Transmission planning in the US has been going through substantial changes in recent years. One critical change has been an expansion of the geographic scope over which planning coordination occurs. A once local exercise, transmission planning is now happening at the interconnection level and including many more stakeholders, some of whom are working together for the first time. This change in scale and scope is requiring new tools and models to examine planning issues.
As with all models, planning models used in the electricity industry employ a variety of simplifications in order to make representations of the complex electricity system more tractable. An open question remains: what models should be used to gain insight on the questions transmission planners are addressing? And what simplifications and abstractions are appropriate and useful in these models? One way to explore the strengths and challenges of models, and the impact of simplifications within them, is to compare the model results to actual data. In this talk I begin laying the groundwork for some of these questions by presenting a comparison of regional interchanges resulting from a resource expansion planning model to scheduled and actual system flows in the Eastern United States.