NOTICE DATE: October 9, 2025

NOTICE TYPE: M-A100925-01 Operations

SHORT DESCRIPTION: Live production two-hour test for RTC+B closed-loop frequency control on October 30, 2025 between 09:00-13:00

INTENDED AUDIENCE: All Qualified Scheduling Entities (QSEs) with Resources

DAYS AFFECTED: October 30, 2025 for two hours between 09:00-13:00

LONG DESCRIPTION:  This notice is for the second live production two-hour closed-loop test of Real-Time Co-optimization Plus Batteries (RTC+B) planned for October 30, 2025 to occur between 09:00-13:00. 

This second production test will be similar to the September 11, 2025 test and allow ERCOT and QSEs to observe frequency control tuning changes as well as to ensure that ERCOT and QSEs can re-test functionality and resolve issues before RTC+B go-live for Operating Day December 5, 2025.  

This "live" system-wide production test is to exercise the Real-Time Market and Load Frequency Control (LFC) Dispatch test on October 30, 2025 for two hours.  This production test will be based on QSE RTC+B telemetry, market submissions, and the ability of Resources to follow ERCOT Dispatch Instructions from RTC+B's Security-Constrained Economic Dispatch (SCED) every five minutes and LFC every four seconds to manage the ERCOT dispatch and frequency.

On October 30, 2025, the ERCOT Control Room will issue hotline calls to coordinate the test and QSEs should be adequately staffed and prepared to support the testing in accordance with the prescribed activities in the RTC+B LFC Handbook in terms of:

• Control room operations;
• Accurate telemetry support, including support of any submissions affecting telemetry (e.g., Current Operating Plans);  
• Resource control for Generation Resources, Load Resources, and Energy Storage Resources; and
• Market submissions in alignment with the prescribed offer requirements in the RTC+B LFC Handbook.

In accordance with the RTC+B LFC Handbook, ERCOT filed for and received an exception for good cause from the Public Utility Commission of Texas (PUCT) in PUCT Project No. 55999 to Protocols requirements so that ERCOT is not required to charge, and QSEs with Resources are not required to pay, Base Point Deviation Charges for any Base Point Deviations of the QSEs' Resources that occur during the test while Resources are following RTC+B Dispatch Instructions.  QSEs are expected to manage their Resources to follow RTC+B SCED during the test.

Leading up to the October 30 test are two important supporting activities:

• Thursday, October 16, 0900-1200, Open Loop Testing: ERCOT is conducting an open-loop test window with ERCOT support staff via WebEx for QSEs to enter unscripted Real-Time Market offers for energy and Ancillary Services and observe awards and telemetry signals during this three hour test.  ERCOT staff will offer live support of questions and help troubleshoot issues on the WebEx in order to support focused testing.  Note that this is an open-loop test and no Resources are physically dispatched via RTC+B systems (i.e., simulation only).
• Monday, October 27, 1300-1500, LFC Workshop: ERCOT will be hosting a Closed-Loop LFC Workshop from 1:00-3:00pm to help prepare QSE staff for the production closed-loop test on October 30, 2025.  

QSEs are strongly encouraged to have appropriate technical and operational representatives in place to understand the details and timing in support of these critical production testing activities.

ACTION REQUIRED:  QSEs with Resources are required to support the live production two-hour test of RTC+B on October 30, 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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dg