Performance Key on Maximum Power Point Under Temperature Coefficient of Power and Normal Operating Cell Temperature

  In this research, a potentially useful index for identifying the quality of PV modules is proposed. The index is simply calculated by ratio of maximum power at normal operating cell temperature to maximum power at standard test condition, PNOCT by PSTC ratio. This is a performance key that simultaneously indicates the losses due to (1) the dependence of temperature coefficient of maximum power (γ), (2) the module’s temperature, and (3) in-plane irradiance. This research contributes by (1) collecting information from 110 models of c-Si PV module’s datasheets and evaluating of the descriptive statistic of the ratio on various NOCT,  and (2) analyzing the experimental results of sample PV modules. Obtained PNOCT by PSTC ratio from datasheet showed that most PV modules have ratio which is higher than predicted values. The mean value of the ratio based on NOCT (or nominal module operating temperature, NMOT) between 41°C and 45°C is higher than 0.740 for all values of γ between -0.35%/K and -0.39%/K. Experimental results of sample PV modules showed that majority of ratio values are higher than predicted values. On the other hand, PV modules with γ -0.40%/K and NOCT 45°C, and γ -0.37%/K and NOCT 41°C have lower values than predicted values. By c-Si cell types, the mean value of ratio are 0.7536, 0.7449 and 0.7424 for MONO-PERC, MONO and POLY, respectively. Thus, the quality of PV module is probably identified by the proposed ratio.