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Federal Energy Regulatory Commission

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News Release: March 20, 2014
Docket Nos. RD14-2-000, RM13-16-000, RM13-19-000, RM14-3-000 and RM13-5-001
Item No. E-7

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FERC Refines Bulk Electric System Definition to Bolster Reliability

The Federal Energy Regulatory Commission (FERC) today approved further revisions to the definition of the bulk electric system (BES) to provide greater clarity, consistency and improved reliability by focusing on core facilities that are necessary for operating the interconnected transmission network.

In December 2012, FERC approved a proposal by the North American Electric Reliability Corp (NERC) to replace the then-existing BES definition that allowed for regional discretion with a 100-kilovolt “bright-line” threshold, a list of specifically included and excluded facilities, and a case-by-case exception process to add or remove facilities. That decision, Order No. 773, also directed NERC to propose further revisions.

Today’s order approves NERC’s proposal to refine the exclusions for radial facilities and local networks. Additionally, today’s order approves revisions clarifying that all forms of generation, including variable generation resources, are included in the bulk electric system and that certain generator interconnection facilities also are included in the bulk electric system.

In other actions taken today on reliability standards, FERC:

  • Approved five standards requiring generators owners, and in some cases, transmission owners, to provide verified data for certain power system planning and operational studies, which will improve the accuracy of the studies and enhance the coordination of protection system settings.
  • Proposed to approve a new standard on Generator Relay Loadability designed to prevent generators from tripping offline prematurely or unnecessarily during a system disturbance, and NERC’s proposed revisions to an existing standard on Transmission Relay Loadability.
  • Granted clarification in part and denied rehearing of Order No. 791, which approved version 5 of the Critical Infrastructure Protection standards.