The ERCOT Regional Planning Group (RPG) meeting on August 13, 2024, focused on updates and discussions regarding various transmission projects, severe weather event analysis, and long-term system assessments. The meeting provided insights into ongoing projects and studies, highlighting ERCOT’s efforts to enhance grid resiliency and address future load growth scenarios.
Miscellaneous Updates
The meeting began with general updates from ERCOT, setting the stage for the detailed discussions and presentations that followed.
High-Level Overview of Argonne National Lab (ANL) Study on Potential Severe Weather Event Scenarios
Leah Talabel presented an overview of a study conducted by Argonne National Laboratory (ANL) on the potential impacts of severe weather events on the ERCOT grid. The study utilized ANL’s HEADOUT tool to estimate damage to generators, transmission lines, substations, and customer impacts from hurricanes. The scenarios included worst-case Category 5 hurricanes impacting Houston, Corpus Christi, and the Rio Grande Valley, along with evaluations of nine historical storms. The study’s results, which showed varying levels of damage and restoration times, will be shared with Transmission Service Providers (TSPs). ERCOT plans to use these results in conducting biennial grid resiliency studies as directed by state legislation. The discussion emphasized the importance of considering multiple events for a comprehensive coastal region impact analysis and clarified that detailed results would be shared only with relevant TSPs due to Critical Energy Infrastructure Information (CEII) confidentiality.
EIR Status Update – Brownsville Area Improvements Transmission Project
Caleb Holland provided an update on the Brownsville Area Improvement project, which aims to address thermal overloads and voltage violations in the Brownsville area. The project, estimated to cost $388 million, is expected to be completed by May 2027. Various project options were discussed, with some being removed due to infeasibility, and others being modified based on maintenance outage analysis. Detailed evaluations of the remaining options were provided, including specific construction plans and results. ERCOT’s independent review is ongoing, with regular status updates planned for future RPG meetings.
EIR Status Update – Canton Area Loop Project
Robert Golan presented an update on the Canton Area Loop Project, submitted by Rayburn Electric Cooperative (REC). The project, estimated to cost $26.03 million, aims to provide looped service for the REC Canton Switchyard, limiting radial loads to less than 20 MW. Four project scenarios were evaluated, with Option 3 being selected as the least-cost option that fully addresses REC’s planning criteria. However, ERCOT will not endorse the project as it does not meet NERC or ERCOT planning criteria, and an EIR report will be issued without an endorsement or acceptance letter for PUC filing.
EIR Status Update – Rand Area Loop Project
Abhishek Penti provided a status update on the REC Rand Area Loop Project, which was submitted for review in May 2024. The project, estimated to cost $32.2 million, aims to limit radial load to less than 20 MW and provide looped service to the Rand substation. Six options were evaluated, with four selected for further evaluation. The final recommendation is expected by the third quarter of 2024. A query was raised about tying the project with the Canton Loop Project, but differing service dates and economic justifications resulted in them being addressed separately.
Connell 345/138-kV Switch and Connell to Rockhound 345-kV Double-Circuit Line Project Overview
Eduardo Camilla from Oncor presented an overview of the Connell 345/138-kV Switch and Connell to Rockhound 345-kV Double-Circuit Line Project. The project aims to address post-contingency low voltages and thermal overloads in Martin and Middleton counties. The project includes a 9.2-mile transmission line rebuild, a 13-mile greenfield double-circuit 345-kV line, and the construction of a new 345/138-kV switching station. The estimated project cost is $110 million, with construction expected to begin in 2025 and completion anticipated by 2027. ERCOT’s independent review is expected to be completed by December 7, 2024.
Venus Switch to Sam Switch 345-kV Line Project Overview
Zahra Jianpanah from Oncor presented an overview of the Venus Switch to Sam Switch 345-kV Line Project, which involves rebuilding a 345-kV double-circuit line to address thermal violations under NERC contingencies. The estimated rebuild cost is $118.9 million. Despite the proposed rebuild including a conductor capable of 5000 amps, terminal equipment limitations will cap the effective capacity. Discussion included whether the current and future anticipated loads had been accounted for, with confirmation that they had. The project is classified as tier one, with an independent review by ERCOT ongoing.
ERCOT Independent Review Scope: Venus Switch to Sam Switch 345-kV Line Project
Sarah Gunasekera from ERCOT provided details on the independent review scope for the Venus Switch to Sam Switch 345-kV Line Project. The review will focus on addressing post-contingency thermal overloads, with final recommendations expected in Q4 2024. ERCOT plans to use 2023 cases for the review until 2024 cases are fully vetted.
2024 Long-Term System Assessment (LTSA) High Large Load Adoption Scenario
ERCOT presented an update on the 2024 Long-Term System Assessment, focusing on a high large load adoption scenario. The study examines the potential impacts of large loads on reliability and economic requirements, comparing current trends with high load growth projections. The scenario showed increased capacity expansions, particularly in gas CT, battery, and solar capacity. The discussion included operational challenges and solution strategies for managing the future grid, with an emphasis on transmission planning as the next step in the study process.
2024 Regional Transmission Plan (RTP) Economic Study Stability Interface Limits Update
Pengwei Du provided an update on the 2024 RTP economic study stability interface limits, focusing on South Texas export/import limits. The study identified specific limits for the 2026 and 2029 modeling years, with planned upgrades expected to resolve potential issues by 2029. The discussion included whether the Tango to Lonhill rebuild will be classified as an RPG project, with updates on the south-to-central study affecting the rebuild.
2024 Long-Term Load Forecast with Application of New Waterfalls
Sam Morrison presented updates on the 2024 long-term load forecast, including the application of a new waterfall method to improve forecast accuracy. The scope of the forecast includes historical weather years, economic drivers, and load data. The new method adds transparency by breaking down forecast growth into layers, with the forecast differing from the current one due to updated factors.
