1. Study Results April 16, 2015 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

2. 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 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

3. 10% Increase in load 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4. 10% Increase in load 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

5. Generation Change 5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

6. Generation Change 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

7. Production Cost and CO2 7 Category2024 PC1 15-01-192024 PC2 High LoadDifference Conventional Hydro238,660,400238,659,785(616) Energy Storage3,684,9293,844,299159,370 Steam - Coal231,197,415241,930,67210,733,257 Steam - Other3,014,0114,116,7081,102,696 Nuclear56,167,02356,318,436151,413 Combined Cycle274,985,932336,829,51661,843,585 Combustion Turbine55,245,01181,435,47826,190,467 IC803,0171,957,3391,154,322 Other3,365,2803,364,122(1,158) DG/DR/EE - Incremental17,838,66117,838,845183 Biomass RPS19,528,18721,017,7451,489,557 Geothermal31,944,68031,927,841(16,839) Small Hydro RPS4,360,0254,359,951(73) Solar35,866,28335,799,623(66,660) Wind73,705,85273,654,896(50,956) == Total ==1,050,366,7061,153,055,255102,688,549 0.097764 Cost (M$)22,39927,0264,627 CO2 Cost (M$)1,0501,267217 CO2 Amount (MMetrTn)36842052 Dump Energy (MWh)433,485552,065118,580 Pumping (PL+PS) (MWh)15,528,45715,744,119215,662

8. Planning Reserve Margins 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Common Case AZ-NM-NVBasinAlberta British ColumbiaCA-NorthCA-SouthNWPPRMPA Planning Reserve %13.6%13.7%12.6% 15.0%15.2%17.5%14.5% Peak Load34,65215,55414,3409,03429,39743,06728,05313,465 Gen Requirement (Peak Load + Reserves)39,36517,68516,14710,17233,80749,61332,96215,417 Gen Capacity Available at time of Peak in Dataset44,04518,88915,71915,47933,66140,27835,87915,810 Initial Gap-4,681-1,204428-5,3071469,335-2,917-393 Gap Adjustment (Joint Ownership Plants)4,1891,194000-5,7770394 Gap Adjustment (Region-Region Transfers)49110-4284280-3,4172,917 Resulting PRM13.6%13.7%12.6%66.6%14.5%14.9%17.5%14.5% Increased Load Case AZ-NM- NVBasinAlberta British ColumbiaCA-NorthCA-SouthNWPPRMPA Planning Reserve %13.6%13.7%12.6% 15.0%15.2%17.5%14.5% Peak Load38,11717,10915,7749,93732,33747,37430,85814,812 Gen Requirement (Peak Load + Reserves)43,30119,45317,76211,19037,18754,57536,25916,959 Gen Capacity Available at time of Peak in Dataset44,04518,88915,71915,47933,66140,27835,87915,810 Initial Gap-7445642,043-4,2903,52614,2973801,149 Gap Adjustment (Joint Ownership Plants)4,1891,194000-5,7770394 Gap Adjustment (Region-Region Transfers)49110-4284280-3,4172,917 Resulting PRM3.3%3.4%2.4%51.5%4.1%4.4%6.8%4.1% Unserved Load-AESO 241 MWh

9. P01 Alberta-British Columbia 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

10. Congested Paths 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Interface_Name Congestion Cost (K$) Congestion Hours (Hrs) P01 Alberta-British Columbia723,056543 P03 Northwest-British Columbia3,85117 P15 Midway-LosBanos60429 P18 Montana-Idaho1,93268 P26 Northern-Southern California8,913435 P45 SDG&E-CFE239130

11. Path Flows 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

12. Path Flows 12 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

13. Observations 13 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

14. Questions 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL