The exploitation of resources of renewable energy has become inescapable today. Indeed, facing the oil cost increase, the survival of the economies, particularly of the non oil-producing countries requires the evaluation and the exploitation of their energy potential. The purpose of this paper is to make an analysis of the electrical energy situation in Senegal and to show the relevance in the implementation of a hybrid power plant using renewable energy resources. The design is done to minimize the Annualized Cost of System under the constraints related to the components and the availability of the energy measured with the Loss of Supply Probability.