Solar panels are essential for converting sunlight into electricity. Still, environmental factors can significantly compromise their efficiency and performance, particularly the accumulation of soiling on their surfaces or damage. This study proposes a hybrid model comprising an ensemble of deep-learning models to distinguish between soiled and damaged solar panels and their corresponding conditions. Our approach utilizes pretrained deep learning models, fine-tuned for detecting soiling or damage on photovoltaic (PV) panels, to extract relevant features and build efficient classifiers. Introducing a post-processing ensemble model improves classification metrics compared to a single deep-learning model. Combining Convolutional Neural Networks and Vision Transformers in an ensemble model achieves the highest accuracy, with 96.3% for damage and soiling detection and 91.8% for damage and soiling type identification. These results significantly outperform one-tier deep learning models, which attain an accuracy of 87.7% when classifying all possible damage and soiling categories.

This study addresses a critical issue faced in harsh desert environments characterized by intense sunlight and dusty conditions, which pose significant challenges for applications ranging from solar panels and optical devices to architectural surfaces. In response, we have developed a silica coating that may offer a solution to these environmental challenges. The silica coating exhibits excellent anti-reflective properties, drastically reducing the amount of sunlight reflected from the coated surface and thereby enhancing photon absorption. This study examines the controlled tuning of optical and morphological properties in silica thin films, fabricated through reactive RF magnetron sputtering of an SiO2 target, using various oxygen-to-argon flow ratios [r(O2)=O2/Ar]. Empirical properties of the coatings were systematically examined and demonstrated to be finely tunable by adjusting r(O2). Additionally, surface morphology, as assessed by average roughness (Ra) measurements, was found to be strongly influenced by the oxygen concentration during deposition. Hydrophilicity of the silica coatings was assessed using contact angle measurements, demonstrating that the oxygen content in the films plays a significant role in influencing their hydrophilic properties. Furthermore, micromechanical properties of these silica coatings right after sputtering deposition and those exposed to outdoor conditions were systematically evaluated using Vickers indentation, showing, on one hand, that the hardness of the silica coatings can be regulated by adjusting the oxygen levels introduced during the deposition process, and on the other hand, a high mechanical stability of these silica even after 24 months of outdoor exposure in desert environments. Finally, this study also highlights that dust accumulation on the surface of these silica coatings is inversely proportional to the oxygen content into the films, demonstrating the coatings' self-cleaning properties. The hydrophobicity of the deposited silica thin films further contributes to their self-cleaning capabilities, making them particularly valuable in enhancing the performance of photovoltaic modules, especially in desert environments where dust accumulation can significantly impact efficiency. This multifaceted approach not only improves optical and mechanical properties but also offers a sustainable solution for maintaining the efficiency of solar panels and other devices in challenging environmental conditions.

This work demonstrates the development of room-temperature curable and durable anti-soiling coating using fluorine functionalized mesoporous silica (F-SiO2) and silicone resin-based hydrophobic coatings. The use of silicone resin with a catalyst enabled room-temperature curing of the coating and enhanced its mechanical properties. The coating prepared from mesoporous silica and F-SiO2 exhibited contact angles of 102 degrees and 122 degrees, indicating a significant improvement in the wettability of F-SiO2-based coatings. Additionally, the transmittance values were 93 % and 94 %, respectively, which are comparable to those of bare PV cover glass. A soiling study of the fabricated coating was conducted in an outdoor environment for over one month. The results confirmed that the F-SiO2-based hydrophobic coatings showed a minimal transmittance loss compared to non-coated PV cover glass. The durability of the F-SiO2-based coating was confirmed by mechanical properties like adhesive strength (1.86 MPa) and hardness (4H). The photo-conversion efficiency of the F-SiO2 coated PV module was measured in an indoor soiling environment using wind cleaning action. It was observed that the module regained its photoconversion efficiency after only one minute of wind cleaning. These results indicate that the prepared coatings have a significant potential for practical application in PV industry.

The behavior of ice particles impacting against a rigid surface is a topic that has gained more and more relevance in the field of transportation safety, particularly in the automotive and aerospace sectors. The present review outlines the various controlled experimental approaches used to study artificial ice particle collisions, describing the setup configurations, particle release mechanisms, and the selection of materials for impact surfaces. It also assesses fundamental studies that measure the coefficient of restitution (CoR or en) and the fragmentation regime of ice upon impact, clarifying how ice particles react when they strike a surface. The review also includes analytical and empirical formulas that describe the critical impact velocity, which determines the different impact outcomes, like bouncing, sticking, or fragmentation and fragmentation distribution of the ice particles. Lastly, it summarizes how particle size, temperature, and material properties affect the impact responses. In addition, the review proposes a visual representation of the different models and how they compare. The visual representation highlights the differences between each model and the transition from elastic to plastic impact responses, and it is instrumental in understanding the conditions under which ice particles leave a residual mass on the impact surface. The insights gained from this review are vital for better understanding the impact of the ice particle phenomenon and mapping the state of the art in this branch of research.

External contamination (soiling) of the incident surface is a major limiting factor for solar technologies. A 5year field glass coupon study was conducted to better understand external contamination and its effects; compare cleaning methods and the use of preventative coatings; and explore the abrasion resulting from cleaning to advise on accelerated abrasion testing. Test sites included the cities of Dubai (UAE), Kuwait City (Kuwait), Mesa (AZ), Mumbai (India), and Sacramento (CA). Through the 5-year cumulative study, dry brush, water spray, and wet sponge and squeegee cleaning methods were compared to no cleaning. Optical microscopy was used to obtain images, including representative color images, grayscale images for object analysis, and oblique images for coating integrity assessment. A thresholding protocol was developed to analyze and distinguish specimens using the ImageJ software. Optical performance was quantified using a spectrophotometer, including comprehensive optical characterization (transmittance, reflectance, and absorptance in addition to forward- and back- scattering). Atomic force microscopy was used to verify the abrasion damage morphology, including the width and depth of surface scratches. Analysis of the results included correlation of optical performance and particle area coverage, rank order (by coating or location), and the acceleration factor for abrasion damage. The efficacy of external cleaning was more readily distinguished from the effectiveness of antisoiling coatings. The acceleration factor for dry brush cleaning of a porous silica coating was found to be on the order of unity.

Phosphate fertilizers are applied to the soil surface, especially in vineyards in production in subtropical regions. Nowadays, phosphorus (P) is not incorporated into the soil to avoid mechanical damage to the root system in orchards. However, over the years, successive surface P applications can increase the P content only in the topsoil, maintaining low P levels in the subsurface, which can reduce its use by grapevines. For this reason, there is a need to propose strategies to increase the P content in the soil profile of established orchards. The study aimed to evaluate the effect of management strategies to (i) increase the P content in the soil profile; (ii) enhance the grape production; and (iii) maintain the grape must composition. An experiment on the 'Pinot Noir' grape in full production was carried out over three crop seasons. The treatments were without P application (C), P on the soil surface without incorporation (SP), P incorporated at 20 cm (IP20), P incorporated at 40 cm (IP40), and twice the P dose incorporated at 40 cm (2IP40). The P concentration in leaves at flowering and veraison, P content in the soil, grape production and its components, and chemical parameters of the grape must (total soluble solids, total polyphenols, total titratable acidity, total anthocyanins, and pH) were evaluated. The P concentration in leaves did not differ among the P application modes. The application of P associated with soil mobilization, especially at 20 cm depth, increased grape production. The P application modes did not affect the values of the chemical parameters of the grape must except for the total anthocyanins, which had the highest values when the vines were subjected to 2IP40. Finally, the P application and incorporation into the soil profile was an efficient strategy for increasing the grape production in full production vineyards.

Tillage, as a key agricultural operation, has an important influence on soil properties and crop productivity. However, tillage at the same depth is not always the best choice as differences in soil texture, compacted topsoil, or plow pan at different depths, crop rotation, and root penetration potential signal that the depth of tillage should take greater account of the factors involved. Variable depth tillage (VDT) is an important precision farming operation, linking soil, plants, tillage machinery, smart sensors, measuring devices, computer programs, algorithms, and variability maps. This topic is important from an agronomic, energy, and environmental perspective. However, the application of VDTs in practice is currently still very limited. The aim of this study was to carry out a detailed review of scientific work on variable depth tillage, highlighting the importance of soil compaction and VDT; the measurement methods and equipment used; and the impact on soil, crops, the environment, and the economy. Based on the reviewed studies, there is a lack of studies that use fully automated depth control of tillage systems based on input data obtained with on-the-go (also known as online) proximal soil sensing. In precision agriculture, rapidly developing Internet of Things technologies allow the adaptation of various farming operations-including tillage depth-to site-specific and temporal conditions. In this context, the use of proximal soil sensing technologies coupled with electromagnetic induction, gamma rays, and multi-sensor data fusion to provide input for recommended tillage depth would be beneficial in the future. The application of VTD in specific areas is promising as it helps to reduce the negative effects of soil compaction and avoid unnecessary use of this expensive and environmentally damaging technological operation.

Nowadays, renewable energies are capturing the world's attention, particularly in light of the phenomenon of climate change and carbon dioxide emissions, which have caused major environmental damage. As a result, many investors have recently focused on developing investments in renewable energy projects worldwide, specifically photovoltaic and concentrated solar power plant projects. These solar technologies are considered among the most profitable solutions for generating power from a natural, free, and unlimited energy source. This review paper discusses one of the most significant issues affecting the performance of these solar systems, which is known as soiling. It has been supported by several studies in various nations with different climatic conditions, which offered accurate empirical data on the degradation rate of photovoltaic and concentrated solar power systems' production due to the soiling effect. Furthermore, it provides various mitigating soiling ways, including manual and autonomous cleaning methods for both solar technologies. Ultimately, it summarizes each cleaning technique's main advantages and drawbacks, specifying its applicability according to the location characteristics and climatic conditions. Additionally, the review results reported in this work are intriguing enough to warrant further development of concentrated solar power and photovoltaic technologies.

Photovoltaic (PV) module soiling, i.e., the accumulation of soil deposits on the surface of a PV module, directly affects the amount of solar energy received by the PV cells in that module and has also been suggested as a mechanism that can give rise to additional heating, leading to significant power generation losses or even physical degradation, damage and lifetime reduction. Investigations of PV soiling are challenging and limited. We present results from an extensive outdoor experimental testing campaign of soiling, apply detailed characterisation techniques, and consider the resulting losses. Soil from sixty low-iron glass coupons was collected at various tilt angles over a study period of 12 months to capture monthly, seasonal and annual variations. The coupons were exposed to outdoor conditions to mimic the upper surface of PV modules. Transmittance measurements showed that the horizontal coupons experienced the highest degree of soiling. The horizontal wet-season, dry-season and full-year samples experienced a relative transmittance decrease of 62 %, 66 %, and 60 %, respectively, which corresponds to a predicted relative decrease of 62 %, 66 %, and 60 % in electrical power generation. An analysis of the soiling matter using an X-ray diffractometer and a scanning electron microscope showed the presence of particulate matter with diameters <10 mu m (PM10), which was the most prevalent in the studied region. The findings of this study lay the groundwork for research into soiling mitigation practices.