On October 17, 2013, FERC issued a final rule approving the North American Electric Reliability Corporation’s (“NERC”) revisions to the Transmission Planning (“TPL”) Reliability Standards. In the order, FERC approves a new version of the TPL Reliability Standards, TPL-001-4, which includes Requirements R1-R8 and Table 1. TPL-001-4 increases the specificity of data required for modeling conditions and requiring annual assessments addressing near-term and long-term planning horizons for steady state, short circuit, and stability conditions. Additionally, the modified reliability standard includes a provision that allows a transmission planner to plan for non-consequential load loss after a single contingency. FERC directed NERC to modify TPL-001-4 to address concerns about the planned outage threshold length and the Requirement R1 Violation Risk Factor (“VRF”).
Overall, FERC found that TPL-001-4 improves uniformity and transparency in transmission planning and clarifies when planners may use planned load loss in establishing planning performance requirements for Bulk Electric System (“BES”) operations in both normal and contingency conditions. In its Order, FERC identified several specific items regarding TPL-001-4. First, Requirement R1 both requires transmission planners and the planning coordinators to maintain system models and provides a list of specific items required for system models. Requirement R1 also provides that system models must conform to projected system conditions and that the transmission planner must model the items that are variable based specifically on expected system conditions.
Second, TPL-001-4 requires annual assessments addressing planning horizons for steady state, short circuit, and stability conditions. Requirement R2 requires each planner and coordinator to prepare an annual planning assessment for their BES and clarifies which documents planners and coordinators must use to analyze steady state, short circuit, and stability conditions.
Third, Table 1 includes a series of planning events and system performance requirements for a range of contingencies that planners must evaluate. Footnote 12 to Table 1 provides a blend of quantitative and qualitative parameters for permissible use of non-consequential load loss to meet BES performance issues. Parameters include firm limitations on the amount of load that an entity can plan to shed, safeguards against adverse reliability impacts, and an improved stakeholder process. FERC found that footnote 12 provides guidelines for transmission planners to plan for a non-consequential load loss following a single contingency.
FERC also directed NERC to make two modifications to TPL-001-4. First, FERC directed NERC to modify Requirement R1 to address the concern that the six month threshold for planned outages excluded planned outages of significant facilities for maintenance purposes. Second, FERC directed NERC to modify Requirement R1 to change the VRF from medium to high in order to prevent faulty studies that could lead to the misoperation of the system. The final rule is effective 60 days after publication in the Federal Register.
A copy of the final rule is available here.