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Rule2025-14304

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

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Published

July 29, 2025

Effective

August 28, 2025

Issuing agencies

Energy DepartmentFederal Energy Regulatory Commission

Abstract

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.

Full Text

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<title>Federal Register, Volume 90 Issue 143 (Tuesday, July 29, 2025)</title>
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[Federal Register Volume 90, Number 143 (Tuesday, July 29, 2025)]
[Rules and Regulations]
[Pages 35599-35616]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-14304]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

18 CFR Part 40

[Docket No. RM25-3-000; Order No. 909]

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

AGENCY: Federal Energy Regulatory Commission.

ACTION: Final rule.

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SUMMARY: 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.

DATES: This rule is effective August 28, 2025.

FOR FURTHER INFORMATION CONTACT:
Syed Ahmad (Technical Information), Office of Electric Reliability,
Federal Energy Regulatory Commission, 888 First Street NE, Washington,
DC 20426, (202) 502-8718, <a href="/cdn-cgi/l/email-protection#4c1f352928620d24212d280c2a293e2f622b233a">[email&#160;protected]</a>
Boris Voynik (Technical Information), Office of Electric Reliability,
Federal Energy Regulatory Commission, 888 First Street NE, Washington,
DC 20426, (202) 502-8902, <a href="/cdn-cgi/l/email-protection#165479647f653840796f787f7d567073647538717960">[email&#160;protected]</a>
Hampden T. Macbeth (Legal Information), Office of General Counsel,
Federal Energy Regulatory Commission, 888 First Street NE, Washington,
DC 20426, (202) 502-8957, <a href="/cdn-cgi/l/email-protection#b1f9d0dcc1d5d4df9ffcd0d2d3d4c5d9f1d7d4c3d29fd6dec7">[email&#160;protected]</a>
Felicia West (Legal Information), Office of General Counsel, Federal
Energy Regulatory Commission, 888 First Street NE, Washington, DC
20426, (202) 502-8948, <a href="/cdn-cgi/l/email-protection#f6b0939a9f959f97d8a1938582b690938495d8919980">[email&#160;protected]</a>

SUPPLEMENTARY INFORMATION:
1. Pursuant to section 215(d)(2) of the Federal Power Act (FPA),\1\
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.\2\ 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.\3\
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\1\ 16 U.S.C. 824o(d)(2).
\2\ Reliability Standards to Address Inverter-Based Res., Order
No. 901, 88 FR 74250 (Oct. 30, 2023), 185 FERC ] 61,042 (2023).
\3\ See id. PP 50-52.
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2. While the final rule largely adopts the Notice of Proposed
Rulemaking's \4\ (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 \5\
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.
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\4\ Reliability Standards for Frequency & Voltage Protection
Settings & Ride-Through for Inverter-Based Res., Notice of Proposed
Rulemaking, 90 FR 6845 (Jan. 21, 2025), 189 FERC ] 61,212 (2025)
(NOPR).
\5\ 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.
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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.\6\ With that frame of
reference, the Commission in Order No. 901 allowed NERC to craft ``a
limited and documented'' exemption to ride-

[[Page 35600]]

through performance requirements ``for existing IBRs with equipment
limitations.'' \7\ 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 \8\ in Reliability Standard PRC-029-1, Requirement 4
is limited to existing IBRs (i.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.
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\6\ 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.'').
\7\ Id. P 193 (noting that the exemption would apply to
``typically older IBR technology with hardware that needs to be
physically replaced . . .'').
\8\ 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.
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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).

I. Background

A. Section 215 and Mandatory Reliability Standards

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.\9\ Reliability Standards may be
enforced by the ERO, subject to Commission oversight, or by the
Commission independently.\10\ Pursuant to section 215 of the FPA, the
Commission established a process to select and certify an ERO,\11\ and
subsequently certified NERC.\12\
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\9\ 16 U.S.C. 824o(c).
\10\ Id. 824o(e).
\11\ Rules Concerning Certification of the Elec. Reliability
Org.; & Procs. for the Establishment, Approval, & Enf't of Elec.
Reliability Standards, Order No. 672, 71 FR 8662 (Feb. 17, 2006),
114 FERC ] 61,104, order on reh'g, Order No. 672-A, 71 FR 19814
(Apr. 18,2006), 114 FERC ] 61,328 (2006); see also 18 CFR 39.4(b).
\12\ N. Am. Elec. Reliability Corp., 116 FERC ] 61,062, order on
reh'g and compliance, 117 FERC ] 61,126 (2006), aff'd sub nom.
Alcoa, Inc. v. FERC, 564 F.3d 1342 (D.C. Cir. 2009) (Certification
Order).
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B. Order No. 901

7. In Order No. 901, the Commission explained, among other things,
that the majority of installed IBRs use grid-following inverters, which
can track grid state parameters (e.g., voltage angle) in milliseconds
and react nearly instantaneously to changing grid conditions.\13\ The
Commission then explained that, as found by multiple NERC reports,\14\
some IBRs ``are not configured or programmed to support grid voltage
and frequency in the event of a system disturbance, and, as a result,
will reduce power output, exhibit momentary cessation, or trip in
response to variations in system voltage or frequency.'' \15\
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\13\ Order No. 901, 185 FERC ] 61,042 at P 12.
\14\ Id. P 26 n.53 (listing 12 NERC reports describing IBR
behavior during disturbances).
\15\ Id. P 12 (footnotes omitted).
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8. Therefore, the Commission directed NERC to develop new or
modified Reliability Standards pertaining to IBRs in four areas: (1)
data sharing; (2) model validation; (3) planning and operational
studies; and (4) performance requirements.\16\ The Commission required
NERC to submit, by November 4, 2024, new or modified Reliability
Standards that require registered IBR generator owners and operators to
use appropriate settings ``to ride through frequency and voltage system
disturbances.'' \17\
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\16\ E.g., id. PP 1, 5, 53.
\17\ Id. P 190.
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9. The Commission mandated that the new or modified ride-through
Reliability Standards must require registered IBRs to continue to
inject current within an established no trip-zone and perform frequency
support during Bulk-Power System disturbances. The Commission directed
that the new or modified Reliability Standards must establish
requirements for post-disturbance ramp rates and phase lock loop
synchronization, and other known causes of IBR tripping or momentary
cessation.\18\
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\18\ Id. P 5.
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10. In response to commenters on the NOPR preceding the issuance of
Order No. 901, the Commission declined to direct NERC to specifically
reference Institute of Electrical and Electronics Engineers (IEEE)
standards in new or modified Reliability Standards developed in
response to the Order. The Commission concluded that the record in the
proceeding provided no support for the conclusion that the performance
requirements of IEEE standard 2800-2022 (IEEE 2800-2022) \19\ are
preferable to NERC's Reliability Standards or would adequately address
the reliability concerns identified in Order No. 901. Instead, the
Commission provided NERC the discretion to consider whether and how to
reference IEEE standards, including IEEE 2800-2022, in the new or
modified Reliability Standards.\20\
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\19\ IEEE 2800-2022 is a voluntary industry standard for
transmission connected IBRs that is intended to enhance the
operating performance and control capabilities of IBRs. Id. P 36.
\20\ Id. P 195.
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11. The Commission also recognized that some older IBRs may have
equipment limitations such that IBR owners would have to physically
replace their hardware and may have settings and configurations that
IBR owners could not modify through software updates, and in such

[[Page 35601]]

circumstances, could not implement voltage ride-through performance
requirements. Thus, the Commission directed NERC to ``determine whether
the new or modified Reliability Standards should provide for a limited
and documented exemption for certain registered IBRs from voltage ride
through performance requirements.'' \21\ The Commission added that if
NERC determined that an exemption is appropriate, the new or modified
Reliability Standards should mitigate the reliability impacts to the
Bulk-Power System of such an exemption.\22\ The Commission also
directed NERC to ensure exemptions would only be for ``those existing
IBRs that are unable to modify their coordinated protection and control
settings to meet the requirements without physical modification of the
IBRs' equipment.'' \23\
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\21\ Id. P 193.
\22\ Id. P 199.
\23\ Id. P 193.
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C. NERC Petition

12. On November 4, 2024, in response to Order No. 901, NERC
submitted for Commission approval the proposed definition of the term
Ride-through for the NERC Glossary of Terms Used in Reliability
Standards (Glossary of Terms), proposed Reliability Standards PRC-024-4
and PRC-029-1, the associated violation risk factors and violation
severity levels, implementation plans and effective dates for
Reliability Standards PRC-024-4 and PRC-029-1, and the retirement of
currently effective Reliability Standard PRC-024-3. NERC asserted that
proposed Reliability Standards PRC-024-4 and PRC-029-1 would ensure
that applicable Bulk-Power System-connected resources ride-through
system disturbances.\24\
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\24\ NERC Petition at 1, 19-20.
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1. Addition of Defined Term Ride-Through to NERC Glossary of Terms
13. NERC stated that proposed Reliability Standard PRC-029-1 uses
the term Ride-through, which NERC proposed to include in the NERC
Glossary of Terms. NERC explained that the term Ride-through would mean
that ``the plant/facility remains connected and continues to operate
through voltage or frequency system disturbances.'' \25\
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\25\ Id. at 23.
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2. Proposed Reliability Standard PRC-024-4
14. NERC explained that proposed Reliability Standard PRC-024-4
removes language relating to IBR functionality in Requirements R1
through R4 because IBR performance requirements are included in
proposed Reliability Standard PRC-029-1. Instead, proposed Reliability
Standard PRC-024-4 would maintain capability-based requirements for
synchronous generators, synchronous condensers, and type 1 and type 2
wind resources.\26\ Moreover, NERC explained that, because synchronous
units do not require performance-based requirements to ride-through
system disturbances, proposed Reliability Standard PRC-024-4 would
continue to address ride-through compatible frequency and voltage
protection setting ranges for synchronous generators, synchronous
condensers, and type 1 and type 2 wind resources.\27\
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\26\ Id. at 15. NERC explained that consistent with the then-
proposed definition for IBRs in the NERC Glossary of Terms, type 1
and type 2 wind resources are not considered IBRs. On February 20,
2025, the Commission approved NERC's proposed definition for IBRs
as: ``A plant/facility consisting of individual devices that are
capable of exporting Real Power through a power electronic
interface(s) such as an inverter or converter, and that are operated
together as a single resource at a common point of interconnection
to the electric system.'' Examples of IBRs include, but are not
limited to, plants/facilities with solar photovoltaic (PV), Type 3
and Type 4 wind, battery energy storage system (BESS), and fuel cell
devices. N. Am. Elec. Reliability Corp., 190 FERC ] 61,098, at PP 3
n.9, 12 (2025) (delegated order) (Milestone 2 Delegated Order).
\27\ NERC Petition at 49.
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3. Proposed Reliability Standard PRC-029-1
15. NERC explained that proposed Reliability Standard PRC-029-1
would address directives in Order No. 901 by establishing frequency and
voltage ride-through performance requirements for generator owners of
IBRs.
a. Proposed Requirement R1
16. Under proposed Requirement R1, each generator owner of a NERC-
registered IBR must ``ensure the design and operation is such that each
IBR meets or exceeds Ride-through requirements, in accordance with the
`must Ride-through zone' as specified in Attachment 1'' of proposed
Reliability Standard PRC-029-1, except in four conditions to protect
hardware from incurring damage, as specified by the Standard.\28\
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\28\ Id. at 25, 29.
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17. NERC explained that it adopted the IEEE 2800-2022's terminology
for ``must ride-through zones,'' which are defined in terms of voltage
and frequency magnitude and time duration.\29\ NERC explained that it
considered, but ultimately rejected, ride-through criteria more
stringent than set forth in IEEE 2800-2022 due to industry comments
raised during the IBR technical conference conveyed by NERC (September
2024 Technical Conference).\30\
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\29\ Id. at 26.
\30\ Id. at 27. Following the failure of the third ballot on
proposed Reliability Standard PRC-024-4 and proposed Reliability
Standard PRC-029-1, NERC convened the September 2024 Technical
Conference under section 321 of the NERC Rules of Procedure to
discuss issues surrounding the Order No. 901 directives. Id. at 22.
Section 321 of the NERC Rules of Procedure allows the NERC Board of
Trustees to take special actions when a ballot pool has ``failed to
approve a proposed Reliability Standard that contains a provision to
adequately address a specific matter identified in a directive
issued'' by the Commission. NERC, Rules of Procedure, Sec. 321 (Nov.
28, 2023), <a href="https://www.nerc.com/AboutNERC/pages/rules-of-procedure.aspx">https://www.nerc.com/AboutNERC/pages/rules-of-procedure.aspx</a>.
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18. NERC asserted that proposed Requirement R1 is responsive to the
directive that NERC develop performance-based Reliability Standards
that require IBRs to ride-through voltage system disturbances and
require post-disturbance ramp rates to return to pre-disturbance
levels.\31\ Additionally, NERC asserted that the provision in proposed
Requirement R1 requiring IBRs to meet or exceed ride-through
requirements in Attachment 1 of proposed Reliability Standard PRC-029-1
that restricts the use of momentary cessation satisfies the directive
to prohibit momentary cessation in the no-trip zone during
disturbances.\32\
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\31\ NERC Petition at 42.
\32\ Id. at 42-43.
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19. In addition, Attachment 1, Tables 1 and 2 (the Tables)
establish performance voltage ride-through criteria, which include
minimum ride-through time requirements for voltage per unit by
operation region.\33\ Points 7 through 9 of Attachment 1 establish a
minimum ride-through time of up to four deviations \34\ of the
applicable system voltage over a cumulative 10 second measurement
window, which covers the 10 second period from the first voltage
deviation and up to the fourth voltage deviation.\35\ During the

[[Page 35602]]

cumulative 10 second measurement window, the IBR must ride-through up
to four deviations.\36\
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\33\ Id., Ex. A-3 (PRC-029-1), attach. 1.
\34\ A deviation means a change in the applicable system
voltage.
\35\ Point 7 clarifies the voltage ride-through minimum time
duration for two system conditions, as specified in the Tables.
First, point 7 clarifies the minimum time duration per system
voltage, as specified in the Tables' values during a disturbance.
Second, point 7 clarifies the minimum time duration when the system
voltage is continuously varying during a disturbance. Point 8
clarifies that the required voltage ride-through time in the
mandatory and permissive operation regions, as specified in the
Tables, is calculated over a 10 second measurement window for one or
more system disturbances. Point 9 explains further that an IBR may
trip when there are more than four voltage deviations within any
cumulative 10 second measurement window. NERC Petition, Ex. A-3,
attach. 1.
\36\ Id.
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b. Proposed Requirement R2
20. Under proposed Requirement R2, each generator owner of a NERC-
registered IBR must adhere to voltage ride-through performance criteria
during system disturbances, unless a documented hardware limitation
exists in accordance with Requirement R4.\37\ NERC asserted that
proposed Requirement R2 satisfies the following directives: (1) that
NERC develop performance-based Reliability Standards that require IBRs
to ride-through voltage system disturbances; and (2) that IBRs inject
current and perform frequency support during a disturbance by requiring
IBRs remain connected and fulfill control and regulation functions to
qualify as riding-through a system disturbance.\38\ Proposed
Requirement R2 defines specific ride-through performance requirements
that an IBR must satisfy when voltage is within the regions specified
in Attachment 1.
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\37\ Id. at 29.
\38\ Id. at 42.
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c. Proposed Requirement R3
21. Under proposed Requirement R3, each generator owner of a NERC-
registered IBR must ensure that its IBR adheres to ride-through
requirements during frequency excursion events by continuing to
exchange current and remain electrically connected in accordance with
the ``must ride-through zone,'' as specified in the proposed
Reliability Standard's Attachment 2, and while the ``absolute rate of
change of frequency (RoCoF) magnitude is less than or equal to 5
[hertz]/second, unless a documented hardware limitation exists in
accordance with Requirement R4.'' \39\
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\39\ Id. at 33.
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22. NERC asserted that proposed Requirement R3 is responsive to the
directive that NERC develop performance-based Reliability Standards
that require IBRs to ride-through frequency system disturbances.
Additionally, NERC contended that proposed Requirement R3 satisfies the
directive that IBRs inject current and perform frequency support during
a disturbance by requiring that IBRs remain connected and fulfill
control and regulation functions to qualify as riding-through a system
disturbance.\40\
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\40\ Id. at 42.
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d. Proposed Requirement R4
23. Proposed Requirement R4 would allow each generator owner of an
existing legacy IBR to obtain an exemption to the ride-through
requirements of Requirements R1 through R3. Specifically, Requirement
R4 provides that ``[e]ach Generator Owner identifying an IBR that is
in-service by the effective date of PRC-029-1, has known hardware
limitations that prevent the IBR from meeting Ride-through criteria as
detailed in Requirements R1-R3, and requires an exemption from specific
Ride-through criteria shall . . . [d]ocument information supporting the
identified hardware limitation.'' \41\
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\41\ Id. at 36-37.
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24. Each generator owner of an IBR must provide the information
supporting the identified hardware limitation (unless it is considered
proprietary by the original equipment manufacturer) to each planning
coordinator, transmission planner, transmission operator, and
reliability coordinator in the footprint in which the legacy IBR is
located.\42\ Moreover, the generator owner must submit documentation to
the relevant Compliance Enforcement Authority--typically a Regional
Entity--that ``must accept that all aspects of the documentation
specified in proposed Requirement R4 have been provided by the
Generator Owner before an exemption can [be] granted.'' \43\
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\42\ Id. at 37.
\43\ Id. at 40.
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25. NERC explained that it determined that an exemption process for
generator owners of legacy IBRs for voltage and frequency performance
requirements is necessary. In its petition, NERC stated the standard
drafting team determined the ``anticipated difficulty of Generator
Owners having to wholesale retrofit and redesign legacy facilities
currently in operation would be unreasonable and unduly burdensome, and
it could lead to undesirable impacts on reliability.'' \44\ Further,
NERC explained that the exemptions must be specific and limited to the
voltage or frequency bands and associated duration that cannot be
satisfied or to the number of cumulative voltage deviations within a 10
second measurement window that the equipment can ride-through if it is
less than four deviations within any 10 second measurement window.\45\
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\44\ Id. at 38.
\45\ Id. at 39-40.
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26. NERC asserted that proposed Requirement R4 meets the directive
that NERC determine whether the new or modified Reliability Standards
should provide a limited and documented exemption from the voltage
ride-through requirements for existing IBRs and equipment.\46\ NERC
determined that a frequency exemption was also necessary and
appropriate because of hardware-based capability limitations for a
significant number of installed IBRs, a concern that was raised during
the September 2024 Technical Conference.\47\
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\46\ Id. at 44.
\47\ Id. at 38-39.
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27. Regarding the Commission directive to NERC to develop new or
modified Reliability Standards to mitigate the reliability impacts to
the Bulk-Power System of approved exemptions, NERC claimed that the
reliability impacts of voltage and frequency ride-through exemptions
are mitigated by existing Reliability Standards that address the
responsibilities of transmission planners, planning coordinators,
reliability coordinators, and transmission operators.\48\ Moreover,
under Milestone 4 of the Order No. 901 Work Plan,\49\ NERC indicated
that it will develop Reliability Standards that will help mitigate the
reliability impact of the exemptions.\50\
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\48\ Id. at 46. See also id. n.67 (providing as examples
existing Reliability Standards IRO-002-7 (Reliability Coordination--
Monitoring and Analysis), IRO-008-3 (Reliability Coordinator
Operational Analyses and Real-time Assessments), TOP-002-4
(Operations Planning), and TPL-001-5.1 (Transmission System Planning
Performance Requirements)).
\49\ Following the issuance of Order No. 901, NERC submitted an
informational filing that included its Order No. 901 Work Plan with
four key milestones for meeting the directives of Order No. 901.
Milestone 1: submit Work Plan (completed Jan. 17, 2024). Milestone
2: submit new or modified Reliability Standards to address
performance requirements and post-event performance validation for
registered IBRs (completed with NERC's filing of the instant
petition and two others on Nov. 4, 2024). Milestone 3: submit new or
modified Reliability Standards to address data sharing and model
validation by Nov. 4, 2025. Milestone 4: submit new or modified
Reliability Standards to address planning and operational studies
requirements for all IBRs by Nov. 4, 2026. NERC, Informational
Filing Regarding the Development of Reliability Standards Responsive
to Order No. 901, Docket No. RM22-12-000, at 6 (filed Jan. 17,
2024).
\50\ NERC Petition at 46.
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D. Notice of Proposed Rulemaking

28. On December 19, 2024, the Commission issued a NOPR proposing to
approve proposed Reliability Standards PRC-024-4 and PRC-029-1 and the
proposed definition of the term Ride-through.\51\
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\51\ NOPR, 189 FERC ] 61,212 at P 1.
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29. The Commission also proposed to find that NERC reasonably
determined it was appropriate to provide an

[[Page 35603]]

exemption process for voltage and frequency ride-through
requirements.\52\ In the NOPR, the Commission proposed to direct that
NERC submit two informational filings 12 months and 24 months after the
conclusion of NERC's proposed 12-month exemption request period for
existing IBRs to ``understand the volume of exemptions, the
circumstances in which entities have invoked the exemption provision,
and ultimately to understand what if any effect the exemption provision
has on the efficacy of Reliability Standard PRC-029-1.'' \53\
---------------------------------------------------------------------------

\52\ Id. PP 29, 31, 32.
\53\ Id. P 5.
---------------------------------------------------------------------------

30. In response to the NOPR, the Commission received 20 sets of
comments.\54\ A list of commenters appears in Appendix A.
---------------------------------------------------------------------------

\54\ Unfrack FERC Coalition's comments fall outside the scope of
this proceeding, and thus are not considered.
---------------------------------------------------------------------------

31. Commenters generally support the NOPR proposal to approve the
proposed definition of the term Ride-through \55\ and proposed
Reliability Standard PRC-024-4 as maintaining a protection-based
standard for synchronous resources, as well as the removal of
references to IBRs.\56\ Although many commenters supported approving
proposed Reliability Standard PRC-029-1,\57\ several raised concerns
with the exception and exemption provisions therein.\58\
---------------------------------------------------------------------------

\55\ See aligned ISOs/RTOs Comments at 4; EEI Initial Comments
at 1; APS Comments at 2 (stating its support for EEI's comments);
NERC Initial Comments at 2-4.
\56\ See aligned ISOs/RTOs Comments at 4-5; Dominion Comments at
2; EEI Initial Comments at 1; APS Comments at 2 (stating its support
for EEI's comments); LA PSC Comments at 1; NYISO Comments at 1. No
comments were received in opposition to the proposed Standard.
\57\ Aligned ISOs/RTOs Comments at 3; Elevate Comments at 12; LA
PSC Comments at 1; NERC Initial Comments at 2-4; NYISO Comments at
1; NYSRC Comments at 8; Tesla Comments at 1. UCS does not explicitly
support approving proposed Reliability Standard PRC-029-1; but
states that it is ``generally in favor of ride-through requirements
for all generation including IBRs.'' UCS Comments at 3.
\58\ Clean Energy Associations Initial Comments at 10-17, 23-25;
Deriva Comments at 5; Dominion Comments at 3-7; DNV Comments at 1-4;
EEI Initial Comments at 2-3; Elevate Comments at 3-4, 9-10;
Invenergy Initial Comments at 19-23, 32-36; LIPA Comments at 4-6;
NYISO Comments at 2-3; NYSERDA Comments at 2-5; [Oslash]rsted
Comments at 7-21; WIRAB Comments at 8.
---------------------------------------------------------------------------

II. Discussion

32. Pursuant to section 215(d)(2) of the FPA, we adopt the NOPR
proposal and approve proposed Reliability Standards PRC-024-4 and PRC-
029-1 and the proposed definition of Ride-through as just, reasonable,
not unduly discriminatory or preferential, and in the public interest.
Below, we discuss the following matters: (A) addition of the defined
term Ride-through to the NERC Glossary of Terms; (B) proposed
Reliability Standard PRC-024-4; (C) proposed Reliability Standard PRC-
029-1; and (D) the Commission directive that NERC submit an
informational filing.

A. Addition of Defined Term Ride-Through to NERC Glossary of Terms

33. As mentioned above, in the NOPR, the Commission proposed to
approve NERC's proposal to define the term Ride-through as ``the plant/
facility remains connected and continues to operate through voltage or
frequency system disturbances.'' \59\
---------------------------------------------------------------------------

\59\ NERC Petition at 23.
---------------------------------------------------------------------------

1. Comments
34. Commenters generally support the proposed definition of the
term Ride-through.\60\ For example, aligned ISOs/RTOs explain that
requiring IBRs to ride-through disturbances necessitates documenting an
agreed-upon definition of the term Ride-through in the NERC Glossary of
Terms.\61\ NERC explains in its comments that the definition
establishes ``a clear understanding of what it means for a generator to
Ride-through a disturbance'' by addressing ``abnormal tripping,
interruption of current injection, and reduced power output, which lead
to the unexpected loss of widespread generating resources.'' \62\
---------------------------------------------------------------------------

\60\ Aligned ISOs/RTOs Comments at 4; EEI Initial Comments at 1;
APS Comments at 2 (stating its support for EEI's comments). No
comments were received in opposition to the proposed definition.
\61\ Aligned ISOs/RTOs Comments at 4.
\62\ NERC Initial Comments at 2-3.
---------------------------------------------------------------------------

2. Commission Determination
35. Pursuant to section 215(d)(2) of the FPA, we adopt the NOPR
proposal to approve the addition of the term Ride-through to the NERC
Glossary of Terms. We find that the addition of the term will provide a
clear and consistent understanding of the term when used in Reliability
Standards. Further, the defined term Ride-through, when considered with
proposed Reliability Standard PRC-029-1, is responsive to the
directives in Order No. 901 to develop Reliability Standards that
establish performance ride-through requirements for IBRs.\63\
---------------------------------------------------------------------------

\63\ Order No. 901, 185 FERC ] 61,042 at P 190.
---------------------------------------------------------------------------

B. Proposed Reliability Standard PRC-024-4

36. In the NOPR, the Commission proposed to approve proposed
Reliability Standard PRC-024-4 as just, reasonable, not unduly
discriminatory or preferential, and in the public interest and as
consistent with applicable directives in Order No. 901.\64\
---------------------------------------------------------------------------

\64\ NOPR, 189 FERC ] 61,212 at PP 4, 31.
---------------------------------------------------------------------------

1. Comments
37. Commenters generally support, or do not oppose, the approval of
proposed Reliability Standard PRC-024-4.\65\ For example, aligned ISOs/
RTOs support the approval of proposed Reliability Standard PRC-024-4 as
consistent with the performance requirement directives of Order No.
901, explaining that it is a protection-based standard applicable only
to synchronous generators, synchronous condensers, and type 1 and type
2 wind units. Aligned ISOs/RTOs also support removing references to
IBRs in proposed Reliability Standard PRC-024-4 because IBRs will be
subject to ride-through requirements in proposed Reliability Standard
PRC-029-1.\66\
---------------------------------------------------------------------------

\65\ See aligned ISOs/RTOs Comments at 4-5; Dominion Comments at
2; EEI Initial Comments at 1; APS Comments at 2 (stating its support
for EEI's comments); LA PSC Comments at 1; NYISO Comments at 1. No
comments were received in opposition to the proposed Standard.
\66\ Aligned ISOs/RTOs Comments at 3-5. Aligned ISOs/RTOs also
explain that if IBRs were not subject to proposed Reliability
Standard PRC-029-1, it would be unjust and unreasonable and
inconsistent with the public interest to remove the references to
IBRs in proposed Reliability Standard PRC-024-4. Id. at 5 n.17.
---------------------------------------------------------------------------

2. Commission Determination
38. Pursuant to section 215(d)(2) of the FPA, we adopt the NOPR
proposal to approve proposed Reliability Standard PRC-024-4 as just,
reasonable, not unduly discriminatory or preferential, and in the
public interest. We find that removal of references to IBRs in proposed
Reliability Standard PRC-024-4 because IBRs will be subject to ride-
through performance requirements under proposed Reliability Standard
PRC-029-1 is consistent with Order No. 901. In Order No. 901, the
Commission provided NERC the discretion to modify PRC-024-3 or to
develop a comprehensive Reliability Standard to satisfy the IBR ride-
through performance requirement directives of Order No. 901.\67\ NERC
adopted the latter approach in developing Reliability Standard PRC-029-
1, which necessitated the removal of references to IBRs in Reliability
Standard PRC-024-4.
---------------------------------------------------------------------------

\67\ Order No. 901, 185 FERC ] 61,042 at P 210.
---------------------------------------------------------------------------

C. Proposed Reliability Standard PRC-029-1

39. In the NOPR, the Commission proposed to approve proposed

[[Page 35604]]

Reliability Standard PRC-029-1 as just, reasonable, not unduly
discriminatory or preferential, and in the public interest.\68\ The
Commission preliminarily found that the proposed Reliability Standard
is consistent with the ride-through performance requirement directives
of Order No. 901, as generator owners of NERC-registered IBRs would
need to comply with the performance requirements unless exempted under
that Standard. The Commission deferred its determination of whether
NERC met the Order No. 901 directives to develop new or modified
Reliability Standards to mitigate the reliability impacts to the Bulk-
Power System of exemptions from Reliability Standard PRC-029-1, until
after NERC files its final tranche of IBR Reliability Standards with
the Commission, due by November 4, 2026.\69\
---------------------------------------------------------------------------

\68\ NOPR, 189 FERC ] 61,212 at P 27.
\69\ Id. P 33.
---------------------------------------------------------------------------

40. While the Commission sought comment on all aspects of the
proposed approval, the Commission expressed a particular interest in
comments (as well as supporting materials where applicable) on: (1) the
IBR performance requirement in Requirement R1; (2) the absolute rate of
change of frequency in Requirement R3; \70\ and (3) the adequacy of
NERC's proposed exemption provision in Requirement R4.
---------------------------------------------------------------------------

\70\ No commenters provided a response to the proposed approval
of the absolute rate of change of frequency in Requirement R3.
---------------------------------------------------------------------------

41. In response to the NOPR, the Commission received comments about
the proposed Standard on the following topics, discussed below: (1)
approving the proposed Reliability Standard; (2) requests for a new
exception under Requirement R1 for certain HVDC-connected IBRs and a
new exemption under Requirement R4 for long-lead time projects; and (3)
requests for clarity regarding the documentation necessary to secure
exemptions.
1. Approving Proposed Reliability Standard PRC-029-1
a. General Comments
42. Many commenters generally support the Commission's proposal to
approve proposed Reliability Standard PRC-029-1,\71\ although one
commenter opposes approval and asks that the Commission remand the
standard.\72\
---------------------------------------------------------------------------

\71\ Aligned ISOs/RTOs Comments at 3; Elevate Comments at 12; LA
PSC Comments at 1; NERC Initial Comments at 2-4; NYISO Comments at
1; NYSRC Comments at 8; Tesla Comments at 1.
\72\ [Oslash]rsted Comments at 2-3.
---------------------------------------------------------------------------

43. Among commenters supporting approval of Reliability Standard
PRC-029-1, aligned ISOs/RTOs appreciate that the terms ``must ride-
through zones'' and ``operation regions'' in Requirement R1 are drafted
in a manner that ensures consistency with IEEE 2800-2022 and reduces
confusion.\73\ NERC explains that proposed Reliability Standard PRC-
029-1 advances the reliability of the Bulk-Power System by establishing
voltage and frequency ride-through criteria for IBRs to prevent
unnecessary tripping and momentary cessation and ensuring that post-
disturbance ramp rates are unrestricted and return to pre-disturbance
power output levels.\74\
---------------------------------------------------------------------------

\73\ Aligned ISOs/RTOs Comments at 6.
\74\ NERC Initial Comments at 3.
---------------------------------------------------------------------------

44. [Oslash]rsted asserts that proposed Reliability Standard PRC-
029-1 is not just and reasonable or in the public interest because its
requirements could cause project delays or cancellations, contributing
to resource adequacy risks.\75\ [Oslash]rsted proposes that the
Commission remand proposed Reliability Standard PRC-029-1 because the
proposed Standard does not satisfy several factors that the Commission
must consider in determining whether a Reliability Standard is just,
reasonable, not unduly discriminatory or preferential, and in the
public interest under Order No. 672.\76\ [Oslash]rsted and LA PSC
assert that the proposed Standard impermissibly violates an Order No.
672 factor--albeit for opposing reasons. Whereas [Oslash]rsted asserts
that developing projects may be abandoned, decreasing generation when
reserve margins are already tight and creating new system reliability
and resource adequacy risks, violating the Order No. 672 factor that a
Reliability Standard cannot have an undue negative effect on
competition,\77\ LA PSC avers that the Standard favors legacy IBR
owners over ``other players in the energy market,'' which is a
``compromise that threatens the reliability of the Bulk-Power System.''
\78\
---------------------------------------------------------------------------

\75\ [Oslash]rsted Comments at 2-3.
\76\ Id. at 22-25.
\77\ Id. at 23 (citing Order No. 672, 114 FERC ] 61,104 at P
332).
\78\ While LA PSC maintains the Standard ``compromises''
reliability, it stops short of opposing the Standard; instead, it
only ``questions the exemption's potential to undermine
reliability'' and ``urges the expeditious approval and enforcement
of Reliability Standards governing IBRs.'' LA PSC Comments at 7.
---------------------------------------------------------------------------

45. Certain commenters express concerns about individual provisions
in proposed Reliability Standard PRC-029-1, discussed in more detail
below.\79\ For example, Elevate and Tesla note the lack of a
requirement for grid strength and grid-forming capabilities in the
proposed Standard, and call for future revisions to consider these
issues.\80\
---------------------------------------------------------------------------

\79\ See e.g., APS, Clean Energy Associations, DNV, EEI,
Elevate, Invenergy, LA PSC, LIPA, NYISO, NYSERDA, Tesla, and WIRAB.
\80\ Elevate Comments at 7-8; Tesla Comments at 1.
---------------------------------------------------------------------------

46. Other commenters raise concerns generally with the Standards
drafting process.\81\ For example, WIRAB recommends reviewing the
standards development process to more efficiently incorporate industry
feedback.\82\ Some commenters also assert that concerns about the
exemption \83\ process in proposed Requirement R4 were unaddressed in
the standard development process. [Oslash]rsted and Dominion claim the
exemption process in proposed Requirement R4 ignores extensive comments
during the standard development process that raised the concern that
the exemption process does not account for projects that are in active
development with contracted equipment not technically capable of
satisfying the ride-through requirements of Requirements R1 through
R3.\84\
---------------------------------------------------------------------------

\81\ [Oslash]rsted Comments at 23; WIRAB Comments at 11-12.
\82\ WIRAB Comments at 11-12.
\83\ We note that commenters often use the word ``exception''
interchangeably with the word ``exemption,'' although ``exceptions''
are restricted to Requirement R1 when IBRs cannot ride-through
disturbances in certain circumstances, and ``exemptions,'' under
Requirement R4, are for legacy IBRs that cannot meet the ride-
through requirements of Requirements R1 through R3 due to hardware
limitations. Indeed, in Order No. 706, the Commission noted that an
``exemption'' is normally understood as a release from a
responsibility, while an exception is ``an alternative obligation.''
Mandatory Reliability Standards for Critical Infrastructure
Protection, Order No. 706, 73 FR 7368 (Feb. 7, 2008), 122 FERC ]
61,040, at P 184, order on reh'g & clarification, Order No. 706-A,
123 FERC ] 61,174 (2008). In summarizing comments, this final rule
uses ``exception'' and ``exemption'' per commenters' use verbatim.
\84\ [Oslash]rsted Comments at 12-14; Dominion Comments at 4.
---------------------------------------------------------------------------

47. In its reply comments, NERC explains that it provided for a
fair and open stakeholder process by following its rules for providing
notice and opportunity for public comment, due process, openness, and a
balance of interests in developing the Standard through multiple ballot
periods. Further, NERC avers it followed its Rule 321 procedure for the
NERC Board of Trustees to act when a ballot pool has failed to approve
a proposed Reliability Standard in response to a Commission directive;
on the fourth ballot the Standard was approved.\85\
---------------------------------------------------------------------------

\85\ NERC Reply Comments at 3-6.
---------------------------------------------------------------------------

48. NERC disputes the assertion that proposed Reliability Standard
PRC-029-1 will result in undue discrimination against IBRs relative to
synchronous generators under proposed Reliability Standard PRC-024-4,
disagreeing with commenter's assertions

[[Page 35605]]

that synchronous generators and IBRs are similarly situated. NERC
explains that in Order No. 901, the Commission directed NERC to develop
proposed Reliability Standards that account for the technical
differences between IBRs and synchronous generators because the
currently effective Reliability Standards ``may not account for the
material technological differences'' in responding to disturbances.
NERC states that the Commission recognized that synchronous generators
and IBRs do not require the same ride-through performance requirements
because the cause of the ride-through issues impacting reliability for
IBRs is different than that for synchronous generators. NERC states
that in response, it developed proposed Reliability Standard PRC-024-4
as a protection-based standard applicable to synchronous generators,
and proposed Reliability Standard PRC-029-1 as a performance-based
standard applicable to IBRs.\86\
---------------------------------------------------------------------------

\86\ Id. at 15-17.
---------------------------------------------------------------------------

49. Additionally, NERC explains that the proposed Standard was
narrowly developed to avoid undue negative effects on competition
beyond what is necessary for reliability and to reflect consideration
of the ``different natures of synchronous generators and IBRs.'' \87\
---------------------------------------------------------------------------

\87\ Id. at 15-16.
---------------------------------------------------------------------------

b. IEEE 2800-2022 Comments
50. [Oslash]rsted asserts that the proposed Reliability Standard
did not consider ``other appropriate factors'' under Order No. 672
because NERC's petition did not discuss why exceptions due to hardware
limitations in IEEE 2800-2022, such as are applicable to HVDC
technology, could not be incorporated into the proposed Standard.\88\
[Oslash]rsted also claims that ``a number of grid operators have
adopted components of IEEE 2800[-2022], creating a conflict with the
proposed Standard''.
---------------------------------------------------------------------------

\88\ Id. at 24 (referring to an Order No. 672 factor that a
Reliability Standard consider ``other appropriate factors'').
---------------------------------------------------------------------------

51. In its petition and reply comments, NERC explains that it
adopted IEEE 2800-2022 terminology for ``must ride-through zones'' and
``operation regions;'' but that it considered and rejected ride-through
criteria more stringent than set forth in IEEE 2800-2022 due to
industry comments raised during the September 2024 Technical
Conference.\89\
---------------------------------------------------------------------------

\89\ NERC Petition at 26-27.
---------------------------------------------------------------------------

52. Elevate, NYSRC, UCS, and WIRAB filed comments noting
inconsistencies between proposed Reliability Standard PRC-029-1 and
IEEE 2800-2022 and pointing to IEEE 2800-2022 as the preferred option
for ride-through standards to address the Commission's concerns and
directives in Order No. 901.\90\ WIRAB is concerned that there may be
conflicts between entities already adopting IEEE 2800-2022 and then
needing to follow Reliability Standards with different requirements--
recommending that this be resolved by indicating in the Standard that
if an entity fully adopts IEEE 2800-2022, it would be compliant with
proposed Reliability Standard PRC-029-1.\91\
---------------------------------------------------------------------------

\90\ See generally Elevate Comments at 3-7; NYSRC Comments at 4-
7; UCS Comments at 4; WIRAB Comments at 7-10.
\91\ WIRAB Comments at 10.
---------------------------------------------------------------------------

53. Elevate avers that proposed Reliability Standard PRC-029-1
lacks many of the technical ``details, clarifications, and equipment
considerations'' that are contained in IEEE 2800-2022.\92\ Elevate and
WIRAB point to several examples where they assert the language of IEEE
2800-2022 is more detailed, such as the explicit reference in IEEE
2800-2022 to 500 kilovolt (kV) systems that have equipment rated up to
550 kV,\93\ and the lack of certain IEEE-2800-2022 terminology, such as
``active or reactive power priority modes.'' \94\ Further, Elevate
requests that the exceptions in IEEE 2800-2022 for self-protection of
IBR equipment and for ride-through requirements during severe and
sustained voltage unbalance conditions be added to the proposed
Standard.\95\ WIRAB requests that the lack of an exception for self-
protection when negative-sequence voltage is greater than a specified
duration and threshold in the proposed Standard be addressed.\96\
---------------------------------------------------------------------------

\92\ Elevate Comments at 3.
\93\ Id. at 3-7; WIRAB Comments at 9.
\94\ Elevate Comments at 6.
\95\ Id. at 4.
\96\ WIRAB Comments at 9.
---------------------------------------------------------------------------

54. NERC replies that the Commission gave it discretion to consider
``whether and how to reference IEEE standards'' in Order No. 901.\97\
NERC explains that there were several reasons that it found that full
adoption of IEEE 2800-2022 was not appropriate, including that proposed
Reliability Standard PRC-029-1 was developed to address the
Commission's directives in Order No. 901, is more stringent than IEEE
2800-2022, and does not conflict with IEEE 2800-2022.\98\
---------------------------------------------------------------------------

\97\ NERC Reply Comments at 13 (citing Order No. 901, 185 FERC ]
61,042 at P 195).
\98\ Id. at 14-15.
---------------------------------------------------------------------------

c. Clarification of Terms and Provisions Comments
55. NYSRC requests that the Commission remand proposed Reliability
Standard PRC-029-1 to NERC for revisions to address a series of
``ambiguities, impractical requirements, or contradictions with the
apparent intent'' of the Standard that makes it difficult to meet the
requirements as written.\99\ For example, NYSRC requests that the
Commission direct modifications to the Standard to provide that
compliance enforcement authorities must apply their own judgment of
reasonableness in interpreting the Standard because there is no
exemption from meeting frequency ride-through requirements when voltage
ride-through is not required. NYSRC avers that, if taken literally, the
omission requires IBRs to ride-through any voltage magnitude, including
a voltage level of zero, for an unlimited duration.\100\
---------------------------------------------------------------------------

\99\ NYSRC Comments at 3-4.
\100\ Id. at 4.
---------------------------------------------------------------------------

56. [Oslash]rsted, Elevate, and NYSRC seek clarification on several
terms and provisions in proposed Reliability Standard PRC-029-1.
[Oslash]rsted claims that the undefined term in-service has neither a
clear nor objective criteria to ensure it will be enforced in a
consistent and non-preferential manner.\101\ Elevate requests that the
terms high voltage thresholds and time durations in proposed
Requirement R2.4 and the term restore in proposed Requirement R2.5 be
defined.\102\ NYSRC requests that the reactive power limit in proposed
Requirement R2.1.2 be defined and that the limit should be voltage
dependent.\103\
---------------------------------------------------------------------------

\101\ [Oslash]rsted Comments at 9 n.17 (describing the in-
service date as ``arbitrary''), 23 (referring to an Order No. 672
factor that there be a clear and objective measurement of compliance
for enforcement purposes); see also Invenergy Initial Comments at
19-20.
\102\ Elevate Comments at 9.
\103\ NYSRC Comments at 7.
---------------------------------------------------------------------------

57. Elevate contends that the language of proposed Requirements
R2.1.1 and R2.1.3 conflict because Requirement R2.1.3 specifies
performance only when the voltage is less than 0.95 per unit and is
within the continuous operating range whereas Requirement R2.1.1 speaks
to general performance in the continuous operating range and does not
specify voltage criteria.\104\ Elevate contends

[[Page 35606]]

that, as a result, satisfying proposed Requirement R2.1.1 can
potentially result in a violation of proposed Requirement R2.1.3 and
vice versa, and requests that the conflict be addressed in an updated
version of the proposed Standard.\105\ NYSRC also requests that the
specification in Attachment 1, point 5 that the applicable voltage for
the Tables is at the ``high-side of the main power transformer'' be
modified to apply, consistent with the intent of the proposed Standard,
at the transmission side of the transformer.\106\
---------------------------------------------------------------------------

\104\ Requirement R2.1.1 requires that when the voltage at the
high-side of the main power transformer remains within the
continuous operation region in Attachment 1, each IBR shall continue
to deliver the pre-disturbance level of Real Power or available Real
Power, whichever is less. While Requirement R2.1.3 requires each
IBR, when the voltage at the high-side of the main power transformer
remains within the continuous operation region in Attachment 1, to
prioritize Real Power or Reactive Power when the voltage is less
than 0.95 per unit, the voltage is within the continuous operating
region, and the IBR cannot deliver both Real Power and Reactive
Power due to a current limit or Reactive Power limit. NERC Petition
at 29.
\105\ Elevate Comments at 8-9.
\106\ NYSRC Comments at 7-8.
---------------------------------------------------------------------------

58. LA PSC is concerned that IBRs that satisfy the design element
to ride-through grid disturbances may not have their equipment set to
meet the ride-through requirements and requests that generator owners
be required to provide documentation that the IBR is programmed or set
to meet ride-through requirements.\107\
---------------------------------------------------------------------------

\107\ LA PSC Comments at 3-4.
---------------------------------------------------------------------------

d. Commission Determination
59. Pursuant to section 215(d)(2) of the FPA, we adopt the NOPR
proposal to approve proposed Reliability Standard PRC-029-1 as just,
reasonable, not unduly discriminatory or preferential, and in the
public interest. Proposed Reliability Standard PRC-029-1 fulfills the
IBR performance requirement directives of Order No. 901. We find that
Requirements R1 through R3 will strengthen the reliability of the Bulk-
Power System by addressing abnormal tripping, interruption of current
injection, and reduced power output. Further, we conclude that NERC
developed a reasonable process in Requirement R4 for generator owners
to seek an exemption to Requirements R1 through R3 for hardware
limitations.
60. We disagree with commenters' arguments that the proposed
Reliability Standard does not satisfy multiple Order No. 672 factors or
reflects issues with NERC's standards development process itself. In
particular, we are not persuaded by [Oslash]rsted's claim that the
exemption process in proposed Requirement R4 fails to provide clear and
objective criteria for compliance because the phrase ``in-service
date'' is undefined.\108\ In-service date is a commonly used term and,
while not controlling in Reliability Standards, is used in Commission
orders in different contexts.\109\ Further, NERC adhered to its
Commission-approved \110\ standards development process in developing
the proposed Standard.\111\
---------------------------------------------------------------------------

\108\ See, e.g., [Oslash]rsted Comments at 23.
\109\ See, e.g., Improvements to Generator Interconnection
Procs. & Agreements, Order No. 2023, 88 FR 61014 (Sept. 6, 2023),
184 FERC ] 61,054, at Appendix C, Sec. 7 (2023) (defining in-
service date as ``the date upon which the Interconnection Customer
reasonably expects it will be ready to begin use of the Transmission
Provider's Interconnection Facilities to obtain back feed power'').
See also Mandatory Reliability Standards for the Bulk-Power Sys.,
Order No. 693, 72 FR 16416 (Apr. 4, 2007), 118 FERC ] 61,218, at PP
275-276, order on reh'g, Order No. 693-A, 120 FERC ] 61,053 (2007)
(discussing appropriate level of detail and precision in Reliability
Standards with regard to compliance and enforceability).
\110\ Certification Order, 116 FERC ] 61,062 at P 250 (finding
that NERC's proposed rules of procedure ``provide for reasonable
notice and opportunity for public comment, due process, openness,
and a balance of interests in developing Reliability Standards'').
\111\ See NERC Petition, Ex. G (Summary of Development and
Complete Record of Development); NERC Reply Comments at 3-6.
---------------------------------------------------------------------------

61. Regarding the divergence of proposed Reliability Standard PRC-
029-1 from IEEE 2800-2022, in Order No. 901 the Commission responded to
commenters' suggestion of the need to align with or reference directly
IEEE 2800-2022 ``in accordance with good utility practice as examples
of technical minimum requirements.'' \112\ As the Commission stated,
NERC is best positioned through its standard development process to
determine necessary technical requirements to ensure frequency and
voltage ride-through.\113\ Further, the Commission ``decline[d] to
direct NERC to specifically reference IEEE standards in its new or
modified Reliability Standards,'' noting that NERC has the discretion
to consider whether and how to reference IEEE standards.\114\ As the
comments of Elevate and WIRAB point to provisions where proposed
Reliability Standard PRC-029-1 diverge from IEEE 2800-2022 and ask them
to align without explanation of what has changed from Order No.
901,\115\ and do not provide an explanation of why NERC's proposed
Standard is deficient in ensuring the reliable operation of the Bulk-
Power System, we maintain the prior finding from Order No. 901.\116\
Moreover, we find that [Oslash]rsted's argument that there is a
conflict between grid operators that have adopted components of IEEE
2800-2022 and the proposed Standard is vague and fails to cite to a
Commission-approved provision that supports the conclusion that there
is such a conflict.
---------------------------------------------------------------------------

\112\ See e.g. Order No. 901, 185 FERC ] 61,042 at P 184 (citing
Electric Power Research Institute Initial NOPR Comments at 5).
\113\ Id. P 192.
\114\ Id. P 195.
\115\ Absent new or changed circumstances, ``it is contrary to
sound administrative practice and a waste of resources to relitigate
issues in succeeding cases once those issues have been finally
determined.'' Alamito Co., 41 FERC ] 61,312, at 61,829 (1987), order
on reh'g, 43 FERC ] 61,274 (1988) (citing Cent. Kan. Power Co., 5
FERC ] 61,291, at 61,621 (1978)); see also Pac. Gas & Elec. Co., 121
FERC ] 61,065, at PP 42-43 (2007) (explaining that the preclusive
effect of collateral estoppel ends when a party presents new
evidence, and finding in that case that there was no new evidence or
significantly changed circumstances that would warrant re-litigation
of the decided issue).
\116\ Order No. 901, 185 FERC ] 61,042 at P 195 (finding that
``. . . NERC has the discretion to consider during its standards
development process whether and how to reference IEEE standards in
the new or modified Reliability Standards'').
---------------------------------------------------------------------------

62. We decline to adopt Tesla's recommendation that the Commission
direct NERC to add a requirement that new IBRs ``have grid-forming
capabilities where technically and economically feasible.'' \117\ We
clarify that NERC continues to have discretion to consider new or
modified standards regarding grid strengthening and grid-forming
inverters, and we encourage NERC to remain proactive in using its
standards development authority to ensure that IBR capabilities are
leveraged appropriately.
---------------------------------------------------------------------------

\117\ Tesla Comments at 1.
---------------------------------------------------------------------------

63. We decline to direct NERC to revise the Standard to make
additional clarifications or define terms as requested by some
commenters. We find the Standard sufficiently clear and unambiguous
regarding what is required of generator owners. However, we encourage
NERC to consider the potential need for incremental changes to the
Standard to address concerns, such as NYSRC's concern the Standard's
reference to the ``high side'' could lead to noncompliance with the
language of the Standard, or the possibility that IBRs may be
noncompliant with the Standard if they fail to ride-through any voltage
magnitude. We encourage NERC and its Regional Entities to use their
available tools--appropriate enforcement discretion, targeted oversight
activities, compliance and enforcement guidance, and the compliance
feedback loop to standards development--to ensure consistency,
reasonably address noncompliance that does not impact reliability, and
to identify, assess, and implement any need for additional improvements
to the Standard through its approved processes.
2. Exceptions and Exemptions to the Requirements of the Reliability
Standard
64. In the NOPR, the Commission, in proposing to approve
Reliability Standard PRC-029-1, also proposed to

[[Page 35607]]

find ``that NERC reasonably determined that an exemption process for
generator owners of legacy IBRs for voltage and frequency performance
requirements'' in Requirement R4 of the Standard is appropriate.\118\
The Commission sought comments on ``the adequacy of NERC's proposed
exemption provision in Requirement R4 as it pertains to both projects
in[-]service and those under contract, but not yet in-service as of the
effective date of Reliability Standard PRC-029-1.'' \119\ Further, the
Commission requested that comments discussing whether the exemption
provision is too broad or too narrow should address the risks and
benefits for enlarging or narrowing the scope of the exemption
provision with ``detailed, quantified, and fact-based support.'' \120\
---------------------------------------------------------------------------

\118\ NOPR, 189 FERC ] 61,212 at P 33.
\119\ Id. P 34.
\120\ Id.
---------------------------------------------------------------------------

a. General Comments
65. With one exception, commenters generally support the exemption
request process in the proposed Standard. Clean Energy Associations
support the availability of an exemption from frequency ride-through
requirements in the proposed Standard because a large percentage of IBR
fleets could not comply with the frequency ride-through requirements,
imperiling resource adequacy.\121\ EEI also supports maintaining the
exemption for legacy IBRs in proposed Reliability Standard PRC-029-
1.\122\ Deriva, in expressing support for the exemption process in
proposed Requirement R4, explains that legacy IBRs will not be able to
comply with the proposed Standard; newer compliant equipment cannot fit
within existing legacy IBRs; and applicable zoning and regulations will
not accommodate compliant equipment. Consequently, Derivia requests
that the Commission, in approving the proposed Standard, ``incorporate
and emphasize'' NERC's statement that generator owners' legacy IBRs
unable to meet full compliance with PRC-029-1 without a wholesale
retrofit or redesign would not be obligated to undertake the wholesale
retrofit or redesign.\123\
---------------------------------------------------------------------------

\121\ Clean Energy Associations Initial Comments at 25-33.
\122\ EEI Reply Comments at 3.
\123\ Deriva Comments at 2-3, 5.
---------------------------------------------------------------------------

66. Aligned ISOs/RTOs, while supporting proposed Reliability
Standard PRC-029-1 as ``a broadly-applicable standard that is applied
in a manner that limits exemptions to limited and rare circumstances,''
\124\ add that they ``would not support . . . broader exemptions or
exemptions driven by cost of non-hardware limitations (e.g., control
systems and software).'' \125\ Aligned ISOs/RTOs note that the
exemption process in proposed Requirement R4 does not contemplate that
exemption requests will also be submitted to system operators, such as
ISOs and RTOs. Aligned ISOs/RTOs support the standard as written based
on the common understanding that nothing in the proposed Standard
prohibits ISOs and RTOs from seeking information or submittals
regarding exemption requests pursuant to their existing tariff
authority.\126\
---------------------------------------------------------------------------

\124\ Aligned ISOs/RTOs Comments at 5.
\125\ Id. at 7 n.22.
\126\ Id. at 7.
---------------------------------------------------------------------------

67. LA PSC argues that the exemption process as written in proposed
Requirement R4 favors legacy IBR owners at the expense of Bulk-Power
System reliability and that there is no way to determine the impact of
the exemptions until 2028 or 2029 when the Standard is fully
implemented.\127\ Further, LA PSC asserts that NERC's mitigation of
these exemptions through future Reliability Standards does not address
the need for transmission owners and transmission operators to plan and
respond for an ``unknown number of IBRs disconnecting at any time in
the future, in an unanticipated manner.'' \128\ Thus, LA PSC recommends
shortening the period for entities to request exemptions and
considering additional mitigation measures to protect the Bulk-Power
System.\129\
---------------------------------------------------------------------------

\127\ LA PSC Comments at 6.
\128\ Id. at 7.
\129\ Id. at 6.
---------------------------------------------------------------------------

68. Multiple commenters note their understanding that the exemption
``only applies to the limited portion of the frequency or voltage ride-
through zone for which the pre-existing hardware was not designed to
meet.'' \130\ Clean Energy Associations note that an IBR that receives
an exemption is still required to make settings changes and software
updates that would permit it to satisfy the rest of the ride-through
curves in the proposed Standard.\131\ Clean Energy Associations and
Invenergy explain that exempted IBRs would be able to ride-through the
types of disturbances that led the Commission to issue Order No.
901.\132\ WIRAB recommends IBRs with exemptions still ride through to
their full capability.\133\
---------------------------------------------------------------------------

\130\ Clean Energy Associations Reply Comments at 2; Invenergy
Reply Comments at 2. See also EEI Reply Comments at 2 (stating that
the exemption process is ``already designed to be narrow'' and
requires generator owners to be specific to the portion of the ride-
through criteria that the IBR cannot meet).
\131\ Clean Energy Associations Reply Comments at 2.
\132\ Clean Energy Associations Initial Comments at 7; Invenergy
Initial Comments at 9.
\133\ WIRAB Comments at 6.
---------------------------------------------------------------------------

69. In its reply comments, NERC explains that the exemption for
legacy IBRs in proposed Requirement R4, including the 12-month
timeframe to request an exemption, is consistent with the directive in
Order No. 901 to determine whether to provide a limited and documented
exemption to existing IBRs and equipment. NERC also notes that an IBR
that receives an exemption must perform per the capability of the plant
while accounting for the limitation to mitigate the reliability impact
of the exemption. NERC claims that it found that exemptions were
necessary because otherwise the proposed Standard would require
entities to take units offline to retrofit or risk noncompliance.\134\
---------------------------------------------------------------------------

\134\ NERC Reply Comments at 6-10.
---------------------------------------------------------------------------

b. HVDC-Connected IBRs With Choppers Comments
70. Several commenters, including Invenergy, [Oslash]rsted and
Clean Energy Associations seek an additional exemption for HVDC-
connected IBRs with choppers.\135\ Commenters explain that voltage
source converter-HVDC transmission technology is commonly used in
modern offshore wind projects and typically relies on equipment known
as choppers to protect the converter during fault conditions by
dissipating excess power during grid faults that cause low voltage at
the point of interconnection.\136\ Invenergy notes

[[Page 35608]]

that a chopper circuit has a thermal limit that is designed to trip the
HVDC system if the duration of the energy dissipation exceeds two
seconds.\137\ Commenters explain that during system faults, voltage
dips and the power cannot be transferred and therefore must be
dissipated.\138\ [Oslash]rsted further indicates that the HVDC chopper
cool down period is a function of the technology and could take 30
minutes to five hours.\139\ Thus, commenters aver that HVDC-connected
IBRs with choppers lack the capability to meet the cumulative 10 second
measurement ride-through window set forth in Attachment 1 of proposed
Reliability Standard PRC-029-1 because a chopper's thermal limit
requires tripping the HVDC system to prevent overheating and thermal
damage beyond two seconds.\140\
---------------------------------------------------------------------------

\135\ An IBR that is connected to the Bulk-Power System using a
voltage source converter-HVDC system with a chopper circuit is
referred to in this final rule as a HVDC-connected IBR with
choppers. A voltage source converter-HVDC system consists of a high-
voltage DC line with two converters (rectifier and inverter) at both
ends of the DC line. The voltage source converter-HVDC system is
capable of mimicking synchronous generation by producing an almost
perfect sinusoidal voltage on the AC side of the converter. European
Network of Transmission Sys. Operators for Elec., HVDC Links in
System Operations 13 (2019), <a href="https://eepublicdownloads.entsoe.eu/clean-documents/SOC%20documents/20191203_HVDC%20links%20in%20system%20operations.pdf">https://eepublicdownloads.entsoe.eu/clean-documents/SOC%20documents/20191203_HVDC%20links%20in%20system%20operations.pdf</a>. A chopper
circuit is a component of the voltage source converter-HVDC system
and is typically used to dissipate excess power during faults. It
can be placed in the DC system of a voltage source converter-HVDC-
connected offshore wind project to absorb excess energy and maintain
DC voltage at an acceptable level during a fault to allow voltage
source converter-HVDC-connected IBRs to ride-through voltage
disturbances.
\136\ HVDC-connected IBRs with choppers should be able to ride-
through individual voltage deviations. However, the voltage ride-
through capability of HVDC-connected IBRs with choppers are limited
by the energy absorption capability and thermal design of the DC
chopper. Once activated to absorb energy, the DC chopper needs time
to cool down before it can be activated again to absorb energy.
Therefore, the HVDC-connected IBR with choppers' ability to ride-
through consecutive voltage deviations is not clear, as it is a
function of the energy absorption capability and thermal design of
the DC chopper.
\137\ Invenergy Initial Comments at 5-6.
\138\ Id. at 5-6; [Oslash]rsted Comments at 18-19, attach. B
(Affidavit of Ewgenij Starschich), at 5 n.1, attach. B-1 (Email from
Eugen Starschich to Jamie Calderon et al.), at 2.
\139\ [Oslash]rsted Comments, Att. B-1, at 2.
\140\ Invenergy Initial Comments at 33; NYSERDA Comments at 4;
see [Oslash]rsted Comments at 19.
---------------------------------------------------------------------------

71. Commenters also explain that designing HVDC-connected IBRs with
choppers that can comply with the ride-through requirements of
Attachment 1 cannot be done in a cost-effective and timely manner.
Clean Energy Associations explain that there is no cost-effective
option yet available to meet the full ride-through requirements, and
manufacturers may not be able to meet compliance deadlines for the
proposed Standard.\141\ [Oslash]rsted explains that original equipment
manufacturers will need at least seven years to produce HVDC-connected
IBRs with choppers that can comply with the ride-through requirement
``given global demand and supply chain issues (the current wait time
for [voltage source converter]-HVDC is approximately seven years).''
\142\
---------------------------------------------------------------------------

\141\ See, e.g., Clean Energy Associations Initial Comments at
23, 25. See also DNV Comments at 2 (explaining that designing
choppers compliant with the ride-through requirements of Attachment
1 will require larger chopper designs, unreasonably increasing the
cost of HVDC-connected IBRs with choppers); Invenergy Initial
Comments at 35 (noting the ``unavailability of a cost-effective
design option for [HVDC-connected IBRs with choppers] to ride
through more than 2 seconds of voltage disturbances (while absorbing
rate power)'').
\142\ [Oslash]rsted Comments at 21.
---------------------------------------------------------------------------

72. Commenters assert that the 10 second cumulative duration
requirement in Attachment 1 could contribute to resource adequacy
issues in certain parts of the country as new HVDC-connected IBRs with
choppers would not be able to come online. Similarly, LIPA contends
that the ``infeasible requirements'' of proposed Reliability Standard
PRC-029-1 ``will delay or impede resources critical to maintaining
adequate generation capacity to meet future system needs.'' \143\
Likewise, Clean Energy Associations indicate 3.7 GW of HVDC-connected
offshore wind projects with choppers could be impacted by Requirement
R1.\144\
---------------------------------------------------------------------------

\143\ LIPA Comments at 5.
\144\ See Clean Energy Associations Initial Comments at 14-15
(counting 1.6 GW, 900 MW, and 1,200 MW of members' long-lead time
offshore wind projects as HVDC-connected IBRs with choppers because
offshore wind projects in the United States exclusively use
choppers).
---------------------------------------------------------------------------

73. [Oslash]rsted claims that the Standard was not developed in an
open and fair manner, as required by an Order No. 672 factor. First, it
avers this is because the process did not align the Standard with
``global standards and practices'' \145\ (i.e., the Standard, unlike
the global IEEE 2800-2022 standard, does not recognize HVDC-connected
IBRs with choppers' thermal limitation).\146\ Second, [Oslash]rsted
also asserts that stakeholder engagement was limited, ``perhaps in part
due to the compressed standards development time.'' \147\
---------------------------------------------------------------------------

\145\ [Oslash]rsted Comments at 23 (referring to an Order No.
672 factor that a Reliability Standard be developed in an open and
fair manner).
\146\ See id., Att. B, at 10 (stating that proposed Reliability
Standard PRC-029-1 is misaligned with ``global needs and standards''
and then mentioning the ``energy capability limitation'' recognized
in IEEE 2800-2022).
\147\ Id. at 23.
---------------------------------------------------------------------------

74. Commenters advance a range of proposals in response to the
concerns they identify with HVDC-connected IBRs with choppers complying
with proposed Attachment 1. Clean Energy Associations request that the
Commission direct NERC to revise proposed Reliability Standard PRC-029-
1 to include a provision that recognizes the thermal limit of HVDC-
connected IBRs with choppers as in IEEE 2800-2022.\148\ Invenergy and
LIPA propose that the proposed Reliability Standard PRC-029-1 be
modified to provide HVDC-connected IBRs with choppers an exception to
the ride-through requirements of Requirement R1.\149\ Clean Energy
Associations also suggest either amending the PRC-029-1 implementation
plan or issuing a compliance guidance document to clarify the HVDC
issues.\150\
---------------------------------------------------------------------------

\148\ Clean Energy Associations Initial Comments at 24. See also
DNV Comments at 2 (``PRC-029-1 and IEEE 2800-2022 should be aligned
regarding the technical design requirements of choppers.''); Elevate
Comments at 3-4; NYSERDA Comments at 5; [Oslash]rsted Comments at 2,
25.
\149\ Invenergy Initial Comments at 35; LIPA Comments at 5.
\150\ Clean Energy Associations Initial Comments at 25.
---------------------------------------------------------------------------

75. In its reply comments, NERC explains that the proposed Standard
was drafted consistent with the limited discretion provided to NERC in
Order No. 901 to include exemptions for existing IBRs.\151\ NERC
explains that Order No. 901 directed NERC, in developing IBR
performance ride-through Reliability Standards, to determine whether
any exemptions were appropriate for voltage ride-through requirements
for existing IBRs and equipment and required NERC to mitigate the
reliability impact on the Bulk-Power System of any exemptions deemed
necessary. NERC states after the September 2024 Technical Conference,
its staff and the Standards Committee concluded that there was
insufficient data available to evaluate potential impacts of allowing
an unknown amount of HVDC-connected IBRs with choppers to seek an
exemption. Thus, to address the directive in Order No. 901 to mitigate
the reliability impact of exemptions, NERC crafted the exemptions to be
technology neutral to ensure fairness across all IBR technologies and
limited the exemption to existing IBRs and equipment.\152\
---------------------------------------------------------------------------

\151\ NERC Reply Comments at 9, 11.
\152\ Id. at 12.
---------------------------------------------------------------------------

76. NERC believes an exemption for HVDC-connected IBRs with
choppers exceeds the discretion provided to NERC in Order No. 901.
However, NERC requests that should the Commission determine that HVDC-
connected IBRs with choppers warrant an exemption, that it ``be as
specific as possible regarding the technology included and the
timeframe that should be considered for any such exemption.'' \153\
---------------------------------------------------------------------------

\153\ Id.
---------------------------------------------------------------------------

77. In response to NERC's reply comments, Invenergy answers that
unlike the exemption process in Requirement R4 that only applies to
existing legacy IBRs, consistent with the exemption directives in Order
No. 901, the relief it seeks for HVDC-connected IBRs with choppers
would apply to existing and future equipment. Invenergy also avers that
a modification to proposed Reliability Standard PRC-029-1 to avoid
damage to chopper equipment is consistent with Order No. 901's language
``that permit IBR tripping only to protect the IBR equipment.'' \154\
---------------------------------------------------------------------------

\154\ Invenergy Answer at 2-4.
---------------------------------------------------------------------------

c. Long-Lead Time Projects Comments
78. Several commenters express concern that limiting exemptions
under

[[Page 35609]]

requirement R4 to legacy IBRs that are in-service as of the effective
date of Reliability Standard PRC-029-1 fails to account for the long-
lead time between adopting IBR design specifications and placing the
IBR in-service. EEI requests that the exemption process be expanded to
accommodate long-lead time projects.\155\ Clean Energy Associations
note that officials from original equipment manufacturers indicated at
the September 2024 Technical Conference that the product design and
development timeline for IBRs is at least five years.\156\ Thus, Clean
Energy Associations aver that it is ``unworkable'' to base exemptions
on the in-service date for projects already in development but which
will not be in service when the Standard becomes effective.\157\
Invenergy claims that conditioning exemption eligibility on the in-
service date presents ``an unacceptable compliance gamble that is
unjust and unreasonable'' because a long-developed IBR that is not in-
service on the date the proposed Standard becomes effective will not be
able to use the exemption process.\158\
---------------------------------------------------------------------------

\155\ EEI Reply Comments at 3.
\156\ Clean Energy Associations Initial Comments at 11. See also
EEI Initial Comments at 3; [Oslash]rsted Comments at 9 (``long-lead
time technology, procurement contracts are entered into 3-5 years
before construction begins'').
\157\ Clean Energy Associations Initial Comments at 10; see also
LIPA Comments at 5-6 (``It is infeasible for IBR projects that are
already in the advanced stages of development, after the
interconnection agreement is signed and long lead-time equipment has
been ordered, to modify the design and specifications of the IBR
plant and its equipment to comply with PRC-029-1.'').
\158\ Invenergy Initial Comments at 19-20. Invenergy also avers
that it is unjust and unreasonable to condition exemption
eligibility on the in-service date because generator owners cannot
control commercial operations timing due to transmission owner and
network upgrade supply chain delays. Id. at 20-21. See also
[Oslash]rsted Comments at 9 n.17.
---------------------------------------------------------------------------

79. Several commenters raise concerns about the economic and
financial impact of providing an exemption only to legacy IBRs.
[Oslash]rsted explains that for IBR projects that have already made
non-refundable financial commitments, it can make projects uneconomical
and result in delays to change the design, acquire new real estate,
obtain new permits, or procure new equipment, as would be necessitated
by the exemption process in Requirement R4.\159\ Clean Energy
Associations provide an example of a 600 megawatt (MW) wind facility in
Oklahoma that has procured a model of wind turbines that will face a
delay of up to two years and incur an additional $551 million in
replacement and retrofit costs to comply with the Standard as
written.\160\ Dominion asserts that the current exemption process in
proposed Requirement R4 could put ``billions of dollars of investment''
at risk.\161\
---------------------------------------------------------------------------

\159\ [Oslash]rsted Comments at 8. See also Dominion Comments at
5-6 (indicating that replacing non-compliant hardware for one of its
smaller IBRs for nearly $7 million could make the project non-
economical).
\160\ Clean Energy Associations Initial Comments at 13-14. Clean
Energy Associations also provide an example of a 250 MW solar
facility in Ohio that has already procured inverters and could face
a delay of up to two years and incur an additional $19 million in
costs to comply with proposed Reliability Standard PRC-029-1. Id. at
14.
\161\ Dominion Comments at 5. See also Clean Energy Associations
Initial Comments at 28 (explaining that developers that operate the
270 GW IBR fleet, which represents an investment of hundreds of
billions of dollars, have no viable path to compliance with proposed
Reliability Standard PRC-029-1 as written); EEI Initial Comments at
3.
---------------------------------------------------------------------------

80. Commenters also raise the concern that failing to account for
long-lead time projects could contribute to resource adequacy
constraints. Clean Energy Associations claim to have identified 22.1
gigawatts (GW) of resources from members that have executed
interconnection agreements or procured equipment that are not yet in-
service and cannot fully comply with the requirements of the Standard.
Clean Energy Associations assert that this quantity of resources is
large enough that failing to accommodate these resources will ``affect
resource adequacy and reliability by preventing their timely
completion'' and reduce electric reliability on net by delaying the
interconnection of IBR facilities.\162\
---------------------------------------------------------------------------

\162\ Clean Energy Associations Initial Comments at 11. See also
Dominion Comments at 5; Invenergy Initial Comments at 18 (resource
adequacy threatened if 2 GW of capacity with executed
interconnection and procurement agreements is unable to come online
because it is not eligible for an exemption); LIPA Comments at 6
(declining to extend the exception for legacy IBRs to long-lead time
projects may contribute to ``extensive IBR project delays or even
cancellations,'' which may lead to an ``inability for the power
system to meet future resource adequacy requirements''); NYSERDA
Comments at 3.
---------------------------------------------------------------------------

81. [Oslash]rsted and Dominion claim the exemption process in
proposed Requirement R4 ignores extensive comments during the standard
development process that raised the concern that the exemption process
does not account for projects that are in active development with
contracted equipment not technically capable of satisfying the ride-
through requirements of Requirements R1 through R3.\163\
---------------------------------------------------------------------------

\163\ [Oslash]rsted Comments at 12-14; Dominion Comments at 3.
---------------------------------------------------------------------------

82. Clean Energy Associations claim that the ability for resources
with executed contracts to secure an exemption is more consistent with
the ability of any resource--new, existing, or planned--``to obtain
exemptions under PRC-024.'' \164\ Clean Energy Associations aver that
synchronous resources, subject to Reliability Standard PRC-024, and
IBRs are similarly situated with regard to the need for exemptions, so
differential treatment of the resources if the exemption process in
Requirement R4 is left as is, would represent undue
discrimination.\165\
---------------------------------------------------------------------------

\164\ Proposed Reliability Standard PRC-024-4, Requirement R3
allows for an exception to Requirements R1 or R2 for known
regulatory or equipment limitations that prevents the generator or
condenser from meeting the protection setting criteria.
\165\ Clean Energy Associations Initial Comments at 17.
---------------------------------------------------------------------------

83. Commenters offer proposals for how to incorporate long-lead
time projects into the exemption process in proposed Requirement R4.
Most proposals center around providing exemptions to IBR projects that
have executed generator interconnection agreements and executed design,
procurement, and/or construction agreements by the effective date of
Reliability Standard PRC-029-1.\166\
---------------------------------------------------------------------------

\166\ See, e.g., Clean Energy Associations Initial Comments at
13; Elevate Comments at 9; Invenergy Initial Comments at 22; LIPA
Comments at 5-6; NYSERDA Comments at 3; [Oslash]rsted Comments at 2.
---------------------------------------------------------------------------

84. In comparison, Dominion repeatedly describes the 12-month
period to seek an exemption under Requirement R4 as ``arbitrary,''
\167\ while Clean Energy Associations appear to request that generator
owners of legacy IBRs have up to 36 months--instead of 12--to request
an exemption.\168\
---------------------------------------------------------------------------

\167\ For example, Dominion says ``the exemption process should
properly account for projects that are well into the development
cycle but may not be commissioned and in- service prior to the
arbitrary 12-month timeframe currently contained in Requirement
R4.'' Dominion Comments at 4.
\168\ Clean Energy Associations requests the addition of the
following sentence to the Implementation plan: ``Entities shall
comply with the portion of Requirements R1, R2, and R3 relating to
the design of their BES IBRs to meet the requirements by 36 months
after the effective date of the standard.'' Clean Energy
Associations Initial Comments at 17.
---------------------------------------------------------------------------

85. NERC rejects the assertion that, because synchronous generators
and IBRs are allegedly similarly situated, proposed Reliability
Standard PRC-029-1 will result in undue discrimination against IBRs
relative to synchronous generators under proposed Reliability Standard
PRC-024-4. NERC explains that in Order No. 901, the Commission directed
NERC to develop proposed Reliability Standards that account for the
technical differences between IBRs and synchronous generators because
the currently effective Reliability Standards ``may not account for the
material technological differences'' in responding to

[[Page 35610]]

disturbances. NERC offers that synchronous generators and IBRs do not
require the same ride-through performance requirements because the
technological cause of the issues impacting reliability for IBRs is
different than that for synchronous generators. Accordingly, NERC
claims it developed proposed Reliability Standard PRC-024-4 as a
protection-based standard applicable to synchronous generators, while
developing proposed Reliability Standard PRC-029-1 as a performance-
based standard applicable to IBRs.\169\
---------------------------------------------------------------------------

\169\ NERC Reply Comments at 15-17.
---------------------------------------------------------------------------

d. Commission Determination
i. Requests for Additional Exceptions and Exemptions
86. We appreciate commenters' concerns that the equipment
limitations of HVDC-connected IBRs with choppers that may physically
prevent them from fully complying with the ride-through provisions of
Reliability Standard PRC-029-1 and their request for exemptions for
long-lead time projects that have executed interconnection agreements
and executed design, procurement, and/or construction agreements.\170\
However, having found proposed Reliability Standard PRC-029-1 and the
proposed exceptions and exemptions just, reasonable, not unduly
discriminatory or preferential, and in the public interest, we decline
to direct a modification to mandate additional exceptions or exemptions
based on the comments in this proceeding. The record in this proceeding
is not sufficient for us to determine whether additional exceptions or
exemptions are warranted. The standard drafting team did not consider
the possibility of additional exceptions or exemptions as NERC believed
that doing so would exceed the discretion granted NERC in Order No. 901
to limit exemptions to existing IBRs and equipment \171\ and this
highly technical matter was not addressed in the NERC standards
development process. We believe that attempts to address these concerns
would benefit from the opportunity to fully vet, in NERC's standards
development process, the need for and parameters of an exception for
HVDC-connected IBRs with choppers and an exemption for long-lead time
projects that have executed interconnection agreements and executed
design, procurement, and/or construction agreements.\172\ Vetting will
allow NERC to appropriately consider stakeholders' concerns and decide
whether modification of the standard, or a different approach, is
warranted.
---------------------------------------------------------------------------

\170\ Clean Energy Associations Initial Comments at 13; Dominion
Comments at 5; Elevate Comments at 9; Invenergy Initial Comments at
22, LIPA Comments at 5-6; NYSERDA Comments at 3; [Oslash]rsted
Comments at 2.
\171\ See, e.g., NERC Reply Comments at 12 (describing comments
in support of providing relief to HVDC-connected IBRs with choppers
as a request for an exemption, which NERC believes exceeds NERC's
discretion under Order No. 901).
\172\ Order No. 693, 118 FERC ] 61,218 at P 188.
---------------------------------------------------------------------------

87. Accordingly, we direct NERC, through its standard development
process, to determine whether, and if so how, to account for: (1) the
equipment limitations of HVDC-connected IBRs with choppers which may
physically prevent them from fully complying with the ride-through
provisions of Reliability Standard PRC-029-1; \173\ and (2) the long-
lead time between adopting IBR design specifications and placing the
IBR in-service. NERC may develop appropriate solutions for these two
issues 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. In response to NERC's concern that Order No. 901 precludes NERC
from considering additional exceptions and exemptions, we clarify that
while the Commission is concerned about the proliferation of exceptions
and exemptions to the performance requirements set forth in Reliability
Standard PRC-029-1, we state now that NERC has the discretion to
develop exceptions and exemptions as it deems appropriate to address
these narrow technical issues.
---------------------------------------------------------------------------

\173\ We note that standards, such as IEEE 2800-2022, may
include certain exceptions that may inform NERC's process as
relevant to HVDC-connected IBRs with choppers.
---------------------------------------------------------------------------

88. If NERC determines that extension of the exemption to long-lead
time projects is warranted, we suggest that it consider including
unequivocal provisions regarding the necessary showing to qualify for
the exemption, e.g., proof of executed interconnection agreements and
executed design, procurement, and/or construction agreements, and a
clearly stated cut-off date for application to long-lead time
projects.\174\ Further, we believe that the issuance of this final rule
should provide notice that, going forward, entities should design IBR
facilities to meet the ride-through obligations set forth in
Reliability Standard PRC-029-1.
---------------------------------------------------------------------------

\174\ Commenters have suggested varying time frames for project
completion. See, e.g., Clean Energy Associations Initial Comments at
11; EEI Initial Comments at 3; [Oslash]rsted Comments at 9.
---------------------------------------------------------------------------

89. As the Commission explained in the NOPR in this proceeding,
``if too many generators are exempt from the frequency and/or voltage
Ride-through requirements, proposed Reliability Standard PRC-029-1 may
fail to address the reliability gaps associated with IBRs tripping or
entering momentary cessation in aggregate that it is intended to
address.'' \175\ Thus, the NERC standards development process should
balance the competing considerations and discuss the balance struck in
any future filing with the Commission. If NERC chooses to modify the
proposed Standard, NERC should include a sunset provision to ensure
exceptions and exemptions are not indefinite when new technology
allowing ride-through for the entire criteria of the Standard is
available.
---------------------------------------------------------------------------

\175\ NOPR, 189 FERC ] 61,212 at P 35.
---------------------------------------------------------------------------

ii. Other Issues
90. We decline the requests of LA PSC, Clean Energy Associations,
and Dominion to adjust the exemption request process under proposed
Requirement R4 and do not find the 12-month time frame to request an
exemption arbitrary. Consistent with the directive in Order No. 901 to
provide only a limited and documented exemption, the 12-month request
period ensures there is a limited, but reasonable, amount of time in
which a generator owner of a legacy IBR can request an exemption.
91. We adopt the NOPR proposal to defer determination of whether
the new or modified Reliability Standards mitigate the reliability
impacts to the Bulk-Power System of exemptions until after NERC files
Milestone 4 Reliability Standards with the Commission by November 4,
2026.\176\ We disagree with LA PSC that, because transmission owners
and operators are allegedly expected to mitigate the reliability impact
of exemptions without knowledge of the number of IBRs disconnecting and
in what manner until Milestone 4 Reliability Standards become
effective, the proposed Standard impermissibly favors generator owners
of legacy IBRs and is a ``lowest common denominator'' \177\ Reliability
Standard. Instead, we find the exemption process adequately protects
Bulk-Power System reliability until Milestone 4 Reliability Standards
become effective by requiring that transmission operators be provided

[[Page 35611]]

the information needed to mitigate the reliability impact of
exemptions.\178\
---------------------------------------------------------------------------

\176\ The Commission will review any Corrective Action Plans
that are filed along with Milestone 4 Reliability Standards.
\177\ Order No. 672, 114 FERC ] 61,104 at P 329.
\178\ Proposed Requirement R4.2 requires generator owners to
provide a copy of the evidence supporting an exemption to
transmission operators, allowing transmission operators to know the
number of IBRs disconnecting and in what manner. NERC Petition at
37. LA PSC mistakenly indicates transmission owners will be
responsible for mitigating the reliability impact of exemptions. LA
PSC Comments at 7. However, proposed Reliability Standard PRC-029-1
does not require transmission owners to mitigate the reliability
impact of IBRs under Requirement R4. NERC Petition at 36-37.
---------------------------------------------------------------------------

92. We decline to adopt Clean Energy Associations' position that
IBRs and synchronous resources are similarly situated with regard to
demonstrating a need for exemptions. IBRs and synchronous resources are
not similarly situated due to differences in physical limitations and
capabilities and in inherent responses to changing system conditions,
which necessitate different approaches for promoting reliability under
proposed Reliability Standards PRC-024-4 and PRC-029-1.\179\
---------------------------------------------------------------------------

\179\ See Order No. 901, 185 FERC ] 61,042 at P 208 (directing
NERC to develop Reliability Standards that account for the
``technical differences'' between IBRs and synchronous resources).
---------------------------------------------------------------------------

93. We decline to adopt WIRAB's recommendation that the Commission
direct NERC to explore the concept of IBR ride-through maximization
because it is unnecessary. As explained by multiple commenters, the
generator owner of the IBR must ride-through all parts of the voltage
and frequency ride-through curves for which it does not receive an
exemption.\180\
---------------------------------------------------------------------------

\180\ See NERC Petition at 39 (explaining that exemptions must
be specific and limited to the voltage or frequency band(s) and
associated duration(s) that cannot be met).
---------------------------------------------------------------------------

94. We are unpersuaded by [Oslash]rsted's argument that the
Standard was not developed in an open and fair manner. [Oslash]rsted
provides no evidence that the process NERC employed was defective
besides claiming it did not seek to align with ``global standards and
practices.'' \181\ Further, [Oslash]rsted also provides no support for
its claim that stakeholder engagement in the standard development
process was limited; instead, as explained above, NERC adhered to its
Commission-approved standards development process in developing the
proposed Standard, which provides for stakeholder engagement.
---------------------------------------------------------------------------

\181\ [Oslash]rsted Comments at 23. We note that while the
proposed Standard did not fully align with ``global standards and
practices''--i.e., IEEE 2800-2022--in a number of places it did
align its requirements with IEEE 2800-2022 provisions. NERC Petition
at 26-27.
---------------------------------------------------------------------------

3. Documentation of Hardware Limitation
95. Proposed Requirement R4 of PRC-029-1 includes a process for
generator owners of legacy IBRs to provide documentation to the
compliance enforcement authority to secure an exemption. Proposed
Requirement R4.1.3 requires that the documentation shall include:
``[i]dentification of the specific piece(s) of hardware causing the
limitation.'' \182\ Proposed Requirement 4.1.4 requires the
documentation shall include: ``[t]echnical documentation verifying the
limitation is due to hardware that would need to be physically replaced
to meet all Ride-through criteria, and that the limitation cannot be
remedied by software updates or setting changes.'' \183\ Measure M4
provides further details: ``[a]cceptable types of evidence for a
hardware limitation may include, but is not limited to damage curves
provided by the original equipment manufacturer.'' \184\
---------------------------------------------------------------------------

\182\ NERC Petition at 37.
\183\ Id.
\184\ Id., Ex. A-3, at 8.
---------------------------------------------------------------------------

a. Comments
96. EEI, Clean Energy Associations, and Invenergy claim it may not
be possible for older legacy IBRs to identify specific pieces of
hardware for which an exemption is necessary, as required by
Requirement R4, because original equipment manufacturers, among other
things: could be out of business; no longer support the IBR equipment
in a legacy resource; or otherwise, are unable to, provide the
requested documentation.\185\
---------------------------------------------------------------------------

\185\ EEI Initial Comments at 4; Clean Energy Associations
Initial Comments at 19; Invenergy Initial Comments at 24. Original
equipment manufacturers could also lack a service contract that
requires them to provide hardware limitation information to a
generator owner; cannot identify the specific piece of equipment
within the 12-month timeline in Requirement R4 or cannot validate a
combination of factors causing the limitation at all; and be under
no regulatory obligation to provide support for older legacy IBRs.
EEI Initial Comments at 4; Invenergy Initial Comments at 24.
---------------------------------------------------------------------------

97. EEI avers that even where original equipment manufacturers
provide support, IBR generator owners may need the support of third-
party engineering consultants to support a conclusion that there is a
hardware limitation that prevents compliance with proposed Reliability
Standard PRC-029-1.\186\
---------------------------------------------------------------------------

\186\ EEI Initial Comments at 4-5.
---------------------------------------------------------------------------

98. Clean Energy Associations argue that a detailed identification
of ``specific piece(s) of hardware'' would require new testing of
legacy equipment, which could take multiple years to complete and be
excessively costly outside of the laboratory, or may be impossible for
resources that have been operating in the field for many years.\187\
---------------------------------------------------------------------------

\187\ Clean Energy Association Initial Comments at 18.
---------------------------------------------------------------------------

99. Commenters raise a series of concerns about the difficulty
generator owners may experience in providing the documentation
necessary to secure an exemption. Clean Energy Associations state that
a generator owner could be subject to uncapped sanctions of up to $1.6
million per day due to an inability to identify the hardware
limitation, at least with any greater specificity than naming the
inverter or turbine in question.\188\
---------------------------------------------------------------------------

\188\ Id.
---------------------------------------------------------------------------

Additionally, Clean Energy Associations and Invenergy aver that the
phrase ``but is not limited to'' in Measure M4 is sufficiently vague
that it would leave the decision about what types of evidence beyond
``damage curves provided by'' the original equipment manufacturer is
acceptable to the subjective interpretation of the compliance
enforcement authority, which could result in evidence requirements
varying by region or over time.\189\ Clean Energy Associations claim
that six ACP members indicate more than 26.2 GW of currently operating
IBR projects would need limited exemptions to the proposed Standard,
which could be susceptible to retirements--raising resource adequacy
concerns--if its proposed documentation fix is not adopted.\190\ Clean
Energy Associations request: ``The Commission . . . direct NERC to
clarify the evidence required for legacy resources to demonstrate a
hardware limitation to obtain an exemption from PRC-029-1.'' \191\
---------------------------------------------------------------------------

\189\ Id. at 19; Invenergy Initial Comments at 25-26 (``Although
the phrase `but is not limited to' appears to provide leeway for
other types of evidence to be deemed acceptable, the vagueness in
this language leaves the decision about what type of evidence is
acceptable to the subjective judgment and interpretation of the
Compliance Enforcement Authority, which could result in evidence
requirements varying by region or over time.'').
\190\ Clean Energy Associations Initial Comments at 22.
\191\ Id. at 17.
---------------------------------------------------------------------------

100. Commenters offer a wide range of potential modifications to
the documentation requirement of proposed Requirement R4. Clean Energy
Associations suggest that documentation requirements in proposed
Measure M4 should match the language from Requirement R3 of proposed
Reliability Standard PRC-024-4 to prevent undue discrimination against
IBRs that are similarly situated as synchronous generators with regards

[[Page 35612]]

to demonstrating a need for exemptions.\192\
---------------------------------------------------------------------------

\192\ Id. at 20.
---------------------------------------------------------------------------

101. Invenergy explains that including examples of additional types
of documentation would ensure that IBRs are treated in a similar manner
to synchronous generators under proposed Reliability Standard PRC-024-
4, which allows demonstration of an equipment limitation in the form of
a dated email or letter that contains such demonstration.\193\
---------------------------------------------------------------------------

\193\ Invenergy Initial Comments at 26-27; see also Elevate
Comments at 10 (stating documentation in Measure M4 should match the
language used in proposed Standard PRC-024-4 for consistency).
---------------------------------------------------------------------------

EEI recommends that generator owners be allowed to submit an
internal engineering analysis for older legacy IBRs.\194\
---------------------------------------------------------------------------

\194\ EEI Initial Comments at 5.
---------------------------------------------------------------------------

102. UCS requests that proposed Requirement R4.1 be modified to
require generator owners to submit a ``preliminary non-binding estimate
of the cost and time required to replace or retrofit the affected
hardware, and an estimate of how long the IBR would need to be offline
to implement the change, if applicable.'' UCS believes this information
would allow the relevant authority to understand anticipated impacts to
the grid of the exemption process in Requirement R4.\195\
---------------------------------------------------------------------------

\195\ UCS Comments at 7.
---------------------------------------------------------------------------

103. UCS also requests that the final rule be updated to include
the NOPR's citation to the footnote in proposed Requirement R4.2 that
states to ``the extent the original equipment manufacturer considers
any material to be proprietary, the Generator Owner is required to
share this proprietary material only with the [compliance enforcement
authority].'' \196\ UCS asserts that the citation will communicate that
the Commission expects the compliance enforcement authority will
``collect such information and use it in preparation of the reports and
filings of the Milestone 4 Reliability Standards to be required to be
filed with the Commission by November 4, 2026.'' \197\
---------------------------------------------------------------------------

\196\ NERC Petition, Ex. A-3, at 7 n.11.
\197\ UCS Comments at 8.
---------------------------------------------------------------------------

104. In its reply comments, NERC states that it considered the
concern that legacy IBRs may face difficulty providing documentation
sufficient to secure an exemption in developing the Standard. NERC
continues: ``The concept of demonstrating operational limitations for
interconnected generation is neither new nor novel, as dynamic model
capability requirements have been in place for generators since the
first version of mandatory and enforceable Reliability Standards.''
NERC further explains that hardware limitations can be found through
testing of facilities that can find relays or equipment that may cause
the unit to trip, as in Reliability Standards MOD-026-1 and MOD-027-
1.\198\
---------------------------------------------------------------------------

\198\ NERC Reply Comments at 10.
---------------------------------------------------------------------------

105. Both Elevate and WIRAB recommend updating proposed Requirement
R4.2 \199\ to more clearly define the details of what should be
communicated between the entity seeking an exemption for a hardware
limitation and its planning coordinators, transmission planners, and
reliability coordinators under Requirement R4.2. Specifically, both
commenters state that details should include ``timeframes for
communication[s], file formats, an explanation of the reason(s) the
equipment cannot meet the requirements, and other general information
to ensure a thoroughly adequate transfer of information for the
equipment limitation requests.'' \200\
---------------------------------------------------------------------------

\199\ Elevate indicates that it has concerns with Requirement
R6. Elevate Comments at 10. However, there is no Requirement R6 in
proposed Reliability Standard PRC-029-1. See NERC Petition. We
believe, based on Elevate's description of Requirement R6 as
detailing communication between the entity seeking an exemption for
a hardware limitation and its planning coordinators, transmission
planners, and reliability coordinators, that Elevate's comments are
discussing Requirement R4.2, which requires that a generator owner
of a legacy IBR seeking an exemption provide a copy of the
documentation supporting the hardware limitation to associated
planning coordinators, transmission planners, and reliability
coordinators, among others.
\200\ Elevate Comments at 10; WIRAB Comments at 7.
---------------------------------------------------------------------------

106. NYISO states that Requirement R4 suggests that the compliance
enforcement authority will make the final determination as to whether
an exemption is accepted, but it does not establish a specific role for
the registered entity receiving information concerning the exemption
and hardware limitations under Requirement R4.2. NYISO supports giving
the registered entity the opportunity to provide feedback to the
compliance enforcement authority if warranted and believes that this is
the intention of receiving and having the right to request additional
information described in Requirement R4. NYISO requests that either the
Commission or NERC confirm that intention.\201\
---------------------------------------------------------------------------

\201\ NYISO Comments at 3-4.
---------------------------------------------------------------------------

b. Commission Determination
107. We are persuaded that it may not be possible for generator
owners of legacy IBRs to provide identification of the ``specific
piece(s) of hardware causing the limitation.'' \202\ As EEI, Clean
Energy Associations, and other commenters explain, generator owners of
legacy IBRs may not be able to secure the necessary documentation from
original equipment manufacturers due to circumstances outside of their
control (i.e., the original equipment manufacturer could be out of
business, no longer supports the IBR equipment in a legacy resource,
etc.). We agree with commenters that entities would benefit from
greater clarity on documentation obligations.
---------------------------------------------------------------------------

\202\ NERC Petition at 37.
---------------------------------------------------------------------------

108. Therefore, pursuant to section 215(d)(5) of the FPA, we direct
NERC, within 12 months of the effective date of this final rule, to
address the concern by developing responsive modifications to proposed
Reliability Standard PRC-029-1. NERC could satisfy the directive by
modifying Requirement R4 or the corresponding Measure to expand 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 criteria in proposed Requirements R1 through R3. For
example, an expanded non-exhaustive list could consist of damage curves
provided by the original equipment manufacturer, internal engineering
analyses, analysis by third-party consultants, study results,
experience from an event, manufacturer's advice, and design data.
109. We decline to adopt Invenergy's position that IBRs and
synchronous generators should be treated similarly as it relates to
documenting an equipment limitation. We note that IBRs and synchronous
generators are not similarly situated when it comes to responses to the
same disturbances on the Bulk-Power System.\203\ Given this, we believe
that there may be circumstances in which it may be necessary to have
different exemption documentation requirements for IBRs and synchronous
generators as they respond differently to similar disturbances on the
Bulk-Power System, as documented in NERC IBR disturbance reports,\204\
as explained in Order No. 901,\205\ and as explained in NERC's
petition.\206\
---------------------------------------------------------------------------

\203\ Order No. 901, 185 FERC ] 61,042 at P 3 (stating that
there are ``material technological differences between the response
of synchronous generation resources and the response of IBRs to the
same disturbances on the Bulk-Power System'').
\204\ Id. PP 26-29.
\205\ See id. PP 11-13, 15.
\206\ NERC's Petition, Ex. E-2 (Technical Rationale PRC-029-1),
at 1 (explaining the Standard's ``proposal is a consequence of . . .
the different natures of synchronous and inverter-based generation
resources'' during faults and other disturbances and as a result of
several recent events exhibiting IBRs ride-through deficiencies).
---------------------------------------------------------------------------

110. We decline UCS's request to modify Requirement R4.1 to require

[[Page 35613]]

generator owners to submit preliminary information about the cost and
delay impacts of replacing or retrofitting hardware. NERC, in proposing
an exemption process in Requirement R4, and the Commission, in
approving the Standard, have already recognized that it would be
unreasonable and unduly burdensome for generator owners of legacy IBRs
to have to retrofit and redesign legacy facilities. Thus, we find that
helping NERC and the Commission better understand the impact of
exemptions on Bulk-Power System reliability would in no way influence
the availability of an exemption for generator owners of legacy IBRs
that can demonstrate a hardware limitation that prevents the IBR from
meeting the ride-through requirements of Requirements R1 through R3. We
believe that the Commission can obtain the information to understand
the reliability impacts of the exemption from the informational filing
we are directing NERC to file with the Commission 18 months after the
conclusion of the 12-month exemption request period in section II.D.
111. We decline to adopt the recommendations of Elevate and WIRAB
to more clearly define the details of what should be provided by an
entity seeking a hardware exemption to its planning coordinators,
transmission planners, and reliability coordinators in proposed
Requirement R4.2, as it is unnecessary. We find that proposed
Requirement R4.2.1 gives these entities the capability to request
additional, necessary information.\207\ Further, proposed Requirement
R4.2.2 requires the generator owner to provide a copy of the compliance
enforcement authority's acceptance of the hardware limitation to these
entities, thus ensuring all involved parties are informed of the reason
for granting an exemption.\208\
---------------------------------------------------------------------------

\207\ Id. at 37.
\208\ Id.
---------------------------------------------------------------------------

112. We decline to direct NERC to include the footnote in proposed
Requirement R4.2 into the body of the Requirement because it is
unnecessary; we are approving proposed Requirement R4.2 and the
associated footnote.
113. We find it unnecessary to confirm that the intention of
providing exemption information under proposed Requirement R4.2 to
registered entities is for the purpose of providing feedback to the
compliance enforcement authority, as requested by NYISO. We believe it
best to leave it to NERC's discretion to decide whether it wishes to
explain the purpose of proposed Requirement R4.2.

D. Informational Filing

114. In the NOPR, the Commission proposed to direct NERC, pursuant
to 18 CFR 39.2(d), to develop and submit two informational filings
pertaining to requests for exemptions by generator owners of legacy
IBRs from the ride-through requirements of Requirements R1 through R3.
The Commission proposed directing that 12 and 24 months after the
conclusion of the 12-month period for requesting an exemption, NERC
submit an informational filing with specified data related to the
reliability impact of the exemptions for (1) each Interconnection and
(2) each reliability coordinator area (within that Interconnection)
within the United States. The Commission also proposed directing NERC
to include in each informational filing an analysis of the reasons that
responsible entities provide for exemptions.\209\
---------------------------------------------------------------------------

\209\ NOPR, 189 FERC ] 61,212 at P 35.
---------------------------------------------------------------------------

1. Comments
115. NERC strongly recommends that the Commission only require a
single informational filing due 18 months after the conclusion of the
exemption request period. NERC explains that the 12-month filing
requirement may be too soon for it to review and issue determinations
for all exemption requests and to provide an analysis of the capacity
exempted. Similarly, NERC asserts that the 24-month filing will not
assist in providing the Commission with timely information and may also
include redundant information contained in the first filing. NERC
argues that a single informational filing 18 months after the
conclusion of the exemption request period will produce a filing
quicker than the 24-month filing timeline and will be more
comprehensive than the 12-month filing.\210\
---------------------------------------------------------------------------

\210\ NERC Initial Comments at 4-6.
---------------------------------------------------------------------------

116. Aligned ISOs/RTOs indicate their support for the proposed
informational filings to allow parties to assess the impact of any
exemptions granted.\211\ Other commenters request modifications to the
proposed informational filings or suggest other information to include.
For example, EEI suggests NERC include the number and net MW capacity
of IBRs that can meet ride-through requirements in addition to those
that cannot.\212\ Invenergy suggests NERC could determine what
proportion of total ride-through performance and what portions of the
ride-through curves the exemptions impact.\213\
---------------------------------------------------------------------------

\211\ Aligned ISOs/RTOs at 7.
\212\ EEI Initial Comments at 9.
\213\ Invenergy Initial Comments at 32.
---------------------------------------------------------------------------

117. WIRAB believes that the Commission will not have all the
information to accurately evaluate the necessity of hardware exemptions
for legacy IBRs and potential risks to the Bulk-Power System without
additional information. WIRAB recommends that the informational filings
include analyses of the reason(s) entities requested exemptions and the
existing ride-through capabilities of legacy IBRs that received an
exemption, as well as a risk assessment study for each Interconnection
of how the exemptions may contribute to reliability risk on the Bulk-
Power System.\214\
---------------------------------------------------------------------------

\214\ WIRAB Comments at 5.
---------------------------------------------------------------------------

118. LA PSC requests that the deadlines for NERC to submit
informational filings should be shortened from 12 and 24 months to 6
and 12 months, respectively, to reflect its request that the exemption
request timeline be shortened from 12 months to 6 months.\215\
---------------------------------------------------------------------------

\215\ LA PSC Comments at 6.
---------------------------------------------------------------------------

119. UCS states that the Commission should require and review
informational filings on the impact of exemptions and any Corrective
Action Plans that NERC files with the Commission as part of its
Milestone 4 Reliability Standards due by November 4, 2026.\216\
---------------------------------------------------------------------------

\216\ UCS Comments at 5.
---------------------------------------------------------------------------

2. Commission Determination
120. We modify the NOPR proposal and, pursuant to 18 CFR 39.2(d),
we direct NERC to develop and submit a single informational filing, to
the Commission, 18 months after the conclusion of the exemption request
period in proposed Requirement R4 to assess the reliability impacts of
the exemptions in a timely and comprehensive manner. We are persuaded
by NERC's comments that a single filing at 18 months will provide the
Commission with more comprehensive information than would be received
in a filing at 12 months, and more timely information than would be
received in a filing at 24 months. We find that it will likely take
NERC more than 12 months to compile the data requested in the first
filing, and a filing at 24 months will not be timely and may include
redundant information.
121. We direct NERC to include in its informational filing an
assessment of the reliability impacts of the exemptions with the
following data for (1) each Interconnection and (2) each reliability
coordinator area (within that

[[Page 35614]]

Interconnection) within the United States:
<bullet> Total number of IBRs for which NERC-registered generator
owners will be subject to compliance with Reliability Standard PRC-029-
1;
<bullet> Aggregated MW capacity of IBRs for which NERC-registered
generator owners will be subject to compliance with Reliability
Standard PRC-029-1;
<bullet> Total number of IBRs for which NERC-registered generator
owners requested exemptions;
<bullet> Aggregated MW capacity of IBRs for which NERC-registered
generator owners requested exemptions;
<bullet> Total number of IBRs for which NERC-registered generator
owners were granted exemptions;
<bullet> Aggregated MW capacity of IBRs for which NERC-registered
generator owners were granted exemptions;
<bullet> Total number of granted exemptions by exemption type
(voltage and/or frequency);
<bullet> Aggregated MW capacity of granted exemptions by exemption
type (voltage and/or frequency);
<bullet> Total number of granted exemptions by IBR type (wind,
solar PV, BESS, fuel cell); and
<bullet> Aggregated MW capacity of granted exemptions by IBR type
(wind, solar PV, BESS, fuel cell).
122. The informational filing must also include an analysis of the
reasons that entities provided for exemptions (both granted and
denied),\217\ an evaluation of the efficacy of the exemption process,
and any recommendations to modify either the substance or procedural
aspects of the exemption process.
---------------------------------------------------------------------------

\217\ NERC Petition at 40 (explaining that under Requirement
R4.2.2, NERC will work with regional entities to evaluate exemption
submissions in a fair and consistent manner across the ERO
Enterprise, and NERC will monitor the disposition of requests as the
proposed standard is implemented).
---------------------------------------------------------------------------

III. Information Collection Statement

123. The FERC-725G information collection requirements are subject
to review by the Office of Management and Budget (OMB) under section
3507(d) of the Paperwork Reduction Act of 1995. OMB's regulations
require approval of certain information collection requirements imposed
by agency rules. Upon approval of a collection of information, OMB will
assign an OMB control number and expiration date. Respondents subject
to the filing requirements will not be penalized for failing to respond
to these collections of information unless the collections of
information display a valid OMB control number. The Commission solicits
comments on the need for this information, whether the information will
have practical utility, the accuracy of the burden estimates, ways to
enhance the quality, utility, and clarity of the information to be
collected or retained, and any suggested methods for minimizing
respondents' burden, including the use of automated information
techniques.
124. The Commission bases its paperwork burden estimates on the
additional paperwork burden presented by Reliability Standards PRC-024-
4 and PRC-029-1, as modified, and new Reliability Standards,
respectively, and the directive for NERC to submit one informational
filing related to ride-through exemption requests.\218\ Reliability
Standards are objective-based and allow entities to choose compliance
approaches best tailored to their systems. The NERC Compliance
Registry, as of September 2024, identifies the following unique U.S.
entities that are subject to mandatory compliance with Reliability
Standard PRC-024-4: 1,294 generator owners will have an additional
compliance burden. It is estimated that there will be no additional
compliance burden for transmission owners that have synchronous
condensers, as that data is not included in the NERC Compliance
Registry, and transmission owners are already subject to Reliability
Standard PRC-024-3. The estimated unique U.S. entities subject to
Reliability Standard PRC-029-1 compliance are based on numbers supplied
by NERC, with 591 registered generator owners that own bulk electric
system (BES) battery, solar, and wind facilities and 781 generator
owners that own non-BES facilities.\219\ Based on these assumptions, we
estimate the following reporting burden:
---------------------------------------------------------------------------

\218\ See supra P 121.
\219\ NERC estimates that 591 BES IBRs and 781 non-BES IBRs will
be subject to proposed Reliability Standard PRC-029-1 and the other
Milestone 2 Reliability Standards that were filed in Docket Nos.
RD25-2-000 and RD25-3-000. See NERC, Petition For Approval of
Proposed Distribution Monitoring Reliability Standards PRC-028-1 and
PRC-002-5, Docket No. RD25-2-000, at 41 n.60 (filed Nov. 4, 2024)
(description of NERC estimate of BES IBRs that would be subject to
compliance with proposed Reliability Standard PRC-028-1); NERC,
Inverter-Based Resources Work Plan Progress Update, Docket No. RD22-
4-001, at 3 (filed May 6, 2025) (description of NERC estimate of
non-BES IBRs).
\220\ The ``Number of Entity'' data is compiled from the May 13,
2025, edition of the NERC Compliance Registry.
\221\ The estimated hourly cost (salary plus benefits) is a
combination of the following categories from the Bureau of Labor
Statistics (BLS) website, <a href="http://www.bls.gov/oes/current/naics2_22.htm:">http://www.bls.gov/oes/current/naics2_22.htm:</a> 75% of the average of an Electrical Engineer (17-
2071) $71.19/hr., 79.31 x .75 = 53.3925 ($53.39-rounded) ($53.39/
hour); and 25% of an Information and Record Clerk (43-4199) $40.51/
hr., $40.51 x .25% = 10.1275 ($10.13 rounded) ($10.13/hour), for a
total ($53.39 + $10.13 = $63.52/hour).

Proposed Changes in Burden PRC-024-4 Docket No. RM25-3-000
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of
Type and number of entity annual Total number of Average number of burden
Reliability standard \220\ responses responses hours per response \221\ Total burden hours
per entity
(1)........................ (2) (1) * (2) = (3) (4)...................... (3) * (4) = (5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual Collection PRC-024-4 FERC-725G
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual review and record 1,294 (GO)................. 1 1,294 20 hrs. $63.52/hr........ 25,880 hrs. $1,643,897.60.
retention.
---------------------------------------------------------------------------------------------
Total for PRC-024-4...... ........................... ........... 1,294 20 hrs. $63.52/hr........ 25,880 hrs. $1,643,897.60.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 35615]]

Annual Changes Proposed in the Final Rule Approving Reliability Standard PRC-029-1 in Docket No. RM25-3-000
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of
Type and number of entity annual Total number of Average number of burden
Reliability standard \222\ responses responses hours per response \223\ Total burden hours
per entity
(1)........................ (2) (1) * (2) = (3) (4)...................... (3) * (4) = (5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual Collection PRC-029-1 FERC-725G
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual review and record 591 (BES IBR GO)........... 1 591 40 hrs. $63.52/hr........ 23,640 hrs. $1,501,612.80.
retention.
781 (Non-BES IBR GO)....... 1 781 80 hrs. $63.52/hr........ 62,480 hrs. $3,968,729.60.
---------------------------------------------------------------------------------------------
Total for PRC-029-1...... ........................... ........... 1,372 ......................... 86,120 hrs. $5,470,342.40.
--------------------------------------------------------------------------------------------------------------------------------------------------------

125. The responses and burden hours for Years 1-3 will total
respectively as follows:
---------------------------------------------------------------------------

\222\ The ``Number of Entity'' data is compiled from NERC's
petition for approval of proposed Reliability Standard PRC-028-1 in
Docket No. RD25-2-000 and NERC's May 2025 Inverter-Based Resources
Work Plan Progress Update in Docket No. RD22-4-001. NERC, Petition
for Approval of Proposed Distribution Monitoring Reliability
Standards PRC-028-1 and PRC-002-5, Docket No. RD25-2-000, at 41 n.60
(filed Nov. 4, 2024); NERC, Inverter-Based Resources Work Plan
Progress Update, Docket No. RD22-4-001, at 3 (filed May 6, 2025).
\223\ The estimated hourly cost (salary plus benefits) is a
combination of the following categories from the Bureau of Labor
Statistics (BLS) website, <a href="http://www.bls.gov/oes/current/naics2_22.htm:">http://www.bls.gov/oes/current/naics2_22.htm:</a> 75% of the average of an Electrical Engineer (17-
2071) $71.19/hr., 79.31 x .75 = 53.3925 ($53.39-rounded) ($53.39/
hour); and 25% of an Information and Record Clerk (43-4199) $40.51/
hr., $40.51 x .25% = 10.1275 ($10.13 rounded) ($10.13/hour), for a
total ($53.39 + $10.13 = $63.52/hour).
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<bullet> Year 1-3 each: for Reliability Standard PRC-024-4 will be
1,294 responses; 25,880 hours; and
<bullet> Year 1-3 each: for Reliability Standard PRC-029-1 will be
1,372 responses; 86,120 hours.
<bullet> The annual cost burden for each year One to Three is
$1,643,897.60 for Reliability Standard PRC-024-4; and $5,470,342.40 for
Reliability Standard PRC-029-1.
126. Title: Mandatory Reliability Standards, Revised Protection and
Control Reliability Standards.
Action: Revision to FERC-725G information collection.
OMB Control No.: 1902-0252.
Respondents: Businesses or other for-profit institutions; not-for-
profit institutions.
Frequency of Responses: On Occasion.
Necessity of the Information: This final rule approves the
requested modifications to Reliability Standards pertaining to the
protection and control of the Bulk-Power System. As discussed above,
the Commission approves proposed Reliability Standards PRC-024-4 and
PRC-029-1 pursuant to section 215(d)(2) of the FPA because it
establishes frequency and voltage ride-through requirements for IBRs.
Additionally, the Commission directs NERC to file one informational
filing with the Commission on ride-through exemption requests.
Internal Review: The Commission has reviewed the proposed
Reliability Standards and made a determination that its action is
necessary to implement section 215 of the FPA.
127. Interested persons may obtain information on the reporting
requirements by contacting the following: Federal Energy Regulatory
Commission, 888 First Street NE, Washington, DC 20426 [Attention: Kayla
Williams, Office of the Executive Director, email:
<a href="/cdn-cgi/l/email-protection#7135100510321d141003101f121431171403125f161e07">[email&#160;protected]</a>, phone: (202) 502-8663, fax: (202) 273-0873].
128. For submitting comments concerning the collection(s) of
information and the associated burden estimate(s), please send your
comments to the Commission, and to the Office of Management and Budget,
Office of Information and Regulatory Affairs, Washington, DC 20503
[Attention: Desk Officer for the Federal Energy Regulatory Commission,
phone: (202) 395-4638, fax: (202) 395-7285]. For security reasons,
comments to OMB should be submitted by email to:
<a href="/cdn-cgi/l/email-protection#2847415a49775b5d4a45415b5b4147466847454a064d4758064f475e">[email&#160;protected]</a>. Comments submitted to OMB should include
Docket Number RM25-3-000 and OMB Control Number 1902-0252.

IV. Environmental Analysis

129. The Commission is required to prepare an Environmental
Assessment or an Environmental Impact Statement for any action that may
have a significant adverse effect on the human environment.\224\ The
Commission has categorically excluded certain actions from this
requirement as not having a significant effect on the human
environment. Included in the exclusion are rules that are clarifying,
corrective, or procedural or that do not substantially change the
effect of the regulations being amended.\225\ The actions proposed
herein falls within this categorical exclusion in the Commission's
regulations.
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\224\ Reguls. Implementing the Nat'l Env't Pol'y Act, Order No.
486, 52 FR 47897 (Dec. 17, 1987), FERC Stats. & Regs. Preambles
1986-1990 ] 30,783 (1987) (cross-referenced at 41 FERC ] 61,284).
\225\ 18 CFR 380.4(a)(2)(ii).
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V. Regulatory Flexibility Act

130. The Regulatory Flexibility Act of 1980 (RFA) \226\ generally
requires a description and analysis of final rules that will have
significant economic impact on a substantial number of small entities.
The Small Business Administration's (SBA) Office of Size Standards
develops the numerical definition of a small business.\227\ The SBA
revised its size standard for electric utilities (effective March 17,
2023) to a standard based on the number of employees, including
affiliates (from the prior standard based on megawatt hour sales).\228\
---------------------------------------------------------------------------

\226\ 5 U.S.C. 601-612.
\227\ 13 CFR 121.101.
\228\ 13 CFR 121.201, Subsector 221 (Utilities).
---------------------------------------------------------------------------

131. Proposed Reliability Standard PRC-024-4 (included in FERC-
725G) will apply to approximately 1,294 generator owners, and proposed
Reliability Standard PRC-029-1 (included in FERC-725G) will apply to
approximately combined 1,372 BES IBR generator owners and non-BES IBR
generator owners in the United States.\229\ Pursuant to SBA
regulations, the employment threshold for generator owners is 950
employees. We estimate that the percentage of employees that are
considered small to be 71.68% based on the North American Industry
Classification System 221121 code (Electric Bulk Power Generation) and
that the annual cost for each entity will be $1,270.40 for each
generator owner and $2,540.80 for each BES IBR

[[Page 35616]]

generator owner and $5,081.50 for each non-BES IBR generator
owner.\230\
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\229\ Many respondents serve multiple roles in the NERC
Compliance Registry, so there is likely double counting in the
estimates.
\230\ The annual cost is the hours assigned for generator
owners, BES IBR generator owners, and non-BES IBR generator owners
in the Annual Collection PRC-024-4 FERC-725G and Annual Collection
PRC-029-1 FERC-725G tables multiplied by $63.52/hour. See n.221,
223.
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132. We view this as a minimal economic impact for each entity.
Accordingly, we certify that the proposed Reliability Standards PRC-
024-4 and PRC-029-1 will not have a significant economic impact on a
substantial number of small entities. Thus, no regulatory flexibility
analysis is required.

VI. Document Availability

133. In addition to publishing the full text of this document in
the Federal Register, the Commission provides all interested persons an
opportunity to view and/or print the contents of this document via the
internet through the Commission's Home Page (<a href="http://www.ferc.gov">http://www.ferc.gov</a>).
134. From the Commission's Home Page on the internet, this
information is available on eLibrary. The full text of this document is
available on eLibrary in PDF and Microsoft Word format for viewing,
printing, and/or downloading. To access this document in eLibrary, type
the docket number excluding the last three digits of this document in
the docket number field.
135. User assistance is available for eLibrary and the Commission's
website during normal business hours from FERC Online Support at 202-
502-6652 (toll free at 1-866-208-3676) or email at
<a href="/cdn-cgi/l/email-protection#167073647579787a7f787365636666796462567073647538717960">[email&#160;protected]</a>, or the Public Reference Room at (202) 502-
8371, TTY (202) 502-8659. Email the Public Reference Room at
<a href="/cdn-cgi/l/email-protection#98e8edfaf4f1fbb6eafdfefdeafdf6fbfdeaf7f7f5d8fefdeafbb6fff7ee">[email&#160;protected]</a>.

VII. Regulatory Planning and Review

136. Executive Orders 12866 and 13563 direct agencies to assess the
costs and benefits of available regulatory alternatives and, if
regulation is necessary, to select regulatory approaches that maximize
net benefits (including potential economic, environmental, public
health and safety effects, distributive impacts, and equity). Executive
Order 13563 emphasizes the importance of quantifying both costs and
benefits, of reducing costs, of harmonizing rules, and of promoting
flexibility. The Office of Information and Regulatory Affairs (OIRA)
has determined this regulatory action is not a ``significant regulatory
action,'' under section 3(f) of Executive Order 12866, as amended.
Accordingly, OIRA has not reviewed this regulatory action for
compliance with the analytical requirements of Executive Order 12866.

VIII. Effective Date and Congressional Notification

137. This final rule is effective August 28, 2025. The Commission
has determined, with the concurrence of OIRA, that this rule is not a
``major rule'' as defined in section 351 of the Small Business
Regulatory Enforcement Fairness Act of 1996.

By the Commission.

Issued: July 24, 2025.
Carlos D. Clay,
Deputy Secretary.

Note: The following appendix will not appear in the Code of
Federal Regulations.

Appendix A

The following entities filed comments:

<bullet> Arizona Public Service Company (APS);
<bullet> California Independent System Operator Corporation, ISO New
England Inc., Midcontinent Independent System Operator, Inc., PJM
Interconnection, L.L.C., and Southwest Power Pool, Inc.
(collectively, aligned ISOs/RTOs);
<bullet> Solar Energy Industries Association (SEIA) and American
Clean Power Association (ACP) (collectively, Clean Energy
Associations);
<bullet> Det Norske Veritas (DNV);
<bullet> Dominion Energy Services Inc. (Dominion);
<bullet> Edison Electric Institute (EEI);
<bullet> Elevate Energy Consulting (Elevate);
<bullet> Invenergy Renewables LLC (Invenergy);
<bullet> Long Island Power Authority (LIPA);
<bullet> Louisiana Public Service Commission (LA PSC);
<bullet> NERC;
<bullet> New York Independent System Operator, Inc. (NYISO);
<bullet> New York State Energy Research and Development Authority
(NYSERDA);
<bullet> New York State Reliability Council (NYSRC);
<bullet> [Oslash]rsted Wind Power North America LLC ([Oslash]rsted);
<bullet> Tesla;
<bullet> Unfrack FERC Coalition;
<bullet> Union of Concerned Scientists (UCS); and
<bullet> Western Interconnection Regional Advisory Body (WIRAB)

The following entity filed a motion for leave to comment out of
time:

<bullet> Deriva Energy (Deriva)

The following entities filed reply comments:

<bullet> Clean Energy Associations;
<bullet> EEI;
<bullet> Invenergy; and
<bullet> NERC

The following entity filed an answer:

<bullet> Invenergy

The following entities filed motions to intervene:

<bullet> ACP;
<bullet> Dominion;
<bullet> Eversource Energy Service Company;
<bullet> Independent Market Monitor for PJM;
<bullet> Indiana Utility Regulatory Commission;
<bullet> Kentucky Attorney General;
<bullet> NYSERDA;
<bullet> North Carolina Electric Membership Corporation;
<bullet> [Oslash]rsted;
<bullet> SEIA;
<bullet> Sunflower Electric Power Corporation; and
<bullet> UCS

The following entity filed a motion to intervene out of time:

<bullet> American Electric Power Service Corporation

[FR Doc. 2025-14304 Filed 7-28-25; 8:45 am]
BILLING CODE 6717-01-P

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