Search Results (2,384)

This study investigates the performance of a novel, low-cost solar air heater equipped with large V-shaped fins using experiments and numerical simulations. The solar air heater consists of an absorber plate, a glass cover and airflow ducts. Its performance is evaluated under varying fin configurations: finless and (a)symmetric V-shaped fins with four, six, and eight fins. Computational fluid dynamics simulations using the RNG k-epsilon and discrete ordinate models were validated by experimental findings, showing good agreement with minimal discrepancies between both. The experimental setup recorded a maximum air temperature of 55 °C, corresponding to a temperature rise of 33 °C from an inlet temperature of 22 °C, under an inlet air velocity of 2.7 m/s. Results demonstrate that increasing the number of fins significantly enhances heat transfer efficiency, with heat transfer rising from 134.35 W (finless) to 233.29 W (8 fins). The large-scale fins improved thermal performance significantly while still maintaining a low-pressure drop. Moreover, the fins are very low-cost to implement, in contrast to most heat transfer enhancements in solar air heaters, making this design a very budget-friendly solution. This study provides valuable insights into optimizing solar air heater systems, contributing to the advancement of solar heating solutions for a wide range of energy-efficient applications. Full article

Due to its unique electrical and optical properties, as well as the tunable band structure based on thickness, 2D phosphorene recently emerged as a research hotspot and holds significant potential for applications across various fields. In this study, due to the special band structure and excellent electron transport performance of phosphorene, it formed a series structure with SnO₂ as the electron transport layer of perovskite solar cells. Consequently, the photocurrent density was enhanced by approximately 20%, and the energy conversion efficiency was effectively elevated from 16.38% for pure SnO₂ to 18.03% for the SnO₂/phosphorene composite. Electrochemical measurements and spectral analyses revealed that the incorporation of phosphorene augmented electron mobility within the absorption layer, reduced the electron–hole recombination rate, and decreased the cell’s series resistance, thereby leading to improved efficiency of the perovskite solar cell. This research not only introduces a novel approach to enhancing solar cell efficiency but also paves a new pathway for the application of phosphorene. Full article

Photovoltaic (PV) panel defect detection is essential for maintaining power generation efficiency and ensuring the safe operation of solar plants. Conventional detectors often suffer from low accuracy and limited adaptability to multi-scale defects. To address this issue, we propose YOLO-PV, an enhanced YOLO11n-based model incorporating three novel modules: the Enhanced Hybrid Multi-Scale Block (EHMSB), the Efficient Scale-Specific Attention Block (ESMSAB), and the ESMSAB-FPN for refined multi-scale feature fusion. YOLO-PV is evaluated on the PVEL-AD dataset and compared against representative detectors including YOLOv5n, YOLOv6n, YOLOv8n, YOLO11n, Faster R-CNN, and RT-DETR. Experimental results demonstrate that YOLO-PV achieves a 6.7% increase in Precision, a 2.9% improvement in mAP@0.5, and a 4.4% improvement in mAP@0.5:0.95, while maintaining real-time performance. These results highlight the effectiveness of the proposed modules in enhancing detection accuracy for PV defect inspection, providing a reliable and efficient solution for smart PV maintenance. Full article

Enhancing solar cell performance is effectively attainable through optimization of the front electrode layout. This research tackles the electrode design problem via a geometry-driven optimization framework to discover high-efficiency front electrode patterns. The introduced methodology employs wide quadratic curves for representing the electrode geometry, wherein both the interpolation points and the widths of these curves function as design variables. Two solar cell configurations are utilized to test the optimization technology. In contrast to traditional shape optimization, the current strategy provides enhanced design flexibility, promoting novel and high-performance electrode configurations. Key parameters analyzed encompass the initial geometry, the count of wide quadratic curves, mesh resolution, and the size of the solar cell. Results demonstrate that the presented approach constitutes a viable and efficient design pathway for elevating solar cell operation. The performance of solar cells optimized using this technology outperforms those processed with a modified Solid Isotropic Material with Penalization (SIMP) approach. Furthermore, relative to typical H-pattern electrode grids, the optimized layouts not only achieve superior efficiency but also considerably minimize the consumption of electrode materials. Full article

This paper presents the development and evaluation of an autonomous solar dryer designed to enhance the drying efficiency of bee bread granules. In contrast to natural open-air drying, the proposed system utilizes solar energy in an oscillating operational mode to achieve a controlled and accelerated drying process. The dryer comprises a solar collector integrated into the base of the drying chamber, which facilitates convective heating of the drying agent (air). The system is further equipped with a photovoltaic panel to generate electricity for powering and controlling the operation of air extraction fans. The methodology combines numerical modeling with experimental studies, structured by an experimental design framework. The modeling component simulates variations in temperature (288–315 K) and relative humidity within a layer of bee bread granules subjected to a convective air flow. The numerical simulation enabled the determination of the following: the time required to achieve a stationary operating mode in the dryer chamber (20 min); and the rate of change in moisture content within the granule layer during conventional drying (18 h) and solar drying treatment (6 h). The experimental investigations focused on determining the effects of granule mass, air flow rate, and drying time on the moisture content and temperature of the granular layer of Bee Bread. A statistically grounded analysis, based on the design of experiments (DoE), demonstrated a reduction in moisture content from an initial 16.2–18.26% to a final 11.1–12.1% under optimized conditions. Linear regression models were developed to describe the dependencies for both natural and forced convection drying. A comparative evaluation using enthalpy–humidity (I-d) diagrams revealed a notable improvement in the drying efficiency of the proposed method compared to natural drying. This enhanced performance is attributed to the system’s intermittent operational mode and its ability to actively remove moist air. The results confirm the potential of the developed system for sustainable and energy-efficient drying of bee bread granules in remote areas with limited access to a conventional power grid. Full article

Solar-energy-driven membrane distillation provides a sustainable pathway to mitigate freshwater scarcity by utilizing an abundant renewable heat source. This study develops a two-dimensional axisymmetric computational fluid dynamics (CFD) model to simulate the transient performance of a hollow fiber water gap membrane distillation (HF-WGMD) module integrated with flat-plate solar collectors (FPCs). A lumped-parameter transient FPC model is coupled with the CFD framework to predict feed water temperature under time-varying solar irradiation, evaluated across four representative days in a Mediterranean city. The model is validated against experimental data, showing strong agreement. A comprehensive parametric analysis reveals that increasing the collector area from 10 to 50 m² enhances the average water flux by a factor of 6.4, reaching 10.9 kg/(m²h), while other parameters such as collector width, tube number and working fluid flow rate exert comparatively minor effects. The module flux strongly correlates with solar intensity, achieving a maximum instantaneous value of 18.4 kg/(m²h) with 35 m² collectors. Multistage HF-WGMD configurations are further investigated, demonstrating substantial reductions in solar energy demand due to internal thermal recovery by the cooling stream. A 40-stage system operating with only 10 m² of solar collectors achieves an average specific thermal energy consumption of 424 kWh/m³, while the overall solar desalination efficiency improves dramatically from 2.6% for a single-stage system with 50 m² collectors to 57.5% for the multistage configuration. The proposed system achieves a maximum freshwater productivity of 51.5 kg/day, highlighting the viability and optimization potential of solar-driven HF-WGMD desalination. Full article

This study investigates the feasibility and possible improvement of microwave power transmission (MPT) in a space-based solar power system (SSPS). SSPS, a concept proposed by Dr. Peter Glaser in 1968, aims to harness solar energy in space, free from atmospheric constraints, and transmit it to Earth using microwaves or lasers. Our focus is on enhancing the efficiency and cost-effectiveness of MPT, which accounts for a significant portion of SSPS expenses. In this work, we propose the use of a novel field emission-based rising-sun magnetron (RM) in the MPT subsystem, aiming to extend system longevity and simplify construction, while dramatically reducing the implementation cost. It is demonstrated that the optimization of the RM design at 2.45 GHz can achieve a high output power of >100 kW with a high efficiency of >85%, based on the well-established conformal finite-difference time-domain particle-in-cell simulations. This research provides valuable insights into improving SSPS, making it a more viable and sustainable renewable energy solution. Full article

Metal-oxide heterostructures represent an effective strategy to overcome the limitations of pristine TiO₂, including its ultraviolet-only light absorption and rapid electron–hole recombination, which hinder its performance in solar-driven applications. Among various configurations, coupling TiO₂ with tungsten oxide (WO_x) forms a favorable type-II band alignment that enhances charge separation. However, a comprehensive understanding of how WO_x overlayer thickness affects the optical and photoelectrochemical (PEC) behavior of device-grade thin films remains limited. In this study, bilayer TiO₂/WO_x heterostructures were fabricated via reactive DC magnetron sputtering, with controlled variation in WO_x thickness to systematically investigate its influence on the structural, optical, and PEC properties. Adjusting the WO_x deposition time enabled precise tuning of light absorption, interfacial charge transfer, and donor density, resulting in markedly distinct PEC responses. The heterostructure obtained with 30 min of WO_x deposition demonstrated a significant enhancement in photocurrent density under AM 1.5G illumination, along with reduced charge-transfer resistance and improved capacitive behavior, indicating efficient charge separation and enhanced charge storage at the electrode–electrolyte interface. These findings underscore the potential of sputtered TiO₂/WO_x bilayers as advanced photoanodes for solar-driven hydrogen generation and light-assisted energy storage applications. Full article

This study numerically investigates and designs, through electromagnetic and ray-tracing simulations, two types of double-sided metasurface thermal insulation glazing to maintain visible light (VIS) transmittance while effectively suppressing near-infrared (NIR) transmission, with a partial reduction in deep-blue (DB) transmission, thus reducing air-conditioning load and lighting energy consumption and contributing to overall building energy efficiency. Both designs were optimized and analyzed entirely through simulations, using structural parameter sweeps and AM 1.5 solar spectrum weighting. Design I is composed of two all-dielectric metasurfaces, aiming to maximize VIS transmittance while partially suppressing DB and reducing NIR transmission. Design II integrates a metallic layer with dielectric structures on the front side and employs an all-dielectric metasurface on the back side to enhance NIR blocking and maintain low transmittance under oblique incidence. Simulation results show that Design II outperforms Design I in NIR suppression, exhibiting lower and more stable transmittance across incident angles, while Design I achieves higher VIS transmittance. These findings present a promising pathway for developing high-performance, lightweight glazing for sustainable buildings, improving energy efficiency by balancing solar heat control and daylight utilization. Full article

The increasing frequency of extreme heat events poses significant challenges to buildings in terms of escalating thermal stress, while courtyards, as a traditional passive cooling strategy, demonstrate considerable potential in improving building thermal performance and in energy savings for cooling. Although existing studies have revealed the role of courtyards in enhancing their internal microclimate, an in-depth understanding of how design parameters regulate the microclimate and thereby affect the thermal performance of adjacent buildings remains limited, constraining their effective application in coping with extreme heat. This study conducts an exploration of relevant research aiming to elucidate the mechanisms of courtyard microclimate regulation, the quantitative methods employed, and effective design strategies in addressing high temperatures. The findings indicate that courtyards influence the building thermal performance through four mechanisms: solar radiation control, airflow organization, evaporative cooling, and thermal buffering. Their effectiveness depends on the optimized combination of geometry, material properties, and landscape configuration. Moreover, different quantitative methods exhibit notable differences in scale, accuracy, and applicability. Finally, based on the identified key factors and their interactions, this study proposes optimization pathways to bridge the gap between design expectations and practical outcomes, thereby providing both a theoretical framework and practical guidance for advancing the scientific application of courtyards in enhancing building thermal performance and energy efficiency. Full article

This paper proposes a coalition-based framework for the coordinated operation of multi-regional power systems subject to extreme uncertainty in demand surges, renewable variability, and resource mobilization delays. Methodologically, we integrate Bayesian learning with distributionally robust optimization (DRO), embedding dynamically updated scenario posteriors into a Wasserstein ambiguity set. This construction captures both stochastic variability from renewable and load realizations and epistemic uncertainty from incomplete knowledge of probability distributions. To align individual incentives with system-level efficiency, we design a risk-adjusted utility mechanism that combines VCG transfers, Shapley allocations, and nucleolus refinements. These mechanisms explicitly consider agent heterogeneity, risk aversion, and coalition stability, ensuring that cooperation remains both efficient and sustainable. The optimization model maximizes expected social welfare while incorporating constraints on transmission corridor capacities, mobilization logistics, demand–response rebound effects, and mobile energy storage operations. A hierarchical decomposition algorithm integrates the Bayesian-DRO dispatch layer with cooperative game-theoretic allocations to maintain tractability and robustness at large scale. A case study on a six-province interconnected system with 14–26 GW peak demand, 10.2 GW solar, 8.6 GW wind, 14 GW peaking units, and 6.8 GW mobile storage demonstrates the effectiveness of the approach. Results indicate that the proposed framework raises expected welfare by nearly 10% relative to a non-cooperative baseline, reduces the probability of unserved energy exceeding 1.5% from almost 2% to negligible levels, and narrows payment disparities across provinces to strengthen coalition stability. Demand response peaks at 250–300 MW with rebound averaging 25%, while mobile BESS units cycle frequently to enhance local reliability. Overall, the findings highlight a robust and incentive-compatible pathway for resilient inter-provincial operation, providing both methodological advances and policy-relevant insights for multi-regional energy governance. Full article

This study presents a numerical investigation of a solar dryer prototype integrated with microencapsulated phase change material (MPCM) for rice drying under tropical climatic conditions. The thermal and drying behavior of the system was evaluated under the following four configurations: a baseline solar dryer, a dryer with MPCM only, a dryer with an auxiliary heater, and a combined system using both MPCM and auxiliary heating. The prototype was also tested with rice layers of 25 mm and 45 mm to assess the influence of layer thickness on drying performance. The results showed that the use of MPCM reduced temperature fluctuations from about $\Delta T\approx 70$ °C in the baseline case to stabilized values near 33–34 °C (MPCM only) and 35–38 °C (MPCM + heater), contributing to a more stable thermal environment. In thinner layers (25 mm), MPCM helped prevent localized overheating, while in thicker layers (45 mm), it promoted more uniform moisture reduction. However, the overall improvement in drying performance was marginal, as efficiency remained strongly dependent on heater support. The study points out the need for improved integration of PCM within dryer design. Enhanced thermal contact and strategic preheating of MPCM could improve heat discharge during non-solar periods. Future work will focus on experimental validation, design optimization, and the development of preheating strategies to maximize the benefits of PCM-assisted solar drying systems. Full article

Accumulation of dust on PV panels is a big challenge, especially in dry and semi-arid environments like Morocco, where the number of dust particles in the atmosphere diminishes the efficiency of solar panels severely. The review analyzes 30 recent studies, which provide insight into performance degradation by dust, as well as the search for solutions that mitigate this effect. Results show that dust reduced solar panel efficiency by between 10% and 40% based on environmental conditions, including dust density, composition, and length of exposure. Many technological approaches have been provided for the problem, including autonomous cleaning systems and advanced coatings, yet economic and scalability barriers are still in existence. Also, using AI in predictive maintenance provides good opportunities to optimize solar panel cleaning schedules to enhance energy production. This review concludes with the observation that, going forward, more research on long-term solutions and the development of sustainable and cost-effective cleaning technologies is urgently needed in order to better exploit solar energy in dusty environments. Full article

Against the backdrop of the world’s increasing reliance on renewable energy, the inherent intermittency and volatility of wind and solar energy pose significant challenges to the stability and economic benefits of the power system. In regions rich in renewable energy resources such as Gansu Province, due to low operational efficiency and underdeveloped market mechanisms, the potential of new energy storage systems is often not fully exploited. This paper proposes an integrated shared energy storage model designed to suppress wind power fluctuations and a two-way market trading mechanism designed to maximize social welfare to solve these problems. Firstly, a hybrid energy storage system combining electrochemical- and hydrogen-based energy storage is constructed. The modular coordination strategy is adopted to dynamically allocate power capacity, and the wind energy fluctuation suppression technology is proposed to achieve fluctuation suppression at multiple time scales. Secondly, a combined dual bidding mechanism is introduced, allowing for combined bidding across time periods and resource types, to better capture user preferences and enhance market flexibility. The model is represented as a mixed-integer nonlinear programming problem aimed at maximizing social welfare, and then transformed into a linear equivalence problem to enhance the traceability of the calculation. The branch and bound algorithm is adopted to solve this problem. Finally, the simulation results based on the bidding data of a certain area enhanced the participation of participants and improved the fairness of the market and the overall social welfare. This system effectively enhances the grid-friendliness of renewable energy grid connection and provides a scalable and replicable framework for highly renewable energy systems. Full article

Photocatalytic oxidation technology harnesses solar energy for pollutant mineralization, presenting significant potential for environmental applications. A critical bottleneck remains the development of high-performance photocatalysts. This study centers on the non-metallic semiconductor material graphitic carbon nitride (g-C₃N₄). To overcome the inherent limitations of pristine g-C₃N₄, including limited surface area, rapid charge carrier recombination, and inadequate active sites, it implements surface engineering strategies employing acidic (H₂SO₄) or basic (K₂CO₃) agents to modulate microstructure, introduce defect sites (cyano/amino groups), and optimize bandgap engineering. These modifications synergistically enhanced photogenerated charge carrier separation efficiency and surface reactivity, leading to efficient dye degradation. Notably, the K₂CO₃-modified catalyst (g-C₃N₄-OH), synthesized with a mass ratio of m(g-C₃N₄):m(K₂CO₃) = 1:1, achieved 92.2% Rhodamine B degradation within 50 min under visible light, surpassing pristine g-C₃N₄ (20.6%), the optimized H₂SO₄-modified sample (g-C₃N₄-HS, 60.9%), and even template-synthesized g-C₃N₄-SBA (79.6%). The g-C₃N₄-OH catalyst demonstrated exceptional performance under both visible light and natural solar illumination. Combining facile synthesis, cost-effectiveness, superior activity, and robust stability, this work provides a novel approach for developing high-efficiency non-metallic photocatalysts applicable to dye wastewater. Full article