Update on System Adequacy Planning (SAP) Activities May 5 th -6 th 2015 SPSG Meeting Ben Brownlee, P.E.., Dan Beckstead, Stan Holland, Vijay Satyal PhD W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Overview Study Case Reporting – Reporting/Posting Process PCM-PFM Conversion Update 2024 Common Case Version W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Study Case Reporting W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4 Study Case Posting Proposal: Your Feedback is Requested For each Study Case (or “Set”), publicly post: – “Dataset” package posted to Dataset Web Page – much like the “Common Case package”:Dataset Web Page GridView case folder GridView change files used – “Reporting” package posted to Transmission Plan Web Page:Transmission Plan Web Page Presentation of Results (e.g., MS PowerPoint) Study Case Scoping Form (e.g., MS Office)

5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL “Comprehensive” Reporting/Posting Proposal*: Your Feedback is Requested Reporting: – Periodic Report* to Pull Together Significant Findings from Study Case(s) Presentation slides & report narrative Posting – Periodic Report* posted to Transmission Plan Web PageTransmission Plan Web Page *Subject to evolution per 2015 Work Plan development

PCM-PFM Conversion Update W ESTERN E LECTRICITY C OORDINATING C OUNCIL Ben Brownlee, P.E. - Staff Engineer (801) /

Current Status (Overview) PF  PCM 1.Firm up PCM-PF Link – Off-load swing buses – Special attention to: Combined Cycle (plant/parts) Distributed Generation Motor Loads 2.Match station service (SS) loads to their generators 3.Develop generic PF models (steady-state AND dynamics) 4.Update PF & PCM to match – Utilize generic PF models – Automate via EPCL PCM  PF 5.Export Hour 6.Check/update load – Fix load distribution – Spread DR & EE adjustments 7.Check/update generation – Net out SS load from all gen – Combined Cycles – Hydro 8.Stabilize & validate solution for steady-state AND dynamics – Overloads/voltage issues – Others as needed 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL In Progress

2024 Common Case Work Plan 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Priorities for the rest of 2015: 1.Investigate & Document PCM-PFM Conversion Processes & Related Data/Model Synergies 2.Gauge Importance/Usage: WECC 2024 Common Case Change Log is Posted (CLICK HERE to download)CLICK HERE Website analytics are turned on to track usage A list of “Version 1.5” enhancement are at the end – any questions?

2024 Common Case Version 1.5 Enhancements (Page 1 of 2) 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Fixed erroneous system emissions modeling in California thermal units (effectively halved the AB-32 emission penalty) Updated emission rates for natural gas and oil fuels Removed all “gap” resources in California intended for resource adequacy Implemented both normal and emergency seasonal branch ratings (for users who run contingencies in their PCM studies) Enhancements to Release Notes: – Added emissions rates modeling and fixed fuel modeling typo – Revised documentation of wind and solar hourly shapes – Refreshed table of Generator Types and Primary Fuels – Refreshed RPS fulfillment per latest RPS calculation – Refreshed hydro modeling summaries to match Common Case dataset

2024 Common Case Version 1.5 Enhancements (Page 2 of 2) 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Inclusion of “red line” Release Notes in Common Case package Inclusion of RPS Calculation spreadsheet in Common Case package Modeled behind-the-meter distributed generation (BTM-DG) and demand response (DR) resources individually so their bus mapping is more apparent Added “unknown power flow” generating units to model to provide transparency of resource mapping gaps Added “plant part” generating units (e.g., the units within a combined cycle facility) to enable an improved link to the power flow model (PFM) Numerous resource modeling updates, including improved PCM- PFM resource mapping Added the development status and state (location) to the resource modeling Fixed minor errors in hourly resource modeling

Study Case Updates to SWG – Load – Wind forecast error – Natural Gas – CO 2 Sensitivity Cases 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Study Case Updates W ESTERN E LECTRICITY C OORDINATING C OUNCIL Dan Beckstead

PC02 Increased Load The purpose of the Increased-load sensitivity case is to continue to attempt to model and plan for a wide variety of futures. – 10% increase in load WECC wide This case is intended to provide the other bookend on the 2024 Common Case. – What are the utilization/congestion impacts – What is the resulting planning reserve margins – How does the system react to increase loads 13 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

10% Increase in load 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Observations 15 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Increasing load by 10% across the Western Interconnection has the following effects: Gas- and coal-fired generation primarily serve the increased demand +20% of CO2 cost and production cost across the Western Interconnection Minor increase in congestion in the Northern and Western regions of the Western Interconnection

PC03 Decreased Load The purpose of the Decreased-Load sensitivity case is to continue to attempt to model and plan for a wide variety of futures. – 10% decrease in load WECC wide This case is intended to provide the other bookend on the 2024 Common Case. – What are the utilization/congestion impacts – What is the resulting planning reserve margins 16 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

10% Decrease in load 17 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Observations 18 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Decreasing load by 10% across the Western Interconnection has the following effects: Gas- and coal-fired generation primarily are ramped back under decreased loads Roughly -19% in CO2 cost and production cost across the Western Interconnection Congestion is decreased from that of the Common Case

PC17 Wind Forecasting Error Objective – Investigate the impacts of wind forecasting error on: Model Dispatch Production Cost Transmission Path Utilization and Congestion Implementation – The test case would use slightly different wind curves for commitment and dispatch, reflecting limitations of forecasting tools. 19 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

±4% of TEPPC Wind Profiles 20 W ESTERN E LECTRICITY C OORDINATING C OUNCIL To model a forecasting error the TEPPC wind profiles in the Common Case Dataset were randomly adjusted +4% -4% Or remained the same

Generation Change 21 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Observations 22 W ESTERN E LECTRICITY C OORDINATING C OUNCIL +/- 4% wind forecasting error has insignificant impact on; Generation dispatch Production cost Transmission path utilization and congestion.

Study Case Updates W ESTERN E LECTRICITY C OORDINATING C OUNCIL Stan Holland

Carbon Price Studies PC10 and PC11 in the 2014 TEPPC Study Program Purpose To study the effect of applying varying levels of a Carbon Price adder while keeping all other assumptions at their original values. 24 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

PC10 Carbon Tax (CO 2 ) Studies Rather than applying a high carbon tax (PC10) and a low carbon tax (PC11), a series of prices were applied. California Global Warming Solutions Act (AB32) was retained System-wide carbon tax applied 25 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Case Carbon Tax ($/metric ton) Description WECC (non- California) California PC Common case with AB32 in California PC Assume that California would not lower their tax PC Apply AB32 tax WECC-wide PC WECC-wide $40 tax PC WECC-wide $50 tax PC WECC-wide $60 tax

Annual Generation - Carbon Price 26 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Annual CO 2 emissions 27 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Annual Energy Share by Fuel 28 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

High and Low NG Price Studies PC6 and PC7 in the 2014 TEPPC Study Program Purpose To study the effect of increasing (and decreasing) the natural gas (NG) prices while keeping all other fuel prices at their original values. 29 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

High and Low NG Price Studies High NG Price (PC06) – Common case NG prices increased by 50% – Example: Colorado average price was increased from 4.91 $/MMBtu to 7.36 $/MMBtu Low NG Price (PC07) – Common case NG prices decreased by 36% – Example: Colorado average price was decreased from 4.91 $/MMBtu to 3.14 $/MMBtu Key Questions – Impact to generation – Impact to transmission 30 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Comparison of Generation Results 31 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

Observation – NG Prices Decreasing the NG prices had a larger overall impact than increasing the prices. The reduced prices provided closer economic parity between coal and gas generation. Increasing the NG prices extended the economic differential. 32 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

SAP team contact information Ben Brownlee P.E. Staff Engineer Dan Beckstead Assoc. Staff Engineer Vijay A Satyal PhD Sr. Policy Analyst Mike Bailey Energy Planning-Policy Analyst Stan Holland Sr. Engineer Colby Johnson Assoc. Engineer 33 W ESTERN E LECTRICITY C OORDINATING C OUNCIL