Reliability Standard BAL-005-1

BAL-005-1 – Balancing Authority Control

A. Introduction
1.

Title:

Balancing Authority Control

2.

Number:

BAL-005-1

3.

Purpose: This standard establishes requirements for acquiring data necessary to
calculate Reporting Area Control Error (Reporting ACE). The standard also specifies a
minimum periodicity, accuracy, and availability requirement for acquisition of the
data and for providing the information to the System Operator.

4.

Applicability:
4.1. Functional Entities:
4.1.1. Balancing Authority
Effective Date: See Implementation Plan for BAL-005-1

B. Requirements and Measures
R1.

The Balancing Authority shall use a design scan rate of no more than six seconds in
acquiring data necessary to calculate Reporting ACE. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]

M1. Each Balancing Authority will have dated documentation demonstrating that the data
necessary to calculate Reporting ACE was designed to be scanned at a rate of no more
than six seconds. Acceptable evidence may include historical data, dated archive files;
or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R2.

A Balancing Authority that is unable to calculate Reporting ACE for more than 30consecutive minutes shall notify its Reliability Coordinator within 45 minutes of the
beginning of the inability to calculate Reporting ACE. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]

M2. Each Balancing Authority will have dated records to show when it was unable to
calculate Reporting ACE for more than 30 consecutive minutes and that it notified its
Reliability Coordinator within 45 minutes of the beginning of the inability to calculate
Reporting ACE. Such evidence may include, but is not limited to, dated voice
recordings, operating logs, or other communication documentation.
R3.

Each Balancing Authority shall use frequency metering equipment for the calculation
of Reporting ACE: [Violation Risk Factor: Medium] [Time Horizon: Real-time
Operations]
3.1. that is available a minimum of 99.95% for each calendar year; and,
3.2. with a minimum accuracy of 0.001 Hz.

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BAL-005-1 – Balancing Authority Control

M3. The Balancing Authority shall have evidence such as dated documents or other
evidence in hard copy or electronic format showing the frequency metering
equipment used for the calculation of Reporting ACE had a minimum availability of
99.95% for each calendar year and had a minimum accuracy of 0.001 Hz to
demonstrate compliance with Requirement R3.
R4.

The Balancing Authority shall make available to the operator information associated
with Reporting ACE including, but not limited to, quality flags indicating missing or
invalid data. [Violation Risk Factor: Medium] [Time Horizon: Real-time Operations]

M4. Each Balancing Authority Area shall have evidence such as a graphical display or dated
alarm log that provides indication of data validity for the real-time Reporting ACE
based on both the calculated result and all of the associated inputs therein.
R5.

Each Balancing Authority’s system used to calculate Reporting ACE shall be available a
minimum of 99.5% of each calendar year. [Violation Risk Factor: Medium] [Time
Horizon: Operations Assessment]

M5. Each Balancing Authority will have dated documentation demonstrating that the
system necessary to calculate Reporting ACE has a minimum availability of 99.5% for
each calendar year. Acceptable evidence may include historical data, dated archive
files; or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R6.

Each Balancing Authority that is within a multiple Balancing Authority Interconnection
shall implement an Operating Process to identify and mitigate errors affecting the
accuracy of scan rate data used in the calculation of Reporting ACE for each Balancing
Authority Area. [Violation Risk Factor: Medium] [Time Horizon: Same-day Operations]

M6. Each Balancing Authority shall have a current Operating Process meeting the
provisions of Requirement R6 and evidence to show that the process was
implemented, such as dated communications or incorporation in System Operator
task verification.
R7.

Each Balancing Authority shall ensure that each Tie-Line, Pseudo-Tie, and Dynamic
Schedule with an Adjacent Balancing Authority is equipped with: [Violation Risk
Factor: Medium] [Time Horizon: Operations Planning]
7.1. a common source to provide information to both Balancing Authorities for the
scan rate values used in the calculation of Reporting ACE; and,
7.2. a time synchronized common source to determine hourly megawatt-hour values
agreed-upon to aid in the identification and mitigation of errors.

M7. The Balancing Authority shall have dated evidence such as voice recordings or
transcripts, operator logs, electronic communications, or other equivalent evidence
that will be used to demonstratea common source for the components used in the
calculation of Reporting ACE with its Adjacent Balancing Authority.

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BAL-005-1 – Balancing Authority Control

C. Compliance
1.

Compliance Monitoring Process
1.1. Compliance Enforcement Authority
As defined in the NERC Rules of Procedure, “Compliance Enforcement
Authority” means NERC or the Regional Entity in their respective roles of
monitoring and enforcing compliance with the NERC Reliability Standards.
1.2. Evidence Retention
The following evidence retention period(s) identify the period of time an
entity is required to retain specific evidence to demonstrate compliance. For
instances where the evidence retention period specified below is shorter than
the time since the last audit, the Compliance Enforcement Authority may ask
an entity to provide other evidence to show that it was compliant for the fulltime period since the last audit.
The applicable entity shall keep data or evidence to show compliance as
identified below unless directed by its Compliance Enforcement Authority to
retain specific evidence for a longer period of time as part of an investigation.
•

The applicable entity shall keep data or evidence to show compliance for
the current year, plus three previous calendar years.

1.3. Compliance Monitoring and Assessment Processes:
As defined in the NERC Rules of Procedure, “Compliance Monitoring and
Assessment Processes” refers to the identification of the processes that will
be used to evaluate data or information for the purpose of assessing
performance or outcomes with the associated Reliability Standard.
1.4. Additional Compliance Information
None

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BAL-005-1 – Balancing Authority Control

Table of Compliance Elements
R#

Time
Horizon

VRF

R1.

Real-time
Operations

R2.

Real-time
Operations

Violation Severity Levels
Lower VSL

Moderate VSL

High VSL

Severe VSL

Medium

N/A

N/A

N/A

Balancing Authority
was using a design
scan rate of greater
than six seconds to
acquire the data
necessary to calculate
Reporting ACE.

Medium

The Balancing
Authority failed to
notify its Reliability
Coordinator within
45 minutes of the
beginning of the
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 50
minutes from the
beginning of the

The Balancing
Authority failed to
notify its Reliability
Coordinator within 50
minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 55
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within
55 minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 60
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within 60
minutes of the
beginning of an
inability to calculate
Reporting ACE.

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BAL-005-1 – Balancing Authority Control

R3.

R4.

Real-time
Operations

Real-time
Operations

Medium

Medium

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.95% of the
calendar year but
was available greater
than or equal to
99.94 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.94% of the
calendar year but was
available greater than
or equal to 99.93 % of
the calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.93% of the
calendar year but
was available greater
than or equal to
99.92 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.92% of the
calendar year

N/A

N/A

N/A

The Balancing
Authority failed to
make available
information
indicating missing or
invalid data
associated with

Or
The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE failed
to have a minimum
accuracy of 0.001 Hz.

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BAL-005-1 – Balancing Authority Control

Reporting ACE to its
operators.
R5.

Operations
Assessment

Medium

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.5% of the calendar
year but was
available greater
than or equal to 99.4
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.4% of the calendar
year but was
available greater than
or equal to 99.3 % of
the calendar year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.3% of the calendar
year but was
available greater
than or equal to 99.2
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.2% of the calendar
year.

R6.

Same-day
Operations

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
implement an
Operating Process to
identify and mitigate
errors affecting the
scan-rate accuracy of
data used in the
calculation of
Reporting ACE.

R7.

Operations
Planning

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
use a common source
for Tie-Lines, Pseudoties and Dynamic
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BAL-005-1 – Balancing Authority Control

Schedules with its
Adjacent Balancing
Authorities
Or
The Balancing
Authority failed to
use a time
synchronized
common source for
hourly megawatt
hour values that are
agreed-upon to aid in
the identification and
mitigation of errors.
D. Regional Variances
None.
E. Interpretations
None.
F. Associated Documents
None.

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BAL-005-1 – Balancing Authority Control

Version History
Version

Date

Action

Change Tracking

0

February 8,
2005

Adopted by NERC Board of Trustees

New

0

April 1, 2005

Effective Date

New

0

August 8, 2005

Removed “Proposed” from Effective Date

Errata

0a

December 19,
2007

Added Appendix 1 – Interpretation of R17 approved
by BOT on May 2, 2007

Addition

0a

January 16,
2008

Section F: added “1.”; changed hyphen to “en dash.”
Changed font style for “Appendix 1” to Arial

Errata

0b

February 12,
2008

Replaced Appendix 1 – Interpretation of R17
approved by BOT on February 12, 2008 (BOT
approved retirement of Interpretation included in
BAL-005-0a)

Replacement

0.1b

October 29,
2008

BOT approved errata changes; updated version
number to “0.1b”

Errata

0.1b

May 13, 2009

FERC approved – Updated Effective Date

Addition

0.2b

March 8, 2012

Errata adopted by Standards Committee; (replaced
Appendix 1 with the FERC-approved revised
interpretation of R17 and corrected standard version
referenced in Interpretation by changing from “BAL005-1” to “BAL-005-0)

Errata

0.2b

September 13,
2012

FERC approved – Updated Effective Date

Addition

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BAL-005-1 – Balancing Authority Control

0.2b

February 7,
2013

R2 and associated elements approved by NERC
Board of Trustees for retirement as part of the
Paragraph 81 project (Project 2013-02) pending
applicable regulatory approval.

0.2b

November 21,
2013

R2 and associated elements approved by FERC for
retirement as part of the Paragraph 81 project
(Project 2013-02) effective January 21, 2014.

February 11,
2016

Adopted by NERC Board of Trustees

1

Complete re-write of standard

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Supplemental Material
Rationale
During development of this standard, text boxes were embedded within the standard to explain
the rationale for various parts of the standard. Upon Board approval, the text from the
rationale boxes will be moved to this section.
Rationale for Requirement R1: Real-time operation of a Balancing Authority requires real-time
information. A sufficient scan rate is key to an Operator’s trust in real-time information.
Without a sufficient scan rate, an operator may question the accuracy of data during events,
which would degrade the operator’s ability to maintain reliability.
Rationale for Requirement R2: The RC is responsible for coordinating the reliability of bulk
electric systems for member BA’s. When a BA is unable to calculate its ACE for an extended
period of time, this information must be communicated to the RC within 15 minutes thereafter
so that the RC has sufficient knowledge of system conditions to assess any unintended
reliability consequences that may occur on the wide area.
Rationale for Requirement R3: Frequency is the basic measurement for interconnection health,
and a critical component for calculating Reporting ACE. Without sufficient available frequency
data the BA operator will lack situational awareness and will be unable to make correct
decisions when maintaining reliability.
Rationale for Requirement R4: System operators utilize Reporting ACE as a primary metric to
determine operating actions or instructions. When data inputs into the ACE calculation are
incorrect, the operator should be made aware through visual display. When an operator
questions the validity of data, actions are delayed and the probability of adverse events
occurring can increase.
Rationale for Requirement R5: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Since Reporting ACE is a measure of the
BA’s reliability performance for BAL-001, and BAL-002, it is critical that Reporting ACE be
sufficiently available to assure reliability.
Rationale for Requirement R6: Reporting ACE is a measure of the BA’s reliability performance
for BAL-001, and BAL-002. Without a process to address persistent errors in the ACE calculation,
the operator can lose trust in the validity of Reporting ACE resulting in delayed or incorrect
decisions regarding the reliability of the bulk electric system.
Rationale for Requirement R7: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Common source data is critical to
calculating Reporting ACE that is consistent between Balancing Authorities. When data sources
are not common, confusion can be created between BAs resulting in delayed or incorrect
operator action.

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Supplemental Material
The intent of Requirement R7 Part 7.1 is to provide accuracy in the measurement and
calculations used in Reporting ACE. It specifies the need for common metering points for
instantaneous values for the tie-line megawatt flow values between Balancing Authority Areas.
Common data source requirements also apply to instantaneous values for pseudo-ties and
dynamic schedules, and can extend to more than two Balancing Authorities that participate in
allocating shares of a generation resource in supplementary regulation, for example.
The intent of Requirement R7 Part 7.2 is to enable accuracy in the measurements and
calculations used in Reporting ACE. It specifies the need for common metering points for
hourly accumulated values for the time synchronized tie line MWh values agreed-upon
between Balancing Authority Areas. These time synchronized agreed-upon values are
necessary for use in the Operating Process required in R6 to identify and mitigate errors in the
scan-rate values used in Reporting ACE.

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