Electrical behavior predicting of photovoltaic modules, at different operating climatic conditions, remains a crucial issue for the estimation of output power from photovoltaic (PV) plants. In this paper, a simplified explicit model to describe the behavior of PV modules is introduced; the model is based on a simple mathematical equation relating the current to the voltage (I-V). The model requires the estimation of three parameters which are: open circuit voltage (Voc), the short circuit current (Isc) and a shape parameter (S). The model validation has been performed through experimental measurements for four different PV modules technologies (mono-crystalline Silicon, multi-crystalline Silicon, Copper Indium Gallium Selenide and Cadmium Telluride) at two different locations. To show its effectiveness, the model is then compared with four explicit models. Results showed that the model accurately predicts the I-V characteristics for the four examined PV modules at different range of solar irradiance levels and cell temperatures. Moreover, the developed model performs better than other investigated models in terms of accuracy and simplicity.