Project 2009-20
Interpretation of BAL-003-0.1b for Energy Mark, Inc.

Status:
The recirculation ballot for an interpretation of standard BAL-003-0.1b — Frequency Response and Bias, Requirements R2 and R5, for Energy Mark, Inc. ended February 26, 2010.  The interpretation will be submitted to the NERC Board of Trustees for approval.

Summary:

Clarification 1: Does NERC BAL-003 require every Balancing Authority to have a Frequency Response close to 1% of its projected peak load?

Clarification 2:Requirement R2 mandates that each Balancing Authority “establish and maintain a Frequency Bias Setting that is as close as practical to, or greater than, the Balancing Authority’s Frequency Response”. Given the sign convention of the Frequency Bias Setting as applied in the ACE equation, is the Frequency Bias Setting required to be a negative value as close as practical to, or greater than (in absolute terms),  the estimated Frequency Response so that AGC will not move resources in a manner that would negate the primary response provided by frequency responsive resources?

Clarification 3: When making the comparison between Frequency Response and Frequency Bias in R2, what is the proper method for this comparison?  Should the estimated Frequency Response and Frequency Bias Setting be compared with their typical negative sign convention or in terms of their absolute values? In other words, in order to ensure that AGC does not drive resources to negate the primary response to frequency deviation provided by system resources, including governor response, does Requirement R2 require that the absolute value of the Frequency Bias Setting be as close as practical to, or greater than, the absolute value of the estimated Frequency Response per 0.1 Hz change?

Clarification 4: Is there any defined measure to determine what “as close as practical” means?  Requirement R5 mandates that each Balancing Authority that serves native load shall “have a monthly average Frequency Bias Setting that is at least 1% of the Balancing Authority’s estimated yearly peak demand per 0.1 Hz change Does Requirement R5 require that the absolute value of the Balancing Authority’s monthly average Frequency Bias Setting be at least 1% of the Balancing Authority’s estimated yearly peak demand per 0.1 Hz change.

Clarification 5: As the Frequency Bias Setting is typically calculated and applied as a negative value under R2, yet in R5 it is compared against a percentage of a Balancing Authority’s estimated yearly peak demand load and is typically a positive value,  is the absolute value of the monthly average Frequency Bias Setting required to be at least 1% of the Balancing Authority’s estimated yearly peak demand per 0.1 Hz change? If not, how does one reconcile the sign convention differences between R2 and R5?

Clarification 6: Does BAL-003 have any requirements that would set a value on the amount of Frequency Response that a Balancing Authority must provide?

Purpose/Industry Need:
In accordance with the Reliability Standards Development Procedure, the interpretation must be posted for a 30-day pre-ballot review, and then balloted.  There is no public comment period for an interpretation.  Balloting will be conducted following the same method used for balloting standards.  If the interpretation is approved by its ballot pool, then the interpretation will be appended to the standard and will become effective when adopted by the NERC Board of Trustees and approved by the applicable regulatory authorities.  The interpretation will remain appended to the standard until the standard is revised through the normal standards development process.  When the standard is revised, the clarifications provided by the interpretation will be incorporated into the revised standard.