Title Real-Time Mitigation Rules and Creation of a Real-Time Constraint Competitiveness Test
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Status Approved on 03/19/2013
Effective Dates

All sections except for Section




Date Gov Body Action Taken Next steps
03/19/2013 BOARD Approved
03/07/2013 TAC Recommended for Approval ERCOT Board Consideration
02/21/2013 PRS Recommended for Approval TAC Consideration

Voting Record

Date Gov Body Motion Result
03/19/2013 BOARD To approve NPRR520 as recommended by TAC in the 3/7/13 TAC Report Passed
03/07/2013 TAC To recommend approval of NPRR520 as revised by the 2/28/13 ERCOT comments and request that WMS provide a draft of the related Other Binding Document to TAC in April Passed
02/21/2013 PRS To recommend approval of NPRR520 as submitted with a recommended priority of 2013 and rank of 205 Passed


Status: Approved
Date Posted: Feb 6, 2013
Sponsor: ERCOT
Urgent: Yes
Sections: 2.1, 3.19, 3.19.1, 3.19.2, 3.19.3, 3.19.4,3.19.5,,
Description: This primary changes in this Nodal Protocol Revision Request (NPPR) are the following: -The Monthly and Daily Constraint Competitiveness Tests (CCTs) will be replaced with a CCT that is performed as part of the Security-Constrained Economic Dispatch (SCED) process considering only those constraints that are active in SCED and using the current system conditions -The Element Competitiveness Index (ECI) calculation for the Long-Term and SCED CCTs will only be performed on the import side of a constraint -The designation of a constraint as competitive or non-competitive in the SCED CCT will not be dependent on the designation during the Long-Term CCT -The Independent Market Monitor (IMM) is given the ability to designate constraints as either competitive or non-competitive, regardless of CCT results -Only those Entities with decision making authority that have a significant impact in making a constraint non-competitive will be considered for mitigation in SCED -Only those Resources that have a significant contribution in getting the Entity with decision making authority considered for mitigation for a Non-Competitive Constraint will have mitigation applied in SCED -The formula for mitigating energy offers in SCED is changed to include a small adder to the reference price from SCED Step 1 in order to minimize issues caused by the tie breaking logic The use of Mitigated Offer Floors in the SCED process is removed.
Reason: To address the following issues: -Mitigated prices or offers being applied in situations that are competitive or in which an Entity with decision making authority does not have a significant competitive advantage. -Base Point oscillations that occur with changes in the reference Locational Marginal Price (LMP) and Resources being unnecessarily mitigated. -Multiple Quick Start Generating Resources (QSGRs) being brought online when not all needed due to having the same mitigated offer applied.These were some of the issues raised in the January 15, 2013 Independent Market Monitor (IMM) report to the ERCOT Board to "implement the changes necessary to address the SCED "over-mitigation" issues".

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