Effect of Anti-Reflective and Dust Spreading on Performance of Solar PV Panels

This study intends to better solar photovoltaic (PV) panel performance by employing anti-reflective coating and explore how dust affects solar panel effectiveness. Three equivalent solar PV panels were compared, having one of them being uncoated, the next one having a TiO2 nanomaterial coating, and the very last one having a SiO2 nanomaterial coating. PV panel surfaces are coated with superhydrophilicity TiO2 as well as superhydrophobic SiO2 nanomaterials using a cloth made of microfibers. With the aid of a photovoltaic (PV) analyser, the power output of each and every PV panel has been monitored during the month of November 2021. After one month of being exposed to the environment, the percentage improvement in efficiency for TiO2-coated panels was 7.66% and for SiO2 coated panels was 19.73% as compared to uncoated PV panels. Results demonstrate that SiO2 covered PV panels outperform the other two scenarios in terms of efficiency and power output. The frequency of photovoltaic panel washing is reduced by the application of coating. Different amounts of dust are evenly scattered on the surface of the PV panel in order to observe the effect of the dust. Additionally, as the amount of dust increases, the effectiveness of PV panels declines considerably. When 20g of dust is dispersed across the surface of a PV panel, its efficiency falls by 34.6 percent.


Introduction
In present days, renewable energy serves as an additional energy source that helps reduce the demands of fossil fuel consumption for the sustainable development of humanity.The equipment used to harness renewable energy should operate in the most effective ways possible without requiring any human input in order to improve engagement with it.The basic inspiration for the current research endeavor is laid out in this argument.PV panels can be used in a wide range of situations.It is one of the safest ways to generate power, however, due to various physical factors, the panel's effectiveness fluctuates.The buildup of dust significantly reduces the effectiveness of a PV panel system.Although manual cleaning is an option, it is a time-consuming process that costs money.Additionally, the installation locations for PV panels are far away, which makes cleaning more challenging.PV panels have also been widely utilized in space missions, where the effectiveness of the panels is of the utmost importance and any type of cleaning is difficult.Consequently, a self-cleaning panel is crucial [1][2][3][4][5].Up till now, extensive research has been done to increase PV panel efficiency, which has been a serious issue.Many study studies suggest a diverse approach to boost the efficiency of PV panels.The majority of research focuses on raising power production, raising performance, and lowering cost.However, it has been discovered that the performance and lifespan of the PV panel are decreased by the accumulation of dust on the panel [6][7].The first researchers to examine the impacts of dust over solar energy systems were Hottel and Woertz in 1942 [8].In a manufacturing region of the continental United States of America close to a thermal power plant, tests on the efficacy of three different types of photovoltaic thermal flat-plate collectors performed between 9 May and 1 July 1940 showed a 1% reduction in collector effectiveness due to dirt or dust development on the surface of a glass plate tilted at an angle of 30° to the plane of the earth.Anti-reflective coatings can be used in a wide range of industries where it is considered desirable to have minimal loss or minimal reflection of light as it travels across a reflective surface.Some examples are antireflective coverings on rooftop solar panels and antiglare films on photographic lens elements including corrective glasses [9].
With an average loss in incoming solar power of 1% or fewer, the most significant decrease in collector effectiveness was found to be 4.7%.Researchers calculated a factor of correction of 0.99 for a glass panel inclined at an angle of 45 degrees from the horizontal in accordance with the findings of their experiments.Said (1990) [10] explored the effects of months of dust accumulation on solar collectors in a maritime-desert-zone-like atmosphere, incorporating a double-glazed flat-plate collector, an evacuate-tube collectors with tubular reflecting surfaces, and a PV panel.The monthly optical efficiency deterioration rate for thermal panels ranged from 2.8% to 7%, while the monthly effectiveness degradation rate for solar power panels was 7%.Bird droppings, dust buildup, and water stains were among the on-site difficulties that Rao et al. (2014) [11] investigated and found that they considerably lower the efficiency of solar panels.These issues are typically ignored.By contrasting the I-V properties of two similar panels that were exposed to identical insolation with temperature in the surrounding environment conditions, with one panel having dust on its outermost layer and the other being dust-free, the influence of dust on panel effectiveness was assessed.A study of I-V curves revealed the phenomenon of power loss caused by dust accumulation on solar surfaces [12][13][14][15][16][17].The effect of the accumulation of dust on solar systems' voltages in the open circuit is minimal.On the others hand, the buildup of dust affects the current during a short circuit by 30-40% indoors and by 4- 5% outdoors depending on the environmental conditions Alamri, Hatem R., et al. carried out experimental studies in order in order to enhance the energy performance of solar PV panels by using hydrophobic SiO2 nanomaterial.The total effectiveness associated with the coated panel increased by 15% and 5%, respectively, when compared with the uncoated panel which had been routinely cleaned every day along with the dusty panel that had been.For the purpose of improving the performance of PV panels, a few investigators have used various coating materials such as TiO2 nanomaterial and anti-reflective zeolite [18][19][20].
In addition to the study results, it is abundantly obvious that location and temperature are the two main variables reducing the efficiency of solar panels.Due to environmental exposure and pollutants spreading over the panels, efficiency, as well as net power output has been significantly impacted.Thus, this study examined the effects of dust spreading on PV panels that were uncoated and coated with SiO2or TiO2, or both [21].Despite the wide variety of solar panel technologies available worldwide and in India.The monocrystalline solar energy system has a single layer made up of homogeneous, 100% silicon crystal plates proactively making up every single panel.A polycrystalline solar energy system consists of a number of crystal layers that have been formed moulded jointly to form single panel.Polycrystalline solar panels are more readily available in the United States because they are considerably more affordable than monocrystalline panels for solar power [22][23].However, it has to decide the choice of the subsequent elements, which vary between the two variations.Monocrystalline solar panels tend to be more efficient in terms of energy compared to polycrystalline ones because of changes in their structural material composition As an example, the highest efficiency of a 100-watt polycrystalline solar panel has become 17%, whereas the maximum efficiency of the same panel in monocrystalline form reaches 19%.
The differences between monocrystalline and polycrystalline solar panels are minimal in this context.Both are offered in a wide variety of output powers that are separated based on their respective efficiency.You have a choice of solar panel sizes ranging from 50 to 400 watts, with polycrystalline panels having an efficiency range of 13-17% and monocrystalline panels having a range of 17-19%.Your choice ought to be based on requirement [24][25][26].The major goal of the current investigation was to examine several coating processes for improving solar panel performance.In order to increase the performance of the PV panel, several coating materials, such as TiO2 and SiO2, have been applied to surfaces after dust particles were eliminated.

Experimental setup and procedure
Experimental testing was done in this study to compare the effectiveness of coated along with uncoated panels in dusty atmospheres.Fig. 1 depicts the whole experimental setup for the outdoor test.

Fig. 1 Experimental setup with PV system analyzer
Before applying the AR coating, the solar panel was cleaned to get rid of impurities and improve the connection between the substrate and the deposited layer.Water was used to rinse the substrates throughout the cleaning process.SiO2 and TiO2 anti-reflective (AR) single layer coatings are applied to PV panel surfaces to increase power conversion efficiency.20 cc of TiO2 coating was now sprayed over the surface, and it was then spread out using a cloth made from microfiber & wiper.20.02 m of average thickness was attained, and the surface optical quality appeared superior to that of a naked one.The same 20 ml of the superhydrophobic SiO2nano-coating material that was utilized to cover the solar PV panel in a way identical to that described above was also taken into considerations.The effective adoption of it resulted in a thickness of 20.02 m.Two of the coated panels were allowed for more than 60 minutes to finish drying after having both coats applied.It is assumed that the PV panel's surface is evenly covered with each of the coatings of the same thickness.The solar panels both with and without coatings are placed on the rooftop to begin the experiment and analyze the outcome.Solar panels and the PV system analyzer are connected.The PV analyzer's data was later exported to the laptop.For a period of one month, each of the three PV panels was set up on the roof in an open environment for dust naturally to gather up on their surfaces.The three distinct panels are displayed in For one month, there was no cleaning of the PV panels at all.Data readings were kept track of between November 1 and November 30, 2021, for a total of 30 days.With the aid of a PV analyser, the generating power of each of the three photovoltaic panels was recorded between 10 a.m. to 4 p.m. throughout the day.It is calculated as the daily average power for a month at intervals of one hour.The discussion of performance comparison between panels comes in the following section.In order to test the anti-static properties of hydrophobic versus hydrophilic nanomaterial, natural dust was allowed to accumulate on the panels' surface.

Results and Discussion
This section presents the findings over tests carried out on rooftop solar panels that were uncoated, TiO2 coated, and SiO2 coated.An investigation was conducted in the open at Pantnagar.Currently, a PV system analyzer is used to record the power of rooftop solar panels on a day-by-day basis.Over the course of one month, the impact of coating was studied.The following analysis and discussion compare the greatest power output of coated and uncoated panels.

Analysis of Solar irradiation
Figure 3 shows an increase or decrease in radiation from the sun with days and hours.It was clearly evident that from dawn until noon, ultraviolet rays intensified.Daytime sunlight was established at 20- minute time intervals from 10:00 AM to 4:00 PM.The maximum ultraviolet (UV) ray from the sun on November 1 was reported to be 747 W/m2 at midday and 12:20 PM, respectively.At ten o'clock in the morning, the radiation from the sun was 580 W/m2.From 3:00 to 4:00 in the afternoon, solar radiation rapidly decreases, going from 436 W/m2 to 215 W/m2.At noon, solar radiation is at its highest, and at its lowest in the early hours of the morning and evening.The average irradiation slightly declines as November month progresses.Figure 3 depicts the maximum irradiation on November 1 at 747 W/m2, which decreased to 720 W/m2 on November 30.

Analysis of Power produces by an uncoated PV panel
Using the PV analyzer during November, the day-by-day output of the solar panel was recorded.The rooftop is the location where the PV panel was kept.The generating capacity of solar panels rises from morning until midday as solar intensity rises, and then it falls sharply between 3:00 PM and 4:00 PM as solar intensity falls sharply.As shown in Fig. 4, the power generated at 10:00 AM, whereas solar irradiation became 580 W/m2, was 63.29 W, whereas at noon, when it was 747 W/m2, was 90.63 W. The solar panel's output peaked in November on the initial day at 90.63 W and dropped to 74.48 W on the last day of the month.
As a result of dust buildup and decreased sun intensity occurrences on rooftop solar panels, a decrease in output was noticed.Dust accumulation was the main factor in power reduction.This results in a reduction of 17.82% of electricity.The accumulative effect of dust on the PV panel's glass surface has become the main factor in power degradation.Dust lowers the glass's transmittance and lowers the solar irradiation that reaches the solar cell.These factors cause solar panel power to decrease when it is left in its natural environment without cleansing.The PV panel's power reached 89.10 W for day 30.After thirty days of use, the silicon dioxide (SiO2) coating panel's reduction in power during solar noon reached 8.52 W. The SiO2-coated panel produced 19.67% more power than the uncoated panel.It results from the SiO2coating's extremely high hydrophobicity.The extraordinary structural and functional characteristics of holy lotus blossoms are the origin of super hydrophobicity.The region of contact between water droplets with the surface of the lotus flower leaves was decreased by using a combination of micro-nano structured roughness along with low energy at the surface waxed crystals.Therefore, the "self-cleaning effect" is demonstrated when the panel rotates by at least 5 degrees, as the water droplet starts to roll off the surface, accumulates, and eliminates the dust particles.Table .1 displays the highest power output for each solar panel during the day.

Comparison of power analysis
The maximum power generated by three PV panels-one uncoated, one TiO2 coated, and one SiO2 coated-on days 1, 10, 20, and 30 at noon during the day is shown in Fig. 7. On day 1, the TiO2 panel produced 4.468% more electricity when compared to the uncoated panel.The TiO2 coated panel produced 7.58% more electricity in comparison to the uncoated panel after thirty days of treatment.On Day 1, the SiO2-coated panels produced 7.71% more electricity than the uncoated panel at its greatest output.After 30 days, the SiO2-coated panels produces 19.67% more power compared to the uncoated panel, and the TiO2-coated panel generates 7.58% more power.This can be attributed because the power reduction has been lowered throughout the course of the 30 days thanks to the two coatings' self-cleaning behavior.Table 2 compares an improvement in maximum power for various coated panels relative to uncoated panels.

Comparison of Efficiency analysis
The proportion of the amount of power generated by sunlight through a solar panel to the area of a PV module multiplied by the amount of solar radiation is known as the effectiveness of solar panels.Thus, the effectiveness has been estimated using Equations 1 and 2, as shown below: The efficiency ratings of the uncoated panel, and the TiO2 -coated panel, as well as the SiO2coated panel, comprised 12.2%, 12.80%, and 13.20 percent, respectively, as shown in Table 3.The SiO2 panel became 1% more efficient than the uncoated panel, whereas the TiO2 panel exhibited an efficiency of 0.60 percent.

Effect of dust on efficiency
The dust small particles reduce the functionality of solar Photovoltaic panels.A certain amount of the incoming ultraviolet (UV) rays that strike the photovoltaic (PV) modules surface becomes blocked whenever dirt gets embedded on its outermost surface.Fig. 9 conclusively demonstrates that the effectiveness of the photovoltaic panel declines as the quantity of dust rises.The conversion efficiency of photovoltaic panels was 12.5% and 11.38%, each, under not having dust conditions at irradiation levels ranging from 634 W/m2 and 594 W/m2.When the total quantity of dust reaches 5g, the PV panel's effectiveness decreases to 12.33% over 634 W/m2 of irradiation compared with 9.87% for 597 W/m2 of irradiation.As the total amount of dust increases, the effectiveness further declines until it reaches 8.26% and 7.43%, as well, for 20g of dust at irradiation intensities of 634 W/m2 as well as 597 W/m2.

Conclusion
The conclusion that can be drawn after analysis of results of the current study is described as follows: The amount of solar energy incident through the sun directly relates to the power generated by photovoltaic solar panels.After an entire month of being exposed in an unclean environment, the maximum power was reduced from 90.63 W to 74.48 W, or 16.15 W. Before cleaning, a PV panel's output was reduced by dust collection by 0.54 W per day.The efficiency of solar PV modules decreases with no cleaning from 12.20% to 10.44% after a single month of being exposed to the environment under the specified conditions.After adding a TiO2 the coating process, the maximum output of the photovoltaic panel went from 90.73 W to 94.68 W. TiO2 coated panels produced 5.65W more electricity compared to uncoated panels after a single month of being exposed to a dusty atmosphere.At noon on day one, SiO2 coated panels generated 6.99 W higher in power than uncoated panels.The panel generates 14.62 W greater power over a without-coating panels during 30 days of being exposed to a dusty atmosphere.The effectiveness of free of coatings, TiO2 -coated, and SiO2coated PV panels decreased by 1.76 percent, 1.56 percent, and 0.7%, respectively, over a single month of being exposed to the environment.
It was evident from the results that SiO2 coated panels are, on day 1, 1% and 0.4% greater in efficiency in comparison to with no coating and TiO2 coated panels, respectively.During one month of being exposed to the atmosphere, the percentage improvement in effectiveness for TiO2 -coated panels is 7.66% whereas SiO2coated panels has 19.73% when compared with uncoated panels.When there is no dust present, the amount of energy loss was 13.86%, 21.29%, 26.57%, and 34.65% when there is 5g, 10g, 15g, and 20g of dust, respectively At a solar irradiation level of 634 W/m2, the percentage of power lost is determined to be 12.39%, 29.78%, 27.63%, and 33.29% as the quantity of dust on the surface of the panels increased from a dust-free conditions to 5g, 10 g, 15 g, and 20 g.As seen in the current work, the effectiveness of SiO2-coated panels drastically declines after twenty days of being subjected to a dusty atmosphere.Therefore, it is advised that the solar panels should be cleaned on a weekly basis according to the findings of the current investigation.

Fig. 3
Fig. 3 Variation of solar irradiation with respect to time

Fig. 5
Fig. 5 Day-wise variation of power of TiO2 coated panel w.r.t time 3.3.2Power produced by SiO2 coated PV panel Figure 6 depicts the difference in power that the SiO2-coated panel generated throughout November month.It illustrates the manner in which the PV panel's output differs based on the number of days it is exposed to the elements.The SiO2 coated panel's output peaked at 97.62 W on the first day and progressively decreased when the number of days it was exposed to the working atmosphere grew.The PV panel's power reached 89.10 W for day 30.After thirty days of use, the silicon dioxide (SiO2) coating panel's reduction in power during solar noon reached 8.52 W. The SiO2-coated panel produced 19.67% more power than the uncoated panel.It results from the SiO2coating's extremely high hydrophobicity.The extraordinary structural and functional characteristics of holy lotus blossoms are the origin of super hydrophobicity.The region of contact between water droplets with the surface of the lotus flower leaves was decreased by using a combination of micro-nano structured roughness along with low energy at the surface waxed crystals.Therefore, the "self-cleaning effect" is demonstrated when the panel rotates by at least 5 degrees, as the water droplet starts to roll off the surface, accumulates, and eliminates the dust particles.Table.1 displays the highest power output for each solar panel during the day.

Fig. 6
Fig. 6 Day-wise variation of power of SiO2coated panel w.r.t time

Fig. 7 2
Fig.7 Comparison between the maximum powers for different solar panelsTable.2 Comparison of increase in maximum power for different coated panels w.r.t.uncoated panel Type of panel Increase in maximum power (%) Day 1 Day 10 Day 20 Day 30 TiO2 coated Panel 4.468 5.65 9.27 7.58 SiO2 coated Panel 7.71 10.42 15.06 19.67

Figure 8
Figure8illustrates how average power varies with respect to dust mass at various irradiation intensities.According to Fig.7, the average output drops when dust buildup on the PV panel's surface grows.Initially, the average power at irradiation 634 W/m2 is found to 78.49W when there is no dust on the PV panel surface.The mean power consumption drops to 77.42 W, 62.96 W, 56.8 W, and 51.88 W for 5g, 10g, 15g, and 20g of dust, respectively, as the total quantity of dust increases.Similar to this, for an irradiated of 597 W/m2, the average power of the PV panel reached 67.28 W for a dustfree condition and reduced to 58.36 W, 52.96 W, 49.40 W, & 43.97 W for various amounts of dust, including 5g, 10g, 15g, and 20g, etc.Using solar PV systems, dust buildup obstructs sunlight and significantly lowers power output.

Fig. 8
Fig.8 Effect of dust on the average power of PV panel at different irradiation level

10 Fig. 9
Fig. 9 Effect of dust on the efficiency of PV panel at different irradiation levels

Table . 1
Highest power on day-wise for different solar panels

Table . 3
Efficiency of the uncoated and coated panels