1. SAC500 Transmission Project
Sacramento Municipal Utility District (SMUD)
Western Area Power Administration – Sierra Nevada Region (WASN)
SAC500 Transmission Project

2. SAC500 Transmission Project
Feb SMUD Board approved agreements to evaluate the feasibility of jointly developing a new 500 kV transmission project with the Western Area Power Administration. The agreements allow initiation of environmental review and to begin regional transmission review activities.

3. Project Overview Joint project between SMUD & WASN
Construct ~50 miles, 500 kV transmission line from near Maxwell to near O'Banion & 500/230 kV transformer at O'Banion.
Configure the new Maxwell switchyard to “double bus, double breaker”

4. Project Objectives / Benefits:
Carbon footprint reduction
Increased flexibility to access low carbon and renewable generation
Meeting SMUD load serving capability for and beyond
Improve system reliability locally and regionally
Less reliance on SMUD’s thermal generation fleet
More independence, preserves local decision making

5. COI Impacts: Base Case Assumptions: WECC 2024HS
Table Mt. – Rio Oso 230 kV reconductor
Palermo – Rio Oso 230 kV line reconductor
South of Palermo Transmission project, which consists of reconductoring the southern portion of the Palermo-Rio Oso 115 kV lines #1 & #2 and the Palermo-Pease-Rio Oso 115 kV lines
DWR RAS unavailable for COI N-S N-2 Contingency

6. Contingency Screen: N-1 Credible N-2 Loss of 2 Nuclear Units
COI Impacts:
Contingency Screen:
N-1
Credible N-2
Loss of 2 Nuclear Units

7. COI Impacts: Study Results:
Provides thermal loading relief on the limiting elements
Improves reactive power support to the northern California transmission grid
Contingency / Loading
COI Flow (MW)
NCH
TMS DLO
RM-TM #1 SLO
Pre - Project
4800
70%
TM – RIO OSO (111%)
RM-TM #2 (99%)
Post - Project
TM – RIO OSO (109%)

8. Reactive Margin (MVAR)
COI Impacts:
Reactive Margin (MVAR)
Base Case
Contingency
ELVERTAS 230
OBANION 230
MALIN 500
TABLE MT 500
TRACY 500
Pre - Project
2024hs-3353-BASE.sav
CptJ-Olinda-slo-ns
478
479
>1000
MPDCI-NS-bipole
551
549
PaloVerde-g2-RAS
389
391
Post – Project
2024hs-3353-MAOB.sav
812
901
909
703
780

9. Transmission Alternatives:
Other transmission alternatives were evaluated:
Alternative
LSC Increase (MW)
Line Length (mi)
Loss Savings (MW)
CVP Flow Reduction (MW)
Cost Estimate ($M) 1
Maxwell – O’Banion 500kV
364 44 19
295
$250 2
Tracy – SMUD Area 500kV 43 21
270
$330 3
Tracy – SMUD Area 230kV
254 17
179
<$330 4
Loop Table Mtn. – Tesla into O’Banion
290
< 1
331
$77 5
Solano - SMUD 230kV
316 40
192

10. Transmission Alternatives:
Conclusions:
More expensive to construct
Unable to meet the project objectives
Requires significant upgrades of existing facilities
Infeasible due to space and zoning concerns

11. WECC Project Review Group:
Invitation to WECC members to be part of the SAC500 Project Coordination Review Group
Contacts:
SMUD: Craig Cameron – (916)
Patrick Truong – (916)
WAPA: Kirk Sornborger – (916)

12. Supplemental Slides

14. Pease-E. Marysville (96%) 4615 90% RM – TM (98%)
Contingency
COI Flow (MW)
NCH
R. Mtn – Table Mtn
TM – VD SLO
Existing System
4800
60%
RM – TM (97%)
70%
4680
80%
RM – TM (99%)
Pease-E. Marysville (96%)
4615
90%
RM – TM (98%)
Pease-E. Marysville (99%)
4373
100%
RM – TM (94%)
Post-Project 2021 System
RM – TM (90%)
Pease-E. Marysville (<90%)
RM – TM (95%)
4682
RM – TM (96%)
4617
4372
RM – TM (91%)

15. MW
BASE
MAOB
DIFF
COI
4763
4766 3
PACIFIC DC INTERTIE (PDCI)
3100
NORTHERN - SOUTHERN CALIFORNIA
3141
3142 1
Bellota-Rancho Seco 230kV:
270.53
199.5
-71.03
Camanch-Rancho Seco 230kV:
265.03
194.33
-70.7
Gold Hill - Lake 230:
167.76
127.06
-40.7
Elverta 230kV Bus Tie:
223.28
188.96
-34.32
Tracy - Hurley #1 230:
257.99
190.77
-67.22
Tracy - Hurley #2 230:
264.01
195.81
-68.2
Folsom - OrangeVale 230:
180.31
155.4
-24.91
Folsom - Lake 230:
-68.37
-1.76
-66.61
Maxwell - O’Banion 500:
413.68
Round MT - COTWD 230 #1:
94.27
86.98
-7.29
Tesla - Tracy 230 #1:
49.62
39.65
-9.97
Tesla - Tracy 230 #2:
Tracy 500/230 kV Bnk #1
423.45
364.43
-59.02
Tracy kV Bnk #2
Keswick - O’Banion 230 #1:
249.9
209.22
-40.68
Keswick - Flanagan 230 #1:
-81.81
-81.2
-0.61
Hurley - Procter 230 #1:
-83.81
-75.75