The photovoltaic solar energy is a theme at center of the topicality since the world conscience hold of the warming of planet by the greenhouse effect and of the rarefaction of the primary resources(Oil, gas…).For solve theseproblems environmental and of energy, the development of the photovoltaic solar energy becomes primordial.The PV system is the device which allows exploiting this inexhaustible energy source. Currently we distinguish several types of which the one met usually in the isolated sites is the autonomous PV system. In this article, we studied the modelling and the optimization of the functioning of an autonomous photovoltaic system equipped with a charge regulator simple.The study is made in considering tensions of 12 V and of 24 V of the storage system.The voltage in open circuit represents the only parameter of the PV field taken into account in this study. After the investigations, the results obtained show on the one hand that a suitable operation of charge or discharge, from a storage system is obtained if the discharge or charge current is weak. On the other hand, the study on autonomous PV system showed that the tension in open circuit of the PV field adapted for the optimal functioning of an autonomous PV system of 12V is in the fork between 16 V to 23 V. In the case of an autonomous photovoltaic system of 24 V, this beach of tension is between 34 V to 43 V.The tension in open circuit of PV field is under the conditions of 1000 W/m2 and a temperature of 25 °C.

PV modules, storage system, charge regulator simple, photovoltaic solar energy, optimization.