Reliability Cost/Worth Assessment

The basic function of a modern electric power system is to provide electric power and energy to its customers at the lowest possible cost and at acceptable levels of reliability. Reliability worth assessment provides the opportunity to incorporate cost analysis and quantitative reliability assessment into a common structured framework.(1) Direct evaluation of reliability worth or benefit is very difficult and perhaps impossible and a variety of methods have evolved to provide monetary estimates.(2,3) Interruption costs are most often used to provide an indirect measure of reliability worth. It is important to realize that, while power system reliability assessment has become a well established practice over the last few decades, reliability worth assessment or unreliability cost evaluation is still relatively immature. The major reason for this is that the quantification of interruption costs is a complex and often subjective task.