This paper offers a new method to extract the equivalent circuit parameters of a single diode photovoltaic (PV) panel. These parameters were determined by using the manufacturer data of the PV panel and an experimental measurement. This method consists in measuring a single parameter which is the shunt resistance R-sh , the other unknown parameters were determined through the resolution of the equations proposed by the method. The strength of the proposed method is that the measurement errors do not affect the values of the calculated parameters. In order to confirm the accuracy of the current work, this method is applied on two different types of solar panels (monocrystalline and polycrystalline). And thereafter, the corresponding power-voltage (P-V) and current-voltage (I-V) curves are compared to manufacturer, PVsyst software and to the results achieved by other authors for various levels of temperature and irradiance. The results indicated that the proposed method is simple, fast and offers accurate results which make it applicable to different types of PV panels.