Siting Transmission Lines in a Changed Milieu: Evolving Notions of the “public Interest” in Balancing State and Regional Considerations

Under the predominant existing paradigm, in balancing the public interest in transmission line planning and siting decisions most state regulatory authorities weigh the benefits to the customers of a specific utility system, or to the consumers in an individual state, against potential adverse consequences. This approach to transmission siting was designed to serve the model of a vertically-integrated public utility monopoly franchise, for which the primary purpose of siting was to locate infrastructure to serve the utility’s native load customers. Under this paradigm, the costs of new transmission infrastructure are typically allocated under cost-of-service ratemaking principles, based on an understanding of anticipated benefits tothem. In making their decisions, siting authorities have been required to first determine the need for transmission infrastructure, usually defined in economic terms.