NOTICE DATE: June 26, 2026

NOTICE TYPE: M-A013126-02 Operations

SHORT DESCRIPTION: Results of Final Ad Hoc Interim VRT Assessment for Large Loads

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: June 26, 2026

LONG DESCRIPTION: The purpose of this notice is to inform all ERCOT Market Participants that ERCOT has concluded the final ad hoc Interim Voltage Ride-Through (VRT) Assessment for Large Loads, as outlined in Market Notice M-A013126-01. 

As discussed at the May 21, 2026, and June 19, 2026, Large Load Working Group (LLWG) meetings, the results of this assessment indicate that four groups of Large Loads that do not have sufficient voltage ride-through capability have the potential to cause load loss exceeding 3,200 MW[1].  ERCOT previously identified 3,200 MW as the load loss threshold necessary to maintain grid frequency stability following a disturbance.[2]  The load loss identified in the assessment is primarily due to insufficient voltage ride-through capability among Large Computational Loads.  

In the Ad Hoc Interim VRT assessment, Large Load consumption was modeled at each load's full approved MW capacity.  Currently, each of thse four identified groups of Large Loads operate below 3,200 MW.  However, if the consumption of these groups exceeds, or is expected to exceed this threshold at any time, ERCOT may need to implement Interconnection Reliability Operating Limit (IROL) operational constraints or mitigation plans to ensure reliability.  ERCOT will continue to monitor the actual consumption of these groups and will endeavor to provide as much additional notice as possible prior to implementing any operational constraints or mitigation plans that may be necessary. 

Additionally, since February 2026, all planned Large Loads that seek Initial Energization to connect to the ERCOT grid must go through the Quarterly Stability Assessment (QSA) process prior to requesting Initial Energization, as described in Sections 5.3.5 and 9.6 of the ERCOT Planning Guide.  If the QSA identifies a stability concern associated with the energization of one or more planned Large Loads that could cause load loss exceeding 3,200 MW, energization will be conditioned on implementation of an appropriate System Operating Limit (SOL) or Interconnection Reliability Operating Limit (IROL).         

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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