NOTICE DATE: January 2, 2026

NOTICE TYPE: W-A010226-01 Operations

SHORT DESCRIPTION: Update Generic Limits identification process for Real Time Operations

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: January 7, 2026

LONG DESCRIPTION: ERCOT has updated the Generic Transmission Limit (GTL) identification process for real time operations. Under the updated methodology, GTLs that are subject to both Voltage Security Assessment (VSAT) and the Transient Security Assessment Tool (TSAT) will use the most limiting value of the real time VSAT and the real time TSAT. For specific GTLs that are subject to both VSAT and off-line dynamic stability studies, the most limiting value of is the pre-determined stability limits from off-line dynamic stability studies and the real time VSAT will be used. When real time tools are unavailable, offline study tools shall be considered to determine the limit.

The purpose of this Notice is to provide contemporaneous notification to all ERCOT Market Participants of these updates. ERCOT will begin enforcing the updated GTL methodology for real time operations on January 7, 2026.

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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