1. Navajo Transmission System
Four Corners Wind Resource Center
April 25, 2017

2. Transmission Systems and Ratings
Western Electricity Coordinating Council (WECC)
Path Rating Process:
“Peer Reviewed” process for single lines or paths
Sets long term capability rating – cannot be
diminished by future lines
Subject to re-rating for changed conditions
Current ratings for Navajo Transmission Elements:
Path 49: 10,100 MW (2,000 MW allocated to Navajo-Crystal line)
Path 51: MW

3. Transmission Systems and Ratings (Con’t)
No. American Electric Reliability Council (NERC):
Total Transfer Capability (TTC): The amount of power that can reliably be transmitted across a line or path (equal to WECC Path Rating if process performed for that element)
Available Transfer Capability (ATC): TTC less committed uses.
TTC and ATC are calculated for discrete time periods – yearly, monthly, weekly, daily, hourly

4. Arizona EHV Transmission System Path 51 EOR or Path 49 500 kV 345 kV
Glen Canyon
Navajo
Four Corners
Crystal
Marketplace
Mead
McCullough
Moenkopi
Eldorado
Path 51
Arizona EHV
Transmission
System
Cedar Mtn.
Cholla
Yavapai
Sugarloaf
Dugas
Coronado
Morgan
Springerville
500 kV
345 kV
230 kV
Navajo Western
Navajo Southern
PPK
Westwing
Colorado River
Rudd
Kyrene
Palo Verde
Silver King
Hassayampa
Jojoba
Gila River
Duke
North Gila
Pinal West
Greenlee
Pinal Central
Saguaro
EOR or Path 49
South
Vail

5. Current Ownership Structure
Navajo Southern System
Navajo Switchyard Navajo – Moenkopi Line
Navajo – Dugas – Morgan – Westwing Line Moenkopi – Cedar Mtn. - Yavapai – Westwing Line
APS 14.0%
LADWP 21.2%
NVE 11.3%
SRP 21.7%
TEP 7.5%
USBR 24.3%
APS 24.7%
SRP 38.3%
TEP 13.3%
USBR 23.7%
Navajo Western System
Navajo – Crystal – McCullough Line
LADWP 48.9%
NVE 26.1%
USBR 25.0%

6. Charlie Reinhold, reinhold@ctcweb.net 208-253-6916
Thank You!
Charlie Reinhold,