Reliability Standards for Frequency and Voltage Protection Settings and Ride-Through for Inverter-Based Resources

<RULE> DEPARTMENT OF ENERGY <SUBAGY>Federal Energy Regulatory Commission</SUBAGY> <CFR>18 CFR Part 40</CFR> <DEPDOC>[Docket No. RM25-3-000; Order No. 909]</DEPDOC> <SUBJECT>Reliability Standards for Frequency and Voltage Protection Settings and Ride-Through for Inverter-Based Resources</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Energy Regulatory Commission. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Federal Energy Regulatory Commission (Commission) approves proposed Reliability Standard PRC-024-4 (Frequency and Voltage Protection Settings for Synchronous Generators, Type 1 and Type 2 Wind Resources, and Synchronous Condensers), Reliability Standard PRC-029-1 (Frequency and Voltage Ride-through Requirements for Inverter-Based Resources), and a definition of “Ride-through,” which the North American Electric Reliability Corporation (NERC) submitted in response to a Commission directive. In addition, the Commission directs NERC to clarify documentation requirements for legacy equipment needed to support an exemption request pursuant to Reliability Standard PRC-029-1; to consider whether, and if so how, to address a total of two exception- and exemption-related issues raised by commenters; and to submit an informational filing that assesses the reliability impact of the exemptions to Reliability Standard PRC-029-1. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective August 28, 2025. </EFFDATE> <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> <FP SOURCE="FP-1"> Syed Ahmad (Technical Information), Office of Electric Reliability, Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426, (202) 502-8718, <E T="03">Syed.Ahmad@ferc.gov</E> </FP> <FP SOURCE="FP-1"> Boris Voynik (Technical Information), Office of Electric Reliability, Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426, (202) 502-8902, <E T="03">Boris.Voynik@ferc.gov</E> </FP> <FP SOURCE="FP-1"> Hampden T. Macbeth (Legal Information), Office of General Counsel, Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426, (202) 502-8957, <E T="03">Hampden.Macbeth@ferc.gov</E> </FP> <FP SOURCE="FP-1"> Felicia West (Legal Information), Office of General Counsel, Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426, (202) 502-8948, <E T="03">Felicia.West@ferc.gov</E> </FP> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> 1. Pursuant to section 215(d)(2) of the Federal Power Act (FPA), <SU>1</SU> <FTREF/> the Commission approves the proposed Protection and Control (PRC) Reliability Standard PRC-024-4 (Frequency and Voltage Protection Settings for Synchronous Generators, Type 1 and Type 2 Wind Resources, and Synchronous Condensers), Reliability Standard PRC-029-1 (Frequency and Voltage Ride-through Requirements for Inverter-Based Resources), and the proposed definition of the term Ride-through, which the North American Electric Reliability Corporation (NERC) submitted in response to Commission directives in Order No. 901. <SU>2</SU> <FTREF/> We also approve the associated violation risk factors and violation severity levels, implementation plan, and effective date, as well as the retirement of currently effective Reliability Standard PRC-024-3. We approve the proposed Reliability Standards and proposed definition because they improve the reliability of the Bulk-Power System by establishing Ride-through performance requirements that mitigate inverter-based resource (IBR) tripping and momentary cessation. <SU>3</SU> <FTREF/> <FTNT> <SU>1</SU>  16 U.S.C. 824o(d)(2). </FTNT> <FTNT> <SU>2</SU>   <E T="03">Reliability Standards to Address Inverter-Based Res.,</E> Order No. 901, 88 FR 74250 (Oct. 30, 2023), 185 FERC ¶ 61,042 (2023). </FTNT> <FTNT> <SU>3</SU>   <E T="03">See id.</E> PP 50-52. </FTNT> 2. While the final rule largely adopts the Notice of Proposed Rulemaking's  <SU>4</SU> <FTREF/> (NOPR) proposals, some commenters raise a concern that additional specificity is needed regarding the acceptable documentation to support an exemption for legacy IBRs pursuant to Requirement 4 of Reliability Standard PRC-029-1. As discussed below, we agree that entities would benefit from greater clarity on documentation obligations and direct that NERC, within 12 months of the effective date of this final rule, submit a responsive modification to the Reliability Standard, for example, by expanding the non-exhaustive list for IBR generator owners of acceptable types of evidence of a hardware limitation that prevents the IBR from meeting the ride-through  <SU>5</SU> <FTREF/> criteria in proposed Requirements R1 through R3. We also direct NERC to submit, to the Commission, an informational filing 18 months after the conclusion of the exemption request period in proposed Reliability Standard PRC-029-1, Requirement R4 that assesses the reliability impact of the exemptions to the Standard. <FTNT> <SU>4</SU>   <E T="03">Reliability Standards for Frequency & Voltage Protection Settings & Ride-Through for Inverter-Based Res.,</E> Notice of Proposed Rulemaking, 90 FR 6845 (Jan. 21, 2025), 189 FERC ¶ 61,212 (2025) (NOPR). </FTNT> <FTNT> <SU>5</SU>  This final rule uses the phrase “Ride-through” to refer to the proposed definition of the term “Ride-through” and uses the phrase “ride-through” to refer to the act of an IBR staying connected to the Bulk-Power System through a voltage or frequency system disturbance. </FTNT> 3. In Order No. 901, the Commission stressed the need for comprehensive and timely Reliability Standards to address the well-documented reliability impacts of IBRs. <SU>6</SU> <FTREF/> With that frame of reference, the Commission in Order No. 901 allowed NERC to craft “a limited and documented” exemption to ride- through performance requirements “for existing IBRs with equipment limitations.”  <SU>7</SU> <FTREF/> NERC's proposed Reliability Standard hews close to the Commission's expectations. Some commenters responding to the NOPR seek modifications to the ride-through provisions to address two concerns. First, according to commenters, certain High-Voltage Direct Current (HVDC)-connected IBRs cannot meet the entire ride-through criteria in Requirement R1 without risking thermal damage to equipment and therefore should receive an exception. Second, while the ride-through exemption  <SU>8</SU> <FTREF/> in Reliability Standard PRC-029-1, Requirement 4 is limited to existing IBRs ( <E T="03">i.e.,</E> “an IBR that is in-service by the effective date of PRC-029-1”) some commenters advocate that the exemption provision should accommodate long-lead time projects, meaning IBR facilities that are currently under development but will not be in-service on the effective date of PRC-029-1. Commenters adjure that without changes to the exemption provision to accommodate these concerns, existing IBR projects may be forced into early retirement and planned IBR projects under construction may be cancelled before reaching operation, thereby removing generation resources from the grid. <FTNT> <SU>6</SU>  Order No. 901, 185 FERC ¶ 61,042 at PP 5, 190, 226 (“[W]e emphasize that industry has been aware of and alerted to the need to address the impacts of IBRs . . . since at least 2016.”). </FTNT> <FTNT> <SU>7</SU>   <E T="03">Id.</E> P 193 (noting that the exemption would apply to “typically older IBR technology with hardware that needs to be physically replaced . . .”). </FTNT> <FTNT> <SU>8</SU>  An exemption under Requirement R4 means that an IBR is exempted in perpetuity or until the hardware is replaced from meeting portions of the voltage and frequency ride-through criteria of Requirements R1 through R3 that the hardware was not designed to meet. </FTNT> 4. As discussed in detail below, it appears that commenters have articulated colorable concerns that were not raised in comments to prior Commission orders in this proceeding. We believe that these matters deserve a more complete vetting in the NERC standards development process given the lack of discussion in the record. Accordingly, we direct NERC through its standard development process to determine whether, and if so how, to account for these concerns. If NERC deems appropriate, NERC may develop appropriate solutions for the two issues raised by commenters beyond the narrow parameter set forth in Order No. 901 for exceptions or exemptions from ride-through requirements. Within 12 months of the effective date of this final rule, we direct NERC to submit to the Commission its determination and, if it deems appropriate, any proposed modifications to Reliability Standard PRC-029-1. 5. While providing latitude to address these two concerns raised by commenters, NERC and industry should be mindful of the Commission's overarching concerns expressed in Order No. 901 that a comprehensive and timely resolution is needed so that IBR performance no longer poses a threat to the reliable operation of the Bulk-Power System. With that in mind, to the extent that NERC develops modifications pertaining to long-lead time projects, this final rule should serve as notice that future IBR projects must fully satisfy the ride-through performance requirements (and not later dates as suggested by some commenters). <HD SOURCE="HD1">I. Background</HD> <HD SOURCE="HD2">A. Section 215 and Mandatory Reliability Standards</HD> 6. Section 215 of the FPA provides that the Commission may certify an Electric Reliability Organization (ERO), the purpose of which is to develop mandatory and enforceable Reliability Standards, subject to Commission review and approval. <SU>9</SU> <FTREF/> Reliability Standards may be enforced by the ERO, subject to Commission oversight, or by the Commission indepen ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 147k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━