# Characterisation of Dust Particles Deposited on Photovoltaic Panels in the United Arab Emirates
## 4 Conclusions  
The study attempted to understand the morphology and composition of dust particles collected from five sites characterised by Optical Microscopy, Scanning Electron Microscopy (SEM), X-ray Powder Diffraction (XRD), and Elemental Composition Analysis (Energy Dispersive Spectrometry, EDS) were employed in this study. Dust samples were collected from the sites in the month of October. The optical images of the dust samples over PV surface reveal different colours compared to the ground sand at the same site, indicating potential interaction between dust particle and the PV surface. The SEM analysis of the dust particles revealed irregularly shaped particles with sizes ranging from 0.01 to 300 \(\upmu\)m, the presence of small cavities and densely packed particles indicative of cohesive behaviour and possible aggregation due to electrostatic forces potentially impacting PV shading. The particle sizes vary across different sites, showcasing notable variations within each sample. For instance, in the case of sample T-10-22, a diverse particle size distribution was observed, ranging from 0.01 to 30 \(\upmu\)m. The distribution displayed a Gaussian curve centred around 15 \(\upmu\)m, highlighting a concentration of medium-sized particles. Conversely, the dust particles in sample R-10-22 exhibited a broad range of sizes and morphologies, with a predominant size falling within the 0.01 to 30 \(\upmu\)m range. The Gaussian distribution for this sample centred around 10 \(\upmu\)m. Sample S-10-22 revealed a particle size distribution ranging from 0.01 to 30 \(\upmu\)m, with the Gaussian curve centred around 10 \(\upmu\)m, indicating a higher prevalence of small-sized particles. In the case of sample GS-10-22, particle sizes ranged from 30 to 300 \(\upmu\)m, with the Gaussian distribution centred around 100 \(\upmu\)m. Lastly, sample GT-10-22 displayed a particle \begin{table}
\begin{tabular}{c c c} \hline
**Element in EDS** & **XRD Peak** & **Source** \\ \hline Ca, C, O & A, C, and E & Calcite, Dolomite, and Gypsum \\ Si, O & B, F & Silica and K-Feldspar \\ Ca, Mg, C, O & C & Dolomite \\ Al, Si, O & D, F & Kaolinite and K-Feldspar \\ S, O & E & Gypsum \\ Cl & & Sodium Chloride \\ Na & & Aluminum Calcium Sodium Silicate \({}^{*}\) \\ \hline \end{tabular} \({}^{*}\)Shown in Figure 3 for GS-10 and GT-10 dust samples.  
\end{table} 
Table 3: Origin of elements in EDS from the XRD analysis. size distribution spanning from 20 to 100 \(\upmu\)m, with a Gaussian curve centred around 50 \(\upmu\)m. These variations in particle sizes underscore the diverse nature of dust particles at different locations, providing valuable insights into their morphological characteristics. The XRD analysis showed variations in the chemical composition among the dust samples, with calcium carbonate and silicon oxide being predominant in all samples. The presence of Cl in certain samples indicated significant variations across different sites within the PV facility, which could be influenced by environmental factors and local conditions. Elemental Composition Analysis via EDS revealed uniformity and variation in dust samples' element presence. Notably, unique elements like Cl found in specific samples highlight diverse environmental influences. Overall, the study provided valuable insights, highlighting the differences among ground dust and PV surface dust of same origin and across the samples of different locations. The findings provide a deeper understanding of dust-related issues and lay the foundation for further research to optimise PV cleaning methods specific to site of PV deployment within the UAE context. Conceptualization, A.A. and A.H.; methodology, A.A., A.H. and M.S.L. ; validation, A.A., A.H. and M.S.L. ; formal analysis, A.A. and A.H.S. ; investigation, A.A. and A.H.S. ; resources, A.H.; data curation, A.A. and A.H.S. ; writing--original draft preparation, A.A. and A.H.; writing--review and editing, A.A., A.H.S.