Natural Dust Deposition Research Articles

Effects of climatic conditions of Al Seeb in Oman on the performance of solar photovoltaic panels

Human activities and climatic elements, including temperature, humidity, and wind speed, have an impact on natural dust deposition. Therefore, this study aims to investigate the effects of wind speed, relative humidity, and ambient temperature on the performance of soiled photovoltaic panels in Al Seeb, Oman. The study was conducted by exposing the solar PV panels to outdoor sunlight for a duration of two months. Parameters such as solar radiation, voltage, current, solar panel temperature, wind speed, relative humidity, and ambient temperature were collected in a short time interval. It was observed that the dust densities of 20.7 g/m2, 27 g/m2, and 41.3 g/m2 resulted in electrical power reductions of 18 %, 33 %, and 40 % for the panels uncleaned for one week, two weeks, and three weeks, respectively. The effect of daily dust resulted in an energy reduction of 14 %. Moreover, dust deposition decreases when the wind speed increases, resulting in a higher power output and vice versa. The higher the humidity, the stronger the dust's adhesion to the surface, resulting in more deposition and reduced power output. The maximum power output of 82.3 W was achieved at the wind speed of 10 m/s, 34.9 % relative humidity, and ambient temperature of 38.5 °C.

Publisher’s note

This study is an experimental investigation of the effect of natural dust deposition on the performance of three (PV) systems installed on the rooftop of the faculty of science and technology in the city of Mohammedia of Morocco in a Mediterranean climate. To determine the local soiling losses in solar PV systems electrical performance analysis using the IEC60891 procedure and the optical, morphological, and thermal properties of the dust deposited on PV systems is assessed. The results show that power production and maximum current of PV modules decrease by 7.4–12.35% and 11.6–18%, respectively, after allowing dust to accumulate naturally without any scheduled cleaning. In addition, the optical transmittance of the glass samples is reduced by 75–5%, from transmittance/absorbance data obtained with a UV-Visible spectrophotometer. The elemental and chemical analysis results by XRF, XRD, and FT-IR indicate that silica and calcite are the predominant components of the dust sample. Differential scanning calorimetry is used to assess the thermal properties (DSC) in a temperature range of 6–85 °C and the Laser-Flash method (LFA) for measuring thermal conductivity and diffusivity in the temperature range of 25 °C to 70 °C. It has been established that, for a given mass, dust particles can accumulate energy in thermal form when the temperature rises.

Direct foliar acquisition of desert dust phosphorus fertilizes forest trees despite reducing photosynthesis.

Phosphorus (P) availability to forest trees is often limited by local soil conditions that increase its fixation to soil minerals. In certain regions, atmospheric-P inputs can compensate for low soil-P availability. Among atmospheric-P sources, desert dust is the most dominant. However, the effects of desert dust on P nutrition and its uptake mechanisms by forest trees are currently unknown. We hypothesized that forest trees that naturally grow on P-poor soils or soils with high soil-P fixation capacity can acquire P from desert dust deposited on their leaves via direct foliar uptake, bypassing the soil, thus promoting tree growth and productivity. We performed a controlled greenhouse experiment with three forest tree species: Palestine Oak (Quercus calliprinos) and Carob (Ceratonia siliqua), native to the NE edge of the Saharan desert, and Brazilian peppertree (Schinus terebinthifolius), native to the Atlantic Forest in Brazil, which is located on the western part of the trans-Atlantic Saharan dust route. To simulate natural dust deposition events, the trees had desert dust applied directly upon their foliage and were monitored for growth and final biomass, P levels, leaf surface pH and the rate of photosynthesis. The dust treatment increased the P concentration significantly by 33-37% in Ceratonia and Schinus trees. On the other hand, trees that received the dust displayed a 17-58% reduction in biomass, probably related to particle coverage of the leaf surface that inhibited photosynthesis by 17-30%. Overall, our findings show that direct P uptake from desert dust can be an alternative P uptake pathway for multiple tree species under P-deficient conditions, with implications for forest trees' P economy.

Impacts of seasonal dust accumulation on a point-focused Fresnel high-concentration photovoltaic/thermal system

Dust accumulation on the concentrator of a high concentration photovoltaic/thermal (HCPVT) system can cause significant performance loss. In our work, the effect of seasonal dust deposition on the output performance of an HCPVT system with a point-focused Fresnel lens was studied in natural dust-deposition experiments. The changes of thermoelectric performance and exergy performance of the system under different dust accumulation levels were analyzed, and the influence of dust accumulation density on the total efficiency was determined. The results show that when the average dust density increases by 1 g/m2, the transmittance of the Fresnel lens decreases by 2.73%, thermal efficiency by 7.58%, and electrical efficiency by 1.74%. The temperature rise of the all-day operation system decreased by 2.31%, and the exergy efficiency loss reached 17.32%. Model fitting and calculation show that when the dust concentration is 8.81 g/m2, the all-day total/thermoelectric power output is 5.27 kW less than that with a clean lens.

The performance of a soiled CSP system in Inner Mongolia under various weather conditions

Sand/dust storms (SDSs) are a common natural phenomenon occurring in the spring in arid and semi-arid areas. To investigate the influence of sand/dust on the performance of concentrating solar power systems, the effects of four SDS events and four natural dust deposition (NDD) periods were tested from March 7 to June 11, 2021, and were compared with the performance of the clean state. The results reveal that the sand/dust concentration on the mirror increased significantly after the occurrence of SDS events. In particular, after a severe sandstorm, the dust density was found to have reached 6.177 g/m2, which was 2.09 times that under the NDD exposure period of 40 days. With the increase in the dust density by 1 g/m2 after the occurrence of the four SDS events, the average reflectivity, energy flux density, and thermal efficiency were found to be decreased by 12.1%, 11.9%, and 12.5%, respectively, whereas they are decreased by 13.7%, 10.5%, and 13.7% under the four NDD periods.

Experimental investigations for dust build-up on low-iron glass exterior and its effects on the performance of solar PV systems

The performance of solar photovoltaic (SPV) power plants is adversely affected by soiling losses caused by natural dust deposition on the module surface. The size and density of dust particles vary depending on the location. Thus, it is essential to investigate the impact of dust collection on SPV module performance. This work investigates the effect of dust build-up on the low-iron glass surface and the performance of SPV modules. To analyze the characteristics of these dust particles, low-iron glass samples have been chosen, which resemble a front glass surface of the SPV module. To study the holistic pattern of the natural dust accumulation of a particular area, low-iron glass samples have been placed with three different positions like vertical, horizontal, and local tilt angle for Building Integrated Photovoltaic Systems (BIPV) and rooftop PV power plant applications. The mineralogical study of dust particles provides insight in determining the transmittance loss from the glass surface of solar PV modules due to the local soiling loss. Furthermore, the electrical power output of the SPV modules has been monitored at various levels of dust accumulation. Moreover, these findings indicate that natural dust deposition at selected site locations significantly reduces energy generation from PV modules.

Study on impacts of dust accumulation and rainfall on PV power reduction in East China

The photovoltaic (PV) power plants’ power generation is affected obviously by the cleanliness of the photovoltaic modules. The dust is the primary source causing the pollution. Natural dust deposition is affected by human activities and meteorological factors such as temperature, humidity, wind speed and PM10 concentration in the region where PV modules are installed. The research efforts so far have been focused on predicting PV power outputs, however, in the real operations the PV outputs can significantly deviate from the prediction due to the dust pollution which, unfortunately, has not been fully investigated. This paper, to the authors’ best knowledge, is the first research to analyze the dust composition and evaluate its impacts on the PV power outputs with the real field test data in East China Collected through a series of experiments completed in the lab of the Institute of Distributed Generation and Microgrid, Zhejiang University of Technology, in East China. A PV output forecasting model was set up first based on the irradiance and the component’s temperature. Then a complete meteorological and electrical data online monitoring system was developed for data acquisition. The morphology of the dust particles on the investigated photovoltaic modules was observed by a scanning electron microscope, and the composition of the dust particles was measured by X-ray fluorescence. The research found that the dust accumulated on the surface of photovoltaic modules tend to form clusters under the influence of rainfall which is one major cause on fast dropping PV outputs. The analysis shows the dust deposit mainly comprises of SiO2 and CaCO3. Further analysis indicates in East China, the average dust density on PV modules is 0.644 g/m2 in a week and consequently the dust reduces the PV output power by 7.4% one week. The research is of significance not only in terms of giving the real-data based analysis on dust properties deposited on PV panels, but also on revealing the relationship between power output attenuation and dust deposition, which helps improve the PV power output prediction accuracy and develop efficient cleaning strategies for photovoltaic modules.

The Effect of the Superhydrophobic Film on the Generation Efficiency of Photovoltaic Modules Affected by Salt-Containing Dust Deposition

Dust deposition on the surface of photovoltaic (PV) modules causes undesirable effects, including shadowing and corrosion, which decrease power generation efficiency. A superhydrophobic film comprising nanometric silica modified by fluorosilane was prepared and coated on the surface of sample glasses. Natural dust deposition was simulated using laterite particles with a 25 μ m diameter, and the salt was dry-mixed with laterite particles using sodium chloride. In addition, condensation was simulated using a constant temperature and humidity incubator. PV module samples were irradiated by a solar simulator after the aforementioned simulation process, and the properties of the PV modules with different dust and salt contents were measured and analyzed by a solar module tester. The experimental results indicate that salt adversely affected the power generation efficiency of PV modules. And the superhydrophobic film can not only effectively remove the dust on the surface but also improve the power generation efficiency of PV modules.

Effect of air quality and dust deposition on power generation performance of photovoltaic module on building roof

Due to the dust deposition on the surface of photovoltaic modules and the air pollution, the power generation performance of photovoltaic modules will be significantly affected. In order to quantitatively estimate the effect of air quality and dust deposition on the power generation performance of photovoltaic modules, a distributed photovoltaic system on a building roof in Shanghai is studied in this paper. Both artificial and natural dust deposition conditions are tested in terms of the influence of these factors on the power generation efficiency of photovoltaic modules. The variation of solar radiation intensity with PM2.5 concentration in Shanghai and the variation of photovoltaic module power generation capacity with PM2.5 concentration are tested and analyzed. The experimental results show that the surface dust of photovoltaic module reduces the power and efficiency of photovoltaic module. Experimental comparison between the dusty photovoltaic module and clean photovoltaic module shows that the dust on photovoltaic modules can reduce the power and efficiency significantly, where the highest power generation decrease is 35.226% and the highest power generation efficiency decrease is 5.546% as indicated in the experiments. Result shows that the amount of solar radiation is exponentially correlated to the PM2.5 concentration. Practical application: The influence of air quality and dust deposition on the performance of distributed PV modules is of vital importance under severe particulate pollution in Shanghai. This research helps predict the degradation of the photovoltaic system power generation efficiency, and determine whether to clean up the dust on the photovoltaic system according to accumulated PM concentration. This reduces the cost of cleaning of the dust on photovoltaic system. This study provides theoretical and experimental basis for the design of the building roof mounted solar photovoltaic system according to the local haze condition.

Reducing the effect of dust deposition on the generating efficiency of solar PV modules by super-hydrophobic films

Dust deposition on photovoltaic (PV) modules is related to environmental and weather conditions and results in a reduction in power generation efficiency over time. The effects of films on the transmittance can be obtained by testing sample glasses coated with silicon and fluorine super-hydrophobic films with a spectrophotometer. Red soil particles with a diameter of 25 μm were selected to simulate the process of natural dust deposition on PV module samples, and an incubator of constant temperature and humidity was used to simulate the condensation process. PV module samples were irradiated by a solar simulator after the aforementioned simulation process, and the effects of different amounts of sediment in unit areas on the photovoltaic properties and spectral characteristics were determined. The experimental results indicate that the influence of dust on the power generation efficiency of PV modules coated with fluorine super-hydrophobic film is smaller than that for PV modules coated with silicon super-hydrophobic film and that the super-hydrophobic films can not only greatly reduce the dust accumulation on the surface of PV modules but also increase the generating efficiency.

The field experiments and model of the natural dust deposition effects on photovoltaic module efficiency

The maximisation of the efficiency of the photovoltaic system is crucial in order to increase the competitiveness of this technology. Unfortunately, several environmental factors in addition to many alterable and unalterable factors can significantly influence the performance of the PV system. Some of the environmental factors that depend on the site have to do with dust, soiling and pollutants. In this study conducted in the city centre of Kraków, Poland, characterised by high pollution and low wind speed, the focus is on the evaluation of the degradation of efficiency of polycrystalline photovoltaic modules due to natural dust deposition. The experimental results that were obtained demonstrated that deposited dust-related efficiency loss gradually increased with the mass and that it follows the exponential. The maximum dust deposition density observed for rainless exposure periods of 1 week exceeds 300 mg/m2 and the results in efficiency loss were about 2.1%. It was observed that efficiency loss is not only mass-dependent but that it also depends on the dust properties. The small positive effect of the tiny dust layer which slightly increases in surface roughness on the module performance was also observed. The results that were obtained enable the development of a reliable model for the degradation of the efficiency of the PV module caused by dust deposition. The novelty consists in the model, which is easy to apply and which is dependent on the dust mass, for low and moderate naturally deposited dust concentration (up to 1 and 5 g/m2 and representative for many geographical regions) and which is applicable to the majority of cases met in an urban and non-urban polluted area can be used to evaluate the dust deposition-related derating factor (efficiency loss), which is very much sought after by the system designers, and tools used for computer modelling and system malfunction detection.

In-situ investigation of the effect of dust deposition on the performance of polycrystalline silicon photovoltaic modules

In this study, a test platform consisting of an array of photovoltaic (PV) modules and different measuring instruments was set up to monitor the real-time temperature of the PV modules, the output power, the solar irradiance, and other environmental parameters. Dust deposition strongly affects the performance of PV modules; therefore, in this study, the effect of dust deposition on the module temperature, the transmittance, and the output power of the PV modules was comprehensively investigated, in particular, focusing on the dust deposition density. The results showed that dust deposition not only reduced the transmittance of the PV glass panel, but also reduced the module temperature, thereby affecting the output power of the PV module. Through an analysis of the test data, the relationships between the dust deposition density and both the relative transmittance and the relative output power rate were successfully established. Moreover, the experiment elucidated that the relative transmittance of a PV module could decline by 20% within only 8 days due to natural dust deposition.

Dust accumulation effects on efficiency of solar PV modules for off grid purpose: A case study of Kathmandu

The future of the world lies with renewable energy resources and solar energy is one such type of clean and sustainable energy resource. Solar PV modules are exposed to outdoor environments where dust accumulation is a prime degrading factor. Soiling and its effect on performance of solar modules are generally of high concern for regions with a high deposition of dust and low frequency and less intensity of rain. But some areas with abundant rainfall may also suffer from high dust deposition in the dry season. Kathmandu, with its peculiar environment conditions, suffers high air pollution and minimum rainfall during the dry winter. In this study, the effect of dust on PV modules is investigated with respect to dust deposition density and meteorological variables for Kathmandu with the objective to calculate a regression equation describing efficiency loss. Outdoor installation of experimental setup showed that during the study period of 5months, the efficiency of dusty solar module left to natural dust deposition phenomena decreases by 29.76% with respect to the module which was cleaned on daily basis. Dust deposition density on the PV module accounted to 9.6711g/m2 over the study period. The research also showed that dust accumulation is highly concentrated at the bottom of the PV modules having a high risk of hot spots which could eventually lead to permanent module damage.

Oasis microclimate effect on the dust deposition in Cele Oasis at southern Tarim Basin, China

Seasonal dustfall was collected in the Cele Oasis at southern Tarim Basin, China, to study the oasis microclimate effect on the spatial distribution of dust deposition. The deposition rates and grain-size parameters were analyzed for each season. In spring, when there is no significant microclimate effect, the deposition rates decreased from the windward margin to the downwind margin. In summer and autumn, when there is a significant microclimate effect, the deposition rates increased slightly from the windward margin to the downwind margin of the oasis, similar with the annual dust deposition pattern. The differences in the dust deposition pattern between seasons indicate that dust deposition is greatly enhanced in the center and downwind directions of the oasis during floating dust days in summer and autumn when there is a significant oasis microclimate effect. Therefore, it can be inferred that the background wind blowing the cold-wet center away from the geometric center of the oasis may be a key factor affecting the dust deposition pattern. The natural dust deposition pattern during winter is uncertain due to deposition from anthropogenic sources. Our results suggest that the dust deposition in the Cele Oasis is affected by a mechanical obstruction effect due to rough surfaces and by an oasis microclimate effect.

Effect of Dust Deposition on Stomatal Conductance and Leaf Temperature of Cotton in Northwest China

The Xinjiang Region in Northwest China is known as the “dust center” of the Eurasian mainland. Dust on the leaf surface affects overall plant development. While emphasis was on studying the impacts of industrial dust particles on crop development, the effect of natural dust deposition on the physiological parameters of cotton had not been studied before. The objective of this study was to examine the effects of dust deposits on cotton leaves and to estimate their impact on crop development and yield. For this purpose, an experiment was set up having two treatments and a control. In Treatment 1, cotton leaves were cleaned with water at three-day intervals or after a natural dust fall. In Treatment 2, 100 g·m−2 of dust was applied at 10-day intervals. The control received neither additional dust nor cleaning. In all of the treatments, stomatal conductance, leaf temperature, biomass and yield were measured. The results show a 28% reduction in yield and 30% reduction in stomatal conductance of the dust treatment compared to the control treatment. This indicates blocking of the stomata on the top of the leaf surface. In addition, the canopy temperature of the dust-applied leaves was always higher than the control and treatment.

On-site PV characterization and the effect of soiling on their performance

This paper presents a study of the characteristics of three types of PV panels: monocrystalline, polycrystalline and amorphous silicon and the effects of soiling on their performance using on-site measurements. The total system consists of the three types of panels in pairs. Initially, the characterization of the PV panels is carried out to prove the similarity of the two pairs. Another test performed is the degradation of PV's performance under extreme soiling conditions caused by the artificial deposition of dust on the panels when their surface was dry and when it was wet before the dust deposition. The results showed that especially the artificial soiling on the wet PV surface presents a serious degradation of the PV performance. Finally, the effect of natural dust deposition on the panel's surfaces for a year is investigated. During this period a total of three dust episodes were recorded. These dust episodes concern the transfer of dust from the Sahara desert and these episodes usually end with a light rain which sticks the dust on exposed surfaces including PVs. Due to the exceptionally wet weather that we had during the testing period all episodes were followed by heavy rain, but even in this case a serious degradation of the performance of about 13% of the affected PV panels was recorded. The first finding of this study is that in winter the occasional rain is adequate to keep the PV surfaces clean whereas when a dust episode occurs, the panels should be cleaned manually. This is not the case for the summer time, which for Cyprus lasts for more than 8 months. The recommended cleaning is immediately after a dust episode and every 2–3 weeks in summer time according to how much loss the owner of the PV is willing to accept and the associated cleaning cost.

Dust deposition: iron source or sink? A case study

Abstract. A significant decrease of dissolved iron (DFe) concentration has been observed after dust addition into mesocosms during the DUst experiment in a low Nutrient low chlorophyll Ecosystem (DUNE), carried out in the summer of 2008. Due to low biological productivity at the experiment site, biological consumption of iron can not explain the magnitude of DFe decrease. To understand processes regulating the observed DFe variation, we simulated the experiment using a one-dimensional model of the Fe biogeochemical cycle, coupled with a simple ecosystem model. Different size classes of particles and particle aggregation are taken into account to describe the particle dynamics. DFe concentration is regulated in the model by dissolution from dust particles and adsorption onto particle surfaces, biological uptake, and photochemical mobilisation of particulate iron. The model reproduces the observed DFe decrease after dust addition well. This is essentially explained by particle adsorption and particle aggregation that produces a high export within the first 24 h. The estimated particle adsorption rates range between the measured adsorption rates of soluble iron and those of colloidal iron, indicating both processes controlling the DFe removal during the experiment. A dissolution timescale of 3 days is used in the model, instead of an instantaneous dissolution, underlining the importance of dissolution kinetics on the short-term impact of dust deposition on seawater DFe. Sensitivity studies reveal that initial DFe concentration before dust addition was crucial for the net impact of dust addition on DFe during the DUNE experiment. Based on the balance between abiotic sinks and sources of DFe, a critical DFe concentration has been defined, above which dust deposition acts as a net sink of DFe, rather than a source. Taking into account the role of excess iron binding ligands and biotic processes, the critical DFe concentration might be applied to explain the short-term variability of DFe after natural dust deposition in various different ocean regions.