Strawman 2017 Study Program Framework: March 22 Portfolio Cases Expansion Cases Special topic studies based on results of portfolio cases, expansion cases, and sensitivities High Wind portfolio – (100-130 TWh) East-West Tx Expansion Medium Wind portfolio - (40-50 TWh) North-South Backbone Tx Curtailment sensitivities Import/Export of Path 46 Coal plant flexibility to reduce RE curtailment Hydro flexibility to reduce RE curtailment Identify contingency event for high renewables Dispatch with opportunity/variable costs Resource Adequacy review 2026 Common Case 2.0 High Solar Portfolio (100-130 TWh) As Needed Tx Medium Solar Portfolio - (40-50 TWh) North-South Backbone Tx Offshore wind NW alternative (12 TWh) Coastal offset E-W Tx Western Electricity Coordinating Council

Initial Concept – March 3 Portfolio Cases Expansion Cases List of in-depth Studies based on 3 portfolio cases and 2 expansion cases (select 5?) 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

March 3 - Options for High and Medium RE portfolios 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 (40-50 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