Metodologia de determinação de propriedades ópticas direcionais em módulos fotovoltaicos de silício utilizando termografia

Abstract

The increasing reliance on renewable energy sources highlights the need for efficient and non invasive maintenance of photovoltaic plants. In this context, infrared thermography emerges as a predictive maintenance technique that enables thermal anomaly diagnostics in silicon photovoltaic modules without interrupting their operation. However, the applicability of thermography as a quantitative tool has been limited by the variability in measurement conditions, which directly affects the accuracy of optical properties such as emissivity and reflectivity of the modules. This study develops a methodology to quantify thermographic measurement uncertainty, applying the GUM (Guide to the Expression of Uncertainty in Measurement) method and modeling through EES ® software. The investigation was conducted at the UFMG Thermometry Laboratory in a controlled environment, simulating real field conditions, including variations in viewing angle and module soiling. Additionally, thermographic inspections were carried out to determine the optical properties of clean and soiled modules, previously characterized using X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) techniques. The validated methodology defines viewing angle ranges and specific operational conditions under which thermography can provide accurate diagnostics, essential for the predictive maintenance of photovoltaic installations. The study revealed that the viewing angle and soiling significantly affect the emissivity and reflectivity of photovoltaic modules, emphasizing the need to maintain a thermographic inspection angle below 60° to minimize uncertainties and ensure accuracy in detecting thermal anomalies.