RPCG – 2026 CCTA Results and Next Steps Colby Johnson & Vijay Satyal W ESTERN E LECTRICITY C OORDINATING C OUNCIL

RPCG process Every 2 year effort Prior webinars- June, October Focus of this webinar- Discuss voting results to WECC proposed “include” and “exclude” list Future meeting/webinar to discuss adjustments 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

2026 CCTA Results Colby Johnson, Associate Engineer W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Overview CCTA Selection Process Review – CCTA Criteria Flow Chart Transmission Projects: Under Construction – Met Criteria 1 &2: Default Inclusion Ballot Review: Inclusion/Exclusion List Transmission Projects: Not Under Construction – Did meet Criteria 3 & 4 & 5 (if necessary) -> Inclusion – Did not meet Criteria 3, 4, 5 -> Exclusion Polling Tie Projects: Include/Exclude? Final 2026 CCTA Project List Future Improvements 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

CCTA Selection Process Review 5 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.

6 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

Transmission Projects: Under Construction These Projects Met Criteria 1 & 2; Included in CCTA – Central Ferry – Lower Monumental - Complete and In-Service – Delaney-Palo Verde 500kV Line – Delaney-Sun Valley 500kV Line – Desert Basin - Pinal Central - Complete and In-Service – Devers - Colorado River 500 kV (DCR) Transmission Line Project - Complete and In-Service – Energy Gateway Transmission Project - Segment G (Sigurd - Red Butte 345 kV line) - Complete and In-Service – Hassayampa - North Gila 500kV #2 line - Complete and In-Service – Interior to Lower Mainland Transmission (ILM) Project – Pinal Central-Tortolita - Complete and In-Service – Pinal West-Pinal Central-Browning (SEV) - Complete and In-Service – West of McNary Reinforcement Project Group 2 (Big Eddy - Knight) 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Ballot Results 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL In instance of a “tie”, this group to determine Neutral votes not counted

Transmission Projects: Not Under Construction Poll Majority – Agree to Include Met CCTA selection Criterion 3, 4, and/or 5 (when applicable): – Boardman-Hemingway 500 kV (B2H) – Delaney - Colorado River 500 kV Transmission Project (Ten West Link) – Energy Gateway: Wallula – McNary (230 kV) – Energy Gateway South: Aeolus-Mona (500 kV) – Energy Gateway West: Bridger – Populus – Energy Gateway West: Windstar to Jim Bridger – Energy Gateway West: Midpoint – Hemingway – Energy Gateway West: Populus – Midpoint – Energy Gateway West: Populus – Cedar Hill - Hemingway – Centennial II: Harry Allen - Eldorado 500 kV Transmission Project – I-5 Corridor Reinforcement Project (Castle Rock - Troutdale) – Morgan-Sun Valley 500kV Line – *Path 8 Upgrade/Colstrip Transmission Upgrade – *Pawnee-Daniels Park *Updates provided after poll sent out; 2 additional “Inclusions” 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Transmission Projects: Not Under Construction Poll Majority – Agree to “Exclude” Did not meet Criteria 3, 4, and/or 5: – Bighorn-Eldorado – Centennial West Clean Line – Chinook – Centennial II (Amargosa-Northwest) – Centennial II (Northwest - Harry Allen) – Great Basin HVDC – Harcuvar Transmission Project – Hemingway-Captain Jack 500 kV Transmission Line – Juan de Fuca HVDC Sea Cable – Juan de Fuca II HVDC Cable – Lamar-Vilas – Lassen 230kV East/West Tie – Lucky Corridor Transmission Project 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL – Mountain States Transmission Intertie (MSTI) (Townsend-Midpoint 500 kV) – North Gila - Imperial Valley #2 Project – NV Energy Robinson - Harry Allen 500 kV Line – Southern Nevada Intertie Project (SNIP) – Southwest Intertie Project - North (SWIP- North) – SunZia Southwest Transmission Project – TransWest Express Transmission Project – West Side Tie – Tres Amigas – Western Spirit Clean Line – Westside Tie 345/500 kV – Wyoming-Colorado Intertie Project – Zephyr – WECC - Eastern Interconnect DC Tie Upgrade Project

Polling Tie Projects (1 to 1 Include/Exclude) What is the will of the group, Include or Exclude? Projects were originally in the “Include” list – Southline Transmission Project (Afton-Apache) Comment: Project sponsor agrees this should not be included at this time – Southline Transmission Project (Apache-Saguaro) Comment: Project sponsor agrees this should not be included at this time – Talega-Escondido / Valley-Serrano 500 kV Interconnect Comment: Project does not appear in CAISO transmission plan, and has not been submitted to CAISO as a “Merchant Project” Current status – Undecided – and seek input from RPCG 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Final 2026 CCTA Project List Central Ferry – Lower Monumental Delaney-Palo Verde 500kV Line Delaney-Sun Valley 500kV Line Desert Basin - Pinal Central Devers - Colorado River 500 kV (DCR) Energy Gateway Transmission Project - Segment G (Sigurd - Red Butte 345 kV line) Hassayampa - North Gila 500kV #2 line Interior to Lower Mainland Transmission (ILM) Pinal Central-Tortolita - Pinal West-Pinal Central-Browning (SEV) West of McNary Reinforcement Project Group 2 (Big Eddy - Knight) Boardman-Hemingway 500 kV (B2H) Delaney - Colorado River 500 kV Transmission Project (Ten West Link) Energy Gateway South: Aeolus-Mona 500 kV 12 Energy Gateway West: Bridger – Populus Energy Gateway West: Windstar to Jim Bridger Energy Gateway West: Midpoint – Hemingway Energy Gateway West: Populus – Midpoint Energy Gateway West: Populus – Cedar Hill – Hemingway Energy Gateway: Wallula – McNary 230 kV Centennial II: Harry Allen - Eldorado 500 kV I-5 Corridor Reinforcement Project (Castle Rock - Troutdale) Morgan-Sun Valley 500kV Line Path 8 Upgrade/Colstrip Transmission Upgrade Pawnee-Daniels Park Blue text denotes under construction or in-service

Overall Feedback on Process Criterion 3 and 4 to be reviewed and/or refined in future planning cycles – Definitions – Thresholds Adjustments to “criteria” ? – FERC Order 1000 planning based improvements? – Other regulatory/state planning/policy drivers? Future meeting – June/July – modify CCTA 2028 process?! 13 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Contact Information 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Colby Johnson System Adequacy Planning Office: (801) Vijay Satyal – Staff Liaison Sr. Policy Analyst