Numerical analysis of the influence of backsheet thickness on the performance of silicon photovoltaic modules

Abstract

The thermal management of photovoltaic (PV) modules is highly dependent on the physical properties of their constituent layers, particularly the back sheet (Tedlar). This study proposes a three-dimensional numerical analysis, developed in COMSOL Multiphysics, to assess the impact of Tedlar layer thickness on the thermal and electrical performance of a silicon PV module. Three thicknesses (0.3 mm, 1.6 mm, and 3.2 mm) were studied under different climatic conditions, with irradiance ranging from 300 to 1100 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and ambient temperature from 20 to 36°C. The results showed that the module’s solar cells had the highest temperature and that the temperature of the rear surface was higher than that of the front. Increasing the thickness of the rear sheet leads to a more marked rise in cell temperature, from 49.02°C to 51.3°C when the thickness varies from 0.3 mm to 3.2 mm, for an irradiance of 1100 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. Ambient temperature also has a direct effect, increasing cell temperature from 45.28°C to 60.23°C when the temperature rises from 20°C to 36°C. In terms of power, this drops from 210.59 W to 197.27 W when irradiance varies from 300 to 1100 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> but decreases slightly with increasing Tedlar thickness. Electrical efficiency drops by 0.15% with increasing Tedlar thickness, for an irradiance of 1100 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and an ambient temperature of 24°C. These results confirm that the thickness of the Tedlar layer is an important lever for improving module performance, particularly under severe climatic conditions.