1. Greg Brinkman Debbie Lew National Renewable Energy Laboratory Golden, Colorado USA Western Wind and Solar Integration Study: February TRC meeting – Transmission build test case

2. NATIONAL RENEWABLE ENERGY LABORATORY Transmission expansion Use high-wind scenario as test case Assume both existing and new transmission is used optimally Run case in PLEXOS for full year Build 500 MW along interfaces with “high” shadow price Cutoff is $10/MW per hour $1600/MW-mi * 0.11/yr (FCR) * 250 miles * 1/8760 yr/hr = $5/MW per hour Continue iterating until no more lines built Initial run plus 9 iterations 2

3. NATIONAL RENEWABLE ENERGY LABORATORY Transmission buildout statistics it0it1it2it3it4it5it6it7it8it9 MW interface capacity built 75006000400030001500 1000 500 Curtailment (TWh) 30.719.313.28.66.44.94.14.03.63.5 Curtailment (fraction of wind + solar) 0.1190.0750.0510.0330.0250.0190.016 0.014 $/MWh reduction in curtailment (marginal) $29 $43 $38 $61 $44 $84 $403 $104 $222 $/MWh reduction in curtailment (average) $29 $34 $35 $37 $38 $39 $40 $41 $42 Production cost (billion) $15.2 $13.9 $13.3 $12.9 $12.6 $12.5 $12.3 $12.2 $12.1 Δ production cost (billion) -$1.33 -$0.61 -$0.38 -$0.27 -$0.16- $0.13 -$0.07 -$0.08 -$0.04 Build cost/yr (billion) - rule of thumb $0.33 $0.26 $0.18 $0.13 $0.07 $0.04 $0.02 Marginal value per $ 4.02.32.1 2.51.91.61.81.7 Average value per $ 4.03.33.02.92.8 2.7 3

4. Iteration 0 (original WECC LRS interface estimates) MW transfer capacity between transmission zones

5. Iteration 1 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

6. Iteration 2 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

7. Iteration 3 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

8. Iteration 4 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

9. Iteration 5 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

10. Iteration 6 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

11. Iteration 7 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

12. Iteration 8 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

13. Iteration 9 MW transfer capacity increase from iteration 0 (WECC LRS interface limits)

14. NATIONAL RENEWABLE ENERGY LABORATORY Transmission expansion Decided at December TRC meeting to produce statistics for a high, low, and medium transmission buildout Metric for low, medium, high buildouts? Value, shadow price, curtailment, etc. Levers to turn Shadow price threshold Number of iterations “Art” 14

15. NATIONAL RENEWABLE ENERGY LABORATORY Buildout by shadow price threshold Shadow price threshold ($/MWh)----> $ 5 $ 10 ** $ 15 $ 20 Alberta_to_British Columbia5000350025001500 Alberta_to_Montana0000 Arizona_to_California_South1000 Arizona_to_Colorado5000150000 Arizona_to_IID500 Arizona_to_LDWP5000500 Arizona_to_Nevada_South0000 Arizona_to_New Mexico0000 Arizona_to_San Diego500 Arizona_to_Utah500 British Columbia_to_Northwest4000200000 California_North_to_California_South0000 California_North_to_Nevada_North50001500 1000 California_North_to_Northwest500000 California_North_to_San Francisco1500 1000500 California_North_to_SMUD0000 California_South_to_IID150050000 California_South_to_LDWP0000 California_South_to_Nevada_North0000 California_South_to_Nevada_South0000 California_South_to_San Diego0000 Colorado_to_Montana1000000 Colorado_to_New Mexico1000000 Colorado_to_Utah0000 Colorado_to_Wyoming1000000 Idaho_to_Montana0000 Idaho_to_Nevada_North3000500 Idaho_to_Northwest0000 Idaho_to_Utah5000100000 Idaho_to_Wyoming0000 IID_to_San Diego500 LDWP_to_Nevada_North0000 LDWP_to_Nevada_South0000 LDWP_to_Northwest500 00 LDWP_to_Utah0000 Mexico (CFE)_to_New Mexico4500500 Mexico (CFE)_to_San Diego45001500 Montana_to_Northwest5000250015001000 Montana_to_Wyoming0000 Nevada_North_to_Nevada_South500 Nevada_North_to_Northwest1000 500 Nevada_North_to_Utah0000 Nevada_South_to_Utah500 Utah_to_Wyoming5000350025001500 15 ** - $10/MW per hour was the shadow price threshold used for this analysis

16. NATIONAL RENEWABLE ENERGY LABORATORY Questions? Greg Brinkman 303-384-7390 gregory.brinkman@nrel.gov Debbie Lew 303-384-7037 debra.lew@nrel.gov 16

17. NATIONAL RENEWABLE ENERGY LABORATORY Extra slides for addressing potential questions 17

18. NATIONAL RENEWABLE ENERGY LABORATORY Renewable generation profiles Solar Remake all solar generation data, down to 1-min resolution PV is 60% of solar, CSP is 40% Distribution to regions based on the ReEDS results Distribution within regions based on the following rules: Rooftop PV is 40% of PV where possible Capacity distributed by population (same capacity per person) Maximum capacity per grid cell of 1 kW/person All scenarios use same sites with different capacity per grid cell Distributed utility PV is ~20% of PV Sited near population areas Scenarios use subset of sites “Remote-site” utility PV is 40% of PV Sited based on capacity factor Scenarios use subset of sites 18

19. NATIONAL RENEWABLE ENERGY LABORATORY Renewable generation profiles Wind Sited by capacity factor within ReEDS region Close capacity factor sites were sometimes substituted so not all wind was in same location Use WWSIS phase 1 data set Statistically downsampled data available for subhourly analysis Load 2006 1-min data available from WECC VGS 2004 or 2005? 19

20. NATIONAL RENEWABLE ENERGY LABORATORY Sample map of solar sites 20

21. NATIONAL RENEWABLE ENERGY LABORATORY High wind (25% wind, 4.8% PV, 3.2% CSP) 21

22. NATIONAL RENEWABLE ENERGY LABORATORY Intermediate (16.5% wind, 9.9% PV, 6.6% CSP) 22

23. NATIONAL RENEWABLE ENERGY LABORATORY High solar (8% wind, 15% PV, 10% CSP) 23

24. NATIONAL RENEWABLE ENERGY LABORATORY Retirement Scenarios All scenarios (including base case TEPPC 2020) Probably use WECC TEPPC DWG projections May need to add capacity if additional units are retired from TEPPC 2020 case Gas CC added in locations where capacity is retired Sensitivity analysis on additional retirements for renewable scenarios Amount retired will be based on capacity value of renewables 24

25. NATIONAL RENEWABLE ENERGY LABORATORY Transmission zones Run zonally initially. Nodal runs at a later date for deeper dives. Propose to use these 20 TEPPC zones. Aiming at more rather than less zones to better approximate actual current operations. Commit and dispatch within each zone with no hurdle rates between zones to allow for interzone transfers. 25

26. NATIONAL RENEWABLE ENERGY LABORATORY Capacity (GW) by state for 3 scenarios 26 HighWindIntermediateHighSolar WindPVCSPWindPVCSPWindPVCSP AZ4.34.84.01.49.5 0.214.59.7 CA11.111.63.05.916.13.85.419.49.2 CO5.52.50.23.92.60.23.05.11.3 ID1.10.0 1.00.0 0.50.0 MT5.90.10.04.00.10.01.00.10.0 NM4.20.40.12.82.10.30.53.20.6 NV2.80.90.61.44.10.60.26.60.6 OR0.0 SD2.30.0 1.90.0 0.30.0 TX0.00.20.0 0.40.0 0.50.0 UT1.10.90.00.62.20.00.34.90.0 WA0.0 WY9.00.0 6.80.0 1.50.0 Total47.321.37.829.637.114.413.054.221.3