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Regulatory Updates

NERC’s FAC-008 Guidance on Facility Ratings

Jim Whitaker, PE | May 24, 2021

Understanding the ability of an energy facility to reliably carry power (Ratings) is key to the consistent operation of the grid. NERC’s FAC-008 Standard requires utilities to ensure that Facility Ratings used in the planning and operation of the Bulk Electric System (BES) are based on technically sound principles for the determination of System Operating Limits.

FAC-008 is one of the most data-intensive standards in the NERC regulatory framework. Compliance has been difficult for many utilities. Over the last decade FERC and NERC have approved revisions to reduce the complexity of the standard and issued extensive guidance for transmission and generation owners. But challenges remain.

Recently, FERC made public it’s intent to address serious allegations of facility ratings violations contained in a FERC Staff report, including a lack of rigor by one utility.

  • FERC Staff alleges the utility violated the facilities rating standards by establishing and having facility ratings that were inconsistent with its own Facilities Rating Methodology.
  • FERC staff alleges that the Facilities Rating Methodology required the consideration of clearance measurements consistent with the National Electric Safety Code.

While this one case is not broadly indicative of compliance conditions across the industry, review of the details can provide guidance to others and support a more thorough review of their own FAC-008 compliance program.

FAC-008 requires a great deal of attention from generation and transmission owning companies to ensure ongoing compliance as systems evolve. Utilities must continuously:

  • Have a regularly updated Facilities Rating Methodology which establishes how Facility Ratings for all components of BES elements are established so they are consistent with industry technical standards such as IEEE or CIGRE, manufacturer ratings or testing;
  • Identify the ratings based limiting components of all BES Elements; and
  • Have strong internal controls tied to their asset management and equipment configuration change processes to track ratings changes over time, to assure continuing compliance with the requirements of the FAC-008 standard.

Next Steps: TRC Can Help

We understand the challenges faced by our clients in implementing Facilities Ratings procedures and controls consistent with the FAC-008 standard. Our asset management experts can provide an independent review of your company’s facilities ratings processes and related  internal controls and suggest corrective measure to prevent compliance violations.


About TRC

TRC’s approach to power system planning, design and operations balances solutions that incorporate appropriate standard requirements, regulatory guidance, compliance obligations, best practices, operational goals and budgets. Our work for both public and private sector clients is a testament to our understanding of power system planning and operations. TRC advises numerous clients how to stay ahead of the curve regarding the technical aspects of their mandatory compliance obligations and business opportunities.

This regulatory update is a service to TRC’s utility clients, helping keep you informed of issues that impact your company’s electric system reliability risks along with related topics regarding regulatory developments to help you achieve your company’s business goals.

Jim Whitaker, PE

Jim Whitaker, PE is Supervisor of Power Systems Studies at TRC. He has over 30 years of experience in Transmission and Distribution Planning, and Substation, Transmission and Distribution Engineering. His Transmission Planning projects include coordinating joint/regional 10-year transmission plans, generator interconnections, regional system assessments, as well as NERC compliance studies. His projects have included studies for both Utilities and Project Developers across the United States in the Eastern and Western Interconnection transmission systems as well as ERCOT. Prior to joining TRC, Jim worked for Xcel Energy, Peak Power Engineering, Tucson Electric Power and Virginia Power. Contact Jim at

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