NOTICE DATE: January 05, 2021

NOTICE TYPE: W-C010520-01 Operations

SHORT DESCRIPTION: Raymondville - Rio Hondo Generic Transmission Constraint (GTC) Limit update

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: January 07, 2021

LONG DESCRIPTION: The Raymondville – Rio Hondo Generic Transmission Constraint (GTC) has been in service since April 15, 2019.  This GTC was needed to resolve local stability issues associated with wind farms connected along the Raymondville – Rio Hondo 138 kV line.  AEP plans to upgrade/convert 69 kV transmission lines from Harlingen Switch - Raymondville 1 and Raymondville 1 – Raymondville 2 stations to 138 kV lines. Dynamic simulations performed with the newer transmission configuration under outage conditions indicate updated limits in the region.

The purpose of this notice is to provide contemporaneous notification to all ERCOT Market Participants on the update to the Raymondville - Rio Hondo GTC. ERCOT will begin enforcing the updated limits for this GTC on January 7, 2021.

Details associated with all GTCs (EMIL ID NP3-766-M, Report ID 11424) can be found on the ERCOT Market Information System (MIS) Grid section under the Generic Transmission Limits page. A Digital Certificate is required to access the MIS Secure Area.

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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