Assessment of customer outage costs due to electric service interruptions: Residential sector

The assessment of the benefit or worth of reliability is perceived as being a major contribution in providing the additional detail in the justification of new system facilities and operating reliability levels provided the required information can be obtained in a consistent and coherent manner. The costs incurred by consumers, customer interruption costs (CIC), as a result of interruptions in their electricity supply are considered key indicators of customer expectations and therefore of reliability worth. The assessment of CIC through surveys is considered to yield the most definitive results. Since the worth of these factors is difficult to quantify, consistent convergence of respondents' opinions on issues related to the electricity service can be useful in lending credibility to the interruption costs derived from surveys. The paper is based on extensive surveys conducted at UMIST. It reports on the customer characteristics of the residential respondents and their experience of interruptions, the undesirability of some effects of interruptions and the variation of undesirability of effects with frequency of interruption, season, time of day and weekday/weekend. The customers' ratings of these aspects are also tested for statistical correlation with the customer and experience of interruption variables. Remarkable agreement on the opinions is displayed across the RECs leading to the expectation that the corresponding CIC derived from the studies will be comparable as well.