1. Rocky Mountain Power Five Year Study Findings & Kick Off Meeting
Attachment K
Rocky Mountain Power Five Year Study Findings & Kick Off Meeting

2. Findings Reports Kickoff Studies
Study Areas for 2016
Findings Reports Kickoff Studies

3. Grace Study Findings
AREA PLANNER:
Prepared by:

4. System Overview Covers 1,030 square miles
Main Sources are Grace and 3 Mile Knoll, contributions from Treasureton
26 substations, 14 being customer owned
Area has 161, 138 and 46 kV lines
There are 14 transmission lines in/out of the area
Bancroft
Conda
Soda Springs
McCammon
Lava Hot Springs
Grace
Arimo

5. Load Growth Base System Loads Growth: Projected System Loads
Summer 2016: 276 MW (Industrial 80%)
Winter : 271 MW
Growth:
Average Summer Percentage 1.1%
Average Winter Percentage 1.5%
Projected System Loads
Summer 2020: 289 MW
Winter : 288 MW
Distribution capacity: 72 MVA
Area Utilization Factor: 28%

6. N-0 Conditions – Replace CB’s
Grace Plant Replace CB’s, 2018
CB 123 will be loaded to 132 % (3 ᶲ rating, continuous 800 Amp, 10.5 kA)
CB 126 will be loaded to 132 % (3 ᶲ rating, continuous 1200 Amp, 10.5 kA)
Solution: Increase both CB’s with 2000 Amp (continuous) 40 kA (interrupting)
Estimated cost: $0.9m

7. N-0 Conditions – Replace CB’s
Bancroft Replace CB’s, 2018
CB 12 will be loaded to 108 % (1 ᶲ rating, continuous 100 Amp, 2 kA)
Solution: Increase both CB with at least 6 kA (interrupting) rating.
Estimated cost: $100k

8. N-0 Conditions – Upgrade Switch
Arimo Upgrade Switch,
This switch lacks the full load break and line dropping capability
Solution: Upgrade switch 5A at Arimo to a LO/LD capability
Estimated cost: $75k

9. N-0 Conditions – Upgrade Switch
Trail Junction Upgrade Switch,
This switch lacks the full load break and line dropping capability
Solution: Upgrade switch 61A at Trail Junction to a LO/LD capability
Estimated cost: $75k

10. N-0 Conditions – Upgrade Switch
Lund Tap Upgrade Switch,
42A switch at Lund Tap lacks the full load break and line dropping capability
Solution: Upgrade switch 42A at Lund Tap to a LO/LD capability
Estimated cost: $75k

11. There were no prominent N-1 conditions

12. Total Construction Costs
Construction Item
2016 CONSTRUCTION
Cost
Investigate the loading discrepancy at Cove substation
O&M
Subtotal
$0.0
2018 CONSTRUCTION
Grace Plant ~ Replace CB 123 and CB 126
$900k
Bancroft ~ Replace CB 12
$100k
$1.0m
Reliability Work Plan Projects
Arimo ~ Upgrade switch to LO/LD
$75k
Trail Junction ~ Upgrade switch to LO/LD
Lund Tap ~ Upgrade switch to LO/LD
$225k
TOTAL COST
$1.225m

13. Any questions or comments?

14. Smithfield/Preston Study Findings
AREA PLANNER:
Prepared by:

15. System Overview Covers 450 square miles
Main Sources are Treasureton, Wheelon and Bridgerland
Generation: Oneida, Preston, Mink Creek and 2 customer
23 substations, 3 being customer owned
Area has 230, 138 and 46 kV lines

16. Load Growth Base System Loads Growth: Projected System Loads
Summer 2015: 238 MVA
Winter : 161 MVA
Growth:
Average Summer Percentage 2.0%
Average Winter Percentage 2.0%
Projected System Loads
Summer 2020: 279 MVA
Winter : 199 MVA
Distribution capacity: 180 MVA
Area Utilization Factor: 79%

17. N-0 Conditions – Low Voltage
Franklin Change No-Load Tap
There is 35 miles of 1/0 and 3/0 ACSR conductor that causes voltage drop between Franklin and Downey
Solution: Change the no-load tap at Franklin to tap #4 (134.5 kV) on the 46 kV system and install a 1.2 Mvar capacitor bank on kV Downey system
Estimated cost: O&M

18. N-0 Conditions – Bypass Hyrum Bus
East Hyrum Bypass
Conductor bus size is 7-#2 Cu will load to 114% (18 MVA)
Solution: Connect the Hyrum City line to the western Nibley-East Hyrum line (capacity is 25 MVA)
Estimated cost: $30k

19. N-0 Conditions – Increase Capacity
Lewiston Upgrade, 2018
Lewiston transformer loads to 101% (14 MVA)
Solution: Install a 22.4 MVA transformer spare equipped with an LTC
Estimated cost: $700k

20. N-1 Conditions - Disable Auto Throwover
Richmond Auto –Throwover, 2018
The loss of Franklin kV transformer will cause Smithfield transformer to load to 106% (33 MVA), with the auto-throwover scheme on
Solution: Disable the Richmond auto-throwover during the summer to prevent overload
Estimated cost: N/A

21. N-0 Conditions – Install Cap Bank
Downey Install Cap Bank, 2019
Low voltage happens on the line between Franklin and Downey substations
Solution: Along with the change of the no-load tap at Franklin, a 1.2 Mvar capacitor bank installed at Downey
Estimated cost: $200k

22. N-0 Conditions – Install Fans
Weston Install Fans
In summer 2013, transformer loaded to 95% of its rating (3.75 MVA). The peaks have gone down but the capacity should be raised.
Solution: Install additional fans on the Weston transformer fins, to increase the rating
Estimated cost: $15k

23. N-0 Conditions – Replace CB
Green Canyon Replace CB
CB L33 will be loaded to 113% (3 ᶲ rating, continuous 600 Amp, 6.3 kA)
Solution: Increase CB L33 with 2000 Amp (continuous) 40 kA (interrupting)
Estimated cost: $640k

24. N-0 Conditions – Replace CB’s
Treasureton Replace CB’s
CB L101 & CB L102 will be loaded to 115% (1 ᶲ rating, continuous 1600 Amp, 18 kA) & 99% (1 ᶲ rating, continuous 1200 Amp, 21 kA)
Solution: Increase both CB with higher fault duties to prevent circuit breakers from failing
Estimated cost: $1.3m

25. N-0 Conditions – Upgrade Switches
Lewiston Upgrade Switches
41A & 42A switches at Lewiston lacks the full load break and line dropping capability
Solution: Upgrade switch 41A & 42A at Lewiston to a LO/LD capability
Estimated cost: $100k

26. There were no prominent N-1 conditions

27. Total Construction Costs
Franklin ~ Low Voltage: change no-load tap
O&M
East Hyrum ~ Connect Hyrum City feed to Nibley-East Hyrum line
$30k
Subtotal
2018 CONSTRUCTION
Lewiston ~ Increase Capacity
$700k
Richmond ~ Disable the auto-throwover during summers
2019 CONSTRUCTION
Downey ~ Install kV 1.2 Mvar capacitor bank
$200k
NO TIMELINE CONSTRUCTION
Weston ~ Install additional fans
$15k
Green Canyon ~ Replace CB L33
$640k
Treasureton ~ Replace CB’s L101 and CB L102
$1.3m
Lewiston ~ Install LO/LD switches in place of 41A and 42A
$100k
$2.06m
TOTAL COST
$2.985m

28. Any questions or comments?

29. Price (Utah) Study Findings
AREA PLANNER:
Prepared by:

30. System Overview Covers 5,200 square miles
Main Sources are Huntington and Hunter (Emery), contributions from Sunnyside gen
Approximately 60 substations, 31 being customer owned
Area has 345, 138, 69 and 46 kV lines

31. Load Growth Base System Loads Growth: Projected System Loads
Summer 2015: 130 MW (Industrial 66%)
Winter : 131 MW
Growth:
Average Summer Percentage 1.3%
Average Winter Percentage 1.1%
Projected System Loads
Summer 2020: 149 MW
Winter : 146 MW
Distribution capacity: 107 MVA
Area Utilization Factor: 50%

32. N-0 Conditions – Increase Capacity
XFMR name Upgrade, 2017
Spanish Fork XFMR at 108% ( MVA Rating)
Install a MVA pole mount substation (North Arm)
Scofield Reservoir
Scofield Reservoir
Estimated cost: $200k

33. N-1 Conditions – Install Breakers
Helper Install Circuit Breakers, 2018
Loss of the Carbon-Helper 138 kV line results in overloading between Price City Tap and Mill Creek Tap 46 kV line to 116% (36 MVA, emergency)
Also, results in low voltage on the 46 kV system being served by Helper
Solution: Place breakers on the second Carbon-Helper 138 kV line, which is normally open producing a second feed to the area.
Estimated cost: $8.3m

34. There were no prominent N-1 conditions

35. Total Construction Costs
Construction Item
2017 CONSTRUCTION
Cost
Scofield Reservoir ~ Increase capacity
$200k
Subtotal
2018 CONSTRUCTION
Helper Substation ~ Install new 138 kV yard with Circuit Breakers
$8.3m
TOTAL COST
$8.5m

36. Any questions or comments?

37. Study Areas for 2016
Kickoff Studies

38. Lakeside is to the North
Tooele (Utah) Study Service Area
Lakeside is to the North
Dividing line is the Tooele county border
Terminal & Oquirrh are the main sources for the area

39. Tooele (Utah) Study Info
Covers 800 square miles in Tooele county.
2 sources – Terminal & Oquirrh serving kV lines.
Approximately 32 substations, 14 are customer owned
1 Alt. (46 kV) Source at Terminal
Transmission voltages 46 & 138 kV

40. Any questions or comments?

41. Southeast Utah Study Service Area
Area is located in Grand and San Juan counties
Pinto (via 345 kV Huntington to Four Corners), Abajo & Moab are the main sources for the area
Dividing lines are counties lines & the Utah border

42. Southeast Utah Study Info
Covers 6,500 square miles in Grand & San Juan counties
Serves NTUA loads (Navajo Tribal Utility Authority)
Approximately 31 substations, 14 are customer owned
Transmission voltages 46, 69, 138 & 345 kV
Study will concentrate mainly on the 138 kV system
& below

43. Any questions or comments?

44. North Salt Lake Study Service Area
Dividing line is North Temple to the South & Farmington to the North kV lines origination at Terminal 46 kV sources at Parrish, Gadsby & Jordan subs.

45. North Salt Lake Study Info
Covers 67 square miles in southern part of Davis & north part of Salt Lake County
Main sources are Terminal, Parrish, Gadsby & Jordan.
Major sources include kV lines originating from Terminal.
Municipalities: Kaysville City & Bountiful City
Approximately 29 substations, 12 are customer owned
Transmission voltages 46 & 138 kV

46. Any questions or comments?