Dirt Accumulation Research Articles

Design and Development of an Autonomous Raspberry PI Cleaning Robot For Photovoltaic Panels

This article presents a solution for the cleaning of solar panels using an autonomous robot based on a rail system and designed for highly inclined panels greater than 30 degrees. The accumulation of dirt and dust on solar panels can significantly reduce their performance. Therefore, the choice of designing this rail-based cleaning robot is based on the topographical nature in Tunisia, as well as other North Africa countries. Indeed, the photovoltaic panels inclination are typically between 20 to 35 degrees, unlike in Europe where the inclination varies between 10 to 20 degrees. Additionally, the climate in North African countries is characterized by significant temperature, humidity and dust which necessitates the use of pure water in the cleaning process. The robot is equipped with a rotating brush positioned on a mobile carriage that moves along the rails and move laterally across the panels allowing a thorough cleaning of the solar panel surfaces. We provide a detailed discussion of the robot's design, its movement mechanism, and how it optimizes solar energy production while contributing to environmental sustainability.

Solar panel surface dirt detection and removal based on arduino color recognition

Color sensing is a technique for identifying physical changes in materials based on appearance assessment. Dirt deposition on solar panels can change their physical appearance and performance. Considering that dirt accumulation on solar panels needs monitoring to make efficient cleaning schedules, reduce unnecessary costs, and optimize solar panel output generation. Color sensing can achieve fast, accurate, and economical dirt detection, unlike the use of robotic cameras, mathematical formulae, and considering varying output current and voltage methods. Here, we introduce a method that detects and removes dirt on solar panels based on TCS3200 and Arduino Uno components. The approach targets (i.) Panel color measurement, calibration, threshold selection process, (ii.) comparison of color measurement values, and (iii.) align further calibration in response to discoloration of solar panels. This method aims to correct the dirt detection methods previously in use. Hence, a high-speed rolling brush arrangement is designed to improve the cleaning of the solar panel without using water. Further investigations of the panel's color may require some improvement in terms of increasing the sensitivity of the color sensor even with increased distance from the solar panel. Combining multiple color sensors may also be necessary.

Weathering of a Nonwoven Polypropylene Geotextile: Field vs. Laboratory Exposure.

Like other plastic materials, geosynthetics can undergo changes in their properties due to weathering. These changes must be known and, if necessary, duly accounted for in the design phase. This work evaluates the resistance of a nonwoven polypropylene geotextile to weathering, both in the field (under natural degradation conditions) and in the laboratory (under accelerated degradation conditions). The damage experienced by the geotextile in the field weathering tests was evaluated by monitoring changes in its physical (mass per unit area and thickness), mechanical (tensile, tearing and puncture behaviour) and hydraulic (water permeability normal to the plane) properties. Microscopic damage was assessed by scanning electron microscopy. In the laboratory weathering tests, only the tensile behaviour of the geotextile was monitored. The results showed that all geotextile properties were affected by weathering. The mechanical strength of the geotextile decreased in the field weathering tests. Microscopic transverse cracks were found in the weathered polypropylene fibres, which may explain the reduction in mechanical strength. The accumulation of dirt on the nonwoven structure altered the physical and hydraulic properties of the geotextile. Comparing the field and laboratory weathering tests, the reduction in tensile strength found after 24 months outdoors (roughly 30%) was very similar to that observed after 4000 h in the laboratory. This relationship may not be valid for other geotextiles or other exposure locations.

Percentage of Parent Stock Chicken Eggs with Thin Shells in Battery Cage and Postal Cage Maintenance Methods at Farm Cariu Bogor

Background: In the maintenance of parent stock chicken, egg production is the main thing to consider because this will produce quality DOC chickens. In this case, the eggshell affects the hatchability of eggs, affecting the egg productivity level. Purpose: To determine the effect of differences in cage maintenance methods on the case of eggs with thin shells. Eggs with thin shells affect the hatchability of eggs in incubators which causes a decrease in egg and saleable chick production. Methods: The method used is primary and secondary data collection, recording eggs for three weeks to determine the number of eggs with thin shells daily in postal and battery cages. Results: In postal cages, the percentage yield was higher for the number of eggs with thin shells than in battery cages, which was about 0.52%, while in battery cages, it was 0.21%. The cause of the high percentage of cases of eggs with thin shells in postal cages is the chickens' direct contact with the litter. Poor litter conditions and rarely replaced cause the accumulation of dirt. The manure will ferment with husks and generate higher ammonia levels in the postal cage, causing disturbances in egg production, one of which is causing the eggshell to become thin. Conclusion: In this study, the shape of the cage floor was one of the factors causing the percentage of eggs with thin shells in the postal cage form that used litter as a base had a higher percentage of eggs with thin shells compared to battery cages.

A Review of the Mitigating Methods against the Energy Conversion Decrease in Solar Panels

Using solar panels is one of the cleanest ways to generate electricity ever created by mankind. The efficiency of rapidly expanding solar panels decreases during their lifetime for several reasons, such as photodegradation, hot spots, potentially induced degradation, etc. Dirt and debris accumulation on the surface of the solar panels can also significantly contribute to their performance degradation due to the diminishing of the solar radiation reaching their active surfaces. Numerous degradation mitigation methods are cited in the literature. This article briefly outlines these basic measures.

Orthogonal Optimization Design of the Compound Impeller for a New Type of Dishwasher Pump

A new type of dishwasher pump without a pipeline system was invented for the first time to form an original sink-type dishwasher avoiding the accumulation of dirt in the hydraulic system. In order to improve the hydraulic performance of this new type of dishwasher pump with twin-volute passive rotation driven by a compound impeller, an orthogonal optimal design method was first introduced to optimize the compound impeller composed of axial cascades and radial blades. Six geometric parameters were selected as the main factors to design the orthogonal table L18(36). All impeller models were manufactured via high-precision 3D printing and tested to determine the optimal solution. Firstly, the hydraulic performance was measured using a specially designed test bench under the assumption of static-volute conditions. Then, the optimization scheme was verified in real machine experiments under the rotating-volute condition, and numerical calculations were used to assess the performance improvement due to optimization under the static- and rotating-volute conditions. The results show that the main factors affecting the pump head and efficiency are impeller outlet diameter D2 and profile line L. The optimized pump head and efficiency are significantly higher than those of the original scheme. Furthermore, the entropy production of each flow passage component of this new type of dishwasher pump is significantly reduced after optimization. Under the static-volute condition, the scheme obtained using the range analysis displays an increase of 0.3 m in the pump head and 2.99% in pump efficiency. Under the rotating-volute condition, the optimization scheme is also effective (pump head increased by 0.54 m, and pump efficiency by 7.46%). At the same time, the passive rotation speed of the twin-volute increases from 60 rpm to 70 rpm, verifying that both the optimization method is reliable and can be used when developing and optimizing dishwasher pumps.

Solar Panels Dirt Monitoring and Cleaning for Performance Improvement: A Systematic Review on Smart Systems

The advancement in technology to manage energy generation using solar panels has proved vital for increased reliability and reduced cost. Solar panels emit no pollution while producing electricity as a renewable energy source. However, the solar panel is adversely affected by dirt, a major environmental factor affecting energy production. The intensity of light falling on the solar panel is reduced when dirt accumulates on the surface. This, in turn, lowers the output of electrical energy generated by the solar panel. Since cleansing the solar panel is essential, constant monitoring and evaluation of these processes are necessary to optimize them. This emphasizes the importance of using smart systems to monitor dirt and clean solar panels to improve their performance. The paper tries to verify the existence and the degree of research interest in this topic and seeks to evaluate the impact of smart systems to detect dirt conditions and clean solar panels compared to autonomous and manual technology. Research on smart systems for addressing dirt accumulation on solar panels was conducted taking into account efficiency, accuracy, complexity, and reliability, initial and running cost. Overall, real-time monitoring and cleaning of the solar panel improved its output power with integrated smart systems. It helps users get real-time updates of the solar panel’s condition and control actions from distant locations. A critical limitation of this research is the insufficient empirical analysis of existing smart systems, which should be thoroughly examined to allow further generalization of theoretical findings.

A Novel Path Planning Strategy for a Cleaning Audit Robot Using Geometrical Features and Swarm Algorithms.

Robot-aided cleaning auditing is pioneering research that uses autonomous robots to assess a region’s cleanliness level by analyzing the dirt samples collected from various locations. Since the dirt sample gathering process is more challenging, adapting a coverage planning strategy from a similar domain for cleaning is non-viable. Alternatively, a path planning approach to gathering dirt samples selectively at locations with a high likelihood of dirt accumulation is more feasible. This work presents a first-of-its-kind dirt sample gathering strategy for the cleaning auditing robots by combining the geometrical feature extraction and swarm algorithms. This combined approach generates an efficient optimal path covering all the identified dirt locations for efficient cleaning auditing. Besides being the foundational effort for cleaning audit, a path planning approach considering the geometric signatures that contribute to the dirt accumulation of a region has not been device so far. The proposed approach is validated systematically through experiment trials. The geometrical feature extraction-based dirt location identification method successfully identified dirt accumulated locations in our post-cleaning analysis as part of the experiment trials. The path generation strategies are validated in a real-world environment using an in-house developed cleaning auditing robot BELUGA. From the experiments conducted, the ant colony optimization algorithm generated the best cleaning auditing path with less travel distance, exploration time, and energy usage.

A novel solution for addressing the problem of soiling and improving performance of PV solar systems

The adoption of photovoltaic (PV) solar technology for power generation is one of the fastest growing sources of renewable energy. In recent years, significant cost reductions of PV modules and rising global demand for energy have been key drivers of the solar industry’s exponential growth. While the majority of research into improving efficiency of solar systems has focused on increasing power output, adverse effects of environmental factors on system performance have largely been neglected. The accumulation of dirt on panel surfaces, known as soiling, can significantly reduce the power generated by PV systems due to blocking the Sun’s irradiation from PV cells. Despite drawbacks associated with mitigating soiling, including wasteful water consumption and the risk of panel damage, such strategies must be implemented in order to maintain system performance and reduce financial losses. This report proposes a new innovation to address the problem of soiling, designed by Kirchner Solar Group, by inverting panels at night and using of natural condensation to remove dirt settlement without causing abrasion to panel surfaces. Known as ‘NightFlip’, this solution has been designed to be an intrinsic, self-cleaning feature that reduces the impact of soiling without using water. A prototype was built to evaluate the real-world performance of the system. Data was recorded for the prototype when operating alongside a standard system, and the extent to which system performance was improved is analyzed.

Dermatosis neglecta.

Dermatosis neglecta (DN) is a frequently underdiagnosed and under-reported dermatological entity, which occurs due to unconscious neglect of self-cleaning in individuals with some underlying physical or mental pathology. The lack of cleaning leads to accumulation of scales, dirt, sweat and sebum compacted together in the skin. Owing to its asymptomatic nature, diverse background and deceptive clinical presentation, DN is often missed or misdiagnosed by physicians. Awareness and recognition of this condition is essential to avoid unnecessary diagnostic and treatment procedures. The focus of this review article is to provide insights into this condition. We also intend to develop an algorithm for practical approach to a clinical diagnosis of dirt-like dermatoses with reasonable accuracy. A few interesting cases of DN encountered in our institution are included in this article.

Differences between design expectations and actual operation of ground source heat pumps for green buildings in the cold region of northern China

Ground source heat pump technology and green buildings have been combined. This is an effective way to improve the utilisation rate of renewable energy, increase energy savings and reduce emissions. However, some green building ground source heat pump systems have high energy consumption and poor energy-saving effects. Data was collected from the ground source heat pump systems in five typical green buildings (T1 to T5) in a cold region of China. The mechanisms of the differences between the actual operation and design expectations were explored for the ground source heat pump systems in cold regions. The results showed that the key factors affecting the efficiency of the building energy systems were the coefficient of performance (COP) and energy efficiency ratio (EER). Of buildings T1 - T5, T1, T3, and T5 experienced excessive heating, with excess heating rates of 19.4%, 18.1%, and 3.7% respectively. The difference between the expected and actual heat pump systems was illustrated by factors such as the water supply temperature at the ground source side, the water leakage at the user side and ground source side, insufficient depth of the water intake and recharge wells, and the dirt accumulation in the plate heat exchanger.

Floating PVs in Terms of Power Generation, Environmental Aspects, Market Potential, and Challenges

Limited reserves of fossil fuels, rising environmental concerns, and a remarkable increase in electricity demand have led to the necessity of harnessing solar energy on a large scale. For this purpose, there has been a noticeable stimulation into photovoltaic power plants (PVPPs) over the last three decades, but the land requirement for PVPPs is still a handicap in many countries since valuable lands are considered for other purposes such as agriculture and livestock. For effective conservation of valuable lands and water resources, PVPPs are preferred to be installed on various water bodies such as oceans, seas, lagoons, lakes, rivers, dams, canals, wastewater treatment plants, irrigation ponds, fish farms, wineries, reservoirs, etc. PV systems on water bodies are called floating PVPPs, and they have outstanding advantages compared with land-based PVPPs including better energy generation owing to passive cooling effects, higher system efficiency and reliability, and lower dirt and dust accumulation on PV modules thus lower operating costs. There are also some significant environmental features provided by floating PVs. Shading effects due to PV coverage reduce water losses arising from evaporation. Moreover, algae growth is limited because of mitigated solar radiation, which yields better water quality. This review presents more insight on floating PVPPs in terms of several aspects such as electricity generation, system efficiency, reliability and sustainability, experimental applications and facilities in operation, water and carbon saving as well as challenges.

Numerical analysis of bladeless ceiling fan: An effective alternative to conventional ceiling fan

A ceiling fan is one of the cost-effective alternatives for poverty-ridden societies and tropical countries short on natural resources. However, due to the inherent working principle, a lot of losses occur during electrical to mechanical energy conversion. Apart from losses, other problems associated with conventional ceiling fans are buffeting airflow, internal heating, and dirt accumulation on fan blades. Recently, the idea of a bladeless ceiling fan has been patented which has the potential to resolve most of the issues associated with the conventional fans, however, no details have been shared regarding flow physics and their effectiveness in constrained spaces. In this study, an annular type bladeless ceiling fan is computationally analyzed in a standard empty room (4m × 4m x 4m) environment. Parametric analysis of different design features such as fan radius, height from the ceiling and floor, fan jet width, mass flow rate, and orientations was studied and their effect on the perceived comfort level in terms of velocity spread and average velocities were captured computationally. The results show that the fan height in the close vicinity of ceiling does not affect the flow field in the occupied zones, however, as the fan gets closer to the floor the velocity field in the occupied zone changes due to creation of a strong vortex at the center of floor. Thus, fan installation closer to the ceiling (less than 0.5m from the ceiling) is a preferred choice. With an increase in fan radius from 0.3m to 0.5m, an increment of 33% was observed in velocity spread thus increasing the zone of influence. A finer jet width under the same volume flow rate produces higher velocities across the room e.g. 2 mm jet produces 36% higher average velocities as compared to 4 mm jet, which effectively increases zone of influence. Effect of jet orientation was also studied and a 90° (straight down) orientation produced better overall velocity spread in comparison with 110° and 130° orientation. In comparison with conventional fans, a minimum of 57% increment in velocity spread was recorded for all bladeless fan configurations under consideration in the present work. The flow physics of bladeless fan has prospects for further increment in the zone of influence by optimizing the geometric features in light of present work.

The Use of Drone Photo Material to Classify the Purity of Photovoltaic Panels Based on Statistical Classifiers.

The subject of this work is the analysis of methods of detecting soiling of photovoltaic panels. Environmental and weather conditions affect the efficiency of renewable energy sources. Accumulation of soil, dust, and dirt on the surface of the solar panels reduces the power generated by the panels. This paper presents several variants of the algorithm that uses various statistical classifiers to classify photovoltaic panels in terms of soiling. The base material was high-resolution photos and videos of solar panels and sets dedicated to solar farms. The classifiers were tested and analyzed in their effectiveness in detecting soiling. Based on the study results, a group of optimal classifiers was defined, and the classifier selected that gives the best results for a given problem. The results obtained in this study proved experimentally that the proposed solution provides a high rate of correct detections. The proposed innovative method is cheap and straightforward to implement, and allows use in most photovoltaic installations.

Central sterile services department: screening of automated cleaning in liposuction cannulae.

To evaluate the effectiveness of automated cleaning of 4 mm liposuction cannulas using ultrasonic washer machine, screening for dirt using a cannulate microscope device and the screening of viable strains of Staphylococcus aureus, with microbiological analysis. Experimental study with 14 units of 4 mm liposuction cannulas performed at the Central Sterile Services Department and at the Microbiology Laboratory of a Hospital Complex, located in Porto Alegre, RS, Brazil, from October 2018 to April 2019. Of the 14 liposuction cannulas that constituted the sample, 42.9% remained dirty despite automated cleaning, and all of them showed recovery of viable microrganisms in the microbiological laboratory. The study showed that it is not possible to ensure the cleaning efficacy of automated cleaning of 4 mm liposuction cannulas, especially due to the conformation of the material with internal spaces with accumulation of dirt.

Soiling accumulation impact on PV modules installed at different tilted angles in São Paulo, Brazil

The present study was carried out at the University of São Paulo (USP), in the capital campus, in Butantã, São Paulo. On the rooftop of the Photovoltaic Systems Laboratory (LSF). This study used twenty photovoltaic modules with a unit power of 20 Wp. Before the beginning of the study, the modules were exposed to natural light so that they would suffer the LID effect. Subsequently, all modules were calibrated to measure the solar irradiance, using IEC 60904-2 using a pyranometer as a secondary reference sensor. After calibration, the modules were arranged in pairs, with angles ranging from 0 to 45° as reference to the surface, with a difference between pairs of 5°. To evaluate the influence of rainfall, which is the main responsible for the natural cleaning of the modules. The pluviometric values were obtained from the meteorological station of the Institute of Astronomy, Geophysics and Atmospheric Sciences of the USP. The module allocated at 0°, “Dirty” was used as reference and all the results obtained were calculated in relation to it. The results for the 18 months of experiment showed the non-linear influence of soiling, acting in a stronger way for the less inclined angles, and after 10°, this influence, became less relevant, in comparison to the previous angle. The largest losses were found for 0° and 5°, the losses exclusively to soiling were 8.16 % and 6.82 % respectively. For angles greater than 10°, the soiling effect was attenuated, which resulted in less significant losses, for 15° the difference between the impact of dirt compared to 10° was only 0.1%. Rainfall also had a very relevant impact on the experiment. This study concluded that the optimal angle, where dirt accumulation was reduced, the rainfall cleaning and relative gains were optimized is in the range between 20° and 30°.

Dermatosis Neglecta Involving Different Age Groups- A Series of Four Cases

Dermatosis neglecta is a benign cutaneous condition which is often misdiagnosed. It occurs due to poor local hygiene or inadequate washing of a part of the body resulting in progressive accumulation of sebum, sweat, keratin and other debris which form an adherent crust of dirt. It mainly occurs in individuals who are unable to take care of themselves, like those with physical disability or psychosis. It is usually asymptomatic and is characterised by localised hyperpigmented patch or verrucous papules and plaques. Rubbing the affected area with alcohol-soaked gauze results in complete clearance of the lesion which is both diagnostic and therapeutic. The present case series describes four patients of different age groups. The first patient was a 65-years-old female, who underwent amputation of the gangrenous toes of right foot. She did not wash that leg for several weeks following surgery and developed cornflakes-like scaly lesions. Later lesions were diagnosed as dermatosis neglecta. Second case was a 18-years-old male, who presented with lesions on neck, which was misdiagnosed initially as Pityriasis vesicolor. The third patient was a 20-yearsold female, who presented with lesions on neck and was earlier diagnosed and treated as acanthosis nigricans. The fourth patient was a two-year-old female who developed lesions on neck due to accumulation of dirt and debris. In all these patients, lesions resolved on rubbing with alcohol-soaked swab. Very little data is available in medical literature about this condition. Therefore this case series is being reported to bring awareness among dermatologists. This would enable prompt clinical recognition and obviate the need for expensive investigations and treatment strategies.

Design and Development of an Online Smart Monitoring and Diagnosis System for Photovoltaic Distributed Generation

In photovoltaic power plants, fault diagnosis tools are essential for ensuring a high energy yield. These tools should be capable of accurately identifying and quantifying the factors behind the various fault mechanisms commonly found in photovoltaic plants. Considering the aforementioned factors, this article proposes an online smart PV monitoring solution, which is capable of detecting malfunctions that arise from accidental and/or technical causes through the analysis of I-V curves, however, without the necessity to interrupt the operation of the system, thus reducing the maintenance cost. Accidental causes can lead to the reduction of energy productivity due to the excessive accumulation of dirt on the photovoltaic modules, partial shading and eventual errors that occur during its installation. On the other hand, technical causes can be attributed to faults found on the photovoltaic modules, which lead to gradual losses in their electric and material characteristics. Therefore, by using the electric characteristics supplied by the manufacturer of the installed modules, the I-V and P-V curves of the operational photovoltaic strings were obtained in real time, compared to the respective theoretical curves obtained through mathematical modeling. In order to validate the proposed online monitoring system and its potential for predictive maintenance application, a field experimentation was mounted in a 93.8 kWp photovoltaic system.

A Reinforcement Learning Based Dirt-Exploration for Cleaning-Auditing Robot.

Cleaning is one of the fundamental tasks with prime importance given in our day-to-day life. Moreover, the importance of cleaning drives the research efforts towards bringing leading edge technologies, including robotics, into the cleaning domain. However, an effective method to assess the quality of cleaning is an equally important research problem to be addressed. The primary footstep towards addressing the fundamental question of “How clean is clean” is addressed using an autonomous cleaning-auditing robot that audits the cleanliness of a given area. This research work focuses on a novel reinforcement learning-based experience-driven dirt exploration strategy for a cleaning-auditing robot. The proposed approach uses proximal policy approximation (PPO) based on-policy learning method to generate waypoints and sampling decisions to explore the probable dirt accumulation regions in a given area. The policy network is trained in multiple environments with simulated dirt patterns. Experiment trials have been conducted to validate the trained policy in both simulated and real-world environments using an in-house developed cleaning audit robot called BELUGA.

Soiling loss characterization for Photovoltaics in buildings: A systematic analysis for the Madrid region

Dirt accumulation (“soiling”) on the surface of photovoltaic (PV) modules may cause significant energy output reductions (“soiling losses”). The adoption of suitable soiling mitigation strategies can make PV deployment more attractive, but it requires the assessment of the magnitude and the seasonal evolution of the soiling losses at local scale, as they are highly dependent on the regional climate, the meteorological conditions and the surrounding environment. For the purpose of estimating them for building integrated and building applied PV systems in Madrid city, Spain (i.e. under Mediterranean climate conditions), a systematic optical analysis was performed during a 15-month experimental campaign using a rooftop soiling test bench which allowed the exposure of multiple glass coupons at two tilt angles of interest (8° and 35°) in a semiurban environment. There was no cleaning schedule so that the exposed glass coupons were simply washed away by the rain. Broadband transmittance reductions (Tloss) indicated the occurrence of low soiling losses with yearly-averaged Tloss values of 1.49% at 8° and 1.04% at 35°. Regarding the soiling evolution, the local precipitation regime played a fundamental role. Soiling losses were negligible during frequent-rainfall periods, experienced a moderate increment in spring (March–April), and increased notably during the dry summer season, reaching annual maxima in July (5.13% at 8° and 3.89% at 35°). In order to minimize the local soiling losses, performing module cleaning operations at least during these two times of the year is encouraged. Concerning the soiling spectral effects, the optical loss increased towards shorter wavelengths, making wide-bandgap PV technologies more sensitive to local soiling. Finally, when applying PV performance prediction models which include soiling, the recommended local values for the daily soiling rate and the rain threshold are 0.11%/day and 5.3 mm at a tilt angle of 8° and 0.09%/day and 3.3 mm at a tilt angle of 35°.