Citation: Amer Dahham, I.; Mohd Zainuri, M.A.A.; Abdullah, A.A.; Fauzan, M.F. Modeling the Effect of Dust and Wind Speed on Solar Panel Performance in Iraq. Energies 2023, 16, 6397. https://doi.org/10.3390/ en16176397 Academic Editors: Davide Astolfi and Abu-Siada Ahmed Received: 30 June 2023 Revised: 18 August 2023 Accepted: 29 August 2023 Published: 4 September 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article Modeling the Effect of Dust and Wind Speed on Solar Panel Performance in Iraq Israa Amer Dahham 1 , Muhammad Ammirul Atiqi Mohd Zainuri 1,2, * , Ali Abdulabbas Abdullah 2 and Mohd Faizal Fauzan 3 1 Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Selangor, Malaysia 2 Solar Energy Research Institute, Universiti Kebangsaan Malaysia (UKM), Bangi 43600, Selangor, Malaysia; prof.dr.albakry@atu.edu.iq 3 Al Najaf Technical Collage, Al Furat Al Awsat Technical University, Babylon-Najaf Street, Najaf 54003, Iraq; drfaizalfauzan@ukm.edu.my * Correspondence: ammirrulatiqi@ukm.edu.my Abstract: Dust accumulation on a PV panel surface can considerably lead to photovoltaic energy degradation. A particle-based dust accumulation model was proposed to estimate the surface dust coverage fraction on a PV panel. The model determines the effect of the surface dust coverage fraction on the performance of the PV panel. Gravity, wind, and particle-surface interaction forces were resolved to their components, and force balance was established to determine surface-parallel (slipping force) and surface-orthogonal (adhering force) component forces. The proposed model was validated through a schedule of lab and field experiments and by comparing the predicted values with the results of a validated model developed by Lu and Hajimirza. The relationship between a solar panel’s output power and the surface dust coverage fraction under the wind effect was established for three types of dust (graphene, silica, and natural dust) using Response Surface Methodology (RSM). Statistical analysis was applied to determine the most and least influencing variables on the output power of three types of solar panels (mono-crystalline, polycrystalline, and thin-film PV panels) exposed to dust accumulation. The obtained results show that dust particle size, wind velocity, and PV panel tilt angle play important roles in enhancing or degrading PV performance. Lower values of the tilt angle resulted in maximum output power, while high values of the tilt angle reduced the incident sunlight on the surface of the PV panel, resulting in lower output power. However, higher values of the tilt angle led to a lower dust coverage area of the PV panel and consequently decreased the power losses of the PV panel. The results also show that wind velocity has a considerable impact on the dust scraping of fine particles from a PV surface. The enhancement percentages of PV performance due to wind influence are 4.85%, 5.85%, and 10.9% for graphene, silica, and natural dust, respectively. Keywords: photovoltaic panel performance; dust accumulation; gravity; wind effect; tilt angle 1. Introduction Solar systems mainly convert optical energy (sun irradiance) into electrical energy. The performance of the PV modules depends on deterministic and stochastic parameters. The deterministic factors are mainly related to the PV cell design factors, such as the material of construction and design. The stochastic factors consist of environmental parameters such as temperature, wind, humidity, dust, and rain [1,2] Dust accumulation on a PV module surface is considered the most deteriorating environmental factor for PV perfor- mance [3]. Dust absorbs a significant portion of the irradiance and consequently reduces the conversion of the photo (optical) energy to electrical energy, resulting in lower solar cell efficiency. The adverse impact of the dust on the performance of the PV cell has been extensively investigated by many researchers [4–8]. Also, many cleaning mechanisms were Energies 2023, 16, 6397. https://doi.org/10.3390/en16176397 https://www.mdpi.com/journal/energies