NOTICE DATE: March 27, 2026

NOTICE TYPE: M-B032726-01 Operations

SHORT DESCRIPTION: Stale Shift Factors and Constraints in SCED

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: March 18, 2026

LONG DESCRIPTION: On Operating Day (OD) March 18, 2026 between 00:00 and 00:10, ERCOT's Security Constrained Economic Dispatch (SCED) used stale shift factor and transmission constraint data. ERCOT corrected the issue and used current data in all subsequent SCED runs, starting at 00:15.

ERCOT cannot correct prices for OD March 18, 2026 because the correct shift factor and transmission constraint data needed to recalculate affected SCED results cannot be accurately recreated.

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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