# Characterisation of Dust Particles Deposited on Photovoltaic Panels in the United Arab Emirates
## 2 Materials and Methods  
This investigation involves dust samples collected from five distinct locations in Mohammed bin Rashid Al Maktoum Solar Park. This park spreads over a total area of 77 km\({}^{2}\) in Saih Al-Dahal, about 50 km south of the city of Dubai, UAE. It is situated in the arid desert region of Dubai, UAE, where sunlight is abundant. It is one of the world's largest solar parks, with a planned capacity of 1013 megawatts, designed to expand further. The park employs various solar technologies, including PV panels and concentrated solar power systems, to convert sunlight into electricity. The park significantly contributes to reducing carbon emissions and promotes sustainable energy in Dubai. It often incorporates innovative technologies for optimising solar energy production in a desert environment, such as dust mitigation strategies and advanced tracking systems. The dust samples were collected in the month of October from five specific locations within the park: the ground surface of the outdoor test facility (GT), the ground surface of the 13 MW plant (GS), the panel surface of the 13 MW plant (S), the panel surface of the outdoor test facility (T), and the rooftop panels at the outdoor test facility (R). The description of the five locations are provided in Table 1.  
The purpose of this investigation was to identify potential variations in the dust samples from these different locations in the Solar Park and gain insights into their respective compositions and characteristics. Optical images of the collected dust samples were acquired using an optical microscope with suitable magnification and resolution. Images were captured for both the PV surface dust samples and the ground dust samples from each site. The morphology of the dust sample was characterised using SEM by visual inspection of the surface topography of materials at high magnification. In this study, a JCM-5000 SEM was operated under high vacuum conditions (10\({}^{-2}\) Pa) to ensure a stable and fine electron beam. The sample was prepared by fixing it onto the top of the specimen block with conductive tape, and excess dust particles were removed by blowing air onto the sample surface. The chemical composition of the dust sample was investigated using XRD to identify the crystal structure and phase composition of the dust materials of each dust site sample. The diffracted peaks were converted into d-spacing and subsequently compared to standard reference d-spacing patterns database to identify the mineralogical composition of the dust sample. \begin{table}
\begin{tabular}{c p{284.5 pt}} \hline \hline
**Sample Name \({}^{*}\)** & **Description** \\ \hline \multirow{3}{*}{GT-10} & Ground surface of the outdoor test facility. It is located near the building of indoor labs and offices. This area is partially paved, resulting in lesser dust deposition compared to the main power plant. \\ \hline \multirow{3}{*}{GS-10} & Ground surface of the 13 MW plant. This area exhibits a higher concentration of sand and larger particles, particularly rich in silicate content. \\ \hline \multirow{3}{*}{S-10} & Panel surface of the 13 MW plant. In a solar power plant environment, fine particles transported by air currents tend to settle on the surfaces of photovoltaic (PV) panels, making the panel surface of the 13 MW plant more prone to dust deposition. \\ \hline \multirow{3}{*}{T-10} & Panel surface of the outdoor test facility. Due to the paved ground surface of the test facility, the panel surface is less susceptible to dust compared to the panel surface of the 13 MW plant. \\ \hline \multirow{3}{*}{R-10} & Rooftop panels at the outdoor test facility. Being installed at the rooftop, these panels primarily attract only smaller or fine particles for deposition. \\ \cline{1-1}  & \\ \hline \hline \end{tabular} \({}^{*}\) This indicates the location, while number 10 represents the month of collection.  
\end{table} 
Table 1: Description of the characterised samples from the Solar Park, Dubai, UAE. Elemental composition analysis was conducted through EDS.