In this paper, we have presented the results of the characterization and the fine modeling of the electric characteristics current-voltage and power-voltage of the photovoltaic (PV) panels. We have analyzed the electric parameters of PV cells and the optimal electric quantities of PV panels (voltage and power) as a function of the meteorological variations (Temperature, solar irradiation). The obtained results show that the diode parameters of the PV cells depend on solar irradiation. This induces a decrease of the optimal voltage with solar irradiation: when the solar irradiation varies from 300 W/m2 to 900 W/m2, the optimal voltage decreases by 11 %. These results are confirmed by the measures of the manual regulation of the maximum power point (MPP) during one day. By taking into account all the modeling results, we have analyzed the electric behavior of the association of the panels in parallels and in series, as well as the ageing of a PV panel. We have shown that the connection of the PV panels in series (parallels) improves (degrade) the optimal performances of the panel, and a panel undergoes an ageing from 4 to 5 W by year.
