The electric power system is changing due to several reasons and among these one may find the deployment of dispersed generation (DG). The impact of DG into the electrical network has to be cautiously investigated, considering the several constraints that might arise, for instance, in what concerns reliability.
This paper firstly describes the present situation of DG. Afterwards the several concepts around reliability are highlighted. Finally, the state of the art of the evaluation of the distribution networks reliability is reviewed, in presence or not of DG, indicating the different methodologies used.