Efficient Solar Energy Research Articles

Solar Azo-Switches for Effective E→Z Photoisomerization by Sunlight.

Natural photoactive systems have evolved to harness broad-spectrum light from solar radiation for critical functions such as light perception and photosynthetic energy conversion. Molecular photoswitches, which undergo structural changes upon light absorption, are artificial photoactive tools widely used for developing photoresponsive systems and converting light energy. However, photoswitches generally need to be activated by light of specific narrow wavelength ranges for effective photoconversion, which limits their ability to directly work under sunlight and to efficiently harvest solar energy. Here, focusing on azo-switches-the most extensively studied photoswitches, we demonstrate effective solar E→Z photoisomerization with photoconversions exceeding 80 % under unfiltered sunlight. These sunlight-driven azo-switches are developed by rendering the absorption of E isomers overwhelmingly stronger than that of Z isomers across a broad ultraviolet to visible spectrum. This unusual type of spectral profile is realized by a simple yet highly adjustable molecular design strategy, enabling the fine-tuning of spectral window that extends light absorption beyond 600 nm. Notably, back-photoconversion can be achieved without impairing the forward solar isomerization, resulting in unique light-reversible solar switches. Such exceptional solar chemistry of photoswitches provides unprecedented opportunities for developing sustainable light-driven systems and efficient solar energy technologies.

Solar Azo‐Switches for Effective E→Z Photoisomerization by Sunlight

AbstractNatural photoactive systems have evolved to harness broad‐spectrum light from solar radiation for critical functions such as light perception and photosynthetic energy conversion. Molecular photoswitches, which undergo structural changes upon light absorption, are artificial photoactive tools widely used for developing photoresponsive systems and converting light energy. However, photoswitches generally need to be activated by light of specific narrow wavelength ranges for effective photoconversion, which limits their ability to directly work under sunlight and to efficiently harvest solar energy. Here, focusing on azo‐switches—the most extensively studied photoswitches, we demonstrate effective solar E→Z photoisomerization with photoconversions exceeding 80 % under unfiltered sunlight. These sunlight‐driven azo‐switches are developed by rendering the absorption of E isomers overwhelmingly stronger than that of Z isomers across a broad ultraviolet to visible spectrum. This unusual type of spectral profile is realized by a simple yet highly adjustable molecular design strategy, enabling the fine‐tuning of spectral window that extends light absorption beyond 600 nm. Notably, back‐photoconversion can be achieved without impairing the forward solar isomerization, resulting in unique light‐reversible solar switches. Such exceptional solar chemistry of photoswitches provides unprecedented opportunities for developing sustainable light‐driven systems and efficient solar energy technologies.

Development of a combined system with a hybrid solar collector and determination of its thermal characteristics

The object of the study: a system with a photovoltaic thermal hybrid solar collector. The main problem addressed is to enhance the conversion and utilization efficiency of solar energy by developing a new design of photovoltaic thermal hybrid solar collector. A computer model of the proposed design of a photovoltaic thermal hybrid solar collector (PVT) was developed, and its thermotechnical characteristics were investigated. Patterns of temperature changes in the heat transfer fluid in PVT and thermal accumulator over time of irradiation were determined. It is shown that the instantaneous thermal power of the solar collector was 540 W/m2, and the efficiency was 0.6. Changes in the instantaneous specific thermal power of the system with PVT (up to 450 W/m2) and its efficiency in heat accumulation in the accumulator (0.5) were studied. The high efficiency of PVT can be explained by its optimal design, which ensures simultaneous production of thermal and electrical energy, as well as balancing of the operation of the thermal and photovoltaic parts. The main difference between the developed model and existing analogs is the comprehensive consideration of the interaction of the thermal and photovoltaic parts in one installation. The model allows optimizing the PVT design to increase its efficiency. The research has allowed developing a new design of a photovoltaic thermal hybrid solar collector, which ensures high efficiency of conversion and utilization of solar energy. The obtained results and the developed model provide a basis for further improvement of PVT and its implementation in power systems of buildings and technological processes to increase the share of solar energy utilization and reduce fossil fuel consumption

Giant Clams Are Models of Solar-Energy Efficiency

Giant Clams Are Models of Solar-Energy Efficiency

Iterative Root-Finding Algorithm for Accurate Parameter Extraction of Solar Photovoltaic Cells

The performance of photovoltaic models depends significantly on the accuracy of their parameters, which are determined by the chosen method and objective function. Extracting these parameters accurately under different environmental conditions is essential to enhance reliability, accuracy, and minimize system costs. In this research, a novel technique is proposed for extracting the electrical parameters of the solar cell single diode model, including saturation current, serial resistance, parallel resistance, and ideality factor. To overcome the challenges posed by the chaotic behavior of the I-V curve equation, an improved Iterative Root-Finding algorithm is introduced. This algorithm acts as an optimization tool, increasing the likelihood of obtaining highly accurate solutions by minimizing the quadratic error between experimental and theoretical characteristics in a shorter time frame. The numerical and experimental results demonstrate the effectiveness of this approach in solar module modeling, showing squared errors approaching zero. This study opens new possibilities for improving the accuracy and reliability of photovoltaic models, leading to more efficient solar energy systems.

Harnessing synergistic effects in GQD@Pt(II) nanocomposites for enhanced photovoltaic performance: a computational study.

The development of efficient solar energy conversion technologies is crucial for addressing global energy challenges and reducing reliance on fossil fuels. Platinum(II) complexes are promising materials for photovoltaic applications due to their strong light absorption and long-lived excited states. However, their narrow absorption in the visible spectrum and stability issues limit their performance. Combining platinum(II) complexes with graphene quantum dots (GQDs) can enhance photovoltaic performance by leveraging the complementary light harvesting and charge transfer characteristics of the two components. This study utilizes density functional theory (DFT) calculations to explore their electronic structures, charge transfer dynamics, and photoelectric performance. Specifically, it investigates the effects of incorporating different substituents, either electron-donating or electron-withdrawing, onto the fluorene motif of the Pt(II) complex. The findings reveal that combining GQDs with Pt(II) complexes extends light absorption into the UV range, enabling comprehensive solar utilization. Upon photoexcitation, electrons migrate between the GQD conduction band and the Pt(II) complex, stabilizing charges and enhancing extraction. Substituents significantly influence charge transfer dynamics: electron-withdrawing groups promote transfer to the GQD, while electron-donating groups encourage charge separation and delocalization. Nanocomposites featuring electron-donating substituents achieve the highest energy conversion efficiencies, with GQD@Pt(II)-NPh2 reaching 24.6%. This is attributed to improved light harvesting, efficient charge injection, and reduced recombination. These insights guide the rational design of GQD-Pt(II) nanocomposites, optimizing charge separation and transfer processes for enhanced photovoltaic performance. The computational approach employed here provides a robust tool for developing advanced materials in renewable energy technologies. The computational studies reported in this work were performed using the DFT approach, specifically employing the hybrid functional PBE0. The PBE0 functional's accuracy in describing electronic structures and excited-state properties is essential for understanding charge transfer processes, photoabsorption, and emission characteristics in metal-organic complexes. Geometry optimizations and time-dependent DFT (TD-DFT) calculations were carried out to investigate the properties of the nanocomposites. The effects of solvents were replicated using the conductor-like polarizable continuum model (CPCM). The charge transfer length (ΔL) and interfragment charge transfer (ΔQ) were calculated using the Multiwfn software package, and all calculations were performed using the BDF software package.

Enhancing photovoltaic solar panel performance with integration of PCM-based spectral filter and self-cleaning coating

This research investigates the enhancement of photovoltaic (PV) solar panel performance through the application of a paraffin-based spectral splitter. The study aims to improve electrical efficiency and thermal management while mitigating dust deposition effects. A paraffin (RT25) spectral filter is placed above the glass layer of the PV panel, coupled with a ZnO-water nanofluid-filled mini-channel for cooling at the panel's bottom. Optical properties, derived from previous experimental work, are incorporated into simulations. Self-cleaning SiO2 nanoparticle coating is proposed to improve transmissivity of upper glass. Fresnel lens is used to intensify irradiation at two concentration ratios (CR). Three-dimensional simulations integrating source terms based on optical analysis were conducted. Key findings include a decrease in panel temperature (TPV) due to partial irradiation absorption by the spectral filter, leading to lower heat flux to the cooling zone. The spectral filter increased electrical efficiency (ηPV) by 11.28 % and 38.63 % at 20 and 40 min, respectively. The presence of the filter and coatings significantly improved temperature uniformity, with improvements of 68.77 % and 50.35 % at 10 and 40 min, respectively. Increasing CR resulted in a 2.95 % and 83.31 % rise in filter temperature (TPCM) and liquid fraction (LF), with a minor 1.56 % decrease in efficiency. At CR = 2, in the presence of the spectral filter, ηPV decreases by 38.62 %, accounting for dust effects, while it increases by 21.83 % with adding coating. The research highlights the potential of spectral filters and innovative coatings to enhance PV panel performance, offering a novel approach to sustainable and efficient solar energy systems.

Electronic and optical properties of As/Bi2Se3 van der Waals heterostructure: Ab initio insights

In this study, based on the first-principles calculations, we theoretically studied the electronic and optical properties of two dimensional (2D) As/Bi2Se3 van der Waals (vdW) heterostructure. The results show that all the materials exhibit semiconducting behavior with calculated band gaps of Eg = 1.71, 1.0, and 1.65 eV without spin-orbit coupling (SOC), for As monolayer, Bi2Se3 monolayer, and As/Bi2Se3 heterostructure respectively. Notably, the As/Bi2Se3 heterostructure demonstrates a type-II band alignment, facilitating the effective spatial separation of photogenerated carriers. This characteristic offers exciting opportunities for applications in efficient optoelectronic devices, photocatalysis, and solar energy conversion. The optical properties studies show that the heterostructure exhibits significant light absorption across the visible to ultraviolet light spectrum, making it a promising candidate for a wide array of optoelectronic devices.

Open-Cage Copper Complexes Modulate Coordination and Charge Transfer.

This study presents a novel copper-based redox shuttle that employs the PY5 pentadentate polypyridyl ligand in a dye-sensitized solar cell (DSSC). The [Cu(PY5)]2+ complex exhibits a unique five-coordinate square pyramidal geometry, characterized by a strategically labile axial position, to facilitate efficient dye regeneration while minimizing electron recombination, thereby enhancing DSSC performance. Notably, the inclusion of 4-tert-butylpyridine (TBP) as an additive is shown to significantly modulate the electrochemical and photophysical properties of the copper complexes, attributed to its coordination to the vacant axial site. This interaction leads to an improved open-circuit voltage and overall device efficiency, with the complexes achieving promising efficiencies under standard solar irradiance. The findings underscore the potential of utilizing copper-based redox shuttles with designed ligand geometries to overcome the limitations of current DSSC materials, opening new avenues for the design and optimization of solar energy conversion devices. This work not only contributes to the fundamental understanding of the behavior of copper complexes in DSSCs but also paves the way for future research aimed at exploiting the full potential of such geometrical and electronic configurations for the development of more robust and efficient solar energy solutions.

Structural and opto-electronic engineering with ZnS ETL via PVD technique for efficient and durable heterojunction perovskite solar cells

This study presents a comprehensive investigation into fabrication and characterization of HJPSC leveraging chalcogenide Zinc Sulphide (ZnS) thin films as ETL and Selenium (Se) as a protective capping layer through PVD technique. ZnS thin films annealed at 200 °C, 300 °C and 400 °C were systematically analyzed for their structural and opto-electronic properties. Among them, ZnS-1, annealed at 200 °C, demonstrated superior performance with high transmittance, optimal crystallite size, wide bandgap, lowest photoluminescence intensity, high conductivity and low resistivity. Consequently, ZnS-1 was selected as the ETL for HJPSC fabrication. The HJPSC device was fabricated with ZnS/MAPbI3--Se/Ag as device structure with Se as capping layer. SEM images confirmed the smooth and continuous nature of the ZnS-1 film, while X-Ray diffraction analysis validated the purity and crystallinity of MAPbI3 perovskite layer. The successful alignment of the perovskite absorption band with the solar cell emission spectrum obtained by UV–Vis spectra highlighted the potential for efficient solar energy conversion. J-V characteristics of the HJPSC device exhibited a high short-circuit current (Jsc) of 20.18 mA/cm2, an open-circuit voltage (Voc) of 0.99 V, a power conversion efficiency (PCE) of 9.1 % and fill factor (FF) of 45.7 % was accredited to improved electron conductance and of ZnS-1 as an ETL.

Construction of PPS based carbon fiber photothermal foam for crude oil absorption and seawater desalination

Efficient and clean solar energy conversion through photothermal materials has garnered significant attention, finding applications across energy, environmental protection, and healthcare sectors. This project focused on developing waste PPS-based carbon fiber (PCF) foam, emphasizing the high-value utilization of waste fibers in solar photothermal oil-absorption and photothermal evaporation applications. With exceptional light-absorption capabilities exceeding 97 %, the PCF@PDMS foam demonstrated superior photothermal conversion efficiency alongside impressive mechanical properties, facilitating effective absorption of highly viscous crude oil. Through PVA/CNF hydrophilic modification, internal water supply channels were integrated into the mPCF@PDMS foam, optimizing the evaporation surface area by retaining hydrophobic regions. This design not only enhanced thermal insulation but also significantly increased the evaporation rate to 2.00 kg·m−2·h−1 with an efficiency of 89.89 % under 1.0 sun irradiation. The presence of hydrophobic regions endowed the evaporator with self-floating ability, enhancing its practicality. During simulations of seawater desalination, the prepared evaporator exhibited remarkable salt crystallization resistance attributed to the strong water supply capacity and Marangoni effect induced during saltwater evaporation, facilitating salt diffusion and water evaporation. Overall, the foams developed in this project hold substantial application potential in the realm of photothermal technology.

Pivotal role of water vapor–mediated defect engineering on SrTiO3 nanofiber toward efficient photocatalytic water splitting

The oxygen vacancies (OVs) have played key roles as either charge carrier traps for inhibiting recombination or directly as active sites for photocatalytic redox reactions. In this study, the population and types of oxygen vacancies within the electrospun SrTiO3 nanofibers were modulated through water vapor and air atmosphere annealing respectively. Combining the distinctive 1D nanofibrous structure with optimized OVs, the water vapor–mediated OVs-rich SrTiO3 nanofibers achieved a significant enhancement in specific surface area and porosity, effectively suppressing the recombination of photogenerated carriers. The OVs can effectively promote the conversion of photon excitons into charge carriers, accelerate the carrier separation, and facilitate surface redox reaction. The optimized water vapor–mediated STO-W-700 exhibited abundant active sites and rapid surface charge separation/migration across the nanofibers, leading to an exceptional hydrogen production performance of 296.82 μmolg/h. During the photocatalytic process, the OVs act synergistically with nearby metal sites to optimize the adsorption energy of reactants. This work not only provides an effective pathway for manipulating oxygen vacancies through water vapor–mediated defect engineering strategy, but also reveals a new water splitting mechanism, laying the foundation for further research and development of efficient solar energy conversion technologies.

Flexible Aqueous Supercapacitors for Long Cycle-Life Using Electrode with Multiple Active C═S Sites.

Even though a few organic materials have attracted considerable attention for energy storage applications, their dissolution in the electrolyte during the charging-discharging processes presents a formidable challenge to their long-term performance. In this work, according to the principle of like dissolves like, non-polar trithiocyanuric acid (TCA) can effectively inhibit dissolution in an aqueous electrolyte, hence prolonging the cycle life. Moreover, theoretical calculations suggest that TCA lowers lowest unoccupied molecular orbital (LUMO) energy level, thereby promoting reaction kinetics. The CV curves of TCA maintain a rectangular structure even at a high scan rate of 1000 mV s‒1 and exhibit a remarkable capacitance retention rate of 93.1% after 50,000 cycles. Asymmetric flexible supercapacitors utilizing the TCA exhibit an impressive energy density. Moreover, they maintain 94.2% of their capacitance after undergoing 80,000 cycles. Their integration with perovskite solar cells to facilitate the rapid storage of photogenerated charges enables efficient solar energy utilization, providing a practical solution for capturing and storing renewable energy.

Design and fabrication of a novel 2D/3D ZnIn2S4@Ni1/UiO-66-NH2 heterojunction for highly efficient visible-light photocatalytic H2 evolution coupled with benzyl alcohol valorization

Making full use of photogenerated charge carriers by careful design multifunctional photocatalysts to achieving bi-value-added production with high-efficiency is highly desirable and extremely challenge. Herein, a novel 2D/3D ZnIn2S4@Ni1/UiO-66-NH2 (ZIS@Ni1/UN) heterojunction with spatially separated and precise redox sites was designed and fabricated for both photocatalytic H2 production and benzyl alcohol (BA) valorization. By precise structural regulation and modification of UiO-66 integrated with -NH2, ZnIn2S4 (ZIS) and Ni single-atom, the spatial separation of redox sites and directional electron transfer has been achieved. This realizes collaborative and efficient solar energy to chemical energy conversion. The optimal sample 5ZIS@Ni1/UN-6 shows high photocatalytic H2 and benzaldehyde (BAD) production rates of 11.44 mmol∙g−1∙h−1 and 10.02 mmol∙g−1∙h−1 under visible light. This work highlights the importance of rational construction for the engineering of charge behavior in heterogeneous photocatalysts with spatial separation and identifies their crucial role in promoting the photocatalytic redox coupling reactions.

Hygroscopic assisted solar photo-thermal-electric conversion system for all-day power generation and daytime water collection

In the field of solar thermal electricity, it is difficult to achieve efficient solar energy utilization during the day and continuous power supply day and night at the same time. To address this issue, an integrated system for daytime photothermal power generation combined with waste hot water evaporation and nighttime hygroscopic exothermic power generation has been designed. The system consists of multifunctional composite hydrogel, thermoelectric generator, and hydrophilic porous foam from top to bottom. Among them, the multifunctional composite hydrogel is a crosslinked sodium alginate (SA) loaded with photothermal material polypyrrole (PPy) and hygroscopic material CaCl2, and the hydrophilic porous foam is a PDMS treated by pore-making and oxygen plasma. During the night, CaCl2 and SA in the hydrogel absorb ambient moisture and then release heat, causing the temperature difference between the two sides of the thermoelectric generator to generate electricity with a power of 15.1 mW m−2. During the day, PPy in the hydrogel converts sunlight into heat for the thermoelectric generator to generate electricity with a power of 141.8 mW m−2, and the waste heat of the thermoelectric generator is then used to evaporate the water in the porous PDMS with a rate of 1.311 kg m-2h−1, realizing the multi-stage utilization of solar energy with a high efficiency of 80 %. Therefore, this integrated system can not only use solar energy efficiently, but also generate electricity continuously day and night.

Optimal Capacity and Charging Scheduling of Battery Storage through Forecasting of Photovoltaic Power Production and Electric Vehicle Charging Demand with Deep Learning Models

The transition from internal combustion engine vehicles to electric vehicles (EVs) is gaining momentum due to their significant environmental and economic benefits. This study addresses the challenges of integrating renewable energy sources, particularly solar power, into EV charging infrastructures by using deep learning models to predict photovoltaic (PV) power generation and EV charging demand. The study determines the optimal battery energy storage capacity and charging schedule based on the prediction result and actual data. A dataset of a 15 kWp rooftop PV system and simulated EV charging data are used. The results show that simple RNNs are most effective at predicting PV power due to their adept handling of simple patterns, while bidirectional LSTMs excel at predicting EV charging demand by capturing complex dynamics. The study also identifies an optimal battery storage capacity that will balance the use of the grid and surplus solar power through strategic charging scheduling, thereby improving the sustainability and efficiency of solar energy in EV charging infrastructures. This research highlights the potential for integrating renewable energy sources with advanced energy storage solutions to support the growing electric vehicle infrastructure.

Comparison of Greenhouse Gas Emission Assessments of Solar and Energy Efficiency Improvements at Small Water Resource Recovery Facilities

Small water resource recovery facilities (WRRFs) account for the majority of centralized systems in the world and have higher energy intensities than large facilities. This study compares potential greenhouse gas emission reductions based on on-site solar energy and energy efficiency (E2) improvements made at small WRRFs. Case study data from 31 existing small WRRFs in Nebraska were collected and included 35 site-specific energy efficiency (E2) recommendations and on-site solar renewable energy systems integrated at three facilities, and the data were used to compare the benefits of on-site solar energy and E2 improvements made at small WRRFs. Improvements in E2 (e.g., improved aeration control) presented the largest reduction in emissions per dollar invested. They often exhibited shorter paybacks, with operational changes in aeration strategies showing the highest impact (up to 0.2 kg CO2eq/m3 treated water). On-site solar systems showed the largest net potential for reducing environmental footprint (0.35 kg CO2eq/m3) but often showed the smallest emissions reduction per cost. While the use of both E2 improvements and the integration of on-site solar renewable energy can significantly improve the sustainability of small WRRFs, on-site solar has advantages for small facilities in that it often requires less operational involvement, allows for greater facility resiliency, and presents less uncertainty in terms of environmental benefit.

Phase change material microcapsules doped with phosphorus-based flame retardant filled titanium dioxide nanotubes for enhancing the energy storage and temperature regulation performance of buildings

Solar energy is not only a green alternative to fossil energy but also a candidate for future mainstream energy sources. To improve the efficiency and application range of solar energy, we investigated tris (1-chloro-2-propyl) phosphate (TCPP) modified titanium dioxide nanotubes (TNTs) doped phase change material microcapsules (p-t-MPCMs) to enhance the temperature regulation and flame retardancy of epoxy resin (EP) coatings. Transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy determined the successful preparation of p-TNTs and p-t-MPCMs. Moreover, it was confirmed that the p-t-MPCMs had great thermal stability and reliability by the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The p-t-MPCMs increased residual mass by 12.2 % at 600 ℃ while correcting the initial melting temperature of MPCMs by 1.0 ℃. Based on the principle of oxygen consumption, the heat release rate (HRR) of EP coatings containing the p-t-MPCMs (p-t-MPCM/EP) was reduced from 665.92 kW/m2 to 443.78 kW/m2, resulting in a total heat release reduction (THR) of 17.73 % tested by a conical calorimeter. Then the results of the miniature chamber model demonstrated that p-t-MPCM/EP had outstanding temperature control ability. In summary, the p-t-MPCMs expressed great potential in regulating building temperature timely and improving the fire safety of EP coatings.

Suntrack Weather: Real Time Solar Power Weather Update

The need for efficient solar energy utilization has become increasingly evident in the face of climate change and growing energy demands. This led to the recognition of the problem of suboptimal energy capture in fixed solar panels. Through extensive research and observations, it was identified that conventional fixed solar panels do not fully harness the available solar energy due to the sun's changing position throughout the day. This realization prompted the exploration of advanced tracking systems to improve energy capture. How the Problem was identified: In addressing the challenge of maximizing solar energy capture, various solar tracking technologies have been developed. Single-axis trackers are among the initial solutions, adjusting panels on a horizontal axis to follow the sun's east-west movement. However, these systems fail to account for the sun's changing altitude throughout the day. Dual-axis solar tracking systems emerged as a more advanced solution, capable of continuously aligning solar panels in both the horizontal and vertical planes. These systems employ an array of sensors, microcontrollers, and actuators to precisely track the sun's position, thereby significantly enhancing energy output. KEYWORDS: Sun-track weather, Real-time, Solar power, Weather update, Sun tracking technology.

Modeling heat and mass transfer in granular flows between vertical parallel plates

Gravity-driven granular flows between vertical parallel plates at elevated temperatures are integral in the development of the next generation of particle-based heat exchangers for concentrated solar power. Efficient modeling methodologies that accurately captures the heat transfer mechanisms of temperature-dependent granular flows are essential to effectively design and evaluate these heat exchangers. Transient, pseudo-one-dimensional heat and mass transfer models were developed for inlet flow temperatures between 473 and 1073 K. The mass transfer models for the granular flows were resolved using discrete element method simulation, providing detailed temporal and spatial distributions of flow parameters in good agreement with experimental measurements. The heat transfer model employed a one-dimensional, two-phase, continuum approach, and a system of non-linear differential equations was solved via finite difference method. The particle-to-wall contact heat transfer was determined with an effective thermal conductance model. Radiative heat transfer between particles and walls was also considered. The predicted particle and wall temperatures for two different channel widths of 6.4 and 2 mm were well-correlated to previously obtained experimental measurements with Pearson’s correlation coefficients greater than 0.91. A significant disparity in particle temperature of up to 72 K was observed when radiative heat transfer was omitted, and a maximum temperature difference of 11 K was observed when temperature-dependent granular flow properties were not considered. The model revealed that radiative heat transfer potentially contributed to > 30 % of heat losses in wider channels at high inlet temperatures, and conduction was the dominated heat transfer mechanisms in narrower channels (∼70 %) due to increased particle-to-wall contact. This accurate model, leveraging discrete element method in a streamlined approach, advances the understanding and modeling of heat transfer in granular flows at elevated temperatures, enabling more efficient and reliable solar thermal energy storage and transport.