146 FERC ¶ 61,024

UNITED STATES OF AMERICA

FEDERAL ENERGY REGULATORY COMMISSION

18 CFR Part 40

[Docket No. RM13-11-000; Order No. 794]

Frequency Response and Frequency Bias Setting Reliability Standard

(Issued January 16, 2014)

AGENCY: Federal Energy Regulatory Commission.

ACTION: Final rule.

SUMMARY: Pursuant to section 215(d) of the Federal Power Act, the Federal Energy 

Regulatory Commission (Commission) approves Reliability Standard BAL-003-1 

(Frequency Response and Frequency Bias Setting), submitted by the North American 

Electric Reliability Corporation (NERC), the Commission-certified Electric Reliability 

Organization. Reliability Standard BAL-003-1 defines the amount of frequency response 

needed from balancing authorities to maintain Interconnection frequency within 

predefined bounds and includes requirements for the measurement and provision of 

frequency response. In addition, the Commission directs NERC to submit certain reports

to address concerns discussed in the Final Rule.

EFFECTIVE DATE: This rule will become effective [INSERT DATE 60 days after 

publication in the FEDERAL REGISTER].

FOR FURTHER INFORMATION CONTACT:

Daniel Woldemariam (Technical Information)

Office of Electric Reliability, Division of Reliability Standards 

Federal Energy Regulatory Commission 
Docket No. RM13

-11-000 - 2 -

888 First Street, NE 

Washington, DC 20426 

Telephone: (202) 502-8080

Daniel.Woldermariam@ferc.gov

Mark Bennett (Legal Information)

Office of the General Counsel

Federal Energy Regulatory Commission

888 First Street, NE 

Washington, DC 20426

Telephone: (202) 502-8524

Mark.Bennett@ferc.gov 

SUPPLEMENTARY INFORMATION

:
146 FERC ¶ 61,024

UNITED STATES OF AMERICA

FEDERAL ENERGY REGULATORY COMMISSION

Before Commissioners: Cheryl A. LaFleur, Acting Chairman;

 Philip D. Moeller, John R. Norris,

and Tony Clark.

Frequency Response and Frequency Bias Setting 

Reliability Standard

Docket No. RM13-11-000

ORDER NO. 794

FINAL RULE

(Issued January 16, 2014)

1. Pursuant to section 215(d) of the Federal Power Act (FPA),1 the Commission 

approves Reliability Standard BAL-003-1 (Frequency Response and Frequency Bias 

Setting), submitted by the North American Electric Reliability Corporation (NERC), the 

Commission-certified Electric Reliability Organization (ERO). Reliability Standard

BAL-003-1 defines the amount of frequency response needed from balancing authorities 

to maintain Interconnection frequency within defined bounds and includes requirements 

for the measurement and provision of frequency response.2

 We find that Reliability 

 1 16 U.S.C. 824o(d).

2 NERC defines “frequency response” in the NERC Glossary of Terms Used in 

Reliability Standards (NERC Glossary) as follows:

Equipment: The ability of a system or elements of the system to react or respond 

to a change in system frequency. System: The sum of the change in demand, plus 

(continued...)
Docket No. RM13-11-000 - 2 -

Standard BAL-003-1 addresses an existing gap in reliability and the Commission’s

directives set forth in Order No. 693.3

 Reliability Standard BAL-003-1 establishes a 

minimum Frequency Response Obligation4 for each balancing authority; provides a 

uniform calculation of frequency response; establishes Frequency Bias Settings that set 

values closer to actual balancing authority frequency response; and encourages 

coordinated automatic generation control (AGC) operation.5

 These matters are not 

addressed in any currently-effective Reliability Standard. Therefore, pursuant to 

section 215(d) of the FPA, we approve Reliability Standard BAL-003-1.6

 

2. The Commission also approves four new or revised definitions to the NERC 

Glossary and NERC’s implementation plan and, with two exceptions, the violation risk 

 

the change in generation, divided by the change in frequency, expressed in 

megawatts per 0.1 Hertz (MW/0.1 Hz). 

3 See Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, 

FERC Stats. & Regs. ¶ 31,242 at P 375, order on reh’g, Order No. 693-A, 120 FERC 

¶ 61,053 (2007).

4 NERC defines Frequency Response Obligation as “[t]he balancing authority’s 

share of the required Frequency Response needed for the reliable operation of an 

Interconnection. This will be calculated as MW/0.1Hz.”

5 NERC revises the definition of Frequency Bias Setting as “[a] number, either 

fixed or variable, usually expressed in MW/0.1 Hz, included in a balancing authority’s 

Area Control Error equation to account for the balancing authority’s inverse Frequency 

Response contribution to the Interconnection, and discourage response withdrawal 

through secondary control systems.”

6 In a related action, the Commission is approving regional Reliability Standard 

BAL-001-TRE-01 containing provisions for assuring frequency response in the ERCOT 

Interconnection. See Docket No. RD13-12-000, North American Electric Reliability 

Corporation, 146 FERC ¶ 61,025.
Docket No. RM13-11-000 - 3 -

factors and violation severity levels, and NERC’s request for retirement of currentlyeffective Reliability Standard BAL-003-0.1b. 

3. While the Commission believes that the record supports approving Reliability 

Standard BAL-003-1, we have concerns about certain aspects of the Reliability Standard 

that warrant further consideration. Therefore, the Commission directs NERC to submit

two reports, and to continue its ongoing annual analysis of certain aspects of BAL-003-17

 

to address concerns regarding specific provisions of the Reliability Standard and to 

determine the effectiveness of Reliability Standard BAL-003-1 in providing an adequate 

amount of frequency response. First, no later than 15 months after implementation of the 

Reliability Standard, NERC shall submit a report that addresses the results and 

recommendations of a light-load case study of the Eastern Interconnection, using actual 

turbine governor response data. Second, no later than 27 months after implementation of 

the Reliability Standard, NERC shall submit a report(s) addressing: (1) an evaluation of 

the use of the linear regression methodology to calculate frequency response; and (2) the 

availability of resources for applicable entities to meet the Frequency Response 

Obligation. Depending on the results and recommendations of these reports, which 

should provide insight on the effectiveness of the Reliability Standard in assuring that the 

necessary amount of Frequency Response is available in response to system events, 

 7 On December 30, 2013, NERC submitted an informational filing, titled “Annual

Analysis of Frequency Response.” NERC states that the informational filing updates the 

statistical analyses and calculations contained in the 2012 Frequency Response Initiative 

Report, attached to NERC’s Petition as Exhibit F (Frequency Response Initiative Report). 
Docket No. RM13-11-000 - 4 -

further refinements to the standard may be warranted. Moreover, if data indicate that 

sufficient resources are not available for applicable entities to meet their Frequency 

Response Obligation, NERC should provide that information, together with appropriate 

recommendations for mitigation, as this information becomes available.

4. The Commission finds NERC’s December 30, 2013 “Annual Analysis of 

Frequency Response” helpful and notes NERC’s statement that it intends to continue this 

work. Specifically, in its 2013 annual analysis, NERC states that the informational filing 

analyzes the impact of Remedial Action Schemes that trip more than 2,400 MW on the 

calculation of the Interconnection Frequency Response Obligation (IFRO) for the 

Western Interconnection, adjustment factors for calculating IFROs and trends in primary 

frequency response sustainability or withdrawal throughout frequency events. The 

Commission expects NERC to continue to evaluate these aspects of frequency response 

and include them in future annual analyses.

I. Background

A. Section 215 of the FPA

5. Section 215(c) of the FPA requires a Commission-certified Electric Reliability 

Organization (ERO) to develop mandatory and enforceable Reliability Standards that are 

subject to Commission review and approval. Once approved, the Reliability Standards 
Docket No. RM13-11-000 - 5 -

may be enforced by NERC, subject to Commission oversight, or by the Commission 

independently.8

B. Frequency Response and Frequency Bias Setting

6. Sufficient frequency response is necessary to stabilize frequency within an 

Interconnection immediately following the sudden loss of generation or load. NERC 

explains that “[s]ystem frequency reflects the instantaneous balance between generation 

and load. Reliable operation of a power system depends on maintaining frequency within 

predetermined boundaries above and below a scheduled value, which is 60 Hertz (Hz) in 

North America.”9

 Most frequency response is provided by the automatic and 

autonomous actions of turbine-governors, with some response being provided by changes 

in demand due to changes in frequency. Failure to maintain frequency can disrupt the 

operation of equipment and initiate disconnection of power plant equipment to prevent 

equipment from being damaged, which could lead to wide-spread blackouts.

7. Frequency response is provided in two stages, referred to as primary frequency 

response and secondary frequency response.

8. Primary frequency response and control involves the autonomous, automatic, and 

rapid action of a generator, or other resource, to change its output (within seconds) to 

rapidly dampen large changes in frequency. The ability of a power system to withstand a 

 8 16 U.S.C. 824o(e).

9 NERC Petition at 3.
Docket No. RM13-11-000 - 6 -

sudden loss of generation or load depends on the presence and adequacy of resources 

capable of providing rapid incremental power changes to counterbalance the disturbance 

and arrest a frequency deviation. 

9. Secondary frequency response, also known as automatic generation control 

(AGC), is produced from either manual or automated dispatch from a centralized control 

system.10 It is intended to balance generation, interchange and demand by managing the 

response of available resources within minutes as opposed to primary frequency 

response, which manages response within seconds. Frequency bias is an input used in the 

calculation of a balancing authority’s area control error (ACE) to account for the power 

changes associated with primary frequency response. However, frequency bias is not the 

same as frequency response. Frequency Bias Setting is a secondary control setting of the 

AGC system, not a primary control parameter, and changes in the Frequency Bias Setting 

of a balancing authority do not change the primary frequency response. The Frequency 

Bias Setting is used in AGC to prevent premature withdrawal of generator primary 

frequency response following a disturbance as long as frequency is off its nominal 

value.

11

 10 NERC Petition at 11. Additional background information about the engineering 

concepts that pertain to frequency response is discussed in the Frequency Response 

Background Document, NERC Petition, Exh. D.

11 NERC Petition at 11.
Docket No. RM13-11-000 - 7 -

C. NERC Reliability Standard BAL-003-0

10. On March 16, 2007, in Order No. 693, the Commission approved 83 of 107 

Reliability Standards pursuant to FPA section 215(d), including currently-effective 

Reliability Standard BAL-003-0. In addition, pursuant to section 215(d)(5) of the FPA, 

the Commission directed NERC, among other things, to develop modifications to BAL003-0 to address certain issues identified by the Commission. Specifically, the 

Commission directed NERC to: 

develop a modification to BAL-003-0 through the Reliability Standards 

development process that: (1) includes Levels of Non-Compliance; 

(2) determines the appropriate periodicity of frequency response surveys 

necessary to ensure that Requirement R2 and other requirements of the 

Reliability Standard are being met, and to modify Measure M1 based on 

that determination and (3) defines the necessary amount of Frequency 

Response needed for Reliable Operation for each balancing authority with 

methods of obtaining and measuring that the frequency response is 

achieved.12

II. NERC Petition and Reliability Standard BAL-003-1

A. NERC Petition

11. On March 29, 2013, NERC submitted its petition seeking the Commission’s

approval of Reliability Standard BAL-003-1, four new or modified definitions for 

inclusion in the NERC Glossary, violation risk factors and violation severity levels, an 

 12 Order No. 693, FERC Stats. & Regs. ¶ 31,242 at P 375.
Docket No. RM13-11-000 - 8 -

implementation plan for the proposed standard, and retirement of currently-effective 

BAL-003-0.1b.13 

12. The petition states that in 2010 NERC began a frequency response initiative to 

perform an in-depth analysis of Interconnection-wide frequency response “to achieve a 

better understanding of the factors influencing frequency response across North 

America.”14 According to NERC, one of the basic objectives of the frequency response 

initiative included increasing coordinated communication and outreach on the issue, 

including webinars, and NERC alerts.15 NERC states that it developed several reports 

that provide the conclusions and recommendations resulting from the frequency response 

initiative, which NERC includes as exhibits to its petition.16 Further, NERC states that a 

detailed explanation of the development, testing, and implementation of Reliability 

Standard BAL-003-1 is provided in the Frequency Response Standard Background 

Document, included as Exhibit D to the petition. 

13. NERC requests approval of the implementation plan for proposed BAL-003-1, 

under which: (1) Requirement R2, Requirement R3 and Requirement R4 would become 

 13 Reliability Standard BAL-003-1 is not attached to this Final Rule. The 

complete text of Reliability Standard BAL-003-1 is available on the Commission’s 

eLibrary document retrieval system in Docket No. RM13-11-000 and is posted on the 

ERO’s web site, available at: http://www.nerc.com.

14 NERC Petition at 11-12.

15 Id. at 12.

16 See Frequency Response Initiative Report, Exh. G (Status of 

Recommendations), and Exh. H (Supplemental Report).
Docket No. RM13-11-000 - 9 -

effective the first day of the first calendar quarter that is twelve months following the 

effective date of this Final Rule; and (2) Requirement R1 would become effective the 

first day of the first calendar quarter that is twenty-four months following the effective 

date of this Final Rule. NERC proposes the retirement of existing Reliability Standard 

BAL-003-0.1b at midnight of the day immediately prior to the effective date of 

Requirements R2, Requirement R3 and Requirement R4 of the Reliability Standard. 

NERC requests approval of three new definitions and the revised definition of Frequency 

Bias Setting effective the first day of the first calendar quarter that is twelve months 

following the effective date of a Final Rule in this docket.17

B. Reliability Standard BAL-003-1 and NERC Explanation of Provisions

14. NERC states that the purpose of the Reliability Standard is to ensure an adequate 

amount of Frequency Response and also ensure that “a Balancing Authority’s Frequency 

Bias Setting is accurately calculated to match its actual Frequency Response.” The 

Reliability Standard also is intended “to provide consistent methods for measuring 

Frequency Response and determining the Frequency Bias Setting.”

18 The Reliability 

 17 NERC proposes to retire the existing definition of Frequency Bias Setting at 

midnight of the day immediately prior to the effective date of Requirement R2, 

Requirement R3, and Requirement R4 of the Reliability Standard.

18 NERC Petition at 15. See also Reliability Standard BAL-003-1, Purpose 

Statement:

To require sufficient Frequency Response from the balancing authority (BA) to

maintain Interconnection Frequency within predefined bounds by arresting

frequency deviations and supporting frequency until the frequency is restored to 

(continued...)
Docket No. RM13-11-000 - 10 -

Standard consists of four requirements, and is applicable to balancing authorities and 

Frequency Response Sharing Groups.19 

15. Requirement R1 requires that each balancing authority or Frequency Response 

Sharing Group achieve an annual Frequency Response Measure20 that is “equal to or 

more negative than its Frequency Response Obligation” needed to ensure sufficient 

Frequency Response. Specifically, Requirement R1 states:

Each Frequency Response Sharing Group (FRSG) or Balancing Authority

that is not a member of a FRSG shall achieve an annual Frequency 

Response Measure (FRM) (as calculated and reported in accordance with 

Attachment A) that is equal to or more negative than its Frequency 

Response Obligation (FRO) to ensure that sufficient Frequency Response is 

provided by each FRSG or BA that is not a member of a FRSG to maintain 

Interconnection Frequency Response equal to or more negative than the 

Interconnection Frequency Response Obligation.

 

its scheduled value. To provide consistent methods for measuring Frequency 

Response and determining the Frequency Bias Setting.

19 NERC defines Frequency Response Sharing Group as “[a] group whose 

members consist of two or more Balancing Authorities that collectively maintain, 

allocate, and supply operating resources required to jointly meet the sum of the 

Frequency Response Obligations of its members.” NERC Petition at 13. The Reliability 

Standard allows balancing authorities to cooperatively form Frequency Response Sharing 

Groups as a means to jointly meet the obligations of the standard. Id.

20 NERC defines Frequency Response Measure as “[t]he median of all the 

frequency response observations reported annually by Balancing Authorities or 

Frequency Response Sharing Groups for frequency events specified by the ERO. This 

will be calculated as MW/0.1Hz.”
Docket No. RM13-11-000 - 11 -

NERC explains that Requirement R1 has the primary objective of “determin[ing] whether 

a Balancing Authority has sufficient Frequency Response for reliable operations.”

21 

According to NERC, Requirement R1 achieves this objective “via FRS [Frequency 

Response Survey] Form 1 and the process in Attachment A that provides the method for 

determining the Interconnections’ necessary amount of Frequency Response and 

allocating it to the balancing authorities.”22 NERC asserts that Requirement R1 and 

Attachment A satisfy the Commission’s directive in Order No. 693 to “determine the 

appropriate periodicity of frequency response surveys necessary to ensure that 

Requirement R2 and other requirements of the Reliability Standard are met....”

23

16. Requirement R2 states that: 

Each Balancing Authority that is a member of a multiple Balancing 

Authority Interconnection and is not receiving Overlap Regulation 

Service24 and uses a fixed Frequency Bias Setting shall implement the 

 21 NERC Petition at 15.

22 Id. NERC explains that “Attachment A (appended to the proposed standard) is a 

supporting document for Reliability Standard BAL-003-1 that discusses the process the

ERO will follow to validate the Balancing Authority’s FRS Form 1 data and publish the 

official Frequency Bias Settings. FRS Form 1 provides the guidance as to how to 

account for and measure Frequency Response. FRS Form 1, and the underlying data 

retained by the balancing authority, will be used for measuring whether sufficient 

Frequency Response was provided.” NERC Petition at 4. 

23 Id. at 16 (citing Order No. 693, FERC Stats. & Regs. ¶ 31,242 at P 375).

24 NERC explains that overlap regulation service is a method of providing 

regulation service in which a balancing authority incorporates another balancing 

authority’s actual interchange, frequency responses, and schedule into the providing 

balancing authority’s AGC/ACE equation. NERC Petition at 21.
Docket No. RM13-11-000 - 12 -

Frequency Bias Setting determined in accordance with Attachment A, as 

validated by the ERO, into its Area Control Error (ACE) calculation during 

the implementation period specified by the ERO and shall use this 

Frequency Bias Setting until directed to change by the ERO. 

NERC explains that setting the frequency bias to better approximate the balancing 

authority’s natural response characteristic will improve the quality of ACE control and 

general AGC system control response. NERC states that the ERO, in coordination with 

the regions of each Interconnection, will annually review Frequency Bias Setting data 

submitted by the balancing authorities. 

17. Requirement R3 states that:

Each Balancing Authority that is a member of a multiple Balancing 

Authority Interconnection and is not receiving Overlap Regulation Service 

and is utilizing a variable Frequency Bias Setting shall maintain a 

Frequency Bias Setting that is: (1.1) Less than zero at all times, and (1.2) 

Equal to or more negative than its Frequency Response Obligation when 

Frequency varies from 60 [Hertz] Hz by more than +/- 0.036 Hz. 

NERC explains that, in an Interconnection with multiple balancing authorities, the 

Frequency Bias Setting should be coordinated among all balancing authorities in the 

Interconnection. According to NERC, when there is a minimum Frequency Bias Setting 

requirement, it should apply for all balancing authorities. However, balancing authorities

using a variable Frequency Bias Setting may have non-linearity in their actual response 

for a number of reasons including the deadband settings of their generator governors. 

The measurement to ensure that these balancing authorities are conforming to the 
Docket No. RM13-11-000 - 13 -

Interconnection minimum is adjusted to remove the deadband range from the calculated 

average Frequency Bias Setting actually used.25

18. Requirement R4 states that:

Each Balancing Authority that is performing Overlap Regulation Service 

shall modify its Frequency Bias Setting in its ACE calculation, in order to 

represent the Frequency Bias Setting for the combined Balancing Authority

area, to be equivalent to either: 

• the sum of the Frequency Bias Settings as shown on FRS Form 1 

and FRS Form 2 for the participating Balancing Authorities as 

validated by the ERO, or 

• the Frequency Bias Setting shown on FRS Form 1 and FRS Form 2 

for the entirety of the participating Balancing Authorities’ areas.

NERC states that Requirement R4 is similar to Requirement R6 in the currently-effective 

BAL-003-0.1b.

III. Notice of Proposed Rulemaking

19. On July 18, 2013, the Commission issued a Notice of Proposed Rulemaking 

(NOPR) proposing to approve Reliability Standard BAL-003-1 as just, reasonable, not 

unduly discriminatory or preferential, and in the public interest.26 The Commission also 

proposed to approve three new definitions and the revised definition of Frequency Bias 

 25 NERC Petition at 20. NERC further states that “For [balancing authorities]

using variable bias, FRS Form 1 has a data entry location for the previous year’s average 

monthly Bias. The [balancing authority] and the ERO can compare this value to the 

previous year’s Frequency Bias Setting minimum to ensure Requirement R3 has been 

met.” Id.

26 Frequency Response and Frequency Bias Setting Reliability Standard, Notice of 

Proposed Rulemaking, 78 FR 45479 (July 29, 2013), 144 FERC ¶ 61,057 (2013) 

(NOPR).
Docket No. RM13-11-000 - 14 -

Setting, all but one of the associated violation risk factors, most violation severity levels,

the implementation plan, effective date, and the retirement of the “Version 0” Standard 

BAL-003-0.1b. The NOPR stated that the Reliability Standard establishes a minimum 

Frequency Response Obligation and addresses other related matters that are not 

addressed in any currently-effective Reliability Standard. 

20. While the Commission proposed to approve Reliability Standard BAL-003-1, the 

Commission raised concerns regarding certain provisions of the proposed standard, some 

of which NERC itself identified in the reports included in its petition. In the NOPR, the 

Commission sought comments on the following issues: (1) in Requirement R1, the use 

of the median statistical method in the calculation of Frequency Response Measure, i.e., 

selecting the middle value in a set of data that is arranged in an ascending or descending 

order; (2) the potential for early withdrawal of primary frequency response before 

secondary frequency response is activated; (3) the need to study frequency response 

during light-load conditions; (4) whether the resource contingency criteria in the Western 

Interconnection is properly identified; and (5) the need to adequately ensure that each 

balancing authority has available the resources it needs to meet its frequency response 

obligation.27 

 27 On July 18, 2013 the Commission issued a Notice of Request for Comments 

(Docket No. AD13-8) concerning the market implications of frequency response and 

frequency bias setting requirements. See Market Implications of Frequency Response 

and Frequency Bias Setting Requirements, 144 FERC ¶ 61,058 (2013).
Docket No. RM13-11-000 - 15 -

21. In response to the NOPR, the Commission received comments from: NERC, 

Midcontinent Independent System Operator (MISO), Electricity Consumers Resource 

Council (ELCON), ISO/RTO Council (IRC), Arizona Public Service Company (APS), 

Bonneville Power Administration (BPA), and Trade Associations.

28 On October 15, 

2013, NERC submitted reply comments. We address below the issues raised in the 

NOPR and comments. 

IV. Discussion

22. Pursuant to FPA section 215(d), we approve Reliability Standard BAL-003-1 as 

just, reasonable, not unduly discriminatory or preferential, and in the public interest. The 

Reliability Standard establishes a minimum Frequency Response Obligation for each 

balancing authority; provides a uniform calculation of frequency response; establishes 

Frequency Bias Settings that are closer to actual balancing authority frequency response;

and encourages coordinated automatic generation control operation. The Reliability 

Standard addresses an existing gap in reliability, as these matters are either not covered, 

or not adequately addressed, in any currently-effective Reliability Standard. Further,

Reliability Standard BAL-003-1 adequately addresses certain directives from Order 

No. 693. We also approve the new and modified definitions and, with two exceptions, 

 28 The Trade Associations group consists of Edison Electric Institute (EEI), 

National Rural Electric Cooperative Association (NRECA), American Public Power 

Association (APPA) and Electric Power Supply Association (EPSA).
Docket No. RM13-11-000 - 16 -

the proposed violation severity levels and violation risk factors, and retirement of the 

currently-effective standard and NERC’s implementation plan. 

23. We discuss below the following issues raised in the NOPR and addressed in the 

comments: (A) the use of the median statistical method in determining the Frequency 

Response Measure; (B) the determination of Interconnection Frequency Response 

Obligation; (C) methods of obtaining frequency response; (D) withdrawal of primary 

frequency response before secondary frequency response is activated; (E) development of

a new light-load case study; (F) assignment of violation risk factors and violation severity 

levels; and (G) associated and supporting documents. 

A. Use of the “Median” in Determining the Frequency Response Measure

NERC Petition

24. As discussed above, Requirement R1 of Reliability Standard BAL-003-1 provides 

that each balancing authority or Frequency Response Sharing Group achieve an annual 

Frequency Response Measure that is equal to or more negative than its Frequency 

Response Obligation needed to ensure sufficient frequency response. NERC proposed to 

define the Frequency Response Measure as “the median of all the Frequency Response 

observations reported annually by balancing authorities or Frequency Response Sharing 

Groups for the frequency events specified by the ERO.”29 NERC defines the “median” 

as “the numerical value separating the higher half of a one-dimensional sample, a one-

 29 NERC Petition at 13. 
Docket No. RM13-11-000 - 17 -

dimensional population, or a one-dimensional probability distribution from the lower 

half. The median of a finite list of numbers is found by arranging all the observations 

from lowest value to highest value and picking the middle one.”

30 

25. NERC stated in its petition that the standard drafting team evaluated different 

approaches for averaging individual event observations to compute a technically sound 

estimate of Frequency Response Measure, including median and linear regression 

analysis.31 Explaining why the drafting team chose to use the median, NERC stated:

In general, statisticians use the median as the best measure of a central 

tendency when a population has outliers. Based on the analyses performed 

thus far, the standard drafting team believes that the median’s superior 

resiliency to this type of data quality problem makes it the best aggregation 

technique at the time. However, the standard drafting team sees merit and 

promise in future research with sample filtering combined with a technique 

such as linear regression. When compared with the mean, linear regression 

shows superior performance with respect to the elimination of noise 

because the measured data is weighted by the size of the frequency changes 

associated with the event. The standard drafting team acknowledges that 

linear regression should be re-evaluated for use in the BAL-003 Reliability 

Standard once more experience is gained with data collected.

32

 30 Frequency Response Initiative Report at 72. NERC developed a procedure for 

selecting frequency response observations. See NERC Petition, Exh. C (Procedure for 

ERO Support of Frequency Response and Frequency Bias Setting Standard). The 

Procedure is referenced, but not included, in Attachment A of Reliability Standard BAL003-1. 

31 NERC Petition at 17-18. The Frequency Response Initiative Report defines the 

linear regression method as the linear average of a multi-dimensional sample, or a multidimensional population. See id., Exh. F at 73.

32 Id. at 17-18 (footnote omitted). See also id., Exh. F at 72-78. NERC explained 

that the “noise” refers to factors that can influence data and produce outliers. Id. at 18, 

n.34. 
Docket No. RM13-11-000 - 18 -

NOPR

26. In the NOPR, the Commission stated that NERC provided adequate rationale for 

using the median to determine the required Frequency Response Measure.

33 The NOPR 

also noted NERC’s explanation that application of the median is supported by the 

analyses performed to date.

34 Therefore, the Commission proposed to approve BAL003-1 on that basis.

27. However, in the NOPR, the Commission expressed concern “whether use of the 

median adequately represents actual data that could, on occasions, be significantly higher 

or lower than the median.”35 Further, the Commission noted the standard drafting team’s 

support for re-evaluating the use of linear regression when more experience is gained 

with Reliability Standard BAL-003-1. Accordingly, the Commission proposed to direct 

NERC to develop a modification to Reliability Standard BAL-003-1 to replace use of the 

median with a “more appropriate methodology,” suggesting that “based on the record in 

this docket, it appears that the linear regression method is superior to the median when 

determining the Frequency Response Measure.”36 

 33 NOPR, 144 FERC ¶ 61,057 at P 26.

34 Id. P 25 (citing NERC Petition at 17-18).

35 Id. P 27.

36 Id.
Docket No. RM13-11-000 - 19 -

Comments

28. NERC, IRC and Trade Associations disagree with the NOPR proposal, and 

support use of the median statistical measure. NERC states that the Commission’s 

proposed directive to develop a modification to the methodology for determining the 

Frequency Response Measure is premature. NERC asserts that the standard drafting 

team evaluated different approaches for averaging individual event observations to 

compute a technically sound estimate of Frequency Response Measure, including the 

median and linear regression analysis. NERC also notes that, in the NOPR, the 

Commission indicated that NERC provided adequate rationale for using the median to 

determine the required Frequency Response Measure, and that use of the median is 

supported by the analyses performed to date.37 

29. Trade Associations and IRC also disagree with the Commission’s proposal to 

direct NERC to develop a modification to the proposed standard and assert that the 

standard drafting team selected the most appropriate methodology. Trade Associations

assert that the standard drafting team’s reasoning was “well thought out and balanced

considering the advantages and disadvantages of both approaches (i.e., ‘median’ and 

‘linear regression’).”

38 Trade Associations understand that the standard drafting team

evaluated both methods and found that the median approach consistently produced a 

 37 NERC Comments at 5.

38 Trade Associations Comments at 5; see also IRC Comments at 4.
Docket No. RM13-11-000 - 20 -

more conservative Frequency Response Measure value, and was significantly less likely

to result in calculation errors. Thus, Trade Associations support the median methodology 

because “it is far better to err on the side of having slightly more available reserves than 

not having enough.”

39 Finally, Trade Associations and IRC comment that that the 

median methodology is less complicated and will minimize the compliance risks and 

resource burdens of applicable entities. IRC notes that the frequency response

measurement process is easily susceptible to distortion due to a very large noise to signal 

ratio, and that use of the median discards such “outliers,” while results from linear

regression may be skewed by such “noise.” 

30. BPA raises a concern that use of the median method for determining the 

Frequency Response Measure “gives equal weight to large and small disturbances.”

40 In 

particular, BPA expresses concern with NERC’s proposal to use 20 to 30 events per year 

for calculating the Frequency Response Measure because targeting a fixed number of 

events per year may lead to using relatively small (less than 400 MW) events in 

frequency response calculations. BPA asserts that extrapolating from these small events 

to large events could lead to misleading indications of the Interconnection and balancing 

authority’s performance during large events and “undermine the intent” of the Reliability 

 39 Trade Associations Comments at 5.

40 BPA Comments at 2.
Docket No. RM13-11-000 - 21 -

Standard.41 BPA recommends the following specific revisions to the frequency response 

measurement proposal: (1) use resource loss events equal to or greater than 1,000 MW or 

events with frequency deviations below 59.9 Hz for calculating frequency response, 

rather than a fixed number of events per year; and (2) use the smallest of actual maximum 

design frequency or the maximum design delta from NERC Table 1 Interconnection 

Frequency Response Obligation.

31. In reply comments, NERC responds to BPA’s proposed revisions, stating that the 

values in Table 1 are not static and are revised on an annual basis pursuant to a written 

process for identifying candidate frequency events and an annual review of the 

calculations. Further, NERC explains that the methodology set forth in Table 1 of 

Attachment A to Reliability Standard BAL-003-1 is based on frequency and not the size 

of events, as suggested by BPA.

Commission Determination

32. The Commission does not adopt the NOPR proposal that NERC develop a 

modification to replace the use of the median with a more appropriate methodology and,

instead, approves the use of the median methodology to determine the required

Frequency Response Measure as set forth in Reliability Standard BAL-003-1. As 

indicated by NERC, the standard drafting team considered various approaches for 

averaging individual event observations to compute a technically sound estimate of 

 41 Id. 
Docket No. RM13-11-000 - 22 -

Frequency Response Measure and determined that “the median’s superior resiliency to 

this type of data quality problem [i.e., a data set with outliers] makes it the best 

aggregation technique at the time.”42 We also see merit at this time in IRC’s explanation 

that the frequency response measurement process is susceptible to distortion due to a 

large noise to signal ratio, and that use of the median discards such “outliers.” 

Accordingly, we are persuaded that, based on this record, there is sufficient justification 

for NERC’s use of the median method for determining the required Frequency Response 

Measure in the initial implementation of Reliability Standard BAL-003-1. 

33. Further, with respect to BPA’s concerns regarding NERC’s process for 

determining the appropriate Frequency Response Measure, we agree with NERC’s

explanation that NERC has developed an acceptable methodology for identifying 

candidate frequency events and an annual review of the calculations.43 The methodology 

developed by NERC is based on frequency and not the size of events. Therefore, if any 

revisions are necessary, as BPA suggests, they can be implemented via this established 

review process.44

34. In addition, while the use of the median provides an adequate initial means to 

achieve the objectives of Reliability Standard BAL-003-1, we continue to believe that 

 42 NERC Petition at 17-18.

43 NERC Reply Comments at 3-4.

44 Id.
Docket No. RM13-11-000 - 23 -

over the long term the Reliability Standard can be improved by adopting the linear 

method.45 However, we are persuaded by the comments of NERC and others that 

adopting the linear regression method will insert an additional level of complexity to the 

process, and a directive to that effect would be premature. Accordingly, as stated above,

we do not adopt our NOPR proposal to direct that NERC immediately develop a 

modification to Reliability Standard BAL-003-1 to calculate the Frequency Response 

Measure using linear regression. Rather, the Commission acknowledges NERC’s 

commitment to studying the use of linear regression46 and the analysis contained in the 

Frequency Response Initiative Report,47 and directs NERC to continue its evaluation of 

the use of the linear regression methodology based upon experience and data collected 

following the implementation of BAL-003-1 and to submit a report to the Commission 

within three months after two years of operating experience once Requirement R1 of 

BAL-003-1 becomes effective (i.e., 27 months from the effective date of Requirement 

R1). The report should assess the accuracy of the linear regression methodology 

compared to the median methodology for purposes of determining Frequency Response 

 45 See NOPR, 144 FERC ¶ 61,057 at P 27. One of the recommendations contained 

in NERC’s Frequency Response Initiative Report states that “[l]inear regression is the 

method that should be used for calculating Balancing Authority Frequency Response 

Measure (FRM) for compliance with Standard BAL-003-1-Frequency Response.” 

46 NERC Comments at 6 and NERC Petition at 18, fn. 35.

47 See NERC Petition at 17-18; see also id., Exh. F at 72-78. 
Docket No. RM13-11-000 - 24 -

Measure. Based on this report and actual experience, the Commission may revisit this 

issue. 

B. Determination of Interconnection Frequency Response Obligation

NERC Petition

35. Reliability Standard BAL-003-1 establishes an Interconnection Frequency 

Response Obligation designed to require sufficient frequency response for each 

Interconnection to arrest frequency decline even for severe, but possible, contingencies. 

The methodology for determining each Interconnection’s obligation for obtaining the 

necessary amount of frequency response is set forth in Attachment A of the Reliability 

Standard. The Interconnection Frequency Response Obligation is based on the “resource 

contingency criteria,” which is the largest “Category C” event for the Interconnection,48

except for the Eastern Interconnection, which uses the largest event and maximum actual 

change in frequency in the last ten years.

49 The maximum change in frequency is 

calculated by adjusting the starting frequency for each Interconnection by the “prevailing 

UFLS first step,” i.e., under-frequency load shedding for the Interconnection as adjusted 

by specific information on the frequency deviations for the observed events which make 

 48 See Reliability Standard BAL-003-1, Attachment A at 1. Category C events are 

defined in Reliability Standard TPL-003-0 (System Performance Following Loss of Two 

or More Bulk Electric System Elements), Table 1. 

49 For the Eastern Interconnection, the largest event in the last ten years is the loss 

of 4,500 MW of generation, which occurred on August 4, 2007. See Reliability Standard 

BAL-003-1, Attachment A at 1; Frequency Response Initiative Report at 34-37, 54.
Docket No. RM13-11-000 - 25 -

up the data-set used to calculate the Frequency Response Measure.50 For multiple 

balancing authority Interconnections, the Frequency Response Obligation is allocated to 

balancing authorities based on the formula set forth in Attachment A. FRS Form 1 and 

the underlying data retained by the balancing authorities are used for measuring whether 

frequency response was provided. 

NOPR

36. In the NOPR, with respect to the determination of the Interconnection Frequency 

Response Obligation, the Commission discussed two matters: (1) Eastern 

Interconnection – prevailing first step of under-frequency load shedding and (2) Western 

Interconnection – identifying the largest N-2 contingency.

1. Eastern Interconnection – Prevailing UFLS First Step

37. For the Eastern Interconnection, Attachment A to the Reliability Standard

identifies 59.5 Hz as the “first step” of under-frequency load shedding in the calculation 

of the default Interconnection Frequency Response Obligation. Attachment A notes that 

this set point is “a compromise value set midway between the stable frequency minimum 

established in Reliability Standard PRC-006-1 (59.3 Hz) and the local protection under 

 50 Id. Under-frequency load shedding is intended to be a safety net to prevent 

against system collapse from severe contingencies. The resource contingency criterion is 

selected to avoid violating the under-frequency load shedding settings. See NERC 

Petition, Exh. D at 36 (“in general, the goal is to avoid triggering the first step of under‐

frequency load shedding (UFLS) in the given Interconnection for reasonable 

contingencies expected”).
Docket No. RM13-11-000 - 26 -

frequency load shedding setting of 59.7 Hz used in Florida and Manitoba.”

51 The NERC 

Frequency Response Initiative Report notes that the Florida Reliability Coordinating 

Council (FRCC) concluded that the Interconnection Frequency Response Obligation 

starting frequency of the prevalent 59.5 Hz for the Eastern Interconnection is acceptable 

because it imposes no greater risk of triggering under-frequency load shedding operation

for contingencies internal to FRCC than for contingencies external to FRCC.

52 

38. Noting that the actual first-step of under-frequency load shedding for the Eastern 

Interconnection is 59.7 Hz, the NOPR sought comment on the technical source or support 

for NERC’s statement that the first-step value of 59.5 Hz in the calculation of the 

Interconnection Frequency Response Obligation imposes no greater risk of underfrequency load shedding operation in FRCC for an external resource loss than for an 

internal FRCC event. Also, the NOPR sought clarification of whether the intent of the 

proposal is that FRCC will start shedding load automatically before an event meets the 

value of 59.5 Hz used in the Reliability Standard to determine the Interconnection 

Frequency Response Obligation. 

Comments

39. NERC, Trade Associations, and MISO submitted comments in support of using 

the prevailing under-frequency load shedding first step for the Eastern Interconnection of

 51 Reliability Standard BAL-003-1, Attachment A at 2.

52 See Frequency Response Initiative Report at 4, n.3.
Docket No. RM13-11-000 - 27 -

59.5 Hz. Trade Associations state that they understand that FRCC has evaluated the 

impact of the proposed standard and has determined that the probability of a load 

shedding event caused by a generation loss within the Eastern Interconnection is 

comparable with an event internal to the FRCC region.53 

40. NERC comments that FRCC’s 59.7 Hz under-frequency load shedding setting is 

designed to arrest dynamic transients for system events occurring on the Florida 

peninsula to avoid separation from the rest of the Eastern Interconnection. NERC states 

that further analysis by NERC showed that the under-frequency load shedding settings on 

the Florida peninsula are not susceptible to activation even by very large resource losses 

within the main body of the Eastern Interconnection. NERC explains that “[u]sing the 

‘generic’ dynamics case available, a follow-on analysis was performed by NERC staff to 

determine the general order of magnitude of a frequency event that could be sustained by 

the Eastern Interconnection without violating the 59.7 Hz first step under-frequency load 

shedding in FRCC. A simulation was run that tripped about 8,500 MW of generation in 

the southeast United States (north of Florida).”

54 NERC further states that the simulation 

showed that the lowest frequency resulting from that event would be about 59.76 Hz in 

southern Florida. 

 53 Trade Association Comments at 6.

54 NERC Comments at 13.
Docket No. RM13-11-000 - 28 -

41. NERC further states that the initial nadir of 59.78 Hz in southern Florida from the 

simulation is lower than the nadir in northern Florida due to the wave properties of the 

disturbance.

55 Finally, NERC asserts that because the simulation was conducted with 

nearly twice the 4,500 MW resource loss used to determine the Interconnection 

Frequency Response Obligation for the Eastern Interconnection, it is prudent to conclude 

that the smaller resource loss could not generate a transient or momentary system 

disturbance that would trip the FRCC 59.7 Hz under-frequency load shedding. For these

reasons, NERC concludes that the proposed first-step value of 59.5 Hz is adequately 

supported by technical considerations.56 

42. MISO also supports the proposed first-step value of 59.5 Hz for the Eastern 

Interconnection and asserts that NERC has provided sufficient support for using the 

59.5 Hz value. According to MISO, the FRCC 59.7 Hz frequency value reflects local 

concerns specific to Florida, based on the observation that an event in Florida causes a 

wider frequency swing locally than what propagates out to the rest of the Eastern 

Interconnection. MISO asserts that there has been no recorded case of frequency in the 

Eastern Interconnection declining to 59.7 Hz.

57 MISO further submits that, given the 

localized nature of the concerns supporting the first-step value in Florida, and the extreme 

 55 The “nadir” is the lowest point at which frequency excursion is arrested. 

Frequency Response Initiative Report at 13.

56 NERC Comments at 14.

57 MISO Comments at 5.
Docket No. RM13-11-000 - 29 -

nature of the event that would be required to drive Interconnection-wide impact, NERC 

has sufficient justification for establishing 59.5 Hz as the first-step value for the Eastern 

Interconnection.

Commission Determination

43. The Commission accepts NERC’s and MISO’s explanation of the technical 

support for using 59.5 Hz as the “first step” of under-frequency load shedding in the 

calculation of the default Interconnection Frequency Response Obligation. The 

Commission also agrees with Trade Associations’ assertion that FRCC has evaluated the 

impact of the proposed standard and has determined that the probability of a load 

shedding event caused by a generation loss within the Eastern Interconnection is 

comparable with an event within the FRCC region. Accordingly, the Commission is 

satisfied with the NOPR responses and takes no further action on this matter.

2. Western Interconnection – Largest N-2 Event

NERC Petition

44. The Interconnection Frequency Response Obligation is based on the largest 

Category C event, or N-2 (loss of two or more bulk electric system elements) for the 

Interconnection. The default Interconnection Frequency Response Obligation for the 

Western Interconnection is based on the loss of two Palo Verde generating station units,

which results in a resource contingency criterion of 2,740 MW.

58 NERC indicated in its 

 58 See Frequency Response Initiative Report at 53.
Docket No. RM13-11-000 - 30 -

petition that the default Interconnection Frequency Response Obligation calculation 

scenarios and the calculation of the Frequency Response Measure for the Western 

Interconnection do not take into account the intentional tripping of generation that will 

occur during the operation of specific remedial action schemes. According to the 

Frequency Response Initiative Report, operation of the Pacific Northwest Remedial 

Action Scheme trips up to 3,200 MW of generation in the Pacific Northwest due to the

loss of the Pacific DC Intertie.59 The Frequency Response Initiative Report recommends 

that NERC and the Western Interconnection analyze the Frequency Response Obligation 

allocation implications of the activation of the Pacific Northwest Remedial Action 

Scheme that trips 3,200 MW of generation for a single contingency.

60 

NOPR

45. In the NOPR, the Commission expressed concern regarding whether the N-2 

contingency identified as an input to the Attachment A methodology for calculating the 

Interconnection Frequency Response Obligation accurately identifies the largest N-2 

event in the Western Interconnection. The NOPR referenced the Frequency Response 

Initiative Report, which indicates that the Pacific Northwest Remedial Action Scheme 

 59 The Pacific Northwest Remedial Action Scheme, among other things, blocks 

frequency response from a number of generators and Balancing authorities to avoid 

overloading the Pacific AC ties. See Frequency Response Initiative Report at 62.

60 See id. NERC noted that the maximum value of the Pacific Northwest Remedial 

Action Scheme has been updated to be 2,850 MW. See NERC Petition, Exh. G (Status of 

Recommendations of the Frequency Response Initiative Report).
Docket No. RM13-11-000 - 31 -

could result in a larger contingency that, if included as an input to the Attachment A 

calculation, would produce more accurate results.61 Accordingly, the Commission 

proposed in the NOPR to direct NERC to submit a report that analyzes, with supporting 

documentation, the implications of the Pacific Northwest Remedial Action Scheme or 

any other Remedial Action Scheme which involves intentional tripping of greater than

2,400 MW of generation, and whether such a contingency would provide a more accurate 

basis for the determination of the Western Interconnection default Interconnection 

Frequency Response Obligation. 

Comments

46. Trade Associations comment that they recognize the Commission’s issue and have 

no concerns with a directive mandating the ERO to study the implications of the Pacific 

Northwest Remedial Action Scheme and other similar arrangements that intentionally 

involve the tripping of greater than 2,400 MW of generation. 

47. BPA comments that “[Remedial Action Scheme] events should not determine the 

Resource Contingency Criteria in the Western Interconnection” because, inter alia, 

simulation of Remedial Action Scheme events and two Palo Verde events show similar 

system frequency performance and “RAS events off-load the system stress ... while an 

unplanned 2 Palo Verde unit outage would increase the system stress.”

62

 61 See NOPR, 144 FERC ¶ 61,057 at P 32.

62 See BPA Comments at 7 (providing additional rationale for not considering 

Remedial Action Scheme events).
Docket No. RM13-11-000 - 32 -

 Commission Determination

48. In light of NERC’s December 30, 2013 annual analysis informational filing, we

will not adopt our NOPR proposal. In its 2013 annual analysis NERC explains that 

“[Remedial Action Schemes] in the Western Interconnection that trip generation 

resources in excess of 2,400 MW for transmission system contingencies should not be 

used for the resource contingency protection criteria for the Western Interconnection. 

Because of the location of the resources tripped and the fact that [Remedial Action 

Schemes] would not be armed to trip those levels of generation under peak conditions, 

the loss of two Palo Verde units is a larger hazard to the interconnection.”63 

Accordingly, the Commission will not direct NERC to submit a report concerning the 

implications of the Pacific Northwest Remedial Action Scheme or any other Remedial 

Action Scheme which involves intentional tripping of greater than 2,400 MW of 

generation, and whether such a contingency would provide a more accurate basis for 

determining the Western Interconnection default Interconnection Frequency Response 

Obligation. We expect, however, that NERC will continue to study any modified or new 

Remedial Action Schemes that may have an impact greater than the tripping of 2,400 

MW in its annual frequency response analysis, including an assessment of the adequacy 

of the resource contingency protection criteria for the Western Interconnection. 

 63 NERC’s 2013 Annual Analysis at 2.
Docket No. RM13-11-000 - 33 -

49. While BPA advocates that Remedial Action Schemes should not be considered in 

determining the Interconnection Frequency Response Obligation, BPA did not provide 

support in the record for its claim that activation of Remedial Action Schemes will reduce 

system stress while the loss of two Palo Verde units will increase it. Contrary to BPA’s 

argument, we believe that it is appropriate to study this matter, as NERC has done, and 

take possible future action depending on study results because if the obligation is set too 

low, the Western Interconnection may not have sufficient frequency response to arrest 

frequency decline.

C. Method of Obtaining Frequency Response

50. In Order No. 693, the Commission directed NERC to develop a modification to 

BAL-003-0 that includes methods for obtaining frequency response.64 While the 

Reliability Standard establishes an Interconnection Frequency Response Obligation and 

allocates this obligation to the balancing authorities within the Interconnection, the 

Reliability Standard imposes no obligation on resources that are capable of providing 

frequency response. 

 64 Order No. 693, FERC Stats. & Regs. ¶ 31,242 at P 375. The Commission 

directed NERC to develop a modification to BAL-003-0 that “defines the necessary 

amount of Frequency Response needed for Reliable Operation for each balancing 

authority with methods of obtaining and measuring that the frequency response is 

achieved.” Id. (emphasis added).
Docket No. RM13-11-000 - 34 -

NOPR

51. In the NOPR, the Commission stated that Reliability Standard BAL-003-1 

imposes an obligation, subject to compliance and enforcement, on each balancing 

authority to obtain frequency response. The Commission recognized, however, that 

balancing authorities must obtain frequency response from other entities with available 

resources, and Reliability Standard BAL-003-1 imposes no obligation on those entities to 

provide frequency response. 

52. In the NOPR, the Commission proposed to direct NERC to submit a report 

15 months after implementation of BAL-003-1 that provides an analysis of the 

availability of resources for each balancing authority to meet its Frequency Response

Obligation during the first year of implementation.65 The Commission also proposed that 

the report provide data indicating whether actual frequency response was sufficient to 

meet each balancing authority’s Frequency Response Obligation. Further, the NOPR 

proposed that, if NERC’s findings indicate that the Frequency Response Obligation was 

not met, NERC should provide appropriate recommendations to ensure that frequency 

response can be maintained at all times within each balancing authority’s footprint. 

Comments

53. NERC, Trade Associations, IRC, APS, and ELCON generally support the 

Commission’s proposal that NERC submit a report regarding the availability of resources 

 65 NOPR, 144 FERC ¶ 61,057 at P 34.
Docket No. RM13-11-000 - 35 -

for frequency response. Trade Associations comment that they “recognize the potential 

benefit of such a study,” but suggest that 20 to 24 months is a more reasonable time 

frame for a directive. Trade Associations also ask the Commission to exercise care when 

directing NERC to conduct studies to ensure that scarce resources are not expended 

unnecessarily.

54. NERC commits to submitting an analysis of resource availability as proposed in 

the NOPR. However, NERC provides a detailed timeline for implementation and 

indicates that it will not receive the necessary information from responsible entities until 

March 24 of the year following the implementation of Requirement R1 of BAL-003-1, 

beyond the 15 month time frame proposed in the NOPR. Thus, NERC proposes to 

submit the report “within six months of the validation by the ERO of the Frequency Bias 

Setting values and computation of the sum of all Frequency Bias Setting values for each 

Interconnection and determination of the L 10 values for the CPS 2 criterion for each 

Balancing Authority or, if applicable, confirmation of the Frequency Bias Setting to be 

used for the calculation of the Balancing Authority ACE limit.”66 NERC also seeks 

clarification that the study should analyze the availability of resources for both balancing 

authorities and Frequency Response Sharing Groups, since the latter was not specifically 

mentioned in the NOPR proposal. NERC states that, upon completion of the analysis, 

 66 NERC Comments at 16 (footnote omitted).
Docket No. RM13-11-000 - 36 -

“should the findings indicate that the Frequency Response Obligation was not met, 

NERC will provide appropriate recommendations.”67 

55. Several commenters, including IRC, APS and BPA, raise concerns regarding the 

compliance responsibilities of balancing authorities to meet a Frequency Response 

Obligation. IRC asserts that BAL-003-1 creates an inequitable alignment of compliance 

responsibility and generator performance capability. IRC states that while the obligation 

to meet the frequency response requirements lies with the balancing authority, the ability 

to provide the resources necessary to meet those obligations lies primarily with 

generators. Therefore, while IRC supports the analysis proposed in the NOPR, IRC also 

requests that the Commission direct prospective revisions to the Reliability Standard to 

assign responsibilities based on performance capability. IRC contends that this approach 

is appropriate because balancing authorities have no control over generators’ 

performance in supporting the Frequency Response Obligation assigned to balancing 

authorities.

56. BPA agrees with the Commission that Reliability Standard BAL-003-1 does not 

address the ability of each balancing authority to ensure adequacy of resources to meet its 

frequency response obligations. According to BPA, there is a proposal in WECC to 

develop a regional Reliability Standard complementary to NERC BAL‐003‐1 to address 

this gap. BPA comments that, until such a standard is developed, each balancing 

 67 Id. at 17.
Docket No. RM13-11-000 - 37 -

authority must determine how to meet its own frequency response obligation. BPA states 

that this frequency response, measured by balancing authority interchange, includes not 

only the response of balancing authority generation but also incremental transmission 

losses and natural load response to voltage and frequency.68 Finally, BPA asserts that 

balancing authorities that have to acquire resources will also need to develop monitoring 

capabilities to ensure that the contracted resources provide frequency response and that 

such monitoring will further increase the cost of compliance with Reliability Standard 

BAL-003-1. 

57. APS believes it is appropriate for NERC to study and report on the availability 

of resources. However, APS asserts it is neither just nor reasonable for a balancing 

authority to be held to this requirement when frequency response services are simply not 

available. APS states that until such time that NERC has completed the studies, the 

results are reviewed, and appropriate solutions are developed to assure that affected 

entities have the resources available to comply under all conditions, either the 

implementation of the requirements should be delayed, or in the alternative, those 

balancing authorities who cannot obtain the required frequency response should be 

exempt from the proposed requirements. 

58. APS also proposes that the Commission take a phased-in approach to compliance 

obligations to allow adequate time for necessary activities such as testing generation units 

 68 BPA Comments at 20.
Docket No. RM13-11-000 - 38 -

for ramp-up capability, tuning generation and retesting, as well as time to allow a 

frequency response market to develop. APS comments that the types of resources a 

balancing authority has in its portfolio may significantly impact its ability to comply with 

BAL-003-1 because some resources, such as hydroelectric generation, are more effective 

in responding to frequency declines. APS asserts that it does not have sufficient fastramping resources to provide the required frequency response should the Western 

Interconnection experience an event that results in significant frequency response 

deviation. To address its concern, APS suggests a revision to the definition of a 

Balancing Authority’s “annual generation” to exclude non-responsive units and apply a 

higher weighting factor for responsive units. According to APS, this revision would 

align the allocation of Frequency Response Obligation with a generator’s physical ability 

to provide it.

59. In its reply comments, NERC responds to APS, stating that the standard drafting 

team determined technical evidence indicates that sufficient frequency response resources 

would be available for balancing authorities to comply with the requirements of 

Reliability Standard BAL-003-1.69 Therefore, NERC contends that there is no need to 

adjust the implementation plan for Reliability Standard BAL-003-1 on the basis of 

availability.70 Further, NERC disagrees with APS’s suggestion to revise the definition of 

 69 NERC Reply Comments at 4 (citing NERC Report: State of Reliability 2013 

Report (May 2013), Key Finding 3, Page 12).

70 NERC Reply Comments at 4.
Docket No. RM13-11-000 - 39 -

balancing authority “annual generation,” contending that such a change would create a 

“perverse incentive” for entities to install generating units that are not capable of 

providing Frequency Response. Further, NERC explains in response to APS that the 

Reliability Standard is appropriately technology- neutral, does not require every 

generator to respond and provide Frequency Response, and allows for flexibility since 

Frequency Response is measured on a balancing authority and an Interconnection-wide 

basis and permits the formation of Frequency Response Sharing Groups.

Commission Determination

60. The Commission adopts the NOPR proposal and directs NERC to submit a report 

that provides an analysis of the availability of resources for each balancing authority and 

Frequency Response Sharing Group to meet its Frequency Response Obligation during 

the first year of implementation. However, NERC indicates in its comments that it needs 

more than the proposed 15 months to prepare the report based on the time frame for 

NERC to receive relevant data from applicable entities.71 Accordingly, we direct NERC 

to submit this report within 27 months of implementation of Requirement R1. The 

Commission believes that the need for the report is well justified based on the record in 

the proceeding, including the support of most commenters. While we conclude that 

BAL-003-1 is reasonable and should be approved, it includes a new methodology for 

determining the Frequency Response Obligation and the results when applied are not yet 

 71 See NERC Comments at 16.
Docket No. RM13-11-000 - 40 -

known. Further, as discussed above, the ability of balancing authorities and Frequency 

Response Sharing Groups to meet the obligation is untested. Thus, we believe the 

required report is an appropriate means to inform us as to whether additional steps are 

needed on the Frequency Response Obligation and what those might be. The required 

report should provide data indicating whether actual frequency response was sufficient to 

meet each balancing authority’s Frequency Response Obligation. Further, consistent 

with NERC’s representation in its comments, the Commission directs that, upon 

completion of the required analysis, should the findings indicate that the Frequency 

Response Obligation was not met, NERC shall provide appropriate recommendations to 

ensure that frequency response can be maintained at all times within each balancing 

authority’s footprint.72

61. In response to the concerns expressed by the IRC, BPA and APS that balancing 

authorities may not have control over adequate resources necessary to support the 

Frequency Response Obligations assigned to the balancing authorities, we will not forego 

compliance or delay implementation. Certainly, a balancing authority’s ability or 

inability to draw on the necessary resources to meet the compliance obligations of BAL003-1 might be a potential mitigating factor in a compliance action, depending on the 

efforts made to obtain resource commitments. Moreover, NERC and its stakeholders 

had, and still have, the option to propose a Reliability Standard imposing obligations 

 72 See NERC Comments at 17.
Docket No. RM13-11-000 - 41 -

directly on resources, if they find it appropriate. (Similarly, we may consider a directive 

for such a Standard or other options such as market or tariff mechanisms, if appropriate.) 

However, we are not persuaded that a blanket waiver or delay in compliance is 

warranted.

62. While we share concerns regarding the ability of balancing authorities and 

Frequency Response Sharing Groups to meet the Frequency Response Obligation 

pursuant to BAL-003-1, we do not believe that such changes are warranted based on the 

current record in the proceeding. Rather, a recent NERC study indicates that sufficient 

frequency response resources would be available for balancing authorities to comply with 

the requirements of Reliability Standard BAL-003-1.73 Further, as noted by NERC, 

Reliability Standard BAL-003-1 provides flexibility, for example by allowing entities to 

form Frequency Response Sharing Groups to meet the Frequency Response Obligation. 

Likewise, we are not persuaded by APS that a change to the definition of balancing 

authority annual generation is warranted at this time, and we are concerned that APS’s 

suggestion would change the resource-neutral approach of the standard.

63. We do not discount the concerns of APS and others regarding resource 

availability. However, we believe that the prudent course is to have NERC complete the 

 73 See NERC Reply Comments at 4 (citing NERC Report: State of Reliability 

2013 Report (May 2013), Key Finding 3, Page 12). See also APS Comments at 8 (“[a]s 

NERC Reported in its recent State of Reliability 2013 Report, from 2009 to 2012 

interconnection frequency response performance, and expected frequency response ... 

has been higher than the recommended interconnection frequency response obligation”).
Docket No. RM13-11-000 - 42 -

directed report. The Commission will review NERC’s report, any related 

recommendations from NERC, and the record developed in Docket No. AD13-8 

regarding the market implications of frequency response requirements,

74 to determine 

whether additional action is warranted. However, if prior to the deadline for the report 

NERC learns that a lack of resource availability could prevent achieving the purpose of 

Reliability Standard BAL-003-1, (e.g., balancing authorities are experiencing problems 

procuring sufficient resources to satisfy their frequency response obligations), NERC 

should immediately report that to the Commission together with appropriate 

recommendations for mitigation.75 

D. Premature Withdrawal of Primary Frequency Response

NERC Petition

64. In its petition, NERC indicated that, while the standards drafting team addressed 

the early withdrawal of primary frequency response, there are no requirements that 

address this issue and it remains a concern.76 Specifically, during the initial recovery 

 74 See Market Implications of Frequency Response and Frequency Bias Setting 

Requirements, 144 FERC ¶ 61,058 (2013).

75 For example, in such circumstances, NERC could look to regional Reliability 

Standard BAL-001-TRE-01, approved concurrently with this Final Rule, which contains 

provisions for assuring frequency response in the ERCOT Interconnection.

76 See NERC Petition, Exh. D (Frequency Response Standard Background 

Document) at 19 (“the intentional withdrawal of response before frequency has been 

restored to schedule can cause a decline in frequency beyond that which would be 

otherwise expected. This intentional withdrawal of response is highly detrimental to 

(continued...)
Docket No. RM13-11-000 - 43 -

from the loss of a generator, a gap can occur if a significant amount of primary frequency 

response is withdrawn before the secondary response is fully activated. As previously 

noted, the Interconnection Frequency Response Obligation for each Interconnection is a 

function of the resource contingency criteria and the maximum change in frequency.77

65. NERC’s Frequency Response Initiative Report states that “[w]ithdrawal of 

primary frequency response is an undesirable characteristic associated most often with 

digital turbine-generator control systems using set point output targets for generator 

output. These are typically outer-loop control systems that defeat the primary frequency 

response of the governors after a short time to return the unit to operating at a requested 

MW output.”78 The Frequency Response Initiative Report recommends measuring and 

tracking frequency response sustainability trends.79 The Frequency Response Initiative 

Report also recommends that “NERC should include guidance on methods to reduce or 

eliminate the effects of primary frequency response withdrawal by outer-loop unit or 

plant control systems.”80

 

reliability. Therefore, it can be concluded in general that sustained response has a higher 

reliability value than un‐sustained response.”).

77 The maximum change in frequency is an amount of frequency deviation based 

on the loss of the identified resource contingency that will not trigger under-frequency 

load shedding.

78 NERC Petition, Exh. F (Frequency Response Initiative Report) at 31.

79 Id. at 35. The Frequency Response Initiative Report also recognizes unit 

characteristics and operating philosophies as typical causes.

80 Id. at 41-42.
Docket No. RM13-11-000 - 44 -

NOPR

66. In the NOPR, the Commission explained that “following the sudden loss of 

generation, the automatic and immediate increase in power output by resources providing 

primary frequency control seeks to quickly arrest and stabilize the frequency of the 

interconnection, usually within 30 seconds or less. After this rapid primary frequency 

response, AGC provides secondary frequency response to return frequency to the 

scheduled value in time frames of several minutes after the loss of generation.”

81 

However, the withdrawal of a significant amount of primary frequency response before 

the secondary frequency response is activated can cause a further drop in frequency 

response. This drop in frequency is illustrated by the following diagram:82

 81 NOPR, 144 FERC ¶ 61,057 at P 35.

82 Id. P 35 (citing Frequency Response Initiative Report at 35, fig. 21).
Docket No. RM13-11-000 - 45 -

67. In the NOPR, the Commission expressed concern that Reliability Standard BAL003-1 does not adequately address the reliability issue created by the withdrawal of 

primary frequency response prior to activation of secondary frequency response. The 

withdrawal of primary frequency response before the activation of resources providing 

secondary frequency response may lead to under-frequency load shedding and possible 

cascading outages. Accordingly, the Commission proposed to direct NERC to develop a 

modification to BAL-003-1 to address the concern of premature withdrawal of primary 

frequency response prior to the activation of secondary frequency response. 

1. Event

2. Primary Response

3. Early Withdrawal 

of Primary Response
Docket No. RM13-11-000 - 46 -

Comments

68. NERC disagrees with the need for the proposed directive. First, NERC asserts

that Form 1 of the Reliability Standard addresses premature withdrawal of frequency 

response and suggests that experience with the actual implementation of the Reliability 

Standard will better indicate whether premature withdrawal is an issue that requires 

revisions to the Reliability Standard and, if necessary, definitions of the scope and 

parameters of the potential issue. Second, NERC notes that the premature withdrawal 

issue could be impacted by the Commission’s ongoing effort to determine whether action 

is necessary to coordinate the requirements of the Reliability Standard with tariffs and 

market rules.

83 Third, NERC asserts the issue of premature withdrawal can be addressed 

with other mechanisms rather than a revision to the Reliability Standard. Finally, NERC

states that it “commits to monitoring the issue of premature withdrawal on a goingforward basis and will submit an informational filing two years after Requirement R1 of

Reliability Standard BAL-003-1 becomes effective.”

84 

69. NERC maintains that the standard drafting team accounted for the issue of 

premature withdrawal of frequency response in the calculation of the B-value averaging 

period within the Frequency Response Measure. NERC states that “[t]he team 

recognized that there would be more AGC response in the 20 to 52 second period, but the 

 83 See Market Implications of Frequency Response and Frequency Bias Setting 

Requirements, 144 FERC ¶ 61,058 (2013).

84 NERC Comments at 7.
Docket No. RM13-11-000 - 47 -

team also recognized that the 20 to 52 second period would provide a better measure of 

squelched response from outer loop control action. The 20 to 52 second period was 

selected because it would indicate squelched response from outer‐loop control and 

provide incentive to reduce response withdrawal.”85 NERC further explains that if there 

is withdrawal of primary frequency response during the 20 to 52 second interval, the 

metric will have a lower value, which will then lower an entity’s median score thereby

impacting compliance with Requirement R1 of Reliability Standard BAL-003-1. 

70. NERC also maintains that, while Reliability Standard BAL-003-1 applies to 

balancing authorities and Frequency Response Sharing Groups, the premature withdrawal

issue applies to generators. Therefore, NERC asserts, the withdrawal issue could be 

addressed with alternative mechanisms, including other Reliability Standards or 

guidelines. NERC further asserts that there are emerging technologies that can and will 

affect withdrawal, including energy storage devices. NERC notes that the premature 

withdrawal issue could be affected by whatever tariff or market solutions the 

Commission may adopt in related Docket AD13-8. For these reasons, NERC believes

the Commission’s proposed directive requiring a specific solution, i.e., a modification to

BAL-003-1 Reliability Standard, is premature. NERC states that, consistent with the 

recommendations in the Frequency Response Initiative Report, it will evaluate whether a 

modification to Reliability Standard BAL-003-1 is necessary to address premature 

 85 NERC Comments at 9 (citing NERC Petition, Exh. D at 13).
Docket No. RM13-11-000 - 48 -

withdrawal and will submit an informational filing to the Commission two years after 

Requirement R1 of Reliability Standard BAL-003-1 becomes effective.

86 

71. Trade Associations disagree with the Commission’s concern over premature 

withdrawal of frequency response. Trade Associations state that Reliability Standard 

BAL-003-1, along with other Reliability Standards awaiting implementation, such as 

BAL-001-2, sufficiently addresses this concern. Trade Associations assert that the 

Eastern Interconnection has significant inertia which buffers the initial drop in frequency 

in major events making premature primary frequency response withdrawal more 

apparent. Trade Associations state that the exemplary post-contingent recovery of all 

Interconnections’ frequency as demonstrated over time supports their view that premature 

withdrawal is not a significant factor at this time. Finally, Trade Associations state that 

the desired outcome of automatic generation control for a balancing authority should 

result in a dispatch of resources to meet the secondary control requirements of NERC 

BAL-001. Based upon the overall balance of resources and demand, Trade Associations

assert that automatic generation control may at times, guide individual regulating 

resources within a balancing authority, where a positive ACE exists, to withdraw energy 

(i.e., to reduce ACE) to meet the secondary control requirements of CPS2 under 

Reliability Standard BAL-001-1. Trade Associations assert that the response of such a

 86 Id. at 10.
Docket No. RM13-11-000 - 49 -

unit would be to withdraw support, thereby resulting in an outcome contrary to the desire

to sustain frequency response.87 

72. IRC states that the Commission’s concern about premature withdrawal of 

frequency response is unwarranted. IRC maintains that the Commission should adopt a 

more comprehensive perspective, taking into account frequency response and withdrawal 

patterns over an extended period of time and across Interconnections to understand the 

potential impact of premature withdrawal. IRC states that data collected and analyzed 

during the standard drafting team’s field trial indicated how quickly and steadily

frequency is, on average, brought back to a stable level over a five minute response 

window in all three Interconnections. IRC explains that the standard drafting team 

considered data regarding the mean frequency recovery rate (mHz/Sec) for all frequencyrelated events in each of the major Interconnections from 2010 to 2013. IRC states that 

early withdrawal of primary frequency response has not been a significant problem 

because “most responses are incomplete at the time that frequency has been initially 

arrested and the additional response has generally been sufficient to make up for more 

than these unpreventable reductions in response.”88

73. ELCON states that secondary frequency response (Regulation) is primarily 

delivered through automatic generation control, which is governed by Reliability 

 87 Trade Associations Comments at 8-9.

88 IRC Comments at 10.
Docket No. RM13-11-000 - 50 -

Standard BAL-005-0.2b. That Reliability Standard contains requirements applicable to 

balancing authorities which therefore, ELCON states, have “the responsibility to ensure 

its operability.”89 ELCON further states that Reliability Standard TOP-003-1 calls for 

generator operators to coordinate planned outages with transmission operators, who are 

required to share that information with balancing authorities. Therefore, ELCON asserts 

that “[t]his means that the [balancing authority] is aware of all AGC capacity that will be 

unavailable due to planned maintenance well ahead of time—and can plan mitigating 

actions accordingly.”90 ELCON also asserts that Reliability Standard PRC-024-1has 

requirements intended to ensure that generator operators can ride through specifically 

defined frequency deviations, “which can best assure their availability when needed for 

secondary frequency response support.”

91 ELCON suggests that generator concerns with 

possible violations of Reliability Standard PRC-024-1, such as dropping off-line during a 

frequency transient within the standard’s “no-trip zones,” could provide incentives 

against premature withdrawal.

74. BPA states that it shares the Commission’s concerns on early withdrawal of 

frequency response and provides a recorded frequency response withdrawal by a 

 89 ELCON Comments at 8.

90 Id.

91 Id. 
Docket No. RM13-11-000 - 51 -

combined cycle plant.

92 BPA states that the withdrawal was caused by load controllers 

implemented at many power plants and suggests that load controllers include a frequency 

bias term, similar to automatic generation control, to allow plants to sustain their 

frequency response. BPA asserts that the sustainability of frequency response is essential 

not only for Interconnection system frequency support, but also for voltage stability when 

the response withdrawal causes excessive loading on stability‐limited transmission 

paths.93

Commission Determination

75. The Commission is persuaded not to adopt the NOPR proposal to require NERC 

to develop a modification to Reliability Standard BAL-003-1 to address premature 

withdrawal of frequency response. The Commission believes that the nature and extent 

of the problems that could result from the premature withdrawal of primary frequency 

response, and how best to address it if necessary, will be better understood after NERC 

and balancing authorities have more experience with Reliability Standard BAL-003-1. 

Accordingly, in light of NERC’s December 30, 2013 annual analysis informational filing, 

the Commission expects NERC to continue to evaluate the impact of the withdrawal of 

primary frequency response before secondary frequency response is activated in its 

annual analyses. 

 92 BPA Comments at 14-15.

93 Id. at 15.
Docket No. RM13-11-000 - 52 -

76. The Commission recognizes BPA’s concerns about the early withdrawal of 

frequency response, particularly the possibility that load controllers may prematurely 

over-ride primary frequency response. However, we agree with NERC that the need to 

take action, including requiring load controllers to include a frequency bias term similar

to AGC to sustain frequency response or otherwise modifying Reliability Standard BAL003-1, should be decided after we have actual experience with the Reliability Standard. 

E. Light Load Case Study

NOPR

77. In the NOPR, the Commission highlighted NERC’s conclusion in its Frequency 

Response Initiative Report that “[s]ustainability of primary frequency response becomes 

more important during light-load conditions when there are generally fewer frequencyresponsive generators online.”94 Light load conditions require special consideration 

because inertia, i.e., the resistance to a change in the motion of an object, plays a crucial 

role in how fast frequency declines following the sudden loss of generation.95 In the 

NOPR, the Commission further explained that “[W]hen the inertia on the system is low 

 94 NOPR, 144 FERC ¶ 61,057 at P 39 (quoting Frequency Response Initiative 

Report at 32).

95 Id. Inertia is provided from the stored energy in the rotating mass of the 

turbine-generators and synchronous motors on the Interconnection. See NERC Petition,

Exh. D at 16-17.
Docket No. RM13-11-000 - 53 -

(i.e. fewer generators on line), the loss of generation creates a steeper frequency 

excursion and thus the need for faster frequency response.”

96 

78. In the NOPR, the Commission focused on the resource contingency criterion in 

Reliability Standard BAL-003-1 for calculating the Interconnection Frequency Response 

Obligation for the Eastern Interconnection, and the potential concerns with the use of an 

event that took place during heavy system load conditions. The use of a generic governor 

stability case in the stability simulation testing for the Eastern Interconnection resource 

contingency criteria used in the determination of the Interconnection Frequency Response 

Obligation represented conditions far different than light-load conditions. This raises 

questions regarding whether, and by what amount, light load conditions would lower

system inertia and load response. The Frequency Response Initiative Report 

recommended the development of a new light-load case study, and the re-simulation of 

the resource contingency criterion for the Eastern Interconnection Frequency Response 

Obligation.

97 According to NERC, the Eastern Interconnection Reliability Assessment 

Group is preparing an updated generic governor 2013 summer light-load case (from the

 96 Id. (quoting Frequency Response Initiative Report at 40). The reduction in 

inertia also drives a need for higher speed response to frequency excursions. 

97 NERC Petition, Exh. F, Frequency Response Initiative Report at 99.
Docket No. RM13-11-000 - 54 -

2012 case series), and NERC will be evaluating the Eastern Interconnection Frequency 

Response Obligation during the expected light-load conditions.98 

79. The Commission agreed with NERC that the study of light-load scenarios is useful 

in determining an appropriate Interconnection Frequency Response Obligation, especially

for the Eastern Interconnection.99 Accordingly, the Commission proposed to direct 

NERC to submit the results of the light-load case, together with NERC’s 

recommendations on whether further actions are warranted. 

Comments

80. BPA, Trade Associations, and IRC submitted comments agreeing with the 

Commission that the study of light-load scenarios is useful in determining an appropriate

 98 NERC Petition, Exh. G. A study conducted by the National Renewable Energy 

Laboratory explored the relationship between system disturbance and grid frequency 

perturbation. See National Renewable Energy Laboratory, Eastern Frequency Response 

Study (May 2013). A key finding is that the dynamic model of the Eastern 

Interconnection can be adjusted to more closely capture the observed behavior. In 

particular, the assumed amount of generation with governor controls activated was 

increased to model the contingency used in calculating the Eastern Interconnection 

Frequency Response Obligation. In addition, a light load power flow case was selected 

with the expectation that it would represent one of the more challenging conditions for 

the Eastern Interconnection with respect to frequency response. See 

http://www.nrel.gov/docs/fy13osti/58077.pdf.

99 According to NERC, “[m]odeling of frequency response characteristics has been 

a known problem since at least 2008, when forensic modeling of the Eastern 

Interconnection required a ‘de-tuning’ of the existing [Multiregional Modeling Working 

Group] dynamics governor to 20% of modeled (80% error) to approach the measured 

frequency response values from the [August 4, 2007] event.” See NERC Petition, Exh. F, 

Frequency Response Initiative Report at 35.
Docket No. RM13-11-000 - 55 -

Interconnection Frequency Response Obligation, especially for the Eastern 

Interconnection. 

81. IRC states that it does not oppose the development of a new light-load case study, 

but believes that better modeling data needs to be collected before an accurate study can 

be conducted. IRC states that “[i]n particular, inaccurate modeling of governor 

deadbands and adjustments to model governor performance based on observed 

performance for frequency excursions will lead to inaccurate assumptions of performance 

for extreme events during light-load.”

100 IRC encourages the Commission to direct that 

NERC partner with industry to compile the appropriate information needed to ensure an 

accurate case study, and to review that study through an industry stakeholder process. 

Finally, the IRC states that while it agrees that a new light-load case study would be 

useful, the study should also look at tools to estimate frequency response in real time. 

82. BPA states that while frequency response is expected to be lower during off-peak 

light load conditions, there have not been a sufficient number of events under light load 

conditions to confirm the severity of the problem. BPA states that currently all WECC 

regions are exceeding their frequency response obligations. 

83. The Trade Associations support the Commission’s proposal to direct NERC to 

submit their light-load case study and recommendations. 

 100 IRC Comments at 11.
Docket No. RM13-11-000 - 56 -

Commission Determination

84. The Commission adopts the proposal in the NOPR and directs NERC to submit 

the results of the Eastern Interconnection Reliability Assessment Group’s light-load case, 

using actual turbine governor response data. Additionally, the Commission directs 

NERC to submit a recommendation on whether further actions are warranted no later 

than 15 months after implementation of the Final Rule. Further, the report should discuss

any appropriate changes to the Interconnection Frequency Response Obligation 

warranted by the study. 

F. Assignment of Violation Risk Factors and Violation Severity Levels

1. Violation Risk Factor for Requirement R1

NOPR 

85. In the NOPR, the Commission proposed to approve each violation risk factor 

assignment NERC proposed for a requirement of the proposed Reliability Standard, with 

one exception. The Commission indicated that NERC did not adequately justify 

assignment of a medium violation risk factor to Requirement R1, which establishes the 

Frequency Response Measure that a balancing authority must achieve to arrest a decline 

in system frequency. While NERC asserted that a violation of this requirement will not 

cause bulk electric system instability, separation or cascading failures because “a 

balancing authority’s previous year’s Frequency Bias setting is included within its ACE 

equation and would provide support for the contingency,” the Commission indicated that 

this explanation does not apply to Requirement R1. The Commission noted that the ACE 

equation provides input to secondary frequency control, which differs from the primary 
Docket No. RM13-11-000 - 57 -

control needed to arrest a frequency decline, as established by Requirement R1. The 

Commission proposed to direct NERC to assign a high violation risk factor to 

Requirement R1 because (1) NERC described frequency response as a critical component 

to the reliable operation of the Bulk-Power System, indicating that Requirement R1 does 

not impose merely an administrative burden, and (2) the medium violation risk factor that 

the Commission approved for each BAL-003-0.1b requirement does not apply to 

Requirement R1 because it has no equivalent in that standard.

101 The Commission 

sought comments on this proposal.

Comments 

86. Trade Associations state that while Requirement R1 may merit a high violation 

risk factor, responsible entities must achieve an annual Frequency Response Measure as 

calculated in accordance with Attachment A to Reliability Standard BAL-003-1. The 

Trade Associations therefore observe that it would be inappropriate to apply the violation 

risk factor for Requirement R1 to a single event rather than to an annual Frequency 

Response Measure.102 

87. Commenting that the standard drafting team took a rational approach to its 

violation risk factor assignments, and that each such assignment appears appropriate and 

well-reasoned to approximate the impact of a violation on reliability, IRC requests that 

 101 NOPR, 144 FERC ¶ 61,057 at P 42.

102 Trade Associations Comment at 10-11.
Docket No. RM13-11-000 - 58 -

the Commission accept the medium violation risk factor for Requirement R1 as 

developed by the standard drafting team and agreed to by industry.103 

88. APS disagrees with the Commission’s proposal to assign a high violation risk 

factor to Requirement R1. APS agrees with NERC that a violation of this requirement 

will not cause Bulk Electric System instability, separation or cascading failures. APS 

maintains that frequency response in the Western Interconnection is and has been stable. 

APS states that there are almost forty balancing authorities in the Western 

Interconnection, and even if individual balancing authorities should fall short of their 

obligation, there is no measurable risk to the Interconnection.104 

89. APS also states that the worst case scenario from a violation of Requirement R1 is 

some loss of load due to under-frequency load shedding. APS contends that over the last 

fifteen years in the Western Interconnection, frequency has not declined below 59.7 Hertz 

for a generation loss of 3,000 megawatts or less. APS states that the first underfrequency load shedding in the Western Interconnection occurs at 59.5 Hertz, and hence, 

there has not been a significant impact to the bulk electric system for loss of generation. 

APS submits that a medium violation risk factor is appropriate.105

 103 IRC Comments at 12.

104 APS Comments at 9.

105 APS Comments at 9.
Docket No. RM13-11-000 - 59 -

Commission Determination 

90. We direct NERC to change the violation risk factor for Requirement R1 to “high,” 

as proposed in the NOPR. No commenter disagreed with the Commission’s observation 

that Requirement R1 addresses primary frequency control that is necessary to arrest 

frequency decline within seconds after it begins. Without sufficient primary frequency 

control, a frequency decline may not be arrested in sufficient time to prevent instability, 

uncontrolled separation or cascading failures. While APS maintains that frequency in the 

Western Interconnection is and has been stable, that stability depends on compliance with 

Requirement R1 by balancing authorities that have sufficient resources to meet 

Requirement R1. The fact that one entity’s violation of Requirement R1 may be offset by 

the efforts of others is not a basis for ignoring or downplaying the substantial risk posed 

by inadequate frequency response. Accordingly, we conclude that a “high” violation risk 

factor for Requirement R1 is appropriate. We agree with Trade Associations that 

Requirement R1 mandates achievement of an annual Frequency Response Measure, and 

that compliance with that requirement cannot be determined by a single event. 

2. Violation Severity Levels for Requirement R1

NOPR

91. In the NOPR, the Commission proposed changes to NERC’s proposed violation 

severity level assignments for Requirement R1. NERC proposed two violation severity 

levels depending upon whether a balancing authority or a Frequency Response Sharing 

Group has an annual Frequency Response Measure “less negative than its Frequency 

Response Obligation by more than 1 percent but by at most 30 percent or 15 MW/0.1Hz, 
Docket No. RM13-11-000 - 60 -

whichever one is the greater deviation from its [Frequency Response Obligation].” This 

violation would have a “lower” severity level if “[t]he summation of the Balancing 

authorities’ [Frequency Response Measure] within an Interconnection was equal to or 

more negative than the Interconnection’s [Interconnection Frequency Response 

Obligation],” and a “high” severity level if this summation “did not meet its 

[Interconnection Frequency Response Obligation].” Based on these two possibilities for 

this summation, NERC proposed either a “medium” severity level and a “severe” severity 

level for a balancing authority or Frequency Response Sharing Group with an Frequency 

Response Measure that is “less negative than its [Frequency Response Obligation] by 

more than 30% or by more than 15 MW/0.1 Hz, whichever is the greater deviation from 

its [Frequency Response Obligation].”106 

92. The Commission proposed that NERC modify its severity level assignments for 

Requirement R1 to remove references to performance by other entities or otherwise so as 

to address a concern that NERC assigned these severity levels partly on performance of 

Requirement R1 by all other responsible entities in the Interconnection in which a 

violator is located. The Commission concluded that it would be unfair to base a penalty 

on a responsible entity in part upon the collective compliance or lack of compliance by 

independent entities, because: (1) NERC’s sanction guidelines focus violation severity 

levels on a violator’s deviation from required performance, not the risk the violation is 

 106 NOPR, 144 FERC ¶ 61,057 at P 43.
Docket No. RM13-11-000 - 61 -

expected to pose to reliability or performance by other entities; and (2) a balancing 

authority or Frequency Response Sharing Group subject to Requirement R1 does not 

control any other responsible entity’s compliance with this requirement.107 The 

Commission sought comments on its proposal.

Comments

93. APS agrees with the Commission's proposal that NERC change Requirement R1 

violation severity level assignments that are in part based on the performance of other 

entities in the Interconnection. However, APS contends that there is no justification for a 

“severe” violation severity level applicable to this requirement. APS comments that the 

violation severity level should be “low” for a responsible entity missing its annual 

Frequency Response Obligation by small amounts (less than 20 percent) and “medium”

for missing by a larger amount (greater than 20 percent).108 

94. IRC states that the standard drafting team took an appropriate, rational approach to 

its violation severity level proposal, taking into account that frequency response is an 

interconnection-wide service, not balancing authority specific. IRC contends that a 

single balancing authority should not be penalized for a 10 percent decrease in response, 

where frequency response is otherwise sufficient amongst its surrounding balancing 

authorities and the reliability of the Interconnection as a whole is not in jeopardy. IRC 

 107 Id. P 44.

108 APS Comments at 9-10.
Docket No. RM13-11-000 - 62 -

asserts that, in contrast, a 10 percent decrease in frequency response within the 

Interconnection as a whole clearly would signal a reliability issue. IRC contends that, by 

suggesting that the VSLs for Requirement R1 be modified to remove references to 

performance by other entities, the Commission essentially suggested that a small 

deficiency within a single balancing authority is equivalent to deficient frequency 

response within an Interconnection, and should be equivalently penalized as such.109 

Commission Determination

95. As proposed in the NOPR, we direct NERC to remove from its violation severity 

level assignments for Requirement R1 any references to performance of that requirement 

by other entities. No commenter has questioned the Commission’s analysis in the NOPR 

that NERC’s Sanction Guidelines define violation severity levels as a violator’s deviation 

from required performance, not as the risk the violation is expected to pose to reliability 

or performance by other entities, and that a particular responsible entity’s compliance 

with Requirement R1 is not controlled by performance of the requirement by other 

responsible entities in an Interconnection. Nor has any commenter suggested any 

rationale sufficient to support a departure from the Sanction Guidelines in this regard. 

While we agree with IRC that frequency response is an Interconnection-wide service, a 

failure by each responsible entity in an Interconnection to comply with Requirement R1 

will result in a failure to meet the Interconnection-wide annual Frequency Response 

 109 IRC Comments at 12-13.
Docket No. RM13-11-000 - 63 -

Measure, to the detriment of reliability across the Interconnection. We believe that 

violation severity levels for this requirement should be set so as to discourage particular 

responsible entities from “leaning on” other entities to provide sufficient frequency 

response collectively to meet the relevant Interconnection Frequency Response 

Obligation. 

96. We leave it to NERC to consider how its violation severity level assignments for 

Requirement R1 should be changed in response to our concerns, including consideration 

of APS’s suggestions. However, we note that APS did not provide in its comments any 

rationale for its suggested severity level assignments. 

G. Supporting/Associated Documents

97. In the NOPR, the Commission explained that Reliability Standard BAL-003-1 has 

several supporting or associated documents. For example, Attachment A, appended to 

the Reliability Standard, is explicitly referenced in Requirements R1 and R2.110 Further, 

NERC’s Procedure for ERO Support of Frequency Response and Frequency Bias Setting 

Standard (Procedure), is included as an “associated document” in the Reliability 

Standard, and is referenced in Attachment A.111 Likewise, Requirement 4 of proposed 

BAL-003-1 references FRS Forms 1 and 2, stating that “each balancing authority that 

 110 See NOPR, 144 FERC ¶ 61,057 at P 45.

111 Id. The Procedure is provided as Exh. C to the NERC petition. NERC stated 

that it included the Procedure in the petition for informational purposes. NERC Petition 

at 4.
Docket No. RM13-11-000 - 64 -

provides Overlap Regulation Service shall modify its Frequency Bias Setting in its ACE 

calculation ... to be equivalent to ‘the sum of Frequency Bias Settings as shown on FRS 

Form 1 and Form 2 ... as validated by the ERO.’”

112

98. In the NOPR, the Commission stated that “[t]hese associated and supporting 

documents are explicitly referenced in the Requirements of the Reliability Standard. 

Thus, failure of a Balancing Authority to comply with such associated and supporting 

documents could result in non-compliance with the underlying Requirement.”113

Commission Determination

99. No entity submitted comments on this matter. Accordingly, the Commission 

affirms its NOPR statement that the failure of a balancing authority to comply with the 

associated and supporting documents that are referenced in the Requirements of BAL003-1 could result in non-compliance with the underlying Requirement.114 

 112 NOPR, 144 FERC ¶ 61,057 at P 45. Reliability Standard BAL-003-1 identifies 

FRS Form 1 and FRS Form 2 as “associated documents.” 

113 Id. P 46 (footnote omitted).

114 Attachment A and the Procedures also require NERC to take certain actions 

pertaining to the calculation of frequency response measure and allocation among 

balancing authorities. The ERO is not an applicable entity pursuant to Reliability 

Standard BAL-003-1. The ERO, however, has an independent obligation to “ensure 

compliance with a reliability standard or any Commission order affecting the ERO or a 

regional entity” and the Commission can take “such action as is necessary or appropriate” 

to ensure that the ERO fulfills this responsibility under Attachment A and the Procedures. 

See id. P 46, n.73 (citing 16 U.S.C. 824o(e)(5)).
Docket No. RM13-11-000 - 65 -

100. NERC, in its Reply Comments, states that “the values in Table 1 of Attachment A 

are not static. As explained in Attachment A to the proposed Reliability Standard and the 

Procedure for ERO Support of Frequency Response and Frequency Bias Setting 

Standard, the values in Table 1 are determined and revised on an annual basis.”115 While 

the Procedure sets forth a mechanical and objective formula for calculating the IFRO 

value in Table 1 of Attachment A, we believe that any changes to the inputs or IFRO 

value in Table 1 should occur in a transparent manner. Accordingly, should NERC make 

changes to Table 1 based upon NERC’s Procedure document, the Commission directs 

NERC to submit an informational notice describing the basis for the changes at least 30 

days in advance of the effective date of any such changes.116

IV. Information Collection Statement

101. The following collection of information contained in this Final Rule is subject to 

review by the Office of Management and Budget (OMB) under section 3507(d) of the 

Paperwork Reduction Act of 1995 (PRA).

117 OMB’s regulations require approval of 

 115 NERC Reply Comments at 3-4.

116 Cf. Version One Regional Reliability Standard for Transmission Operations, 

Order No. 752, 135 FERC ¶ 61,062, at P 43 (2011) (requiring WECC to notify the 

Commission of changes to the WECC Transfer Path Table). See also NERC Petition, 

Exh. C at 1 (changes to the Procedure for ERO Support of Frequency Response must be 

posted for comment by NERC, approved by the NERC Board of Trustees, and filed with 

the Commission “for informational purposes”). 

117 44 U.S.C. 3507(d).
Docket No. RM13-11-000 - 66 -

certain information collection requirements imposed by agency rules.118 Upon approval 

of a collection(s) of information, OMB will assign an OMB control number and an 

expiration date. Respondents subject to the filing requirements of a rule 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 solicited 

comments on the need for this information, whether the information will have practical 

utility, the accuracy of the provided burden estimate, ways to enhance the quality, utility, 

and clarity of the information to be collected, and any suggested methods for minimizing 

the respondent’s burden, including the use of automated information techniques. The 

Commission received comments on specific requirements in the Reliability Standard, 

which we address in this Final Rule. However, the Commission did not receive any 

comments on our reporting burden estimates.

102. Public Reporting Burden: The burden and cost estimates below are based on the 

collection of certain information to establish the Interconnection Frequency Response 

Obligation and the Frequency Bias Setting for each balancing authority. Each balancing 

authority reports its previous year Frequency Response Measure and Frequency Bias 

Setting to NERC, and revised Frequency Bias Settings are based on data from events the 

balancing authorities report on the proposed FRS Form 1. The information provided on 

 118 5 CFR 1320.11.
Docket No. RM13-11-000 - 67 -

the FRS Form 1 is based on events which qualify for analyses,119 and NERC states that it 

will identify between 20 to 35 events in each Interconnection for calculating the 

Frequency Response Measure and Frequency Bias Setting.

120 Allotting eight hours for 

balancing authorities to compile the information on candidate events,121 multiplied by 

28 events per balancing authority per year yields 224 hours per year per balancing 

authority as the regulatory burden for compliance.122 Our estimates are based on the 

NERC Compliance Registry as of May 31, 2013, which indicates that there are about 

132 registered balancing authorities.

123 Accordingly, the Commission estimates the 

annual regulatory burden for compliance with the Reliability Standard to be $13,560 

per balancing authority,

124 with an estimated total annual cost for all balancing authorities

to be $1,789,920.125

 119 NERC stated that it will provide quarterly posting of candidate events to assist 

the balancing authorities with compliance, and lessen the burden of the annual 

submission of FRS Form 1 data. NERC Petition, Exh. C at 3-4.

120 Id. at 1. The Frequency Response Initiative Report states that between 20 and 

25 events are necessary for statistical analysis. Frequency Response Initiative Report at 

72.

121 The information is automatically generated from computer data bases. 

However, time is allotted to compile, verify, and review the information. 

122 Assuming an average of between 20 and 35 events per year.

123 NERC Compliance Registry List, May 31, 2013, available at: 

http://www.nerc.com.

124 The estimated hourly loaded cost (salary plus benefits) for an engineer is 

assumed to be $60/hour, based on salaries as reported by the Bureau of Labor Statistics 

(continued...)
Docket No. RM13-11-000 - 68 -

BAL-003-1 

(Frequency 

Response and 

Frequency Bias 

Setting) 

Number of 

Balancing 

Authority

Respondents

Number of 

Responses 

per 

Respondent

Average 

Burden 

Hours 

Per 

Response

Total 

Annua

l 

Burde

n 

Hours

Estimated 

Total Annual 

Cost ($)

(1) (2) (3)

(1)x(2)

x

(3)

Total hours x 

$60

Annual 

Reporting 132 28 8 29,568 $1,774,080

Data Retention 132 1 2 264 $15,840

TOTAL 29,832 $1,789,920

Title: FERC-725R, Mandatory Reliability Standards: Reliability Standard BAL-003-1.

Action: Proposed Collection of Information.

OMB Control No: To be determined.

Respondents: Business or other for-profit, and not-for-profit institutions.

Frequency of Responses: Annual.

Necessity of the Information: The revision of NERC Reliability Standard BAL-003-1 is 

part of the implementation of the Congressional mandate of the Energy Policy Act of 

 

(BLS) (http://bls.gov/oes/current/naics2_22.htm). Loaded costs are BLS rates divided by 

0.703 and rounded to the nearest dollar. (http://www.bls.gov/news.release/ecec.nr0.htm.)

125 The estimated total annual cost includes an annual data retention burden of 

$15,840 for all balancing authorities.
Docket No. RM13-11-000 - 69 -

2005 to develop mandatory and enforceable Reliability Standards to better ensure the 

reliability of the nation’s Bulk Power System. Specifically, Reliability Standard BAL003-1 is intended to ensure sufficient Frequency Response from balancing authorities to 

maintain Interconnection Frequency within predefined bounds.

Internal Review: The Commission has reviewed the revisions to the Reliability Standard 

and determined that its action is necessary to implement section 215 of the FPA. The 

Commission has assured itself, by means of its internal review, that there is specific, 

objective support for the burden estimate associated with the information requirements. 

103. 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: Ellen Brown, Office of the Executive Director, 

e-mail: DataClearance@ferc.gov, phone: (202) 502-8663, fax: (202) 273-0873].

V. Environmental Analysis

104. 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.126 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 

 126 Regulations Implementing the National Environmental Policy Act, Order 

No. 486, 52 FR 47897 (Dec. 17, 1987), FERC Stats. & Regs., Regulations Preambles 

1986-1990 ¶ 30,783 (1987).
Docket No. RM13-11-000 - 70 -

procedural or that do not substantially change the effect of the regulations being 

amended.

127 The actions directed herein fall within this categorical exclusion in the 

Commission’s regulations.

VI. Regulatory Flexibility Act

105. The Regulatory Flexibility Act of 1980 (RFA)128 generally requires a description 

and analysis of proposed rules that will have significant economic impact on a substantial 

number of small entities. The NERC registry includes about 132 individual balancing 

authorities. Comparison of the NERC Compliance Registry with data submitted to the 

Energy Information Administration on Form EIA-861 indicates that, of these entities, 

15 may qualify as small entities.

129

106. As noted above, the Commission estimates the annual regulatory burden for 

compliance with the Reliability Standard to be $13,560 per balancing authority. This 

estimate for all balancing authorities was established using 28 events per year, but 

 127 18 CFR 380.4(a)(2)(ii).

128 5 U.S.C. 601-612.

129 The RFA definition of “small entity” refers to the definition provided in the 

Small Business Act (SBA), which defines a “small business concern” as a business that is 

independently owned and operated and that is not dominant in its field of operation. See

15 U.S.C. 632 (2006). According to the Small Business Administration, an electric 

utility is defined as “small” if, including its affiliates, it is primarily engaged in the 

generation, transmission, and/or distribution of electric energy for sale and its total 

electric output for the preceding fiscal year did not exceed 4 million megawatt hours.
Docket No. RM13-11-000 - 71 -

smaller entities may have fewer events which qualify for analysis,130 and the costs for 

these smaller entities may be reduced. Further, while the Reliability Standard establishes 

a balancing authority’s Frequency Response Obligation, because balancing authorities are 

currently providing frequency response, we do not anticipate additional compliance costs. 

Accordingly, we do not consider the cost of compliance with the Reliability Standard to 

be a significant economic impact for small entities because it should not represent a 

significant percentage of an affected small entity’s operating budget. Accordingly, no 

regulatory flexibility analysis is required. 

VII. Document Availability

107. 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 

(http://www.ferc.gov) and in the Commission's Public Reference Room during normal 

business hours (8:30 am to 5:00 pm Eastern time) at 888 First Street, NE, Room 2A, 

Washington, DC 20426.

108. 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 

 130 The Procedures establish a minimum of 20 events for analysis, and a process 

for identifying when fewer than 20 events are available for analysis.
Docket No. RM13-11-000 - 72 -

document in eLibrary, type the docket number excluding the last three digits of this 

document in the docket number field.

109. User assistance is available for eLibrary and the Commission’s website during 

normal business hours from the Commission’s Online Support at 202-502-6652 (toll free 

at 1-866-208-3676) or email at ferconlinesupport@ferc.gov, or the Public Reference 

Room at (202) 502-8371, TTY (202)502-8659. E-mail the Public Reference Room 

at public.referenceroom@ferc.gov.

VIII. Effective Date and Congressional Notification

110. These regulations are effective [Insert Date 60 days after publication in the 

FEDERAL REGISTER]. The Commission has determined, with the concurrence of the 

Administrator of the Office of Information and Regulatory Affairs of OMB, 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.

( S E A L )

Nathaniel J. Davis, Sr.,

Deputy Secretary.