NOTICE DATE: November 6, 2025
NOTICE TYPE: M-B110625-01 Operations
SHORT DESCRIPTION: RTC+B: Acknowledgment from QSEs without Resources of RTC+B impacts
INTENDED AUDIENCE: Qualified Scheduling Entities (QSEs) without Resources
DAYS AFFECTED: December 4-5, 2025
LONG DESCRIPTION: This notice is specifically to QSEs without Resources to require acknowledgment of receiving the information below as it relates to technical and commercial changes that may impact their operations December 4-5, 2025 with the transition to Real-Time Co-optimization plus Batteries (RTC+B) systems.
ERCOT has required QSE with Resources to configure and test their systems for RTC+B market trials, however, there has been little- to- no participation in the RTC+B Day-Ahead Market (DAM) trials by QSEs without Resources. Although DAM testing has not been required, ERCOT wants to ensure all QSEs are aware of the system changes and cutover activities that will occur on December 5, 2025.
There will also be connectivity changes under RTC+B which could impact the ability to submit trades and other market submissions after implementation.
This notice requires acknowledgment of three key changes that may impact QSEs without Resources:
- Trade impacts: During the RTC+B transition and cutover, QSEs that enter trades will potentially need to enter and confirm those trades in both the current system and the RTC+B system for December 4 and December 5, 2025.
- Connectivity impacts: At the midnight cutover going into December 5, ERCOT will change the end-point for any applications that use the ERCOT API/XML interface.
- Day-Ahead Market impacts: Incremental changes made to the DAM.
Although no trial activity is required, the ERCOT market trials systems are available in November and QSEs without Resources have the option to participate to prepare their systems.
Also, ERCOT will conduct a RTC+B Transition/Cutover meeting on November 13, 2025 from 1:00 - 3:00 pm. All QSEs are encouraged to attend this meeting, as well as weekly market calls every Monday at 10:00 am, and daily market calls December 1-4, 2025 leading up to the December 5, 2025 cutover (ERCOT Calendar).
ACTION REQUIRED: QSEs without Resources are required to respond by 5:00 pm on November 12, 2025 to RTCB@ercot.com and acknowledge they have received this notice and are aware of the changes that will be made to systems on December 5, 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.
If you are receiving email from a public ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com.
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