Energy Conversion and Management-X最新文献

{"title":"Optimizing hybrid renewable energy based automated railway level crossing in Bangladesh: Techno-economic, emission and sensitivity analysis","authors":"","doi":"10.1016/j.ecmx.2024.100744","DOIUrl":"10.1016/j.ecmx.2024.100744","url":null,"abstract":"<div><div>The railway system in Bangladesh, particularly the level crossing system, needs significant advancements, including a shift towards using renewable energy to power these crossings. As a solution, this study proposes optimal hybrid systems powered by renewable energy on an automated railway level crossing system, which is reliable, efficient, and sustainable. The main contribution of this study is to introduce an optimal hybrid renewable energy-based automated railway level crossing system in Bangladesh, focusing on technical and economic evaluation, emissions, and sensitivity assessment using HOMER Pro. The proposed system examines the optimal outcome for a 1 kW vertical-axis wind turbine and a 0.440 kW photovoltaic system at five selected locations. The results reveal satisfactory net present cost values amounting to USD 8495, USD 8505, USD 8564, USD 8262, and USD 8357 for Narayanganj, Cox’s Bazaar, Noakhali, Dinajpur, and Rajshahi respectively. Moreover, HOMER Pro indicates that the photovoltaic-wind turbine–grid-connected model offers a lower Cost of Energy which is around 0.03 USD/kWh compared to other configurations. The Internal Rate of Return for the selected locations are 20 %, 33.7 %, 31.5 %, 5.2 %, and 4.6 % for Narayanganj, Cox’s Bazaar, Noakhali, Dinajpur, and Rajshahi, respectively. The developed structure is projected to have a payback period ranging from 4.57 to 13.29 years across the five selected locations. Furthermore, the proposed systems reduce greenhouse gas emissions by up to 44.23 % compared to a grid-only system. Additionally, sensitivity analysis is performed by varying wind speed and solar irradiation to emphasize the robustness of the proposed systems.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420635","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":"Electrical Performance and Degradation Analysis of Field-Aged PV Modules in Tropical Climates: A Comparative Experimental Study","authors":"","doi":"10.1016/j.ecmx.2024.100719","DOIUrl":"10.1016/j.ecmx.2024.100719","url":null,"abstract":"<div><div>Performance degradation is a prevalent phenomenon in solar photovoltaic systems globally, with varying aging profiles and effects depending on environmental and climatic conditions. This paper presents an extensive investigation of the electrical performance, aging mechanisms, and degradation analysis of field-aged PV modules under the tropical climate of Malaysia. Utilizing a combination of visual inspection, I-V curve measurement, and thermal imaging techniques, this research provides a comprehensive assessment of the electrical and thermal properties of field-aged PV modules from two locations in Malaysia over extended periods (8 years at UMPSA and 10 years at Pasir Mas). The multi-faceted approach of the study allows for a deeper understanding of the degradation process, offering insights into the causes and effects of higher current and lower voltage in aged modules. The study found the average annual degradation rates at UMPSA were 0.3% for open circuit voltage (<span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>oc</mi></mrow></msub></mrow></math></span>), 0.23% for short circuit current (<span><math><mrow><msub><mrow><mi>I</mi></mrow><mrow><mi>sc</mi></mrow></msub></mrow></math></span>), 0.81% for maximum power (<span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mi>max</mi></mrow></msub></mrow></math></span>), and 0.35% for fill factor (FF) and at Pasir Mas, the average annual degradation rates were 1.124% for Voc, −0.166% for Isc, 1.276% for Pmax, and 0.43% for FF. The study also found that monocrystalline silicon (m-Si) panels experienced an average power degradation of 6.48%, while polycrystalline silicon (p-Si) panels showed a higher degradation of 12.76%. However, Thermal imaging revealed significant temperature variations across the modules, with hotspots reaching up to 11.2 °C above cooler areas in UMPSA panels and an even more pronounced 26.1 °C difference in Pasir Mas modules. These temperature disparities highlight the uneven heat distribution and potential performance issues in the panels. This research contributes to the understanding of PV module degradation in tropical climates and aligns with sustainable development, climate change mitigation efforts, and SDG 7 by promoting sustainable energy solutions.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420636","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":"Novel energy efficient integration of chimney ventilation, liquid desiccant dehumidification, and evaporative cooling for humid climates","authors":"","doi":"10.1016/j.ecmx.2024.100755","DOIUrl":"10.1016/j.ecmx.2024.100755","url":null,"abstract":"<div><div>The chimney effect for driving passively building ventilation is effective in dry and moderate climates to introduce cool fresh air into the space. However, its application in hot humid climates is limited due to the high energy demands associated with dehumidifying and cooling outdoor air. Thus, a novel energy-efficient assistive system is proposed integrating a chimney-driven ventilation with liquid desiccant dehumidification membrane loop and indirect evaporative cooling. This system leverages natural buoyancy to supply ventilation airflow and uses potassium formate loops through semi-permeable membranes for effective dehumidification. The objective is to dehumidify and cool the induced outdoor air to the room conditions of <span><math><mrow><mn>24</mn><msup><mspace></mspace><mo>°</mo></msup><mi>C</mi></mrow></math></span> and relative humidity between <span><math><mrow><mn>40</mn><mo>%</mo></mrow></math></span> and <span><math><mrow><mn>60</mn><mo>%</mo></mrow></math></span> at minimal energy consumption. Mathematical models were developed to simulate the heat and mass transfer processes in the air and liquid desiccant flows within the system components. The system was sized, and its operation was optimized using an advanced machine learning-genetic algorithm model for a typical office space in Beirut. During the summer, the chimney air flowrate ranged from <span><math><mrow><mn>45</mn><mi>L</mi><mo>/</mo><mi>s</mi></mrow></math></span> to <span><math><mrow><mn>48</mn><mi>L</mi><mo>/</mo><mi>s</mi></mrow></math></span>, and it was delivered at the target room conditions. The system saved around <span><math><mrow><mn>350</mn><mi>k</mi><mi>W</mi><mi>h</mi></mrow></math></span> of electrical energy during the summer months due to elimination of the need to treat ventilation air by room cooling system. This was equivalent to the total energy required to handle the ventilation load during the summer season and resulted in a saving of $50/month in the case study.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445677","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":"An Ecoflex-encapsulated interlayer-structured triboelectric nanogenerator for Sports activity monitoring","authors":"","doi":"10.1016/j.ecmx.2024.100759","DOIUrl":"10.1016/j.ecmx.2024.100759","url":null,"abstract":"<div><div>Incorporating self-powered devices with flexible sensors not only tackles the power obstacles linked to wearable electronics but also greatly broadens their capability and application fields. Triboelectric nanogenerator (TENG) have garnered significant interest in the wearable electronics sector because of their distinct ability to harness ambient energy. Several techniques have been suggested to improve the efficiency of TENG, but these strategies often result in higher intricacy and manufacturing expenses. This study presents an interlayer structure that efficiently increases the surface contact area of TENG, consequently improving their output performance. Using this structure, a cost-effective, highly sensitive, and easily manufacturable sensor called the Ecoflex-encapsulated interlayered triboelectric nanogenerator (EI-TENG), has been developed. The EI-TENG demonstrates superior performance compared to a monolayer TENG (M-TENG) of identical dimensions, exhibiting a 1.6-fold increase in voltage output, a fivefold enhancement in minimum measurement precision, and a 2.29-fold increase in sensitivity. In addition, the EI-TENG exhibits exceptional endurance, as it maintains a consistent output even after undergoing 10,000 cycles. Furthermore, it reliably functions under different temperature and humidity situations. The energy produced by the EI-TENG is adequate to power 45 LED lamps directly. The EI-TENG, when affixed to an athlete’s hand, is capable of sensing the distribution of pressure while dribbling and shooting a ball, which assists athletes in honing their methods and making necessary adjustments to their hand strength. This study not only demonstrates the creation of interlayer-structured TENG, which produces a high amount of electrical energy and is durable and stable in many environments, but also provides valuable information for the future advancement of affordable, self-sustaining electronic devices.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540336","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 economywide impact of bioethanol production in South Africa","authors":"","doi":"10.1016/j.ecmx.2024.100729","DOIUrl":"10.1016/j.ecmx.2024.100729","url":null,"abstract":"<div><div>Bioethanol production as a substitute for petroleum in road transport fuels has been identified as a potential partial solution to environmental and socioeconomic challenges facing developing countries, including South Africa. Biofuels in motor vehicles emit fewer GHGs relative to conventional fuels, and their production can lead to economic growth and associated socioeconomic outcomes, including increased labour employment and improved household welfare. The objective of this paper was to quantify the socioeconomic impact of bioethanol production in South Africa using sugarcane as a feedstock and to assess the effects of increasing the size of the bioethanol plant. The study is based on the 2018 KwaZulu-Natal and South African Social Accounting Matrices (SAM), and two assumed scenarios are considered, namely a scenario where only export destined sugarcane is used to produce bioethanol (scenario I) and a scenario when all sugarcane is used to produce bioethanol (Scenario II). The SAMs modified from the SAMs initially compiled by Conningarth Economists were used to develop an input–output multipliers economic impact model. The production of bioethanol from sugarcane was anticipated to have positive socioeconomic impacts namely, an increase in the country’s GDP, employment growth, gross-capital formation, positive contribution to fiscus, improvement in household welfare and positive contribution to the balance of payment (BOP). Expanding the size of the bioethanol plant is expected to magnify the impacts. The study, therefore, recommends a removal of bottlenecks in bioethanol expansion, including high feedstock cost, limited investment, and absence of mandatory blending policy, amongst others.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420637","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 material properties and performance of flexible thermoelectric generators with/without graphene","authors":"","doi":"10.1016/j.ecmx.2024.100741","DOIUrl":"10.1016/j.ecmx.2024.100741","url":null,"abstract":"<div><div>With the advancement of energy harvesting methods, the power level consumed by electronic circuits and sensors has been reduced so that self-sufficiency in power can be achieved, and the use of flexible thermoelectric generators to supply electrical energy is one of these methods. In this study, the manufacture of flexible thermoelectric generators is successfully developed and verified using a numerical method. The process follows the sandwich method of the conventional thermoelectric module and utilizes two different elastomers (polydimethylsiloxane and Eco-Flex) and thin copper sheets. Among the nine cases designed by the Taguchi method, the maximum tensile strength of the elastomer is 0.967 MPa, stemming from the operation conditions of 6 min stirring time, 85 °C heating temperature, and 3 h heating time. This strength is substantially higher than those of the other eight cases. The open-circuit voltage of the manufactured flexible thermoelectric generator with an internal resistance of 1.5 Ω is 0.011 V. The output power under a temperature difference of 75 °C is 11 μW. After blending graphene into polydimethylsiloxane, the elastomer’s thermal conductivity at 370 K rises by 9.6 folds. This results in the output power being lifted to 0.0515 W (75 °C temperature difference), accounting for an amplification of 4,681 times. Numerical simulations are also performed to aid in figuring out the detailed performance of the flexible thermoelectric generator. The errors between numerical simulations and experiments are between 4.6 % and 5.2 %, showing the reliability of the numerical predictions. The fabricated flexible thermoelectric generators can be practically used for green power generation by harvesting industrial low-temperature waste heat and biothermal energy, potentially driving sensors on industrial devices, the human body, and animals.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420639","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":"Water desalination using waste heat recovery of thermal power plant in tropical climate; optimization by AI","authors":"","doi":"10.1016/j.ecmx.2024.100731","DOIUrl":"10.1016/j.ecmx.2024.100731","url":null,"abstract":"<div><div>The primary objective of the current research is to address the pressing issue of water scarcity in Khuzestan Province, Iran, specifically targeting the Khorramshahr gas power plant. The proposed redesign incorporates a Multi-Effect Distillation (MED) unit with Thermal Vapor Compression (TVC) and dual-pressure heat recovery steam generators. This innovative system aims to optimize cost reduction, minimize CO₂ emissions, and maximize both net output power &amp; energy efficiency, simultaneously. The optimization process is facilitated by artificial neural networks and genetic algorithms, utilizing EES and MATLAB software. Optimized system is projected to gain more average cost of 1,912.1 $/h, reflecting the investment required for the redesign and upgrades. Water production is expected to reach 64 kg/s, and the energy efficiency is anticipated to increase by more than 10 %. CO₂ emissions are forecasted to decrease by approximately 23 %. From exergy point of view, the exergy efficiency of the system has been enhanced from 31.1 % for the conventional state to 41.7 % as the best optimized case (10.6 % improvement). In the suggested system, outlet gas exergy, with an amount of 136.9 MW, is recovered. Finally, the net power output is set to rise by around 32 %, further enhancing the overall performance of the power plant.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358521","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":"Life cycle greenhouse gas emissions and cost of energy transport from Saudi Arabia with conventional fuels and liquefied natural gas","authors":"","doi":"10.1016/j.ecmx.2024.100747","DOIUrl":"10.1016/j.ecmx.2024.100747","url":null,"abstract":"<div><div>The International Maritime Organization has recently developed several regulations to reduce greenhouse gas (GHG) emissions. To meet these targets, ship builders and operators must either replace or upgrade the existing fleet with new decarbonized vessel technologies and/or switch to alternative fuels. The latter has been of interest, especially using liquefied natural gas (LNG), among other alternative fuels, which can have lower emissions than conventional fuels. In Saudi Arabia in 2023, LNG was priced about 10 times lower than in Europe. In this study, Well-to-Wake life cycle GHG emissions and cost are calculated for a SUEZMAX tanker operating with three fuel options: high sulfur fuel oil, very low sulfur fuel oil and LNG. This is done for two different trips, for Saudi Arabia to Japan and Saudi Arabia to the Netherlands. Results show 11% and 12% life cycle GHG emissions reduction with LNG for trips to the Netherlands and Japan, respectively. From a sensitivity analysis of methane slip, LNG cost and anchoring time, the cost of GHG abatement for the LNG vessel varied from 171 United States dollars (USD) to –255 USD, and from 206 USD to –191 USD per ton of GHG, for the trip to the Netherlands and Japan, respectively.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420250","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":"Circulation of self-supplied water for significant energy recovery through heat integration","authors":"","doi":"10.1016/j.ecmx.2024.100740","DOIUrl":"10.1016/j.ecmx.2024.100740","url":null,"abstract":"<div><div>This study introduces an overhead heat-integrated distillation column (OHIDiC), a novel approach that maximizes heat recovery by multiple heat exchanges and product circulation. By utilizing the overhead vapor as a direct heat source, low-temperature feed and product water were used as cooling agents, thereby significantly reducing the condenser duty and reliance on cooling utilities. Additionally, the heated feed transfers heat to the column, leading to a substantial reduction of reboiler heat duty. Some of the heated product water is recycled back to the decanter for product cycling, while the rest is released as the final product. This circulation process ensures a continuous coolant supply, which contributes the reduction of condenser duty. Two processes were considered in this study, utilizing the water product from a non-reactive, and from a reactive separation within the system. When applied to the separation of a water-dodecanol mixture, OHIDiC reduced the condenser duty by 69.21% compared to a traditional distillation column, with a 31.46% reduction in the total utility consumption. When reactive distillation was incorporated into the OHIDiC, the higher overhead vapor temperature facilitated high heat transfer in the multiple heat exchange sections, thereby significantly reducing the total thermal load. This resulted in a reduction of up to 46.96% in total heat duty and a 36.06% decrease in CO₂ emissions. These findings confirm that the OHIDiC achieves significant energy savings through the utilization of process-derived substances, with pronounced benefits when the temperature of the overhead vapor becomes higher.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420627","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 novel algorithm for optimizing genset operations to minimize fuel consumption in remote diesel-RES microgrids","authors":"","doi":"10.1016/j.ecmx.2024.100728","DOIUrl":"10.1016/j.ecmx.2024.100728","url":null,"abstract":"<div><div>This paper addresses the challenge of reducing fuel consumption in Diesel-RES (Renewable Energy Sources) isolated microgrids, particularly focusing on Diesel Genset’s (DG) operation. The study introduces a basic rule based energy management system that serves as a platform to test out various DG operational strategies with a novel approach. Two optimization strategies—load dispatch optimization and unit commitment optimization—are explored to unequally distribute loads among different grid-connected DGs and sequence their start/stop based on predictive demand profiles respectively. Additionally, the integration of a spinning reserve-providing battery is investigated to alleviate DGs from their spinning reserve constraint, resulting in higher operational loads and consequently higher efficiency. The proposed model is applied on a case study of the Tahitian power system, demonstrating reductions in fuel consumption. The combined application of the proposed DG load dispatch and unit commitment optimizations, along with the integration a spinning-reserve-providing battery, yielded a 2.6 % reduction in fuel consumption and 6kt decrease in CO2 emissions over a year compared to a basic DG operation without a battery.</div></div>","PeriodicalId":37131,"journal":{"name":"Energy Conversion and Management-X","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420628","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}