NOTICE DATE: Sep 4, 2026

NOTICE TYPE: M-B083126-02 Retail/Wholesale

SHORT DESCRIPTION: Planned system maintenance with impacted services

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: Sep 10, 2026, 15:30 - 16:30

LONG DESCRIPTION:  ERCOT will be performing planned system maintenance of Energy and Market Management systems (EMS, MMS, ITRON, and EIN) applications and databases on Sep 10, 2026, during a maintenance window of 15:30 - 18:00.

During the maintenance window on Sep 10, 2026, Market Participants will experience an outage on the following services from 15:30 until 15:55.

• Market Management System (MMS) - Security-Constrained Economic Dispatch (SCED)/Look- Ahead SCED applications may be unavailable for 3 SCED intervals during the 15:30 to 15:55 timeframe.
• Base Points from SCED may not be created for 3 SCED intervals during the 15:30 to 15:55 timeframe. During this period, Qualified Scheduling Entities (QSEs) with Resources may be required to follow Emergency Base Points from ERCOT Load Frequency Control.
• Market submissions and requests via Web Services, Market Manager, and Outage Scheduler may be unavailable.
• Current Day Report (CDR) publishing and downloading, which may cause the following reports to be unavailable: 
  • SCED and Real-Time Dispatch (RTD) Reports
  • NSA Active and Inactive Constraint Reports
  • State Estimator Reports
  • Real-Time Dynamic Rating Data Reports
  • Wind Power Production - Actual 5-Minute Averaged Values
  • Solar Power Production - Actual 5-Minute Averaged Values
  • SOL Exceedance Report
• The Public Dashboards and ERCOT.com price displays will not be populated.

Note: Start and completion times of this maintenance may be delayed depending on system conditions at that time. A Hotline call to Market Participants will be executed prior to and following completion of the maintenance.

ADDITIONAL INFORMATION: In the event of Settlement Intervals for which the Real-Time Settlement Point Prices are identified as erroneous, and ERCOT sets the SCED intervals as failed in accordance with Section 6.3, Adjustment Period and Real-Time Operations Timeline, then the LMPs, Real-Time MCPCs, Real-Time Reliability Deployment Price Adders for Energy, and Real-Time Reliability Deployment Price Adders for Ancillary Service, for the failed SCED intervals are equal to the LMPs, Real-Time MCPCs, Real-Time Reliability Deployment Price Adders for Energy, and Real-Time Reliability Deployment Price Adders for Ancillary Service, in the most recently solved SCED interval that is not set as failed.

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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