Based on actual operating conditions, this paper focuses on the I-V characteristics of the two common types of silicon photovoltaic (PV) modules i.e. the polycrystalline and monocrystalline silicon modules using, for analysis the PV module behaviors, two mathematical models: the implicit model and the explicit model. In the implicit model, five coefficients are calculated analytically whereas in the explicit model, two coefficients are calculated from experimental measurements. These two models allow obtaining the I-V characteristics evaluating the marketed PV module quality and predicting its life and so its behavior according to environmental parameters changes. In the experimental part of this work, I-V characterizations of polycrystalline and monocrystalline silicon PV modules were performed to establish their explicit models. In real environmental conditions, considering illumination and temperature, and in addition to data provided by manufacturers, I-V characteristics are plotted and compared for the two models using codes developed under Matlab software environment. The results show a strong agreement between the implicit model and the experimental characteristics.