Field Analysis of three different silicon-based Technologies in Composite Climate Condition – Part II – Seasonal assessment and performance degradation rates using statistical tools

This paper is an extension study to the ‘Field Analysis of three different Silicon-based Technologies in Composite Climate Condition’ wherein, monthly average performance ratio, temperature corrected performance ratio, series resistance and effective peak power of multi-crystalline (mc-si), heterojunction with intrinsic thin layer (HIT) and amorphous silicon (a-si) based photovoltaic modules for three years were presented. The present study attempts to investigate seasonal performance and determine the degradation rates using three statistical tools, i.e. linear regression, classical seasonal decomposition (CSD), and locally weighted scatterplot smoothing (LOESS) on normalized performance ratio and normalized efficiency for three years. Further, comparative analysis of nine PV modules, i.e. three modules of each technology, and sensitivity analysis of solar irradiance and module temperature on performance ratio have been evaluated. The degradation rates are found to be 1.24%/year, 1.16%/year and 1.16%/year for a-si modules, 0.14%/year, 0.56%/year and 0.11%/year for HIT modules and 1.50%/year, 0.82%/year and 1.46%/year for mc-si modules using linear regression, CSD and LOESS analysis respectively. The average efficiency is found to be 5.17% for a-si, 15.40% for HIT and 10.78% of mc-si modules. Furthermore, the performance of these module technologies during particular season after three years of outdoor operation has also been assessed.