NOTICE DATE: December 5, 2025

NOTICE TYPE: M-F110525-04 Operations

SHORT DESCRIPTION: RTC+B: Implementation Go-Live Complete for Operating Day December 5, 2025

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: December 5, 2025

LONG DESCRIPTION: This notice is a follow-up to the 1-day Market Notice to confirm the successful completion of the production implementation of Real-Time Co-optimization Plus Batteries (RTC+B) for Operating Day (OD) December 5, 2025.

ERCOT and the Qualified Scheduling Entities (QSEs) successfully transitioned the current control systems and Real-Time Market to the RTC+B systems at midnight between December 4, 2025, and December 5, 2025. Since that time, the Real-Time Market and Load Frequency Control systems have been clearing energy and Ancillary Services in real time, as well as dispatching Regulation Services to successfully control system frequency. Additional tools and markets, such as ERCOT dashboards, Reliability Unit Commitment studies, and the Day-Ahead Market have also been implemented.

ERCOT will provide a brief update on the implementation cutover at the ERCOT Board Meeting on Monday, December 8, 2025.

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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