Comparative study of cracks in mono and multicrystalline photovoltaic modules

Cracks in solar cells are one of the problems responsible for low efficiency among photovoltaic (PV) modules and these cracks are hard to avoid. Cracks usually can occur during transportation, handling or manufacturing process. Micro cracks degrade the power output in photovoltaic modules due to the inactive cell area. Micro-cracks are invisible to detect by naked eye and hence the Electroluminescence (EL) imaging were introduced to analyse the cracks in PV module. The electroluminescence is the most useful method to detect the cracks in the solar cell. A si-CCD camera was used in the dark condition to capture the EL image under forward bias conditions. In this study, mono-crystalline and multicrystalline were taken from the outdoor condition which were exposed for almost eight years and were analysed using electroluminescence imaging. From the electroluminescence imaging, the cracks were measured. The cracks were analysed by pattern and both panels were compared. From the study it was found that multicrystalline photovoltaic module shows the more crack compared with monocrystalline photovoltaic module. The crack in the individual solar cell and their relative efficiency in the two different types of crystalline modules have been also been presented.