This paper presents a seasonal based comparative study about energy performances of c-Si and Cd-Te solar panels under same real weather conditions. For this purpose, two on-grid photovoltaic power systems (PPS) were installed on the different metal construction with same tilt angle and monitored between December 2013 and November 2014. Energy performance comparison has been carried out by using performance ratio (PR) and mean array efficiency (MAE) and energy performance index specified in IEC 61724, normalized energy and capacity factor (CF). It is shown that since temperature coefficient of power in Cd-Te is lower than that of c-Si, Cd-Te array performs better than another array. Some key result of this study can be summarized as follows: Generated energy of Cd-Te is higher than that of c-Si array by rate of 9.2%-10.8 within measurement period. In addition, due to the low dependency on temperature, PR, MAE and CF result in higher value than c-Si array as indicated in literature.