Western Electricity Coordinating Council Linking Requests (#1,2,3,6,7,8,9,10,11,12,13) Expansion Cases List of in-depth Studies based on 3 portfolio cases and 2 expansion cases (select 5?) Portfolio Cases East-West Tx Expansion Wind Heavy portfolio Curtailment sensitivities Coal plant flexibility sensitivities Import/Export of Path 46 Hydro flexibility to reduce RE curtailment Identify contingency event of high renewables Dispatch with opportunity/variable costs Resource Adequacy review North-South Backbone Tx 2026 Common Case Solar heavy portfolio North-South Backbone Tx Offshore wind alternative Coastal Tx offset E-W Tx Storage alternative Storage offsets Tx additions Western Electricity Coordinating Council

Option to build a High and Medium RE portfolio cases Benefit of a using a High and Medium Wind and Solar portfolio case that it would provide more data points to perform the in-depth studies selected. Gives us more information to perform follow up work. Portfolio Cases High Wind portfolio – 2026 PC12 (130 GWh) Wind portfolio Medium Wind portfolio – 2026 PC 21+23 (4050 GWh RE) 2026 Common Case High Solar Portfolio (130 GWh) Solar heavy portfolio Medium Solar Portfolio – 2026 PC22 (40-50 GWh) Western Electricity Coordinating Council