EPS Updates ColumbiaGrid Planning Meeting October 13, 2016

Outline Regional Coordination Power Flow & PCM Planned PCM Modeling Changes Results Northwest Exports to California

Regional Coordination Bi-weekly meeting regional coordination call First Segment: Regional review of active power flow case and PCM Second Segment: PCM Modeling Review: Issue in WECC PCM dataset Summary of regional applied/planned changes to PCM Discuses modeling with GridView Data shared: CAISO and WestConnect are have some issues exchanging Exchange area set up by WestConnect NTTG has made available the change set they applied for their reliability cases

Planned PCM Modeling Changes WECC release WECC 2026CC v1.3: Aug 26, 2016 Applied NTTG change set Implement ColumbiaGrid changes

Applied NTTG Corrections NTTG Provided the 15 change set/scenario used in their Cases Summary of change set/scenario: Finished resource corrections provided by the four regions 1000+ changes Removed duplicate transmission facilities Energized open branches to connect 108 islanded generators to the system Fixed interface definitions Added Hemingway to Longhorn Applied all NTTG change set to WECC 2026CC v1.3

PCM Clean Up Items #1 Coal cost by plant Correct hourly load: Assume 50% of coal cost are fixed, therefore dispatch price is 50% of delivered cost Correct hourly load: Abnormal seasonal load shapes Implementation of CA load forecast Eliminate dispatchability in non-dispatchable supply: Changed GEO, CG, QF, Bio, and other non-dispatchable supply to flat monthly generation profile based on historic generation Aggregated the core Columbia and Lower Snake River generation by plant. This eliminated 193 units Delete Pancake wheeling cost with economic hurdles between major markets (NW, CA, SW, & RM)

PCM Clean Up Items #2 Complete Hydro changes sent to WECC. This allows CA Hydro to shift daily generation to respond to the “Duck Curve” Switched most CA mid size Hydro from fixed hourly shape to Proportional Load Following (PLF) Turned on Hydro scheduling to regional Load – Solar * %Solar Coefficient – Wind * %Wind Coefficient Deleted station service load Deleted temporal data: WECC has monthly changing capacity imbedded in dataset Review key Interfaces definitions Eliminate 25% min generation (commit and dispatch) in CA for dispatchable supply Lower Start cost for CC and peakers

PCM Clean Up Items #3 Change modeling of “Asset Control Supply” from monthly (aMW) to hourly BPA surplus (BPA core Columbia river generation + CGS – BPA hourly load) Correct NW Scheduled Maintenance: In the NW about a 1/3 of all thermal maintenance is scheduled during the fall. Shift most of the scheduled maintenance from the fall to spring. Castaic PS: Lower PS Eff to operational average of 70% BTM-PV is proportional distributed to all load busses

WECC 2026CC v1.3 Flow

ColumbiaGrid Flow

Observations It is not uncommon to see hourly flow north on PDCI and south on COI Asset Control Supply assumption set a ceiling or floor on California imports from the Northwest CO2 import fee to California Import from California would decrease if historic limits are used in Northwest

Compare Monthly Average Flow

Question: Kevin Harris (503) 943-4932 harris@columbiagrid.org