1. PC30 BLM High Priority RE SWG – 10/26/15 WECC Staff W ESTERN E LECTRICITY C OORDINATING C OUNCIL

2. Overview Study Description – Scope and assumptions – Background – Study constants Study Results – Details Generation Paths – Observations 2 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

3. Study Description 3 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

4. Scope - PC30 BLM Study Study Requestor: Bureau of Land Management Key Questions: – How does the system respond to the added generation? – How does the energy “injection” impact path utilization throughout the region and on the interties? Changes from 2024CC: – Increased Solar generation throughout California and Nevada by approximately 2800 MW Utility-scale single-axis tracking PV and CSP (zero storage) tech types were used in this study 4 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

5. Background 2022 BLM Study Noted unrealistic amount of renewable development Model had difficulty solving PC30  More realistic renewable development NREL compiled locations and capacities with greatest real- world potential for renewable development Addition of nine solar generators Spread across Southern California and Nevada Approximately 2800 MW 5 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

6. Study Constants Transmission Load Path Ratings Constraints Flexibility Reserves Resource Adequacy System Stability 6 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

7. Results 7 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

8. Annual Generation Change 8 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

9. Generation Change & Production Cost 9 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Annual Generation by Category (MWh) Category2024 PC1 v1.52024 PC30 BLM StudyDifference Conventional Hydro238,955,786238,955,370(416) Energy Storage3,592,4123,618,33025,918 Steam - Coal227,755,474226,004,910(1,750,564) Steam - Other2,637,9102,635,228(2,681) Nuclear56,254,78656,253,181(1,606) Combined Cycle278,957,656273,299,559(5,658,097) Combustion Turbine51,794,12851,286,717(507,411) IC818,909796,032(22,877) Other3,365,280 0 DG/DR/EE - Incremental17,916,70717,914,919(1,787) Biomass RPS19,581,28719,477,895(103,392) Geothermal31,937,13931,936,284(855) Small Hydro RPS4,360,0544,359,685(369) Solar38,182,16344,752,3356,570,172 Wind74,232,54674,232,268(278) == Total == 1,050,342,2371,048,887,994(1,454,242) Cost (M$)22,84322,559(284) CO 2 Cost (M$)1,7301,695(34) CO 2 Amount (MMetrTn)363359(4) Dump Energy (MWh)357,799486,247128,448 Pumping (PL+PS) (MWh)15,426,00815,455,48729,479 Exports (MWh)5,364,720 0

10. Annual Generation Change 10 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

11. Generation Change By State 11 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

12. Generation Change by Subregion 12 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

13. Generation by Category 13 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

14. WECC Paths 14 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

15. Top 15 Heavily Utilized in PC30 15 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

16. Comparison of Net Annual Flow – Top 15 U90 16 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

17. Changes in Path Utilization Overall Changes: ↓P60: ~5% ↓P52: ~3.5% ↑P26: ~1% ↑P45: ~4% ↓P76: ~1% ↑P15: ~4% 17 W ESTERN E LECTRICITY C OORDINATING C OUNCIL P60 P52 P45 P26 P76 P15 *paths shown are approximations

18. Path Flows 18 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

19. Path Flows 19 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

20. Path Flows 20 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

21. Observations Change in Generation: System accepts nearly all added generation without adverse effect (minimal dump energy on one generator) Increase in solar offset by decrease in coal, combined cycle, and combustion turbine Change in Production Cost Overall decrease in production cost Decrease in carbon dioxide (CO 2 ) emissions No change in exports noted Change in Transmission Utilization Overall incremental improvement in transmission utilization No unserved load noted 21 W ESTERN E LECTRICITY C OORDINATING C OUNCIL

22. 22 W ESTERN E LECTRICITY C OORDINATING C OUNCIL Contact Western Electricity Coordinating Council Colby Johnson Associate Engineer cjohnson@wecc.biz 801-819-7662