Customer Demand for Service Reliability in the Electric Power Industry: A Synthesis of the Outage Cost Literature

The purpose of this paper is to review and synthesize recent North American research into the demand for service reliability and to draw conclusions of general interest to the utility industry. The electric power industry has, over the past 15 years, experienced increasing pressures to become more efficient, that is to provide greater value to its customers for the same resource utilization. The industry's response to these pressures has given rise to the potential for major changes in the theory and practice of utility planning, operations and pricing. A common thread running through many of these changes is a recognition that the consumer's demand for service reliability plays a key role in designing prices and services. To date the demand for service reliability has been characterized almost exclusively in terms of `outage costs', which refer to loss in value to the customer resulting from a sudden interruption of power. In the case of industrial and commercial customers, these costs may take the form of lost sales, idle labor, or product and input spoilage. While residential outage costs may also include spoilage, the less tangible costs of inconvenience are likely to play a more dominant role.