NOTICE DATE:  May 13, 2013

NOTICE TYPE:  M-C051313-01 NPRR

SHORT DESCRIPTION:  Implementation of NPRR520, Real-Time Mitigation Rules and Creation of a Real-Time Constraint Competitiveness Test

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  June 13, 2013

LONG DESCRIPTION:  On June 13, 2013, ERCOT will be partially implementing NPRR520, Real-Time Mitigation Rules and Creation of a Real-Time Constraint Competitiveness Test, which was approved by the ERCOT Board on March 19, 2013, in the production environment, pending PUCT approval on June 6, 2013. In the event that the PUCT does not approve the change, a Market Notice advising of the cancellation of NPRR520 implementation will be published.

NPRR520 changes how mitigation is applied to Generation Resource Energy Offer Curves in Security-Constrained Economic Dispatch (SCED).  Each active constraint and Generation Resource will be evaluated for competitiveness and mitigation by SCED according to the rules stated in Section 3.19.4, Security-Constrained Economic Dispatch Constraint Competitiveness Test.  This may result in changing competitiveness and mitigation statuses in each SCED interval.

The Constraint Competitiveness Test (CCT) status of each constraint per SCED execution will be reflected in a new column labeled "CCTStatus" in report NP6-86, SCED Shadow Prices and Binding Transmission Constraints, posted at https://mis.ercot.com/pps/tibco/mis/Pages/Market+Information/Real+Time+Market.  The possible values for this column are "COMP" for constraints evaluated as competitive and "NONCOMP" for constraints evaluated as non-competitive.  The format change to this report is reflected in the Current Day Reports XSD posted at http://www.ercot.com/services/mdt/xsds/.

Each Generation Resource will be assigned a new ICCP flag to indicate that the Generation Resource's Energy Offer Curve was subject to mitigation in a future software release, as specified in Section 6.5.7.4, Base Points. This release is tentatively scheduled for August 2013.

A new report, NP3-195-M, TAC-approved Threshold Values for Competitive Constraint Test will be posted on an as-needed basis on ERCOT.com on the Grid Information, Transmission page (http://www.ercot.com/gridinfo/transmission/) and on MIS on the Markets-Real-Time Markets landing page and the Grid-Transmission landing page.  Report NP3-191-M, Approved Competitive Constraints, will be posted on an annual basis at https://mis.ercot.com/pps/tibco/mis/Pages/Grid+Information/Transmission.

Report NP3-129, Daily Competitive Constraints, which is required by the current process, will be removed.

ADDITIONAL INFORMATION:

Pursuant to Section 21.6, Nodal Protocol Revision Implementation, ERCOT is required to provide notice as soon as practicable, but no later than ten days prior to implementation.

NPRR520 and associated documents can be found on the ERCOT website, under Market Rules, at http://www.ercot.com/mktrules/issues/nprr/501-525/520/index.

This partial implementation will specifically unbox the grey-boxed language in Section 2.1, Definitions, Section 3.19, Constraint Competitiveness Tests, Section 3.19.1, Constraint Competitiveness Test Definitions, Section 3.19.2, Element Competitiveness Index Calculation, Section 3.19.3, Long-Term Constraint Competitiveness Test, Section 3.19.4, Monthly Constraint Competitiveness Test, Section 3.19.5, Daily Constraint Competitiveness Test and Section 6.5.7.3, Security Constrained Economic Dispatch.

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 email at [log in to unmask]<mailto:[log in to unmask]>.

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