Applied Solar Energy最新文献

{"title":"Features of Sodium Ferrat Synthesized in a Solar Furnace","authors":"M. S. Paizullakhanov,&nbsp;O. R. Parpiev,&nbsp;Zh. Z. Shermatov,&nbsp;E. Z. Nodirmatov,&nbsp;H. H. Salohiddinov","doi":"10.3103/S0003701X25600304","DOIUrl":"10.3103/S0003701X25600304","url":null,"abstract":"<p>It has been shown that a material based on sodium ferrate α-NaFeO₂ can be obtained by synthesis from a melt in a solar oven. The crystal structure is trigonal with lattice parameters <i>a</i> = 3.03 Å, <i>c</i> = 16.02 Å. The average particle size of the material is 2 µm. It was revealed that a sample of the NaFeO₂ material provides the redox activity of Na⁺/Na and Fe³⁺/Fe⁴⁺. Therefore, α-NaFeO₂ could be a potential cathode material for sodium-ion battery. It was found that sodium ferrate α-NaFeO₂ exhibits fairly good resistance to water. That is, sodium ferrate does not decompose in water at a water temperature of 80–100°C.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"322 - 326"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367332","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}

{"title":"Explaining Solar Radiation Concurrent Estimation and Conditional Multi-Horizon Prediction with SHAP and LIME: Interpretable CatBoost Benchmarking Using Long-Term NASA POWER Data","authors":"Moein Jazayeri,&nbsp;Kian Jazayeri","doi":"10.3103/S0003701X26600220","DOIUrl":"10.3103/S0003701X26600220","url":null,"abstract":"<p>Accurate hourly solar-radiation estimation is important for photovoltaic and solar-cell applications because irradiance directly influences power generation, conversion behavior, and operational decision-making. This study develops a unified benchmarking and explainable artificial intelligence (XAI) framework for hourly solar-radiation modelling under two settings: (i) concurrent estimation and conditional (ii) multi-horizon prediction. Twenty-four years of hourly NASA POWER meteorological data for San Diego were used to benchmark eighteen statistical, machine-learning, and deep-learning models for (i) Task A: Concurrent Estimation <span>(left( {h = 0,;Xleft( t right) to {text{GHI}}left( t right)} right);)</span> and (ii) Task B: Conditional Multi-Horizon Prediction <span>(left( {h = 1,3,6,24,{;}Xleft( t right) to {text{GHI}}left( {t + h} right)} right))</span>. In Task B, only predictors available at time <span>(t)</span> were used; therefore, the multi-horizon results should be interpreted as retrospective conditional prediction baselines under time-<span>(t)</span> information rather than as a fully operational forecasting system with forward-looking forecast inputs. Model performance was evaluated using RMSE, MAE, MSE, <span>({R^2})</span>, normalized RMSE, and a persistence-relative skill score. For concurrent estimation, CatBoost achieved the highest accuracy, with RMSE = 4.99 Wh/m², MAE = 3.67 Wh/m², MSE = 24.89 (Wh/m²)² and <span>({R^2} = 0.9997)</span>. For conditional multi-horizon prediction, CatBoost provided the most robust overall performance across horizons, achieving RMSE = 73.71 Wh/m² at <span>(h = 1)</span> and RMSE = 197.18 Wh/m² at <span>(h = 24)</span>, while consistently outperforming the persistence baseline. To address the interpretability limitations of high-performing ensemble models, SHAP and LIME were applied to the selected CatBoost models for both Task A and Task B. The XAI analysis showed that concurrent estimation is governed primarily by the Clearness Index, Solar Zenith Angle, and UV Index, whereas the conditional multi-horizon setting preserves the importance of these physically meaningful predictors but exhibits horizon-dependent changes in their relative influence, with broader meteorological variables becoming more relevant at longer lead times. Global SHAP results, dependence analysis, and local SHAP–LIME case studies consistently revealed physically coherent and horizon-aware explanatory patterns. Overall, the proposed framework provides not only strong predictive benchmarking but also transparent, physics-consistent interpretation for retrospective solar-radiation estimation and conditional multi-horizon prediction.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"374 - 402"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367411","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}

{"title":"Reassessment of Sunshine Duration in Uzbekistan: Implications for Solar Resource Evaluation","authors":"E. Yu. Rakhimov,&nbsp;N. R. Avezova,&nbsp;A. A. Imyaminov,&nbsp;B. Yu. Omonov","doi":"10.3103/S0003701X26600505","DOIUrl":"10.3103/S0003701X26600505","url":null,"abstract":"<p>This short communication presents an updated analysis of the spatial distribution and day-to-day persistence of sunshine duration (SD) across Uzbekistan based on quality-filtered observations from 21 meteorological stations for the period 2000–2020. The results reveal pronounced spatial heterogeneity: annual SD ranges from 2164 h/year at the mountain station of Chimgan to 3186 h/year at Termez in the southern lowlands, with a network mean of 2749 h/year. The derived annual totals agree closely with the WMO 1991–2020 climate normals at the 12 stations in common, with station-level annual differences remaining within ±1.5%. Across the 144 corresponding station–month pairs, the mean absolute relative difference was 2.2%. The classification of daily conditions by relative SD (SD/SD₀) shows that clear days dominate at lowland stations, reaching up to 251 days/year at Termez. A first-order Markov chain analysis of sunless-day persistence reveals systematic spatial gradients: the sunless-state persistence probability <i>P</i>₀₀ ranges from 0.328 at Termez to 0.626 at Chimgan, while the stationary probability of a sunless day, π₀, ranges from 0.075 to 0.304 across the network. The maximum duration of consecutive sunless periods reaches 23 days at Chimgan in March, compared with 5–16 days at lowland stations in winter. The results provide an updated observational basis for solar energy resource assessment and photovoltaic system planning in Uzbekistan.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"403 - 410"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367412","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}

{"title":"Influence of Al2O3-Based Nanofluids on the Heat Transfer Efficiency of Solar Thermal Collectors","authors":"T. I. Juraev,&nbsp;D. R. Kokharova,&nbsp;D. Yu. Jalilov,&nbsp;Z. S. Iskandarov,&nbsp;A. S. Halimov,&nbsp;J. S. Akhatov","doi":"10.3103/S0003701X2660089X","DOIUrl":"10.3103/S0003701X2660089X","url":null,"abstract":"<p>The paper presents the results of a study on the application of aluminum (Al₂O₃)-based nanofluids to enhance the thermal efficiency of solar thermal collectors. At maximum concentration, the coefficient value reaches ≈1260 W/(m² K), which is approximately 40% higher than the corresponding value for pure water. Dynamic Light Scattering (DLS) revealed a uniform nanoparticle size distribution, while ζ -potential measurements confirmed the stable colloidal stability of the nanofluids at various temperatures. A mathematical model of a parabolic trough collector (PTC) implemented in Python and was verified by comparison with experimental data from SEGS LS-2, showing high predictive accuracy (RMSE = 0.61 K; <i>R</i>² = 0.99995). Real climatic data for Tashkent (TMY) were used as initial inputs, allowing for an evaluation of the system’s behavior under conditions close to real-world operation. The results confirm that the use of Al₂O₃ nanofluids in solar thermal systems significantly improves heat transfer and can serve as an effective solution for increasing the energy efficiency of renewable energy installations.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"290 - 300"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367326","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}

{"title":"Energy and Exergy Analyses of Passive & PVT-CPC Integrated Active Solar Stills under Natural and Forced Modes of Circulation: A detailed Comparative Study","authors":"Md. Meraj,&nbsp;Md. Azhar","doi":"10.3103/S0003701X25603850","DOIUrl":"10.3103/S0003701X25603850","url":null,"abstract":"<p>The development of effective and sustainable desalination technology is imperative due to the increasing need for freshwater in arid and semi-arid countries. Low productivity and poor energy utilization often constrain the performance of solar stills, despite their simplicity and low cost. In the Present study, an analytical simulation has been conducted to evaluate and compare the performance of a conventional passive solar still with two PVT–CPC (Photovoltaic Thermal–Compound Parabolic Concentrator) integrated active solar stills operating under the natural and forced circulation modes. The governing energy balance equations for the system components were formulated and numerically solved in MATLAB software using representative summer climatic data of New Delhi, India. The model predicted transient temperatures of the glass cover, basin water, absorber plate, PV module, and working fluid. These thermal states were subsequently used to determine the hourly distillate yield, instantaneous efficiency, daily thermal efficiency, and exergetic efficiency. Results showed that the passive still produced 3.16 kg/m² day, whereas natural and forced circulation modes yielded 4.178 and 7.668 kg/m² day, respectively. The overall thermal efficiency of the system enhanced from 5.03% in the passive mode to 20.25% under the natural mode of circulation whereas 25.14% enhancement with forced mode of circulation. From exergy analysis, it is inferred that the forced mode of circulation produced the best performance in terms of overall daily exergetic efficiency of 6.47% compared with natural mode of circulation (5.95%) and passive solar still (0.75%), highlighting reduction of irreversibilities in the evaporation–condensation cycle and electrical energy gain. In addition to improved freshwater productivity, the PVT–CPC integration provided supplementary electrical energy, enabling circulation or auxiliary applications and enhancing system versatility.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"301 - 321"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367327","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}

{"title":"Effect of Distributed Generation with a Hybrid Composition of Conventional and Green Sources on the Reliability of Power-System Operating Modes","authors":"H. B. Guliyev,&nbsp;O. Z. Toirov,&nbsp;N. R. Avezova,&nbsp;F. Sh. Ibrahimov","doi":"10.3103/S0003701X26601079","DOIUrl":"10.3103/S0003701X26601079","url":null,"abstract":"<p>Hybrid schemes that combine green and conventional generation units create new opportunities for improving the efficiency of energy-resource utilization and reducing emissions; however, they also introduce additional challenges for ensuring reliable power-system operation. This paper analyzes the reliability of operating modes of an interconnected power system that incorporates distributed generation (DG) systems with a combined composition of sources, including conventional and green (renewable) units. The study considers the impact of mixed-type DG integration on power-system operating modes and analyzes the key reliability-related factors, including voltage stability, power balance, and power quality. Using a specific real power system as a case study, computational experiments of steady-state and transient modes were carried out for different power-generation scenarios of all DG sources. The calculations account for the stochastic nature of power output from wind installations and wind turbines, as well as random variations in nodal loads. Probabilistic characteristics of voltage variation at the point of common coupling between the DG system and the power system were obtained, confirming that the voltage magnitude tends to increase as the power output from DG sources grows. The results demonstrate that a rational combination of conventional and green sources, provided that they are properly regulated, can enhance power-system reliability while delivering environmental and economic benefits.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"336 - 345"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367331","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}

{"title":"Numerical Modeling of Energy Parameters for Photovoltaic Panels under Shading Conditions and Localized Overheating","authors":"L. Knysh,&nbsp;N. Guk,&nbsp;A. Knysh","doi":"10.3103/S0003701X26600591","DOIUrl":"10.3103/S0003701X26600591","url":null,"abstract":"<p>The computer modeling for the energy parameters of the PV panel with partial shading and overheating are conducted in the study. The non-linear steady-state 2D mathematical model, corresponding numerical algorithm and in-house software were developed for the modeling. A temperature plateau with increased values was detected in the fully illuminated PV panel. An area of the temperature plateau does not depend on a wind speed that simplifies design of the temperature stabilization systems. The impacts of partial shading and overheating on the PV panel electrical performance were compared. It was determined that at wind speed of 2 m/s and ambient temperature of 10°C, the decrease in electrical power due to partial shading is 1.5 times greater than by overheating. The obtained results are important for selecting the temperature stabilization systems of the PV panels, as well as for optimizing their energy load. The developed in-house Fortran software can be used as an independent software application or as part of a digital twin to estimate the PV panel energy performance.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"327 - 335"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367410","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}

{"title":"Thermokinetic Analysis and Energy Performance Evaluation of a Hybrid Forced Convection Solar Dryer Applied to Ziziphus Lotus Leaves","authors":"Khaoula Chatir,&nbsp;Faiz Ameachaq,&nbsp;El Houssayne Bougayr,&nbsp;Lhoucine Oufni,&nbsp;Haytem Moussaoui","doi":"10.3103/S0003701X26600165","DOIUrl":"10.3103/S0003701X26600165","url":null,"abstract":"<p>This study investigates the convective solar drying behavior of Ziziphus lotus leaves using an forced-convection hybrid solar dryer equipped with active temperature regulation and electrical auxiliary heating, which integrates forced convection and electrical backup to ensure controlled thermal conditions. Experiments were conducted at varying drying temperatures (40–70°C) and a constant air velocity of 1.55 m/s to evaluate drying kinetics, energy consumption, and efficiency. A characteristic drying curve (CDC) was successfully developed using Van Meel’s method and fitted with a second-degree polynomial model (<i>R</i>² = 0.9567), demonstrating its robustness for predictive modeling. Energy performance metrics, including specific energy consumption (SEC), thermal energy utilization ratio (TEUR), and energy/thermal efficiencies, were systematically analyzed. Results indicated a 28% reduction in Specific Energy Consumption (SEC) when operating at 70°C compared to 40°C, a benefit directly enabled by the solar integration. The Thermal Energy Utilization Ratio (TEUR), which quantifies the solar contribution, reached a maximum of 95% at 70°C, demonstrating that the solar collector supplied 95% of the total thermal energy required for drying at this temperature, with the electrical backup providing only the remaining 5%. This high level of solar fraction highlights the strong potential of this hybrid approach for decarbonized drying. The process achieved peak thermal and energy efficiencies of 10 and 9.5%, respectively, at the highest temperature.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"271 - 289"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367325","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}

{"title":"Stability Enhancement and Optimal Scheduling Methods for Grid-Forming Energy Storage Systems with Frequency Constraints","authors":"L. J. Chen","doi":"10.3103/S0003701X25603916","DOIUrl":"10.3103/S0003701X25603916","url":null,"abstract":"<p>To enhance the stability of new energy grid connection and address insufficient system inertia, this study proposes a frequency constrained GFM system power system stability enhancement and optimization scheduling technology. Firstly, this study constructs a networked ESC optimization model built on inertia balance constraints, and determines the optimal ESC configuration through AWPSO algorithm. Secondly, a scheduling optimization model with frequency response constraints is constructed, and the GUROBI solver is used to handle the constraints and search for the optima. In the experiment of optimizing the ESC of the GFM, the optimal fitness of the research model in the Sphere function was 0.00002, which was better than similar solving models and had the best comprehensive performance. In the WPO test, the maximum wind power deviation under the research model was 15.21 MW, and the system load power was lower, with a maximum load deviation of 21.24 MW, showing the best overall performance. In the experiment of grid-connected energy storage scheduling, the maximum fluctuation frequency of frequency constrained regulation after a sudden increase in disturbance in 0.1 s was controlled at 50.5 Hz, and the maximum voltage fluctuation value was only 0.03 V, showing the best overall performance. In addition, in the three types of scenario tests, the frequency change rate of scenario C was controlled within 0.45 Hz, the lowest point frequency was closer to the reference frequency, the steady-state frequency met the requirements of each time period, and the overall performance was the best. Research technology to satisfy the demands of power grid stability and provide technical support for power grid stability control and safety scheduling.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"360 - 373"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367335","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}

{"title":"Topological Data Analysis for Fault Diagnosis in Photovoltaic Systems","authors":"Brayan Hernández,&nbsp;Ahtziri González,&nbsp;Juan Anzurez Marin","doi":"10.3103/S0003701X26600074","DOIUrl":"10.3103/S0003701X26600074","url":null,"abstract":"<p>Photovoltaic systems have emerged as one of the most effective solutions to meet energy demands while preserving the environment. However, the performance of these systems can be compromised by a range of faults, including partial shading, soiling, disconnections, module defects, and degradation of electronic components. This article proposes a data-driven approach based on topological data analysis for fault diagnosis through power analysis of photovoltaic systems, aiming to contribute to more robust and efficient system monitoring. The proposed methodology utilizes the bottleneck distance as a comparative metric, enabling the detection of behavioral deviations as small as 5%. The simulated scenarios show that the proposed method is sensitive enough to detect subtle changes, such as the removal of a single panel or small losses due to environmental factors.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"62 3","pages":"346 - 359"},"PeriodicalIF":1.204,"publicationDate":"2026-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149367334","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}