PHD IN MECHANICAL POWER ENGINEERING transition toward sustainable and renewable energy. However, its performance is significantly influenced by environmental conditions, particularly dust accumulation on the surface of PV modules. Dust deposition represents a major operational challenge in arid and semi-arid regions, such as Iraq, where high temperatures, limited rainfall, and frequent dust storms accelerate soiling. Dust accumulation reduces the amount of solar irradiance reaching photovoltaic cells by absorbing, scattering, and reflecting incident sunlight. Consequently, the electrical power output and energy conversion efficiency of PV modules decrease. The severity of these losses depends on several factors, including dust particle size, composition, deposition density, surface characteristics, wind velocity, humidity, and the duration between cleaning cycles. Fine particles may adhere strongly to glass surfaces, while moisture can promote the formation of compact deposits that are more difficult to remove. Furthermore, non-uniform dust deposition can create partial shading across individual cells, potentially causing electrical mismatch and localized heating, commonly known as hot spots, under certain operating conditions. These effects may reduce system reliability and increase maintenance requirements. In regions with high dust exposure, accumulated soiling losses can become economically significant, reducing annual electricity generation and increasing the levelized cost of energy. Several mitigation strategies have been investigated, including scheduled water-based cleaning, dry-brushing techniques, robotic cleaning systems, and hydrophobic or self-cleaning coatings. Selecting an appropriate strategy requires balancing cleaning effectiveness, water consumption, maintenance costs, and environmental conditions. In conclusion, dust accumulation is a critical factor affecting the efficiency, reliability, and economic performance of solar PV systems. Developing effective, cost-efficient, and environmentally sustainable dust-mitigation technologies is essential for maximizing energy production, particularly in dusty climates such as Iraq. Al-Mustaqbal University – The First Private University in Iraq