A CFD Approach to Thermal Analysis of Soiled Fixed Roof Mount and Tracking Solar Photovoltaic Arrays

Abstract

The efficiency of solar photovoltaic (PV) energy conversion is significantly impacted by temperature, and soiling remains a critical factor influencing module performance. Alternative solutions, including cleaning, antisoiling coatings, the use of tracking systems, and the implementation of thermal mitigation strategies, have been explored to minimize the effects of soiling and thermal impacts on solar cell performance. This study approached the problem from a different perspective by employing a three-dimensional (3D) computational fluid dynamics (CFD) model to analyze the correlation between soiling and PV module temperature. The simulations incorporated varying dust thermophysical properties, installation geometries, and environmental conditions using user-defined functions (UDFs). Key findings revealed strong relationships between dust density, specific heat capacity, thermal conductivity, and cell temperature, mediated by thermal density. Maximum temperature rises were observed with low thermal density dust, elevating cell temperatures by up to 3.15%. Fixed configurations maintained lower temperatures by up to 1.7% compared to tracking systems. Dust temperature averaged 1.15% higher than the underlying cell, while directly soiled cells exhibited a 1.93% temperature increase compared to clean modules. Higher tilt angles experienced enhanced wind turbulence, reducing solar cell temperatures, whereas collectors oriented to prevailing winds showed lower temperatures, with minimal effects when winds aligned parallel to the installation azimuth. The study highlighted the dual role of dust thermal conductivity in heat transfer, where low values acted as insulators, elevating cell temperatures, and high values facilitated efficient heat dissipation. Soiling-induced thermal impacts contributed to a maximum 12% energy reduction, emphasizing the importance of mitigating these effects. Tracking systems, although susceptible to higher temperatures, demonstrated potential to reduce soiling impacts and improve overall module efficiency. These findings provide actionable insights for optimizing solar PV performance under diverse environmental and operational conditions.