ABSTRACT
Availability of service, when and how much electric power is available for use and how that may vary in a predictable or unpredictable manner, is a key factor in Distributed generator (DG) assessment and planning, because it is one of the two primary measures of power supply effectiveness; the other is cost. Availability of power from a DG system or a traditional central station power system depends on the reliability of that system. This chapter examines DG reliability assessment, along with the analytical methods for study of reliability and availability. It reviews the concepts and methods necessary to assess reliability and time between failures and provides some examples. The simplest workable approach to the analysis of service reliability with DG units is to model their unavailability likelihood as a probability that they are in a failed state and use that to compute the expectation of their being either in or out of service.
