The smart grid system can be integrated from different sources of renewable energy, such as photovoltaic panels, built by a large number of solar cells. The aim of this work is to study the influence of the single-diode model parameters on the current-voltage and power-voltage characteristics of the polycrystalline silicon photovoltaic (PV) cells. These parameters are series resistance, shunt resistance, and ideality factor. In addition the influence of the illumination and the temperature is examined. It was found that, the simulation results are acceptable; the model confirms that it is in agreement with the PV panel behavior as given by the manufacturer.