MWG Webinar January 25, 2016 Tom Miller- MWG Chair W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Agenda Welcome- Introduction WECC Anti-trust statement (WECC Staff) Reserve Modeling Pertinent to FERC Order 789- (Xiaobo Wang- CAISO) TAS Approval- High Priority Modeling Enhancements Upcoming Review - Modeling Enhancements 2026 Common Case Draft- Review Individual Modeling Enhancements for TAS Approval Wrap-up 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Reserve Modeling Pertinent to FERC Order 789 Xiaobo Wang- CAISO 3

TAS Approval- Modeling Enhancements TAS Quarterly Meeting February 1-2 First Order for first release 2026 Common Case Multi-Day Look Ahead Modeling FERC 789 Reserves Demand Response Programs (LBNL) CAISO Minimum Generation Requirement Constraint Protocol CA Dispatchable CHP Second Order for first release 2026 Common Case Canadian GHG Policy CA CAISO AB 32 Update 4

Upcoming Review - Modeling Enhancements 2026 Common Case Demand Response Modeling Update- Andy Satchwell- LBNL – DRP Program Forecasts – Collect DR event data to help inform the dispatch assumptions Canadian GHG Policy – BC Hydro: outlining the input parameters for BC Hydro (Amir Amjadi- BC Hydro) – Alberta ? California Global Warming – AB32 GHG model – LP instead of emission hurdle model (New functionality) BTM-PV- Negative Load vs. Resource modeling? 5

Multi-Day Look Ahead Model 6

FERC 789 Reserve Requirement 7 DRAFT

Demand Response 8 DRAFT

Modeling Frequency Response CAISO (Minimum Generation Requirement) 9 DRAFT

Constraint Protocol 10 DRAFT

CA CHP Modeling 11

Wrap-up Questions and Comments TEPPC Quarterly Meeting February 1-4 Next MWG Meeting- Week of February

MWG Work Plan Reference Slides for Discussion 13

ABB Gridview Enhancements ABB Gridview Updates & New Enhancements Current Status and Implementation Effort Recommendation for 1 st Release 2026 CC Multi-Day Look-ahead Logic: provides unit commitment logic especially useful for storage Under testing now. May require more time and energy to tune parameters to get the best results Postpone implementation until after first release of the 2026 Common Case v1.0 FERC 789 Reserves: updates contingency reserve modelling to current requirements FERC 789 Operating Reserve ready now. Easy to implement. Yes, implement for V Demand Response Modeling (LBNL): simplified but practical modeling will replace laborious current DRP practice Demand Response Programs (assume LBNL will consult on implementation) under LBNL review. Moderate effort. Yes, implement for V Contingency Protocol: critical to align what constraints have merit over others and much better understanding of study results Easy to implement. MWG to develop priorities and “proxy” costs Yes, implement for V Intertie Ramping: Constrains volatile ramps across major Ca interfaces Available in GridView version. MWG to work with stakeholders on monthly ramp limits leveraging work already Defer to Q2. Moderate effort to implement. Need MWG Recommendation/TAS approval?. Draft 2010 data ramp limits available. Gridview Version UpdatesNeed to aggregate enhancementsSeek WECC Budget support 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

MWG Work Plan Draft 15 W ESTERN E LECTRICITY C OORDINATING C OUNCIL ItemTimelineModeling Enhancement 1Q (1) Investigate Expected GridView Capability; (2) Prioritize Modeling; (3) MWG/WECC Staff Work Plan 2Q Develop modeling enhancement test cases. Modeling Enhancement implementation on 2026 CC. 3Q Common Case first releases: (1) FERC 789 Reserves; (2) System Constraints (3) Multi-day look-ahead logic; (4) Demand Response; (5) CHP Enhancements; (6) Min-Gen Requirement Update; (7) Initial Validation/Calibration 5Q Batch-2 Enhancements (test, validate/calibrate) Validation/Calibration (deeper dive) 5Q Batch-3 Enhancements (test, validate/calibrate) (1) Hydro Reserves; (2) Intertie Ramp Limits (3) Resource Modeling 6Q Batch-4 Enhancements (test, validate/calibrate) Hydro PLF Load net-solar/wind; (2) GHG Linear Programing