# Presentation: 373513

## 2006 IRP Transmission Plans

## Nevada Power System Overview

- Transmission System Composed of Three Major Sections
- Uncongested Grid
- Southern Cut Plane
- Northern Cut Plane

## Major NPC Projects Revealed in 2006 IRP

- Ely Energy Center (EEC), Including Eastern Nevada Transmission Intertie (ENTI)
- White Pine Energy Associates (WPEA) and Great Basin Transmission Company (GBT)
- East Valley Area Master Plan (EVAMP)
- Northwest Las Vegas Area Routing and Siting Master Plan (VARS)
- Other Projects : Sinatra, LV Core Service, etc.
- Also Addressed: Import / Export Capabilities, Centennial Project Status

## Ely Energy Center & EN-ti Projects

- EEC 500 kV Switching Station
- EEC – Robinson Summit 500 kV No. 1 Transmission Line
- Robinson Summit 500/345 kV Switching Station
- Fold of Falcon – Gonder 345 kV Line Into Robinson Summit Substation
- Harry Allen – Robinson Summit 500 kV No. 1 Transmission Line (ENTI)
- Harry Allen 500 kV Improvements for EEC (ENTI)

## Robinson Summit Substation One-line Diagram

## White Pine Energy Center / Great Basin Transmission Interconnection 

## Justification of EEC & EN-ti Projects

- 1,550 MW new resources to Nevada Power loads
- 300 MW new resources to Sierra Pacific loads
- Deliver IGCC plants at EEC
- Interconnect White Pine Energy Center
- Point-to-point transmission service for Great Basin Transmission additions

**Notes:**
Deliver up to 1,550 MW of new resources to Nevada Power loads
Deliver up to 300 MW of new resources to Sierra Pacific loads
Accommodate delivery of potential IGCC plants at EEC in the future
Accommodate interconnection of the proposed White Pine Energy Center
Provide point-to-point transmission service for the proposed Great Basin Transmission additions

## White Pine Energy Associates Transmission Service Request 

## White Pine (WPEA) and Great Basin (GBT) Project

- Robinson Summit 500 kV terminals for connection of White Pine Energy Center
- Robinson Summit and Harry Allen Substation for GBT (LS Power) Transmission Interconnection of its Robinson Summit – Harry Allen 500 kV line
- Harry Allen – Mead 500 kV line No. 2 and substation work for the WPEA (LS Power) point-to-point Transmission Service Request –

**Notes:**
Robinson Summit 500 kV terminals for connection of White Pine Energy Center 
Robinson Summit and Harry Allen Substation work necessary for GBT (LS Power) Transmission Interconnection of its Robinson Summit – Harry Allen 500 kV line
Harry Allen – Mead 500 kV line No. 2 and associated substation work for the WPEA (LS Power) point-to-point Transmission Service Request – if executed or filed unexecuted

## EEC & White Pine Interconnection, Final Diagram

## East Valley Area Master Plan (EVAMP) Projects

- Northwest Substation 500/230 kV No. 2 Transformer
- Sunrise 500/230/138 kV Substation, The ‘Sunrise’ Option
- Equestrian North 500/230 kV Substation, The ‘Equestrian’ Option

## EVAMP: Sunrise Option Oneline Diagram

## EVAMP: Equestrian Option Oneline Diagram

## NEVP and SPPC Development Plan in 2008 -2014:  EN-ti, WPEA/GBT and EVAMP 

## Justification of EVAMP Projects

- Northwest #2 Transformer
- Northwest valley
- Crystal Sub
- Crystal – McCullough 500 kV line
- NW 500/230 kV No. 1 transformer
- Sunrise 500/230/138 kV Substation
- Load service to Las Vegas valley
- Bulk power transfer or EEC 600 MW block into Harry Allen
- Close to load center and other transmission subs
- Equestrian 500/230 kV Substation - Bulk power transfer Capability
- New generation at Harry Allen
- Change in Transmission at Crystal – McCullough 500 kV line
- Crystal – McCullough 500 kV line / South of the Harry Allen 230 kV cut plane
- Beyond 2014
- Further development of 500/230 kV sources into the LV valley
- Participate in Federal Corridor Study
- Investigate feasibility of a 500 kV loop around LV

**Notes:**
Northwest #2 Transformer
Transmission service for new load in the northwest valley
Prevent overload of the 230 kV phase shifters at Crystal Sub
Crystal – McCullough 500 kV line is fully subscribed
NW 500/230 kV No. 1 transformer overloads during several single contingency conditions
Sunrise 500/230/138 kV Substation
Deliver 900 MW of load service into the Las Vegas valley
Provides new bulk power transfer needed for high import scenario or EEC 600 MW block into Harry Allen
Close to load center and other transmission subs 
Equestrian 500/230 kV Substation
Additional bulk power transfer capability forced by:
New generation at Harry Allen (above the Centennial 3,000 MW and EEC 1,200 MW)
Loss of transmission capacity or change in operating agreements on the Crystal – McCullough 500 kV line
Desire to reduce reliance on the Crystal – McCullough 500 kV line or the South of the Harry Allen 230 kV cut plane
Beyond 2014
Further development of 500/230 kV sources into the LV valley (independent of the Harry Allen – Sunrise – Equestrian – Mead line)
Participate in Federal Corridor Study to establish various corridors (to include the Harry Allen to Jean and Jean to Arden corridors)
Investigate feasibility of a 500 kV loop around LV to meet future loads

## Summary of EVAMP, EN-ti & WPEA/GBT  Interconnection Facilities 

## VARS Projects One-line Diagram

## Northwest Las Vegas Area Routing and Siting Master Plan (VARS)

- New 230/12 kV Substations
- Grand Teton
- Iron Mountain/Rainbow
- Log Cabin
- Elkhorn/Commerce
- Elkhorn/Pecos
- Mobile 230/12 kV substation
- Thunderbird Sub and VARS Transmission System Additions
- Iron Mountain 230/138 kV, 336 MVA Transformer
- Northwest 230/138 kV, 336 MVA Transformer
- Brooks 230/138/12 kV Substation & Pecos – Brooks 230 kV line

**Notes:**
New 230/12 kV Substations (5 total – Grand Teton, Iron Mountain/Rainbow, Log Cabin, Elkhorn/Commerce, Elkhorn/Pecos, plus mobile 230/12 kV substation)
Thunderbird Sub and VARS Transmission System Additions (complete Thunderbird 230/138 kV sub, complete Thunderbird to Northwest 230 kV line, 8 new 138 kV substations)
Iron Mountain 230/138 kV, 336 MVA Transformer
Northwest 230/138 kV, 336 MVA Transformer
Brooks 230/138/12 kV Substation and Pecos – Brooks 230 kV line

## Justification of VARS Projects

- New 230/12 kV Subs
- Thunderbird Sub and VARS Transmission Additions
- Iron Mountain 230/138 kV, 336 MVA Transformer
- Northwest 230/138 kV, 336 MVA Transformer
- Brooks 230/138/12 kV Substation and Pecos – Brooks 230 kV line

**Notes:**
New 230/12 kV Subs
Meet VARS area load growth
Converting existing 230 kV to 138 kV not feasible
Delay Thunderbird Sub and Thunderbird – Iron Mountain line
Thunderbird Sub and VARS Transmission Additions
8 new 138 kV subs to meet future load growth in LV valley
T-Bird sub to serve projected load growth in North LV valley
Thunderbird – Northwest and Thunderbird – Iron Mountain for bulk transmission service and improved reliability
Harry Allen – Northwest fold into T-Bird and Pecos subs for bulk transmission system reliability and operational flexibility
Iron Mountain 230/138 kV, 336 MVA Transformer
Meet future 138 kV distribution station growth and voltage requirements due to load growth
Existing 230/138 kV transformer overloads during Pecos – Allen outage
Northwest 230/138 kV, 336 MVA Transformer
Meet future load growth and future distribution subs fed from NW Sub
Meet N-1 contingency reliability criteria
Brooks 230/138/12 kV Substation and Pecos – Brooks 230 kV line
Provide bulk transmission support and relieve Pecos sub heavy loads during various N-1 contingencies
Eliminate N-1 low voltage issues

## Additional Projects Proposed

- Sinatra Substation
- Strategic Plan for Las Vegas Core Service
- McDonald 230/138 kV Transformer
- Arden 230/138 kV Transformer
- Clark 230/138 kV Bank No. 6 Change out
- Valley Electric Association Interconnection
- Clark Generating Station Peakers
- Solar One Interconnection
- Import/Export Capability

**Notes:**
Sinatra Substation
Serve projected load on LV strip including Project City Center (PCC)
Strategic Plan for Las Vegas Core Service
New 230 kV ties: N. Las Vegas to the strip, E. LV to strip, S. LV to strip
Serve vertical load growth on the strip
Limited capacity on 69/138 kV subs in the strip area
West Henderson Area Improvements
Accommodate development in rapidly growing West Henderson
McDonald 230/138 kV Transformer
Load growth driven
Arden 230/138 kV Transformer
Relieve loading of Tolson 230/138 kV bank for outage on Arden 230/138 kV #1
Clark 230/138 kV Bank No. 6 Change out
Change to 400 MVA bank to deliver NPC’s resources from Harry Allen into the uncongested grid
Valley Electric Association Interconnection
Interconnection request allowing VEA to meet NERC voltage requirements during N-1 contingencies
Clark Generating Station Peakers
Clark 1, 2, and 3 retired (lost 175 MW of internal valley generation as well as much needed voltage support)
Provides voltage support during high imports, quick start spinning reserve, and peaking capacity
Solar One Interconnection
Requested generation interconnection
Import/Export Capability

## SPR Transmission Projects

-  $785 Million completed since 1998 or currently under construction
-  $ 740 Million proposed  in-service through 2014 not including EEC transmission
-  Total $ 1.5 Billion completed since 1998, under construction, or proposed through 2014