NOTICE DATE: April 2, 2025
NOTICE TYPE: M-B040225-01 Operations
SHORT DESCRIPTION: Price correction due to Generic Transmission Constraint incorrectly being considered in SCED
INTENDED AUDIENCE: All Market Participants
DAYS AFFECTED: March 28, 2025 and March 29, 2025
LONG DESCRIPTION: On March 27, 2025, during a routine software release update for the Energy Management System (EMS), a configuration parameter was inadvertently reset to its default value resulting in a more restrictive limitation. As a result, a post-contingency overload on the Generic Transmission Constraint (GTC) was activated such that it impacted the optimization of Security-Constrained Economic Dispatch (SCED). At times the constraint reached its maximum shadow price of $5,251 per megawatt hour (MWh). This impacted multiple SCED intervals on Operating Days (ODs) March 28, 2025 and March 29, 2025.
The issue was discovered and the configuration corrected on March 31, 2025.
Upon completion of the analysis, the criteria in ERCOT Protocol 6.3 for pursuing a price correction were met and prices could be corrected before prices become final on the second Business Day following the affected OD. For ODs March 28, 2025 and March 29, 2025, the deadline was April 1, 2025 at 4:00 PM. ERCOT was able to complete price corrections for OD March 28, 2025 but did not meet the deadline to complete price corrections for OD March 29, 2025. Further analysis will be performed for that OD to determine if it meets criteria in ERCOT Protocol 6.3(7)(b) for review of prices by the ERCOT Board of Directors.
Price correction files for OD March 28, 2025 have been posted on the Market Information System (MIS).
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 ClientServices@ercot.com.
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