The growing world interest in clean and sustainable energy has tremendously driven research on photovoltaic systems, with a strong emphasis on the need for accurate modeling and parameter extraction. Accurate PV modeling is vital for optimizing, simulating, and generally enhancing PV device performance. As much as there has been great development, available techniques have commonly faced limitations in finding an adequate balance between analytical accuracy and numerical reliability. In order to overcome these limitations, this paper proposes an innovative hybrid technique that integrates analytical solutions with numerical iterative strategies to accurately extract parameters of the single diode model using the Regula Falsi method. The new approach provides high accuracy in simulating photovoltaic modules by minimizing the Root Mean Square Error (RMSE) between experimental and simulated current-voltage data. It achieves an RMSE value of 7.746E-04 A, which is 1.35 % better than the best alternative approach for RTC France. For Photowatt-PWP 201, it achieves 2.148E-03 A with a 0.12 % improvement. It maintains comparable accuracy for PVM 752 GaAs, with an RMSE of 2.912E-04A, and reaches 1.731E-03A with an increase of 9.02 % for the STM6-40/36 module. Comparative analysis with state-of-the-art techniques highlights the superior efficiency and reliability of the proposed method.
{"title":"A hybrid numerical-analytical approach for solar cells and modules parameter extraction using the Regula-Falsi method","authors":"Fatima Ezzahrae Souaidi, Mustapha Elyaqouti, El Hanafi Arjdal, Driss Saadaoui, Imade Choulli, Abdelfattah Elhammoudy, Brahim Ydir, Ismail Abazine, Souad Lidaighbi, Dris Ben Hmamou, Chahir Omar, Lahboub Ayoub, Bendriouich Youssouf","doi":"10.1016/j.uncres.2025.100266","DOIUrl":"10.1016/j.uncres.2025.100266","url":null,"abstract":"<div><div>The growing world interest in clean and sustainable energy has tremendously driven research on photovoltaic systems, with a strong emphasis on the need for accurate modeling and parameter extraction. Accurate PV modeling is vital for optimizing, simulating, and generally enhancing PV device performance. As much as there has been great development, available techniques have commonly faced limitations in finding an adequate balance between analytical accuracy and numerical reliability. In order to overcome these limitations, this paper proposes an innovative hybrid technique that integrates analytical solutions with numerical iterative strategies to accurately extract parameters of the single diode model using the Regula Falsi method. The new approach provides high accuracy in simulating photovoltaic modules by minimizing the Root Mean Square Error (RMSE) between experimental and simulated current-voltage data. It achieves an RMSE value of 7.746E-04 A, which is 1.35 % better than the best alternative approach for RTC France. For Photowatt-PWP 201, it achieves 2.148E-03 A with a 0.12 % improvement. It maintains comparable accuracy for PVM 752 GaAs, with an RMSE of 2.912E-04A, and reaches 1.731E-03A with an increase of 9.02 % for the STM6-40/36 module. Comparative analysis with state-of-the-art techniques highlights the superior efficiency and reliability of the proposed method.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100266"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145365589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-07DOI: 10.1016/j.uncres.2025.100276
Sumit Verma , D.K. Yadav , Birinchi Bora , Shiv Lal
Solar photovoltaic modules convert solar energy into electrical energy, but defects like cell cracks, cell breakage, inactive cell area, and other defects impact the long-term performance and reliability of photovoltaic modules. Therefore, developing effective techniques for identifying such defects is crucial for optimising photovoltaic power plants efficiency. Using electroluminescence imaging, a method is proposed to quantify defects in mono PERC and polycrystalline solar photovoltaic modules.
Various statistical measures, such as mean intensity, variance, kurtosis, and skewness of the electroluminescence intensity histogram, were compared. Healthy mono PERC modules exhibit higher values (for mean intensity: 0.530, variance: 0.867, kurtosis: 1.352, and skewness: 1.697) than defective modules (mean intensity: 0.441, variance: 0.396, kurtosis: 0.797, skewness: 1.466), indicating fewer defects with better performance. The polycrystalline photovoltaic module showed higher degradation with Pmax and Imp reductions of 15.13 % and 14.09 %, respectively, during static mechanical load testing. Results also show that modules with fewer defects exhibit better long-term performance, durability, and efficiency, particularly for mono PERC photovoltaic modules, which outperform polycrystalline modules in degradation analysis. Analysing electroluminescence images enables researchers and industry professionals to identify reliability issues in photovoltaic modules and to optimise the performance of solar photovoltaic power plants.
{"title":"Quantifying mechanical stress effects on mono PERC and polycrystalline PV modules with EL imaging and statistical analysis","authors":"Sumit Verma , D.K. Yadav , Birinchi Bora , Shiv Lal","doi":"10.1016/j.uncres.2025.100276","DOIUrl":"10.1016/j.uncres.2025.100276","url":null,"abstract":"<div><div>Solar photovoltaic modules convert solar energy into electrical energy, but defects like cell cracks, cell breakage, inactive cell area, and other defects impact the long-term performance and reliability of photovoltaic modules. Therefore, developing effective techniques for identifying such defects is crucial for optimising photovoltaic power plants efficiency. Using electroluminescence imaging, a method is proposed to quantify defects in mono PERC and polycrystalline solar photovoltaic modules.</div><div>Various statistical measures, such as mean intensity, variance, kurtosis, and skewness of the electroluminescence intensity histogram, were compared. Healthy mono PERC modules exhibit higher values (for mean intensity: 0.530, variance: 0.867, kurtosis: 1.352, and skewness: 1.697) than defective modules (mean intensity: 0.441, variance: 0.396, kurtosis: 0.797, skewness: 1.466), indicating fewer defects with better performance. The polycrystalline photovoltaic module showed higher degradation with P<sub>max</sub> and I<sub>mp</sub> reductions of 15.13 % and 14.09 %, respectively, during static mechanical load testing. Results also show that modules with fewer defects exhibit better long-term performance, durability, and efficiency, particularly for mono PERC photovoltaic modules, which outperform polycrystalline modules in degradation analysis. Analysing electroluminescence images enables researchers and industry professionals to identify reliability issues in photovoltaic modules and to optimise the performance of solar photovoltaic power plants.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100276"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-17DOI: 10.1016/j.uncres.2025.100263
Xinyu Liu , Sandong Zhou , Weixin Zhang , Qiaoyun Cheng , Dameng Liu , Detian Yan , Hua Wang
Movable fluid porosity (Φmf) is a key parameter to evaluate the seepage capacity and movable oil volume of shale reservoirs. Accurate measurement of the Φmf relies on expensive and time-consuming experimental methods, and little work has been done on intelligent prediction. In this study, the Upper Cretaceous Qingshankou Formation shale in the Changling Depression of the Songliao Basin is selected as the research object. The 635 data points are divided into three datasets: training set, validation set, and testing set, allocated in a ratio of 0.7:0.15:0.15. Using five logging parameters including Gamma ray log (GR), Deep lateral resistivity log (RLLD), Acoustic log (AC), Density log (DEN), and Neutron log (CNL), four machine learning models are selected to predict Φmf, including Decision tree (DT), Random forest (RF), Gradient boosting decision tree (GBDT), and Artificial neural network (ANN). Multiple evaluation indicators are adopted to compare the accuracy and applicability of different algorithms. The results show the performance of different algorithms in predicting Φmf, from highest to lowest, as follows: GBDT > RF > DT > ANN. The sensitivity analysis based on the Shapley Additive exPlanations (SHAP) indicates that AC has the greatest positive impact on predicting the Φmf. The applicability analysis shows that compared with the traditional Multiple regression analysis (MRA), the use of machine learning algorithms can effectively improve the prediction accuracy, with a maximum increase of 24 %. This study holds that the GBDT can predict the Φmf of shale reservoirs efficiently and accurately, providing valuable insights for the global evaluation and development of lacustrine shale oil resources.
{"title":"Machine learning method for lacustrine shale oil reservoirs: Improving movable fluid porosity prediction","authors":"Xinyu Liu , Sandong Zhou , Weixin Zhang , Qiaoyun Cheng , Dameng Liu , Detian Yan , Hua Wang","doi":"10.1016/j.uncres.2025.100263","DOIUrl":"10.1016/j.uncres.2025.100263","url":null,"abstract":"<div><div>Movable fluid porosity (Φ<sub>mf</sub>) is a key parameter to evaluate the seepage capacity and movable oil volume of shale reservoirs. Accurate measurement of the Φ<sub>mf</sub> relies on expensive and time-consuming experimental methods, and little work has been done on intelligent prediction. In this study, the Upper Cretaceous Qingshankou Formation shale in the Changling Depression of the Songliao Basin is selected as the research object. The 635 data points are divided into three datasets: training set, validation set, and testing set, allocated in a ratio of 0.7:0.15:0.15. Using five logging parameters including Gamma ray log (GR), Deep lateral resistivity log (RLLD), Acoustic log (AC), Density log (DEN), and Neutron log (CNL), four machine learning models are selected to predict Φ<sub>mf</sub>, including Decision tree (DT), Random forest (RF), Gradient boosting decision tree (GBDT), and Artificial neural network (ANN). Multiple evaluation indicators are adopted to compare the accuracy and applicability of different algorithms. The results show the performance of different algorithms in predicting Φ<sub>mf</sub>, from highest to lowest, as follows: GBDT > RF > DT > ANN. The sensitivity analysis based on the Shapley Additive exPlanations (SHAP) indicates that AC has the greatest positive impact on predicting the Φ<sub>mf</sub>. The applicability analysis shows that compared with the traditional Multiple regression analysis (MRA), the use of machine learning algorithms can effectively improve the prediction accuracy, with a maximum increase of 24 %. This study holds that the GBDT can predict the Φ<sub>mf</sub> of shale reservoirs efficiently and accurately, providing valuable insights for the global evaluation and development of lacustrine shale oil resources.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100263"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145365442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2026-01-08DOI: 10.1016/j.uncres.2026.100309
Fahad Khan , Arshad Raza , Mohamed Mahmoud , Murtadha J. AlTammar , Talal Al Shafloot
High breakdown pressure poses a significant challenges in terms of pumping pressure and associated costs during stimulation operations in unconventional reservoirs. These reservoirs are characterized with low porosity, low permeability, and high in-situ temperature due to greater depths. To address this challenge, the current study investigates the effectiveness of various cooling strategies and their comparative impact on the breakdown pressure and strength of unconventional rocks (Kentucky sandstone and Eagleford shale). These rocks were heated up to 150 °C and cooled down by following three different strategies: ⅰ) spontaneous cooling i.e. without any external aid ⅱ) cooling with cold water and ⅲ) cooling with endothermic chemicals involving NH4Cl and NaOH. With endothermic cooling, the temperature of Kentucky sandstone decreases from 150 °C to 56.7 °C in 14 s, while Eagleford shale cools from 150 °C to 43.8 °C in 10 s. The endothermic cooling was followed by the Cold water and spontaneous cooling which showed slower and less pronounced temperature drops in both rocks as compared to the endothermic cooling. The endothermic cooling also leads to highest reduction in rock strength and breakdown pressure. The strength shows a reduction of 21.9 % in Kentucky sandstone and 25.4 % in Eagleford shale while the breakdown pressure reduces by 38.6 % and 37.3 % for the Kentucky sandstone and Eagleford shale respectively. The study also shows the structural changes in the rocks, particularly rock morphology and pore volume. FIB-SEM analysis shows the development of multiple micro-cracks in the rocks which plays an important role in reducing the breakdown pressure. The outcomes of this study indicate that pre-fracturing cooling treatment using endothermic fluids can enhance the effectiveness of hydraulic fracturing operations by reducing the formation breakdown pressure.
{"title":"Comparative impact of cold water and thermochemical cooling methods on breakdown pressure for improved stimulation in unconventional formations","authors":"Fahad Khan , Arshad Raza , Mohamed Mahmoud , Murtadha J. AlTammar , Talal Al Shafloot","doi":"10.1016/j.uncres.2026.100309","DOIUrl":"10.1016/j.uncres.2026.100309","url":null,"abstract":"<div><div>High breakdown pressure poses a significant challenges in terms of pumping pressure and associated costs during stimulation operations in unconventional reservoirs. These reservoirs are characterized with low porosity, low permeability, and high in-situ temperature due to greater depths. To address this challenge, the current study investigates the effectiveness of various cooling strategies and their comparative impact on the breakdown pressure and strength of unconventional rocks (Kentucky sandstone and Eagleford shale). These rocks were heated up to 150 °C and cooled down by following three different strategies: ⅰ) spontaneous cooling i.e. without any external aid ⅱ) cooling with cold water and ⅲ) cooling with endothermic chemicals involving NH<sub>4</sub>Cl and NaOH. With endothermic cooling, the temperature of Kentucky sandstone decreases from 150 °C to 56.7 °C in 14 s, while Eagleford shale cools from 150 °C to 43.8 °C in 10 s. The endothermic cooling was followed by the Cold water and spontaneous cooling which showed slower and less pronounced temperature drops in both rocks as compared to the endothermic cooling. The endothermic cooling also leads to highest reduction in rock strength and breakdown pressure. The strength shows a reduction of 21.9 % in Kentucky sandstone and 25.4 % in Eagleford shale while the breakdown pressure reduces by 38.6 % and 37.3 % for the Kentucky sandstone and Eagleford shale respectively. The study also shows the structural changes in the rocks, particularly rock morphology and pore volume. FIB-SEM analysis shows the development of multiple micro-cracks in the rocks which plays an important role in reducing the breakdown pressure. The outcomes of this study indicate that pre-fracturing cooling treatment using endothermic fluids can enhance the effectiveness of hydraulic fracturing operations by reducing the formation breakdown pressure.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100309"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-09DOI: 10.1016/j.uncres.2025.100252
Abdullah M. Shaheen , Aya R. Ellien , Adel A. El-Ela , Ali M. El-Rifaie
-Electric vehicles (EVs) are becoming a key part of future transportation and energy systems as the world moves towards decarbonization and sustainable mobility. This review explores the evolution, classification, and technical architecture of EVs, emphasizing their integration within renewable energy-powered electrical networks. It examines the main EV technologies, such as battery systems, drivetrains, and charging infrastructure, highlighting recent advancements such as fast-charging capabilities and bidirectional energy flows (e.g., V2G, V2B). A critical analysis of energy storage technologies and battery management systems (BMS) is presented, addressing their influence on vehicle performance and grid interaction. To deal with the unpredictability that comes with EVs and renewables, the study examines many ways to simulate uncertainty, such as Monte Carlo simulation, Markov chains, copula functions, point estimate methods, and neural networks. These tools are essential for forecasting load demand, charging behavior, and battery performance in dynamic grid conditions. Furthermore, the paper surveys recent optimization frameworks developed for planning and operation of EV infrastructure, focusing on objectives such as loss minimization, voltage profile improvement, cost reduction, and environmental impact mitigation. This study observes common research gaps by considering a number of different studies, including limited treatment of unbalanced distribution networks, insufficient real-time control strategies, and the underutilization of advanced optimization methods for large-scale deployment. The study reveals that EVs can enhance electrical systems by integrating with renewable energy sources, and suggests future research to overcome technical hurdles and expedite their adoption in modern power grids.
{"title":"Electric vehicles with renewables integration in electrical power systems: A review of technologies, uncertainties and optimization allocations","authors":"Abdullah M. Shaheen , Aya R. Ellien , Adel A. El-Ela , Ali M. El-Rifaie","doi":"10.1016/j.uncres.2025.100252","DOIUrl":"10.1016/j.uncres.2025.100252","url":null,"abstract":"<div><div>-Electric vehicles (EVs) are becoming a key part of future transportation and energy systems as the world moves towards decarbonization and sustainable mobility. This review explores the evolution, classification, and technical architecture of EVs, emphasizing their integration within renewable energy-powered electrical networks. It examines the main EV technologies, such as battery systems, drivetrains, and charging infrastructure, highlighting recent advancements such as fast-charging capabilities and bidirectional energy flows (e.g., V2G, V2B). A critical analysis of energy storage technologies and battery management systems (BMS) is presented, addressing their influence on vehicle performance and grid interaction. To deal with the unpredictability that comes with EVs and renewables, the study examines many ways to simulate uncertainty, such as Monte Carlo simulation, Markov chains, copula functions, point estimate methods, and neural networks. These tools are essential for forecasting load demand, charging behavior, and battery performance in dynamic grid conditions. Furthermore, the paper surveys recent optimization frameworks developed for planning and operation of EV infrastructure, focusing on objectives such as loss minimization, voltage profile improvement, cost reduction, and environmental impact mitigation. This study observes common research gaps by considering a number of different studies, including limited treatment of unbalanced distribution networks, insufficient real-time control strategies, and the underutilization of advanced optimization methods for large-scale deployment. The study reveals that EVs can enhance electrical systems by integrating with renewable energy sources, and suggests future research to overcome technical hurdles and expedite their adoption in modern power grids.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100252"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-12-10DOI: 10.1016/j.uncres.2025.100292
Eliseo Curcio
This study evaluates the real-world feasibility of deploying on-site hydrogen production at the Port of New York and New Jersey using seawater-fed proton exchange membrane (PEM) electrolysis under hard infrastructure constraints. Unlike greenfield assessments that assume unconstrained access to land, electricity, or freshwater, this analysis adopts a constraint-based systems model. It incorporates validated electrolyzer performance metrics, land footprint requirements, seawater treatment demands, interconnection limits, and actual port fuel consumption to simulate realistic deployment scenarios. The model identifies configurations capable of displacing 10–40 % of the port's current diesel and natural gas use. A system designed to meet 20 % of fuel demand (1000 kg/day of hydrogen) requires 60 MW of PEM capacity, 6000 m2 of land, and 120 m3/day of treated seawater, while avoiding over 3700 tonnes of CO2 annually when benchmarked against GREET diesel emissions. Applying the U.S. §45V clean hydrogen tax credit reduces system costs by more than 60 %, bringing the effective hydrogen price near diesel parity for yard tractors and cargo-handling equipment (CHE). Spatial screening confirms that such systems can be integrated at three terminal sites without disrupting core port operations. These findings validate that phased hydrogen deployment starting at 500–1000 kg/day is technically, economically, and spatially feasible using only existing port-controlled infrastructure. As such, hydrogen is positioned not as a long-term contingency but as an immediate and actionable decarbonization solution for high-throughput, urbanized ports.
{"title":"Feasibility of PEM electrolysis using seawater for on-site hydrogen production at the port of New York and New Jersey","authors":"Eliseo Curcio","doi":"10.1016/j.uncres.2025.100292","DOIUrl":"10.1016/j.uncres.2025.100292","url":null,"abstract":"<div><div>This study evaluates the real-world feasibility of deploying on-site hydrogen production at the Port of New York and New Jersey using seawater-fed proton exchange membrane (PEM) electrolysis under hard infrastructure constraints. Unlike greenfield assessments that assume unconstrained access to land, electricity, or freshwater, this analysis adopts a constraint-based systems model. It incorporates validated electrolyzer performance metrics, land footprint requirements, seawater treatment demands, interconnection limits, and actual port fuel consumption to simulate realistic deployment scenarios. The model identifies configurations capable of displacing 10–40 % of the port's current diesel and natural gas use. A system designed to meet 20 % of fuel demand (1000 kg/day of hydrogen) requires 60 MW of PEM capacity, 6000 m<sup>2</sup> of land, and 120 m<sup>3</sup>/day of treated seawater, while avoiding over 3700 tonnes of CO<sub>2</sub> annually when benchmarked against GREET diesel emissions. Applying the U.S. §45V clean hydrogen tax credit reduces system costs by more than 60 %, bringing the effective hydrogen price near diesel parity for yard tractors and cargo-handling equipment (CHE). Spatial screening confirms that such systems can be integrated at three terminal sites without disrupting core port operations. These findings validate that phased hydrogen deployment starting at 500–1000 kg/day is technically, economically, and spatially feasible using only existing port-controlled infrastructure. As such, hydrogen is positioned not as a long-term contingency but as an immediate and actionable decarbonization solution for high-throughput, urbanized ports.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100292"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-12-11DOI: 10.1016/j.uncres.2025.100294
Jiayi He , Taohua He , Haotian Liu , Huijun Wang , Can Huang , Jiuhong Qi , Jin Xu , Yuanzhen Zhou , Juan Teng , Yaohui Xu , Changjun Ji , Zhigang Wen
Accurate evaluation of the brittleness index (BI) is crucial for optimizing hydraulic fracturing during the extraction of hydrocarbon fluids in hybrid shale reservoirs, yet conventional petrophysical methods face limitations in scalability and generalizability. This study presents an integrated evaluation framework utilizing four ensemble learning algorithms—Random Forest (RF), AdaBoost, XGBoost, and CatBoost—to predict BI from well logging data in the second member of Funing Formation (E1f2) shale from the Gaoyou Sag, Subei Basin, eastern China. A dataset comprising 1295 well logging data points and mineralogical compositions from 174 core samples was used to train and validate the models. These models were optimized by Particle Swarm Optimization (PSO) to resolve nonlinear interdependencies between logging responses and mechanical brittleness. Comparative analysis demonstrates that RF achieves the highest prediction accuracy (R2 = 0.84 on the test set), outperforming CatBoost (R2 = 0.79), AdaBoost (R2 = 0.71), and XGBoost (R2 = 0.65). The superior performance of RF is attributed to its robustness against overfitting and its ability to effectively capture complex nonlinear relationships in logging responses. SHapley Additive exPlanations (SHAP) analysis identifies acoustic (AC) and resistivity (Rt) logs as the most influential predictors, reinforcing their strong physical correlations with mineralogical brittleness. This study represents the application of ensemble learning for BI evaluation in the Funing Formation shale, providing a cost-effective alternative to laboratory-based methods and demonstrating the viability of data-driven approaches for fracturability assessment. The proposed framework offers significant potential for extension to other unconventional reservoirs, contributing to enhanced hydraulic fracturing design and improved reservoir development strategies for unconventional hydrocarbon fluid development.
{"title":"Ensemble learning for well logging evaluation of the hybrid shale brittleness index: A case from the Gaoyou sag, Subei basin","authors":"Jiayi He , Taohua He , Haotian Liu , Huijun Wang , Can Huang , Jiuhong Qi , Jin Xu , Yuanzhen Zhou , Juan Teng , Yaohui Xu , Changjun Ji , Zhigang Wen","doi":"10.1016/j.uncres.2025.100294","DOIUrl":"10.1016/j.uncres.2025.100294","url":null,"abstract":"<div><div>Accurate evaluation of the brittleness index (BI) is crucial for optimizing hydraulic fracturing during the extraction of hydrocarbon fluids in hybrid shale reservoirs, yet conventional petrophysical methods face limitations in scalability and generalizability. This study presents an integrated evaluation framework utilizing four ensemble learning algorithms—Random Forest (RF), AdaBoost, XGBoost, and CatBoost—to predict BI from well logging data in the second member of Funing Formation (E<sub>1</sub>f<sub>2</sub>) shale from the Gaoyou Sag, Subei Basin, eastern China. A dataset comprising 1295 well logging data points and mineralogical compositions from 174 core samples was used to train and validate the models. These models were optimized by Particle Swarm Optimization (PSO) to resolve nonlinear interdependencies between logging responses and mechanical brittleness. Comparative analysis demonstrates that RF achieves the highest prediction accuracy (R<sup>2</sup> = 0.84 on the test set), outperforming CatBoost (R<sup>2</sup> = 0.79), AdaBoost (R<sup>2</sup> = 0.71), and XGBoost (R<sup>2</sup> = 0.65). The superior performance of RF is attributed to its robustness against overfitting and its ability to effectively capture complex nonlinear relationships in logging responses. SHapley Additive exPlanations (SHAP) analysis identifies acoustic (AC) and resistivity (Rt) logs as the most influential predictors, reinforcing their strong physical correlations with mineralogical brittleness. This study represents the application of ensemble learning for BI evaluation in the Funing Formation shale, providing a cost-effective alternative to laboratory-based methods and demonstrating the viability of data-driven approaches for fracturability assessment. The proposed framework offers significant potential for extension to other unconventional reservoirs, contributing to enhanced hydraulic fracturing design and improved reservoir development strategies for unconventional hydrocarbon fluid development.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100294"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The global shift towards solar energy has intensified the need for advanced research on high-efficiency photovoltaic (PV) systems. Accurate extraction of PV parameters from current-voltage curves is critical for precise simulation, evaluation, and optimization of PV systems. Although numerous methods exist, many suffer from instability, premature convergence, or limited applicability to complex models. In this paper Progressive Differential Evolution with Adaptive Mutation (Pro-DEAM) is presented which eliminates the aforementioned limitations and introduces a new optimization algorithm generation. Pro-DEAM integrates two novel mutation operators: a hybrid DE/rand-to-best/1/bin to strengthen local exploitation and diversity, and a modified DE/rand/2/bin equipped with random scaling factors to dynamically promote exploration. These two strategies are adaptively weighted with exponential increasing to achieve the best trade-off between exploration and exploitation. The efficiency of Pro-DEAM is proved by extensive experiments of parameter extraction of various PV models, including complex multijunction solar cells (15 parameters) as opposed to many more complex five parameters models in traditional. The results indicate that the proposed Pro-DEAM algorithm consistently attains the lowest root mean square error (RMSE) among existing state-of-the-art approaches, highlighting its remarkable accuracy and computational efficiency. Additionally, detailed statistical analysis results confirm that it is highly robust and reliable for various PV module complexities and climates. The proposed algorithm addresses key limitations of existing methods and establishes a new benchmark for stability and convergence in PV parameter extraction. Its adaptive and dynamic framework makes it a powerful tool for both standard and advanced PV technologies, paving the way for more accurate and efficient solar energy systems.
{"title":"Accurate parameter identification of solar cells and photovoltaic modules under real conditions using a new Differential Evolution approach","authors":"Driss Saadaoui, Mustapha Elyaqouti, Imade Choulli, Ismail Abazine, Abdelfattah Elhammoudy, Souad Lidighbi, Dris Ben Hmamou, Brahim Ydir, El Hanafi Arjdal, Khalid Assalaou","doi":"10.1016/j.uncres.2025.100269","DOIUrl":"10.1016/j.uncres.2025.100269","url":null,"abstract":"<div><div>The global shift towards solar energy has intensified the need for advanced research on high-efficiency photovoltaic (PV) systems. Accurate extraction of PV parameters from current-voltage curves is critical for precise simulation, evaluation, and optimization of PV systems. Although numerous methods exist, many suffer from instability, premature convergence, or limited applicability to complex models. In this paper Progressive Differential Evolution with Adaptive Mutation (Pro-DEAM) is presented which eliminates the aforementioned limitations and introduces a new optimization algorithm generation. Pro-DEAM integrates two novel mutation operators: a hybrid DE/rand-to-best/1/bin to strengthen local exploitation and diversity, and a modified DE/rand/2/bin equipped with random scaling factors to dynamically promote exploration. These two strategies are adaptively weighted with exponential increasing to achieve the best trade-off between exploration and exploitation. The efficiency of Pro-DEAM is proved by extensive experiments of parameter extraction of various PV models, including complex multijunction solar cells (15 parameters) as opposed to many more complex five parameters models in traditional. The results indicate that the proposed Pro-DEAM algorithm consistently attains the lowest root mean square error (RMSE) among existing state-of-the-art approaches, highlighting its remarkable accuracy and computational efficiency. Additionally, detailed statistical analysis results confirm that it is highly robust and reliable for various PV module complexities and climates. The proposed algorithm addresses key limitations of existing methods and establishes a new benchmark for stability and convergence in PV parameter extraction. Its adaptive and dynamic framework makes it a powerful tool for both standard and advanced PV technologies, paving the way for more accurate and efficient solar energy systems.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100269"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-12-17DOI: 10.1016/j.uncres.2025.100290
Emmanuel Karikari Duodu , Eric Thompson Brantson , Binshan Ju , Richard Fiifi Annan , Eugene Jerry Adjei
Injecting carbon dioxide into geological formations is a common method, but it carries significant geomechanical risks due to pore pressure buildup. This pressure increase can cause caprock failure, fault reactivation, poroelastic responses, and compromise well integrity. In this study, we develop a predictive model for effective mean stress that directly links reservoir pressure buildup to geomechanical deformation. We introduce a hybrid Artificial Intelligence (AI) workflow that forecasts pressure buildup and its effects on effective stresses, eliminating the need for extensive compositional simulations. Additionally, we compare hybrid algorithms with the traditional ADAM optimizer and Physics-Informed Neural Networks (PINN). Our investigation further examines how pressure-induced effective stresses influence CO2 injection in reservoirs. To improve predictive accuracy and computational efficiency, we utilize innovative hybrid models that combine Artificial Neural Networks (ANNs) with advanced optimization algorithms, including the Whale Optimization Algorithm (WOA), Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Gorilla Troops Optimization (GTO). Among these, the ANN-GTO model exhibits the highest predictive accuracy in our tests, with a correlation coefficient of 0.99970 and an R2 of 0.99941. Microseismic analysis reveals temporal and spatial clustering of induced events, strongly linked to pressure-related stress changes. Event densities increase notably over the simulation period, from 0.1 to 1 event to 30 to 220 events, providing valuable indicators for leakage risk and enabling proactive mitigation. Our results confirm that hybrid ANN models effectively predict leakage risks caused by pressure buildup and microseismic activity, thereby enhancing the safety and efficiency of CO2 sequestration.
{"title":"Prediction of pressure build-up distribution and geomechanical analysis in a CO2 sequestration reservoir using optimized artificial intelligence models","authors":"Emmanuel Karikari Duodu , Eric Thompson Brantson , Binshan Ju , Richard Fiifi Annan , Eugene Jerry Adjei","doi":"10.1016/j.uncres.2025.100290","DOIUrl":"10.1016/j.uncres.2025.100290","url":null,"abstract":"<div><div>Injecting carbon dioxide into geological formations is a common method, but it carries significant geomechanical risks due to pore pressure buildup. This pressure increase can cause caprock failure, fault reactivation, poroelastic responses, and compromise well integrity. In this study, we develop a predictive model for effective mean stress that directly links reservoir pressure buildup to geomechanical deformation. We introduce a hybrid Artificial Intelligence (AI) workflow that forecasts pressure buildup and its effects on effective stresses, eliminating the need for extensive compositional simulations. Additionally, we compare hybrid algorithms with the traditional ADAM optimizer and Physics-Informed Neural Networks (PINN). Our investigation further examines how pressure-induced effective stresses influence CO<sub>2</sub> injection in reservoirs. To improve predictive accuracy and computational efficiency, we utilize innovative hybrid models that combine Artificial Neural Networks (ANNs) with advanced optimization algorithms, including the Whale Optimization Algorithm (WOA), Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Gorilla Troops Optimization (GTO). Among these, the ANN-GTO model exhibits the highest predictive accuracy in our tests, with a correlation coefficient of 0.99970 and an R<sup>2</sup> of 0.99941. Microseismic analysis reveals temporal and spatial clustering of induced events, strongly linked to pressure-related stress changes. Event densities increase notably over the simulation period, from 0.1 to 1 event to 30 to 220 events, providing valuable indicators for leakage risk and enabling proactive mitigation. Our results confirm that hybrid ANN models effectively predict leakage risks caused by pressure buildup and microseismic activity, thereby enhancing the safety and efficiency of CO<sub>2</sub> sequestration.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"9 ","pages":"Article 100290"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}