2021 & 2025 Draft LCR Study Results Humboldt Area Irina Green - PowerPoint PPT Presentation

2021 & 2025 Draft LCR Study Results Humboldt Area Irina Green Senior Advisor Regional Transmission Engineer Stakeholder Call March 16, 2020 ISO Public ISO Public

Humboldt Area Transmission System 60 kV Maple System Ridge Creek Cabin 60 kV 60 kV 60 kV Humboldt ~ 115 kV ~ ~ Humboldt 60 kV ~ Bay Trinity ~ ~ ~ ~ ~ 115 kV Low Gap Wildwood ~ 115 kV Bridgeville 60 kV Cottonwood 115 kV 115 kV 115 kV Pacific Garberville ~ ~ ~ Lumber 60 kV Kekawaka 60 kV Laytonville 60 kV Slide 2 ISO Public

Humboldt: Load and Resources Load (MW) 2025 Generation (MW) 2025 2021 2021 Gross Load 151 151 Market/ Net Seller 191 191 AAEE -8 -8 Solar 0 0 Behind the meter DG 0 0 Wind 0 0 Net Load 143 143 Muni 0 0 Transmission Losses 10 10 QF 0 0 Future preferred resource Pumps 0 0 0 0 and energy storage Load + Losses + 153 153 Total Qualifying Capacity 191 191 Pumps Slide 3 ISO Public

Topology changes Transmission Additions: • No new transmission additions Resource Additions: • No new resource additions Resource Retirements: • No new retirements Slide 4 ISO Public

Humboldt Area : Requirements 60 kV Maple System Ridge Creek Cabin 60 kV 60 kV 60 kV Humboldt ~ 115 kV ~ ~ Humboldt 60 kV ~ Trinity Bay ~ ~ ~ ~ ~ Low Gap Wildwood 115 kV ~ 115 kV Bridgeville 60 kV Cottonwood 115 kV 115 kV 115 kV Pacific Garberville ~ ~ ~ Lumber 60 kV Kekawaka 60 kV Laytonville 60 kV LCR (MW) Year Category Limiting Facility Contingency (Deficiency) Cottonwood – Bridgeville 115 kV line + Thermal overload on Humboldt 2021 P6 130 Humboldt – Humboldt Bay 115kV line -Trinity 115 kV line Cottonwood – Bridgeville 115 kV line + Thermal overload on Humboldt 2025 P6 132 Humboldt – Humboldt Bay 115kV line -Trinity 115 kV line ISO Public Slide 5

Changes between years 2020 2021 Subarea Load LCR Load LCR Humboldt 153 130 153 130 2024 2025 Subarea Load LCR Load LCR Humboldt 153 132 153 132  The CAISO and PG&E to continue to explore and address challenges related to winter peak load forecasting for use in local area studies.  The results above represent the studies done last year. Slide 6 ISO Public

Humboldt Area Total LCR Need Existing Generation Capacity Needed Deficiency (MW) Total MW Need 2021 LCR Need (MW) Category P6 130 0 130 Existing Generation Capacity Needed Deficiency (MW) Total MW Need 2025 LCR Need (MW) Category P6 132 0 132 Slide 7 ISO Public