NOTICE DATE: October 22, 2025

NOTICE TYPE: M-A102225-01 Operations

SHORT DESCRIPTION: Outage Submission Considerations Due to the Addition of Single-Model Representations of Energy Storage Resources to the Current Production Outage Scheduler Prior to RTC+B Go-Live

INTENDED AUDIENCE: Qualified Scheduling Entities

DAYS AFFECTED: October 29, 2025

LONG DESCRIPTION: The Real-Time Co-optimization Plus Batteries (RTC+B) project is anticipated to go-live on December 5, 2025. In addition to making significant market design changes, this project also transitions to a new method of representing Energy Storage Resources (ESRs) in the ERCOT Network Operations Model.

Currently, ESRs are represented in ERCOT systems as a generator and load combination referred to as the "combo-model".  As part of the RTC+B go-live transition, each ESR will be transitioned to the "single-model" approach, in which each ESR is represented as a single device.  Along with this transition, the names of all ESRs will change (e.g., from "BESS1" to "ESR1").

On October 29, as an outcome of these model changes, ERCOT's Outage Scheduler (OS) application will be populated with both single-model and combo-model representations of all ESRs that are commissioned, in the commissioning process, or have an approved Production Load Date (PLD) prior to the December 5, 2025, cutover date. To prevent the possibility of two devices being in effect at the same time, the out-of-service date for combo-model ESR representations and the in-service date for single-model representations will be December 5, 2025.  ESRs with a PLD after the RTC+B transition will only be represented as a single-model ESR.  The in-service date of such ESRs will align with the PLD.

Prior to October 29, only combo-model representations of ESRs are available to outage.  These outages can extend beyond December 5 and will remain valid even after the out-of-service dates of combo-model ESRs are updated as described above.  Prior to cutting over to the RTC+B OS system, to the extent necessary, ERCOT will modify any active or future combo-model outages to reference their corresponding single-model ESR.

On October 29, the OS application will no longer allow new outages of combo-model ESRs to extend past their out-of-service date of December 5.  To reflect an outage crossing over the RTC+B cutover threshold, two submissions must be made - one on the combo-model representation with an end date of December 5 and the other on the single-model representation with a start date of December 5.  Outages starting after the cutover date will only be made on single-model ESRs.

After RTC+B go-live, combo-model representation of ESRs will no longer be available in the OS.

In summary, if you are the QSE for an ESR and anticipate submitting outages between now and RTC+B go-live, please account for the upcoming changes listed above.  If there are any questions, please contact ERCOT Outage Coordination via the OCSupv@ercot.com address and include your ERCOT Account Manager.

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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