# Characterisation of Dust Particles Deposited on Photovoltaic Panels in the United Arab Emirates
## 1 Introduction  
The photovoltaics (PVs) are rapidly being integrated into the energy mix globally and more specifically in the Middle East context in a bid to limit the impact of global warming and safeguard the environment. However, the Middle East being predominantly a desert climate witnesses severe dust accumulation over PV panels, thereby leading to significant power losses. Dust, classified as any particulate matter with a diameter of less than 500 \(\upmu\)m, originates from a range of sources including wind-borne dust, vehicular exhaust, volcanic eruptions, and air pollution. It can contain various substances such as pollen, fungi, bacteria, vegetation, microfibers, and most commonly, organic minerals such as sand, clay, and eroded limestone [1]. [PERSON] et al. emphasises the importance of creating a comprehensive model to understand how different types of dust affect solar panel performance, considering various pollutants and PV technologies, particularly focusing on key pollutants like limestone, ash, red soil, calcium carbonate, silica, and sand [2]. [PERSON] at. investigated dust composition on samples collected from PV modules in Dhahran, Kingdom of Saudi Arabia, through scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), XRD, UV-visible spectroscopy, Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FTIR). The results revealedthe presence of Na, K, Mg, Ca, O\({}_{2}\), Si, and Fe in dust particles and locally scattered white dense regions on the surface [3]. [PERSON] et al. characterised dust collected from PV panels in Doha, Qatar, over a ten-month period employing X-ray Florescence (XRF), XRD and SEM. The authors determined the dust composition, dust accumulation rate (DAR) and the Cleanness Index Change Rate (CICR) indicative of PV power output degradation due to soiling. The results revealed the presence of Ca, Si, Fe, Mg, and Al in descending order which provides insight to devise effective soiling mitigation technologies [4]. [PERSON] et al. investigated the impact of dust on the performance of PV systems in Sharjah, UAE, under indoor and outdoor conditions. They established a general correlation between soiling loss and the degradation of PV performance [5]. The impact of atmospheric particulate pollutants and dust deposition on PV module power generation has been investigated experimentally. Results reveal that both types of dust deposition reduce power generation efficiency, with atmospheric dust having a greater impact. A correlation equation is derived for power efficiency reduction due to dust deposition, and a link between solar radiation decrease and atmospheric PM2.5 concentration is established, underscoring the combined impact of particulate pollution on PV module performance [6]. Another study conducted in Isfahan, Iran, highlights factors influencing dust accumulation and its effects on glass transmission. Results show up to 25% reduction in transmission coefficient due to dust accumulation, proposing a generalised equation that relates transmission reduction to dust density for various regions and weather conditions [7]. An experimental setup investigated dust accumulation's impact on PV modules, with analysis, optical, and electrical experiments conducted using natural dust. The results highlight the substantial reduction in transmittance (35.0%) compared to reflectance (1.1%) due to shading effects, which lower electron-hole pair generation, ultimately reducing power output. The proposed \"dust layer\" concept explains the decrease in short-circuit current, underscoring the need for accurate dust deposition monitoring to optimise cleaning strategies for efficient PV module operation [8]. Another research reviewed the impact of dust on PV system performance, addressing its lesser-known significance and providing a framework for understanding dust settling, assimilation, and potential mitigation measures. [PERSON] et al.