ColumbiaGrid’s planning and expansion agreement calls for preparation of a biennial transmission expansion plan based on the principle of single-utility planning. The plan is to address a 10-year planning horizon and is intended to identify and resolve the projected needs of parties to the agreement so they can meet long-term firm transmission obligations.
Each biennial transmission expansion plan starts with the existing firm transmission plans of utilities in the ColumbiaGrid footprint and is followed by a system assessment to determine the areas of the system that do not meet reliability standards. Study teams are created to resolve the reliability issues identified in the system assessment. The plans that are developed to resolve these issues are then included in the biennial transmission expansion plan.