Analysis of the hail impacts on the performance of commercially available photovoltaic modules of varying front glass thickness

Abstract

Hail has a significant impact on the output of photovoltaic (PV) modules. Hence, this paper aims to give complete understanding of hail impacts on PV modules performance analytically and experimentally. The investigation was carried out followed the guidelines as prescribed by the IEC 61215–2:2016/IS 14286: 2019 standard on three PV modules of different thicknesses (2.8 mm, 3 mm, 4 mm) of the front glass. Hail size has been varied from 25 mm to 55 mm, the variation in weight of the ice ball is 7.5 gm to 80 gm, and the variation in speed of the ice ball is from 23 m/s to 34 m/s. After each round of the hail test, the samples are tested for Standard Test Condition (STC), Insulation Test (IT) and Wet Leakage Current Test (WLCT). In addition to measuring electric power output, an electroluminescence (EL) inspection of the cracks of the PV module has been performed. The scientific novelty is the optimization of the PV module based on experimental data under hail tests. Results show that the there is a continuous irreversible effect of the excitation force on the PV modules in the event of hail, and it can reduce the power output. Parametric analysis reveals that the glass thickness of 4 mm is sufficient to withstand severe damage; sample 3 only loses 1.1% of its power output compared to the initial value. However, samples 1 and 2 lose 21.8% and 11.74%, respectively. The insulating resistance of the samples appears to be decreasing with each round of the testing. The % reduction in wet leakage current resistance with respect to the initial value for samples 1, 2 and 3 are 55.25%, 46.81% and 27.23%, respectively. Lesser decrement in wet leakage current resistance indicates that sample 3 is more reliable for the hail-prone area. According to the findings, PV modules with a front glass thickness of 3.2 mm are exemplary when hit by hail up to 35 mm in diameter at a velocity of 27 m/s. However, in hail-prone areas, installers should choose PV modules with a front glass thickness of 4 mm or higher to minimize or eliminate hail damage.