefits for industrial waste heat recovery systems.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":"26 ","pages":"Article 100943"},"PeriodicalIF":7.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}