Offshore photovoltaic (PV) systems are vulnerable to salt deposition and corrosion on the front glass, which significantly impacts the optical transmittance and power output of the modules. In this study, we experimentally investigated the effects of seawater-induced salt deposition and corrosion on PV glass under accelerated exposure to simulated seawater. By employing multiple characterization techniques, we analyzed the evolution of surface deposits and corrosion overtime. After 98 days of immersion in simulated seawater, the transmittance of PV glass decreased from 91.46% to 70.35%. EPMA-EDS mapping and FIB cross-sectional analyses revealed that the Mg-salt layer accelerates local corrosion, while the subsequent formation of a Ca-salt layer, along with ongoing glass dissolution, further exacerbated optical losses and reduced module output. These results provide a mechanistic understanding of how seawater-induced surface processes drive the degradation of offshore PV performance, establishing a foundation for the development of anti-deposition and anti-corrosion coatings to enhance the durability and efficiency of PV modules in marine environments.

Trough solar reflectors are widely applied in solar thermal power generation, especially in arid and desert regions with abundant solar resources where dust accumulation is prevalent. However, particle deposition on trough solar reflectors significantly reduces the optical performance and efficiency. In this study, the computational fluid dynamics–discrete phase model method is used to establish a particle deposition model for trough solar reflectors. The air flow field structure and the particle motion and deposition processes are analyzed. Additionally, the effects of different conditions on particle deposition laws are investigated. The results indicate that the air flow field structure includes five regions. The low-pressure and low-velocity region is distributed behind the reflectors and within the reflector spacing with air flow separation, settling, and refluxing. Particle deposition occurs when the influences of gravitational, van der Waals, and electrostatic forces are greater than those of the drag, collision, Magnus, and Saffman forces. The minimum particle deposition rate on the reflectors occurs when the angle of inclination is approximately 36°, where the increasing drag effect gradually balances the decreasing influence of collision-related forces. Increasing the array row number greatly reduces the particle deposition rate except in the fourth row, where enhanced wake recirculation increases particle residence and deposition near the reflector surface. Decreasing the array spacing without affecting the focusing effect of the reflectors can mitigate the negative influence of dust deposition. The study can provide an important theoretical basis for reducing dust deposition on trough solar reflectors.

Photovoltaic power generation technology is pivotal to energy transition and sustainable development, with bifacial photovoltaic (BPV) modules outperforming monofacial counterparts. However, dust deposition severely degrades BPV performance. This study experimentally investigates the self-cleaning dynamics of hydrophobic/ super-hydrophobic surfaces (HBS/SHBS) on BPV under condensation, evaluates their condensation characteristics in clean and dusty states, and probes the effects of particle size, condensation time, initial contamination level, and BPV installation angle. A kinetic model for particle-condensate interaction was established to reveal mechanisms. Results show HBS/SHBS exhibit droplet condensation in the clean state, with local film condensation only under severe contamination (transmissivity <= 70%). Dust promotes condensate nucleation and coalescence but inhibits movement, prolonging the condensation cycle by 10-80 min. The gas-liquid interface force is the dominant self-cleaning driver. Friction and contact angle hysteresis are primary impediments. Contact angle hysteresis increases significantly under heavy dust. Particle gravity hinders front-side but enhances backside self-cleaning. Key findings: the cleaning efficiency for the back-side of HBS/SHBS approaches 87.0% for particles exceeding 109 mu m. The cleaning efficiency of SHBS is slightly better than that of HBS under different installation angles. The optimal installation angle is 90 degrees. Under low contamination, SHBS outperforms HBS, with the back super-hydrophobic surface achieving an optimal 19.21% transmissivity recovery rate. Severe contamination causes SHBS to lose super-hydrophobicity, transitioning dust removal from rolling to sliding. These results establish a dust-mitigation framework for BPV systems.

Hotspots can significantly affect the efficiency and lifetime of photovoltaic (PV) modules. In this study, the effects of hotspots on the electrical output characteristics, temperature field, and thermo-mechanical strain of PV modules were experimentally investigated. An electro-thermal-structural coupled simulation model of hotspot PV modules based on micro-cells was established, and a topology-based lifetime evaluation method for hotspot PV modules was proposed for predicting the lifetime of PV modules under hotspot conditions. The experimental results of a given monocrystalline silicon PV module confirmed that the partial shading of PV cells caused distortion in the I-U and the P-U characteristic curves, leading to a maximum local temperature of the hotspot cell reaching up to 141 degrees C. The simulation results demonstrated that the maximum principal stress, Von Mises stress, shear stress, and strain of the hotspot cell increased by 2.37, 13.77, 13.11, and 1.51 times, respectively, compared with those without hotspots. This indicated that the hotspot cell was subjected to cyclic thermal stress and strain caused by day-night cycles over a long-term operation process. The lifetime evaluation results showed that the effect of hotspots on the lifetime of PV modules depended on the module structure as well as the shading ratio, number, and distribution of hotspot cells. For the given PV module, the annual degradation factor of a normal cell was 0.009-1.094%/a, while that of a hotspot cell with a shading ratio of 0.4 sharply increased to 0.102-8.573%/a, thereby reducing the PV module's lifetime to 15.27 a, which was 54.36% lower than that of a normal module.

Dust accumulation on a photovoltaic (PV) surface hinders sunlight transmission, reduces photoelectric efficiency, and poses security risks. Although condensation affects dust agglomeration, self-cleaning superhydrophobic surfaces can effectively remove dust accumulated on a PV surface. However, the mechanism of agglomeration and adhesion of dust particles on the superhydrophobic surface remains unclear. The mechanism of particles carried by jumping droplets on a superhydrophobic surface has not been well understood. Therefore, we performed dust particle agglomeration and self-cleaning experiments on a superhydrophobic surface during condensation. The agglomeration process of dust particles on the superhydrophobic surface was observed using a three-dimensional microscope. We analyzed the causes that facilitate dust removal by droplets jumping away from the superhydrophobic surface. The particle agglomeration process primarily entailed four processes: coalescence of two droplets, coalescence of partially wetted particles and droplets, agglomeration of partially wetted particles, and coalescence of droplets wrapped with multiparticles. We analyzed the mechanisms of condensation-induced droplet jumping and particle agglomeration on the superhydrophobic surface. Droplets jumping away from a superhydrophobic surface can induce the formation of stacked spherical agglomerates. These agglomerates exhibited reduced contact areas and adhesion forces between the agglomerates and superhydrophobic surfaces, which facilitated the removal of dust particles from the surface. The smaller the particles, the better the dust cleaning effectiveness of the droplet jumping phenomenon. In addition, outdoor self-cleaning and wind cleaning simulation experiments were performed to confirm the self-cleaning effect of superhydrophobic surfaces. The obtained results provide a theoretical guidance for the optimal design of self-cleaning surfaces.

The influence of sand size on motion and transport characteristics of wind-sand two-phase flow is a crucial theoretical foundation for addressing global desertification issues. This study conducts a detailed investigation into the influence of sand size on air flow characteristics, sand motion behaviors, and transport distributions in the wind-sand two-phase flow using TFM method. The results indicate that the existence of sand particles decreases the air velocity, widens the air dynamic range and intensifies the momentum transfer process. When the sand size increases from 10 to 400 mu m, the dynamic height and maximum turbulent kinetic energy decrease by 79.3 % and 82.1 %, respectively. The initial saltation velocities in the horizontal and vertical directions are predominantly distributed within the ranges of -0.1 to 0.7 m/s and 0-0.6 m/s, respectively. The initial horizontal and vertical saltation velocities corresponding to the peak proportion increase with decreasing sand size. The horizontal and vertical distributions of sediment transport flux conform to the exponential decline law, reflecting the magnitude, distribution and extent of sand transportation into the desert flow field. When the sand diameter rises from 100 to 400 mu m, the maximum values of sediment transport flux in vertical and horizontal directions increase by 1.83 times and 1.01 times, respectively, while the transport indexes decrease by 5.6 % and 10.3 %, respectively. The variation characteristics of sediment transport range differ between low and high air friction velocities as sand size increases. These research findings provide important theoretical guidance for the control of desertification. (c) 2025 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Dust deposition can significantly reduce the conversion efficiency of bifacial photovoltaic modules. In order to solve this problem, the condensation characteristics of bifacial photovoltaic panels with hydrophilic and super-hydrophilic surfaces are studied. The kinetical models of condensation liquid and particles are established, and their dynamic interactions are analyzed. The self-cleaning mechanisms of hydrophilic and super-hydrophilic surfaces are revealed. The results indicate that condensate on hydrophilic surfaces primarily forms droplets condensation, with a small amount of film-like condensation. In contrast, super-hydrophilic surfaces exhibit only film-like condensation. The head of droplet condensation has a slight self-cleaning power. The increased thermal resistance caused by the film-like tail prolongs the condensation cycle, thereby inhibiting the self-cleaning process. When transmissivity drops to approximately 65 % after PV dust accumulation, dust particles reduce the hydrophilic surfaces condensation cycle by about 25 %. Under the condition of dust deposition at the photovoltaic site, the transmissivity recovery values for bifacial photovoltaic modules are below 6.21 % for hydrophilic surfaces and 2.00 % for super-hydrophilic surfaces, respectively. Super-hydrophilic surfaces exhibit inferior self-cleaning performance compared to hydrophilic surfaces. These results provide theoretical support for solving the problem of bifacial photovoltaic panels dust accumulation.

Photovoltaic power plants are typically located in desert regions with high solar irradiation but are prone to dust contamination due to wind and sand. To mitigate dust deposition on Photovoltaic panels, a physical model based on the Hobq Desert power station was developed. Using the computational fluid dynamics-discrete phase model, dust movement within the plant was simulated, and the motion and deposition mechanisms of dust particles were analyzed microscopically based on aerodynamic principles. Results reveal that the flow field divides into five regions after passing through the PV panel, with low-speed regions effectively suppressing dust formation. Vortices reduce airflow velocity behind the panel by up to 84 %, and the low-speed region, covering 31.95 % of the area, acts as a barrier to dust deposition. The maximum dust deposition rate of 2.27 x 10-3 occurs at a wind speed of 6 m/s. Maintaining a spacing of less than 18 m between adjacent modules significantly reduces dust accumulation. These findings offer critical theoretical insights and practical strategies for minimizing dust on PV panels, improving their efficiency and longevity.

Bifacial solar PV power generation is one of the most promising and popular power generation technologies for overcoming environmental pollution and energy shortages. The phenomenon of dust deposition on bifacial PV modules greatly weakens the power generation performance and threatens safe operation. In this work, the dust deposition laws of bifacial PV modules are studied using the DEM. Besides, the influence of dust deposition and installation conditions on the power generation gain of bifacial PV modules is investigated. The results indicate that the dust concentration on windward surfaces is greater than that on leeward sides during nonfree deposition but smaller than that on upper surfaces during free deposition. The particle morphological distribution and motion behaviour differ among the left, right and top inlets under the coupled effects of deposition and separation forces. The power generation gain increases when the inclination angle, PV installation height and ground reflectivity increase. The power generation gain under overcast weather conditions is the greatest among the three kinds of typical weather conditions. When the dust deposition density varies from 0 to 0.95 g/m2, the power generation gain greatly decreases by 41–65

The dust deposited on a photovoltaic (PV) surface decreases the photoelectric efficiency of a module, leading to potential security risks. A few studies have demonstrated that condensation affects dust accumulation on PV surfaces; however, the mechanism remains unclear. Therefore, this study investigated the effects of dust agglomeration dynamic factors on PV surfaces using micro-experiments and mechanical analysis. An experimental platform for dust particle agglomeration due to condensation was designed and developed, and microscopic experiments were conducted to study the dust particle agglomeration process on the PV panel surface. The particles on the hydrophilic PV surface were confirmed to agglomerate owing to condensation. The particle agglomeration process on the hydrophilic PV surface primarily entails three typical processes that occur sequentially: fusion between droplets, fusion between the semi-submerged particles and droplets, and agglomeration between semi-submerged particles. The particles agglomerated on the hydrophilic PV surfaces have a tiled morphology. An analysis of the particle agglomeration mechanism on the hydrophilic PV surface due to condensation was performed. Water surface tension was identified as the main dynamic factor leading to particle agglomeration during condensation. The results provide theoretical guidance for reducing the dust deposited on PV surfaces.

The utilization of solar photovoltaic (PV) power generation represents a highly promising technological solution for addressing environmental challenges and energy crises. Dust deposition on the front and back surfaces of solar bifacial PV panels greatly decreases the optical performance and power generation. In this study, the dust deposition characteristics and mechanism of solar bifacial PV panels are investigated using the CFD-DEM method. The effects of the dust deposition rate on the output characteristics of bifacial PV panels are discussed. The research results show that the particle deposition behaviors on the back and front surfaces of bifacial PV panels are influenced by the deposition and separation forces at the left or right inlets. The dust deposition rate of windward surfaces can be 1.48-7.60 times that of the leeward surfaces of bifacial PV panels. The particle motion trajectories on the windward and leeward sides can be mainly divided into five and three kinds, respectively. The dust deposition rate of bifacial PV panels increases when the air inlet velocity decreases and the particle size and concentration and relative humidity increase. The open circuit voltage and short circuit current of bifacial PV panels decreased by 26.7% and 16.4%, respectively, when the dust deposition rate increases by 45.8%. The attenuation rate of the maximum output power of PV panels has a positive linear correlation with the dust deposition rate, as shown in Eq. 22. The bifacial PV panels have better output characteristics than the mono-facial PV panels with consideration of dust deposition.

The vigorous development of photovoltaic (PV) power generation technology is crucial for addressing the high energy demand and severe environmental issues. The accumulation of dust on solar PV glass significantly decreases its ability to convert sunlight into electricity. In this study, the dust accumulation characteristics and a comparison of the particle adhesion forces on the ground and PV glass in Dengkou and Wuhan are investigated. In addition, the particle adhesion laws and dynamic behavior after deposition are studied. The results indicate that the distribution of dust particles on the PV glass and ground is non-uniform and the particle size and shape distributions diversify. The dust particles on the PV glass are mostly from the ground. The greatest and smallest mean adhesion forces are for the dust particles on the PV glass at Wuhan and the ground at Dengkou, respectively. The particle adhesion forces on PV glass mainly consist of the liquid bridge and electrostatic forces. The dominant adhesion force of particles varies across different ranges of air relative humidity. Increasing the air humidity can promote particle agglomeration and adhesion behavior, thus increasing the particle adhesion force on PV glass.

The components of dust accumulation on PV panel surfaces under three different scenarios were analyzed, the adhesion strength between dust and PV panels under condensation conditions was measured, the microstructure of the adhesion interfaces, using metallographic microscopy and environmental scanning electron microscopy, was observed, the main factors of dust-PV panel adhesion were investigated, and the adhesion mechanism was explored. The results showed that calcium sulfate dihydrate (CSD) was the main soluble component in most PV panel dusts. It significantly increased the adhesion strength of the dust to the PV panels under the effect of condensation. The kinetic friction coefficients of the dust adhered samples after 150 condensation cycles increased by approximately 100% and 170% when the CSD content increased from 0 to 2.8% and 5.53%, respectively. This was attributed to the recrystallization of the CSD into blocky and rod-shaped particles. The blocky CSD particles wrapped and cemented other particles while promoting adhesion through a larger contact area with the PV panel surface and formation of hydrogen bonds. A rod-shaped CSD was interlaced to enhance agglomeration and increase friction at the adhesion interface to improve the adhesion. Moreover, CSD caused the decrease of power generation of PV panels. For 150 condensation cycles and the same cleaning conditions, dust sample with 2.88% CSD resulted in a power generation reduction of about 2.37% compared to that of dust sample without CSD. It was recommended that a hydrophobic or super hydrophobic surface was used on PV panels to reduce the residence time and contact area of water on the surface to inhibit the recrystallizing of CSD on PV panels.

The non-uniform solar flux distribution on the absorber surface in a parabolic trough collector results in a large temperature gradient and stress, thus leading to safety hazards. This study proposed a installation mode of the absorber in a parabolic trough collector, with an initial offset. The geometric centre of the absorber deviates from the focal line by an initial offset to increase the uniformity of the solar flux distribution and reduce the stress on the absorber surface, without incurring an additional cost. A mechanism model of the parabolic trough collector was established, and a theoretical equation for the critical initial offset was derived. Moreover, an optical-thermal-fluid-structural multiphysics coupled model of the system was developed via the software COMSOL to study the system performance with an absorber having an initial offset. The simulation results indicated that the absorber with an initial offset of-24 mm significantly decreased the circumferential temperature difference and maximum stress of the absorber by up to 45% and 39.5%, respectively, and the optical-thermal efficiency is slightly increased by 2.5%, in comparison with that without an initial offset.(c) 2022 Elsevier Ltd. All rights reserved.

Dust deposition and erosion phenomena on solar photovoltaic (PV) panels substantially reduce their power generation efficiency, useful life and safe operation. In the present study, the dust motion and erosion characteristics of clear and dusty PV panels are investigated using a discrete element model. The physical properties of dust particles and PV panels are experimentally compared between the POWERCHINA Hubei Electric Engineering Corporation (HEEC) Limited building and the power building of the Huazhong University of Science and Technology (HUST). In addition, the effects of the physical properties of dust particles on their dynamic behaviours and erosion rates are discussed. The phase composition of the dust particles at the HUST is mostly SiO 2 , while the dust particles from the HEEC consist of CaO, Fe 2 O 3 , Al 2 O 3 , CaCO 3 , SiO 2 and Ca(OH) 2 . Dust deposits with multiple phase compositions exert a greater negative effect on the panel working performance than dust deposits with a single phase composition. Maximum panel erosion may cause irreparable mechanical damage to PV panels even after cleaning. For dust particles and panels from the HEEC, gravitational, liquid bridge, electrostatic and van der Waals forces are the primary deposition forces; the largest adhesion rates are observed for Fe 2 O 3 , Ca(OH) 2 , SiO 2 and Ca(OH) 2 . The greatest and lowest maximum erosion rates are observed for Fe 2 O 3 and SiO 2 , respectively. Long-term erosion will lead to a significant increase in the maximum erosion value and the erosion areas and even cause the whole panel to undergo wear. These research findings are very important for power generation optimization and the safe and efficient operation of PV panels.

The deposition and adhesion of dust on the surface of photovoltaic (PV) panels cause a reduction in efficiency and pose safety hazards. It is necessary to investigate the factors and mechanisms of dust adhesion to PV panels to provide theoretical guidance in preventing the dust from adhering on the PV panels. This study analysed the chemical components of actual dust samples from five typical scenarios for PV applications, measured the adhesion strength of dust to PV panels with different organic contents under condensation, observed and analysed the morphology of dust adhesion interface, based on a series of experiments. At last, the mechanism by which organics promote dust adhesion was investigated. The results showed that human activities (life, transportation, production, and so on) were one of the main reasons for the difference of dust composition, especially for organic content. It was discovered that a higher organic content or more condensation cycles enhanced the adhesion strength. Condensation leaded to the accumulation of organics at the adhesion interface to form organic films, which increased the contact area at adhesion interface. Moreover, the organic films may form hydrogen bonds with the hydroxylated silica surface of the PV panels, increasing the adhesion strength. Finally, recommendations were provided to inhibit the dust adhesion to the PV panels.

Solar photovoltaics (PVs) are one of the most promising renewable energy sources to solve the global environmental and energy crises. Dust agglomeration on PV panels greatly affects their operation life and power generation efficiency. In this study, the evaporation mechanism and laws of liquid bridges as well as the evaporation time and interaction forces for liquid bridges and particles are investigated. The effects of liquid bridge evaporation and its influencing factors on dust dynamic behaviour are discussed. Liquid bridge evaporation in the muddy state with small particle spacing can cause particle agglomeration on PV panels. However, it is very difficult for the capillary, the ribbon, and the pendulum states or the muddy state with large particle spacing to affect particle motion. In the muddy state, the interaction force for a small particle spacing consists of not only the liquid bridge force but also the drag force caused by liquid bridge evaporation, and that for a large particle spacing consists of only the drag force; in the other three states, the interaction force consists of only the liquid bridge force. Liquid bridge evaporation can greatly intensify particle agglomeration and even scaling processes with decreasing particle size. These findings can provide important theoretical guidance and value for engineering improvements in power generation and safe operation of PV panels.

Compressed air energy storage（CAES）technology is an important way to solve the power network congestion,improve the capacity of power grid peak-shaving units,increase the penetration rate of renewable energy into the main grid,and improve the consumption of new energy. Its future development is the current research focus. This paper reviews the principles of CAES technology and summarizes its application scenarios.Then,the paper classifies and summarizes the current hot research progress of compressed air energy storage,at the same time introducing the CAES technology engineering demonstration under construction. Finally,the paper prospects the research direction and development prospect of compressed air energy storage.

Dust accumulation on solar photovoltaic (PV) glass greatly reduces its efficiency of power generation and service life. Traditional methods for cleaning PV glass generally exhibit serious shortcomings, such as excessive water consumption, high cost and low cleaning efficiency. Hydrophobic and hydrophilic surfaces have excellent self-cleaning characteristics and good mechanical properties, and their use for PV glass is expected to lead to efficient self-cleaning. In this study, extensive experimental and theoretical studies were conducted on the self-cleaning characteristics and dynamic behaviours of particles and droplets on both hydrophilic and hydrophobic surfaces. The effects of the condition of PV glass and the properties of particles and liquid droplets on self-cleaning by these two types of surfaces were studied. Furthermore, the self-cleaning mechanisms for hydrophilic and hydrophobic surfaces were compared. The results indicated that the hydrophobic and hydrophilic surfaces underwent self-cleaning in five and three stages, respectively, under the coupled effects of gravitational, gasliquid interfacial, adhesive and frictional forces. The cleaning time of hydrophilic and hydrophobic surfaces increased by approximately 141% and decreased by approximately 73%, respectively, when the contact angle increased by 60°. The self-cleaning abilities of hydrophilic and hydrophobic surfaces were improved by increasing the liquid droplet volume, surface tension or installation angles and decreasing the particle masses.

Photovoltaic (PV) power generation technology is one of the most important methods for reaching the carbon peak and achieving carbon neutralization. Dust accumulation on the surface of PV glass greatly reduces the working performance and power generation efficiency of PVs. The hydrophobic or hydrophilic surfaces on the PV glass have substantial self-cleaning potential. In this study, the liquid bridges formed between particles and the hydrophobic or hydrophilic surfaces of solar PV glass are investigated. The effects of the liquid bridge force and the influencing factors for these two surfaces on particle dynamics behaviours are studied. Furthermore, the self-cleaning abilities of these two surfaces are also discussed. The results indicate that the liquid bridges formed between a particle and a hydrophilic PV glass placed horizontally or obliquely exhibit similar saddle shapes, but the liquid bridges wrap the particle on the surface of hydrophobic PV glass. The influence of the liquid bridges causes particles to adhere to the tilted hydrophilic or hydrophobic surfaces at liquid bridge volumes (VL) < 6 μL, making initially moving particles stay on these two tilted surfaces with 6 μL ≤ VL ≤ 20 μL and even achieving self-cleaning properties at VL > 20 μL. Both hydrophobic and hydrophilic surfaces increase the self-cleaning forces resulting from the liquid bridge formation with increasing VL, thus completing the self-cleaning process. Increasing the self-cleaning forces and decreasing the friction force and the liquid bridge force improves the self-cleaning abilities of the surface. These research findings have important theoretical significance and commercial engineering value in preventing and reducing dust accumulation on glass.