NOTICE DATE: June 4, 2021

NOTICE TYPE: M-A060421-01 Operations

SHORT DESCRIPTION: Additional implementation Details of SCR811 - Update on implementation date

INTENDED AUDIENCE: Qualified Scheduling Entities

DAY AFFECTED: June 4, 2021

LONG DESCRIPTION: On June 1, 2021 at 10 am, ERCOT activated System Change Request (SCR) 811, Addition of Intra-Hour PhotoVoltaic Power Forecast to GTBD Calculation. SCR 811 updates the formula used by the Resource Limit Calculator to calculate the Generation To Be Dispatched (GTBD) value. The updated formula for GTBD includes the addition of the Intra-Hour PhotoVoltaic Power Forecast (IHPPF) via a calculated predicted solar ramp (PSRR) times five and a configurable factor. This addition will help Security-Constrained Economic Dispatch (SCED) take into account the anticipated 5-minute solar ramp in its 5-minute Base Points. This change will result in the GTBD being calculated as the following:

GTBD = Total Gen + K1*10*System Load Frequency Bias + K2*[(net non-conforming Load) – (net filtered non-conforming Load)] + K3*5*PLRR + K4*Regulation Deployed - K5*ACE Integral – K6*5*PWRR – K8*5*PSRR

            |PSRR| ≤ Max PSRR Threshold

Between June 1 and June 4, 2021, the configuration factors in GTBD were incrementally tuned to start including predicted solar ramp rate.

ADDITIONAL INFORMATION: SCR811 and associated documents can be found on the ERCOT website.

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 [log in to unmask].

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