Expanding Transmission Capacity: Examples of Regulatory Paths for Five Alternative Strategies

Transmission capacity expansion using existing lines and rights-of-way (ROW) is a strategy that deserves greater attention. The need to acquire siting approval and ROW for a new line can increase a project timeline by many years, and in some cases may even lead to project cancellation. Projects that use or expand an existing ROW face different regulatory pathways and typically result in different responses from the public and other entities than those that involve siting an entirely new line. In order to identify and compare some of the issues that arise in reconductoring existing lines, expanding rights of way for existing lines, and building entirely new lines, we obtained input from a number of PUCs and siting authorities across the United States, reviewed a large number of projects, and identified the types of approvals that different types of projects can expect. In this paper, we develop a taxonomy of technical strategies that can be used to increase the capacity in an existing transmission corridor and identify the regulatory and other issues that must be addressed in each case. We compare these options with that of building an entirely new line and illustrate the various strategies with examples drawn from U.S. transmission projects that have been undertaken over the past 20 years. © 2020 The Authors