NOTICE DATE: October 22, 2026

NOTICE TYPE: W-A102226-01 Operations

SHORT DESCRIPTION: New Nueces County 138 kV (NUECES) Generic Transmission Constraint (GTC)

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: November 4, 2026

LONG DESCRIPTION: Based on the results of the Quarterly Stability Assessment (QSA) for Q2 of 2026, performed pursuant to Planning Guide Section 5.3.5, ERCOT Quarterly Stability Assessment, ERCOT has identified the need to create a new bidirectional GTC in the Nueces County 138 kV area to limit the aggregate power flow across its interface in both import and export directions . The new GTC is modeled in the Network Operations Model as NUECES, and results from the installation of new Generation Resources in the area.

The purpose of this Notice is to provide contemporaneous notification to all ERCOT Market Participants of these updates. Beginning on November 4, 2026, ERCOT will enforce the new Nueces County 138 kV Area GTC Generic Limits for power flows in both import and export directions.

Details associated with all GTCs (EMIL ID NP3-770-M, Report ID 11425) can be found on the ERCOT Market Information System (MIS) Grid Transmission page under the Generic Transmission Constraints Methodology Secured Area. A Digital Certificate with role ICE_M_VIEW_ECEII is required to access this ECEII data.

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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