A popular explicit analytic Borowy 2C PV module model is proposed for power generation prediction. The maximum power poi nt and the open-circuit point which are calculated in this model cannot be equalto the data given by manufacturers under standard test condition (STC). The derivation of this model has never been mentioned in any literatures. The parameter forms of 2Cmodel in this paper are more simplified,and the model is decomposed into a STC sub-model and an incrementalsub-model. The STC model is derived successfully froman ideal single-diode circuit model. Relative error esti-mations are developed to do the conformity error measurements. The analysis res ults showed that though the biases at those critical points are very small, the conformity will depend on both of the two ratio values Im/ IscandVm/ Voc,which can beusedtoverify whether 2C model is applicable for the PV module produced by a particular manufacturer.