In this paper, an accurate modeling procedure of a photovoltaic (PV) cell or module is proposed. The simulation behavior of the solar module is presented under different operation conditions, considering the effect of mismatch conditions due to the shadow patterns. The model is flexible in accurately predicting the current-voltage (I-V) and power-voltage (P-V) curves and maximum power point under partial shading of different solar module types. In this paper, a single STP080S PV module was experimentally tested for more than eight years of exposure on the roof of the University of Constantine (Mediterranean climate). For the first time, the evaluation of ageing due to the failure of the PV module in the Mediterranean climate was tested using visual inspection and I-V output. These two inspections show a decrease in the conversion efficiency of the STP080S PV module over time. Finally, the experimental and simulated I-V and P-V curves of the STP080S PV module are compared and demonstrate the effectiveness of the proposed modeling.