Operating temperature prediction and comparison for rooftop PV arrays in coastal climates of India

This article predicts the operational temperature of a 1-MWp rooftop photovoltaic (PV) system installed on buildings of GITAM University, Andhra Pradesh, India, using various temperature models. In the process of photovoltaic conversion, the operating temperature plays a key role, where the module efficiency and output power of the PV module are linearly dependent on temperature. Various temperature models are presented in the literature with simplified working formulas to find the module temperature involving environment and PV system parameters. This study adopts four models NOCT (normal operating cell temperature), Fiaman, Scandia and arbitrary mounting model (AMM), to assess the power, module temperature of the photovoltaic plant and identify the best model to suit the present study location. Their precision is evaluated on a seasonal day (winter, summer, monsoon and autumn) from the measured data. It is observed that winter, summer, monsoon and autumn days have hourly average module temperatures of 45.4 °C, 48.1 °C, 48.2 °C and 45.3 °C, respectively. Results show the highest average DC voltage of 231.2 kW on a summer day with an hourly module temperature of 48.1 °C recorded. The slightest error values of 3.71% MBE, 5.8% NRMSE, 1.89% TS and 0.03% WMBE are noted with the arbitrary mounting temperature model. This study is helpful to validate that the AMM model is best suited for PV simulation in coastal regions.