TAS & TEPPC Update CCTA Assumptions Vijay Satyal - RPCG Liaison, Sr. Policy Analyst & Colby Johnson - Associate Engineer, SAP W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Inputs to the WECC Common Case Process: 2026 Common Case Loads (DWG) Resources (DWG/SWG) Transmission Assumptions (RPCG) 2

CCTA process Transmission topology  C Case 2026 Regional Planning Groups  Key entities – Mindful of RPGs’ complying with FERC Order 1000 and their criteria – Not influenced by FERC Order 1000 criteria – Cost-allocation is not the focus for selection RPCG – Ideal forum for such feedback 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Project Information Portal (PIP) 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL 1 2 3

5 Edit existing projects through interactive map Add new/edit projects through “list view” *Paths shown are approximations and are provided to us in the form of Keyhole Markup Language (KML) by project sponsors/contacts

CCTA Selection Process Review 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL All Prior CCTA Projects Newly-Submitted CCTA Projects 2026 CCTA Inclusions 2026 CCTA Exclusions 2026 CCTA Criteria Under Constr. Not Under Constr.

7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Project A Project … Project Z Criteria 3 Financial Indicators Criteria 3 Financial Indicators Criteria 2 Under Construction Criteria 2 Under Construction Criteria 1 Regional Significance Criteria 1 Regional Significance Criteria 4 Implement. Indicators Criteria 4 Implement. Indicators CCTA Not CCTA Yes No Yes No Yes No Passed RPCG Screen No Criteria 5 Dependency Check Criteria 5 Dependency Check Yes No Yes N/A

5 criteria used for review Criteria 1: Regional Significance Based on Voltage: – 500 kV and above – 200 kV or greater if “backbone” 1 facility Criteria 2: Construction Status Is the project currently under construction? Criteria 3: Financial Indicators Financial questions added to project survey to indicate if the project has financial commitment Criteria 4: Implementation Status Indicators Environmental Impact Status (EIS – if required) questions added to survey Criteria 5: Project Dependency Is this project dependent upon another transmission project to be completed and used for its intended purpose? If so, did the dependent project pass the CCTA criteria? 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL 1 Backbone transmissions are facilities that provide network connectivity, typically kV

CCTA Process Demo: “Everett – Madison Transmission Project” 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Highlighted fields will be considered in CCTA criteria/flow Similar table to be created for all potential transmission projects

Ballot Results 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL In instance of a “tie”, this group to determine Neutral votes not counted

2024 CCTA Update 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

12 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Overall Feedback on Process CCTA 2026 Report by mid- Feb’ 2016 General RPCG consensus – – Effective forum to give WECC feedback – Review CCTA process for future improvements – Criterion 3 and 4 to be reviewed and/or refined in future planning cycles Definitions Thresholds 13 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

CCTA process TAS received updates on Jan 22 nd TAS webinar Update – Feb 12 th – 10 am. to go out soon. 2 / 3 hour RPCG meeting prior to late Summer TEPPC meeting 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Acknowledgements RPCG membership – 7 month process. – Gary DeShazo – Chair – Jeff Hein – Vice Chair Colby Johnson and Jon Jensen – SAP team WECC – IT (Taylor A) and Business Services – Project Portal and 2026 CCTA voting survey Non-RPCG TAS-TEPPC members 15 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

16 Vijay Satyal – RPCG Liaison Colby Johnson – Assoc. Planning Engineer CCTA Team Contact Information