NOTICE DATE:  February 18, 2009

NOTICE TYPE:  M-A021809-01 Operations

SHORT DESCRIPTION:  Changes to ERCOT Ancillary Services Methodology Approved by the Board

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  March 1, 2009

LONG DESCRIPTION:  On February 17, 2009, the ERCOT Board of Directors (Board) approved the new ERCOT Methodologies for Determining Ancillary Service (AS) Requirements document for 2009. The two affected Ancillary Services are Non-Spin Reserve Service (NSRS) and Responsive Reserve Service (RRS).

The change made to NSRS allows for procurement of NSRS into four blocks for the operating day instead of 2 blocks for on-peak and off-peak hours.  This recommendation was part of the effort to optimize the purchase of NSRS and was approved by TAC.

The change made to RRS involves Load Acting as A Resource (LaaR) participation in RRS.  LaaRs will be allowed to provide up to 50% of RRS for procurements of RRS that range from 2300 MW to 2800 MW.  This change was recommended by ROS and approved by TAC and was based upon the results of a Dynamics Working Group.

The methodologies described in the document will be used to calculate the AS requirements starting March 1, 2009.

ADDITIONAL INFORMATION:  Please refer to the following link under Item 06 for the approved document and other supporting documentation:
http://www.ercot.com/calendar/2009/02/20090217-BOD


CONTACT:  If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via e-mail at [log in to unmask]<mailto:[log in to unmask]>.

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