[Insert Recipient’s Name] Page 3 of 8 [Insert Date]

March 4, 2011

Mark D. Hanson
System Planning Engineer

(208) 388-2253

Kyle Kohne
Chair, Technical Studies Subcommittee
Bonneville Power Administration
7500 NW 41st Street, Suite 130
P.O. Box 61409 – MS TPP-OPP-3
Vancouver, WA 98666-1409

Kent Bolton
Western Electricity Coordinating Council
615 Arapeen Drive, Suite 210
Salt Lake City, UT 84108-1262

Subject: Idaho Power’s 2011 WECC Annual Progress Report

Dear Kyle and Kent:

Attached is Idaho Power’s 2011 WECC Annual Progress Report. Please contact me if you have any questions.

Sincerely,

Mark D. Hanson

System Planning Engineer

TSS Representative

Enclosure

cc: D. M. Angell – PCC Representative

D. W. Streebel – SRWG Representative

O. A. Ciniglio – System Planning Engineering Leader

Idaho Power 2011 WECC Annual Progress Report

Brownlee East (Path 55) 65 MW Up-rate Project

To accommodate additional transfers to the Treasure Valley due to the addition of the Elkhorn Wind Generation project near North Powder, OR, the proposed Brownlee East up-rate project will increase the Brownlee East (Path 55) transmission capacity an additional 65 MW from 1850 MW to 1915 MW.

The Brownlee East up-rate project facilities for an additional 65 MW increase in transmission capacity are listed below:

Ontario C231 Series Capacitor, Increase Nominal/Emergency Current Ratings to 1588 and 2145 amperes, respectively - Complete

Brownlee 230 kV, Install 75 Mvar Shunt Capacitor – Complete

Expanded an additional 37.5 Mvar – Complete

The Brownlee East transmission up-rate project will conform to the NERC/WECC “Reliability Criteria for Transmission System Planning”, and the WECC “Procedures for Regional Project Review and Rating Transmission Facilities.” A Brownlee East (Path 55) Increase to 1915 MW Comprehensive Progress Report (Phase I) was sent out for comment in March 2008. A revised Final Comprehensive Progress Report (Phase I and II) and the request for Phase III status was sent March 25, 2010 and was granted Phase III status on June 14, 2010. All facilities have been placed in-service and the project has been completed.

King 230/138 kV Project

A new 230/138 kV 300 MVA transformer will be installed in the existing King 138 kV substation to accommodate approximately 135 – 150 MW of additional wind generation in the Hagerman area. The King substation will be interconnected to the 230 kV transmission system by looping in-and-out the existing Midpoint-Dram 230 kV line. Because the wind generation projects, which the King 230/138 kV project is to accommodate, have been slow in their development; the in-service date has been deferred to spring 2012. This project has no significant impact on the WECC transmission system.

Langley Gulch Generation Project

The Langley Gulch combined cycle generation project will be constructed near New Plymouth, ID in Payette County, Idaho. The Langley Gulch combined cycle generating plant will consist of one natural gas combustion turbine/generator and one steam turbine/generator. The maximum summer output of the plant is 300 MW (at 32o C) and the maximum winter output is 325 MW (at -7o C) to 345 MW (at -18o C). The proposed commercial operation date is July 1, 2012.

The integration of the Langley Gulch combined cycle generation project requires the construction of a new short double-circuit 230 kV line and a new 138 kV line. A new 2.5 mile double-circuit with single conductor 1272 MCM ACSR 230 kV line will be constructed to loop in-and-out the Ontario-Caldwell 230 kV line into the proposed Langley Gulch generation site; thus creating an Ontario-Langley Gulch 230 kV line and a Caldwell-Langley Gulch 230 kV line. And, a new 18 mile single conductor 1272 MCM ACSR 138 kV line (constructed 230 kV and operate at 138 kV) will be constructed from the proposed Langley Gulch generation site tapping the existing Caldwell-Willis 138 kV line at the proposed future Wagner Tap location which is approximately three miles out from the Caldwell substation; and, thus creating a Langley Gulch-Caldwell 138 kV line. The Langley Gulch-Caldwell 138 kV circuit will share double-circuit towers with the Langley Gulch-Caldwell 230 kV line for approximately 2.0+ miles entering into the Caldwell substation. In addition to the transmission line improvements, a new 230/138 kV 335 MVA transformer will be installed at the Langley Gulch generation site. This project has no significant impact on the WECC transmission system.

Pearl Transmission Substation

Because of the addition of the Langley Gulch Generation Project in the Treasure Valley (see Langley Gulch Generation Project above) and developing the Hemingway 500/230 kV station and its associated 230 kV transmission integration into the Treasure Valley (see Hemingway – Boardman Transmission Project below), the Pearl Transmission Substation project has been deferred beyond Idaho Power’s 10-year planning horizon.

Hemingway - Boardman Transmission Project

Idaho Power’s 2009 Integrated Resource Plan, a biennially-produced 20-year resource plan for meeting our electric service obligation, identified Pacific Northwest generation resources as one component of the preferred resource portfolio. Requirements of Idaho Power’s wholesale transmission customers are also increasing. The existing transmission system to the Pacific Northwest has been fully subscribed during high-demand periods. To meet the need for more transmission capacity, Idaho Power plans to build 500 kV transmission line from southern Idaho to northeast Oregon.

The plan of service is to construct a 299 mile 500 kV transmission line from Hemingway station in southwestern Idaho to the Boardman Power Plant in northeastern Oregon. The Idaho terminal will be the proposed Hemingway Substation located near Walter Ferry, ID in the vicinity of the towns of Melba and Murphy on the south side of the Snake River near PacifiCorp’s Midpoint-Summer Lake 500 kV transmission line. The Hemingway-Boardman Transmission Project scheduled in-service date is June 2016.

The Hemingway-Boardman Transmission Project facilities to accommodate a 1300 MW west to east and an 800 MW east to west transfer capacity are listed below:

Hemingway 500 kV Transmission Substation, near Walter Ferry, ID – In Service: Complete

Existing Midpoint-Summer Lake 500 kV line looped in-and-out of the Hemingway 500 kV Substation – In Service: Complete

Hemingway, 500/230 kV 1000 MVA Auto-Transformer (4 x 1Φ) – In Service: Complete

Hemingway-Bowmont 230 kV line, 13 miles with single 1590 MCM ACSR “Lapwing” conductor – In Service: Complete

Bowmont, 230/138 kV 300 MVA Auto-Transformer – In Service: Complete

Hemingway-Boardman 500 kV line, 299 miles with approximately 50% series compensation – the termination will be at the Grassland switching station near the Boardman Power Plant

Hemingway-Bowmont #2 230 kV line, 13 miles with single 1590 MCM ACSR “Lapwing” conductor

Bowmont-Hubbard 230 kV line, 16 miles with single 1590 MCM ACSR “Lapwing” conductor

Increase the Midpoint 500 kV Series Capacitor current rating

Increase the Burns 500 kV Series Capacitor current rating

The initial phase of the Hemingway-Boardman 500 kV project; the loop in-and-out of the Midpoint-Summer Lake 500 kV line in to the Hemingway 500 kV substation with 230 kV integration (230 kV line and 230/138 kV transformer) to the existing Bowmont substation was completed in mid-July, 2010.

The Hemingway-Boardman Transmission Project will conform to the NERC/WECC “Reliability Criteria for Transmission System Planning”, and the WECC “Procedures for Regional Project Review and Rating Transmission Facilities.” A Hemingway-Boardman Transmission Project Comprehensive Progress Report (Phase I) was released for comment in November 2008 and was granted Phase II status in March 2009. Idaho Power has participated in the Pacific Northwest Transmission Coordination Workgroup (TCWG) for the past two years. Many of the proposed projects have been placed on hold. Idaho Power has continued to adjust the scope of work for the Phase II study and is now prepared to engage the project review workgroup in study work.

Gateway West Transmission Project

The Gateway West Transmission Project as jointly proposed by Idaho Power and PacifiCorp is a 500 kV and 230 kV transmission project from a new station, Windstar - near the Dave Johnston Generating Plant, to a new substation, Hemingway - in southwest Idaho. Idaho Power is leading the planning effort and managing the WECC rating process for the project through southern Idaho.

Idaho Power and PacifiCorp are proposing this transmission project because of service-area load growth internal to both companies. Idaho Power forecasts the need for 800 MW of additional power to serve its southern Idaho load by 2017 and PacifiCorp forecasts that its load on the Wasatch Front of Utah will double in the next 20 years. Additionally, both companies have independent obligations, pursuant to their Open Access Transmission Tariffs, to plan for and expand their respective transmission systems based upon the needs of their native load and network customers along with eligible customers that agree to expand the transmission system.

Plan of Service

The new transmission from southwestern Wyoming through southern Idaho will be parallel 500 kV transmission lines from Jim Bridger to Hemingway, as shown in Figure 2. The following new stations will be constructed: Populus, Cedar Hill, and Hemingway. The purpose of each station follows:

Populus – Connection with New Path C transmission

Cedar Hill – Connection of Idaho southern route to Midpoint for reliability

Hemingway – Connection to Idaho-Northwest 500 kV transmission

The transmission line construction will consist of the following:

Wyoming/Idaho

Jim Bridger – Populus Section

Construction of two new 500 kV circuits from Jim Bridger to Populus with approximately 50% series compensation

Idaho

Populus – Midpoint Section

Construction of the Populus – Borah 500 kV and Borah – Midpoint 500 kV lines. These line sections will be built by conversion of the operating voltage of the existing Kinport/Borah to Midpoint 345 kV line section to 500 kV, and the addition of a new 500 kV circuit between Populus and Borah; both sections will have approximately 50% series compensation. A 500/345 kV 1500 MVA Auto-Transformer (3 x 1Φ) will be installed at Borah.

Populus – Cedar Hill500 kV

Construction of one new 500 kV circuit from Populus to Cedar Hill with approximately 50% series compensation.

Cedar Hill – Hemingway 500 kV

Construction of one new 500 kV circuit from Cedar Hill to Hemingway with approximately 50% series compensation.

Midpoint – Hemingway Section

This section of the project will include two-500 kV circuits.

Midpoint Hemingway 500 kV #1 will be developed by interconnecting the existing Midpoint – Summer Lake 500 kV line into the Hemingway Station.

Midpoint – Hemingway 500 kV #2 will be a new 500 kV circuit from Midpoint to Hemingway with approximately 50% series compensation.

Cedar Hill – Midpoint 500 kV

Construction of one new 500 kV circuit from Cedar Hill to Midpoint. This line will connect the Idaho southern route to Midpoint for improved reliability.

Geographic System Configuration

The following diagrams depict the project and adjacent paths.

Figure 2

Figure 3 Project with adjacent paths

Planned Operating Date

The Gateway West schedule currently identifies the following in-service dates for key portions of the transmission project:

·  Jim Bridger - Populus June 2014

·  Populus – Cedar Hill June 2016

·  Cedar Hill – Hemmingway June 2016

·  Populus – Borah – Midpoint June 2016

·  Cedar Hill – Midpoint June 2017

·  Midpoint – Hemingway #2 June 2017

Transfer Capability

The transfer capabilities vary along the project, and are detailed in Table 1

Project Section / Existing Path / Existing Rating (MW) / Increase (MW) / New Rating (MW)
Jim Bridger-Populus / Bridger West / 2200 / 3000 / 5200
Populus – Midpoint / Borah West / 2557 / 3000 / 5557
Midpoint – Hemingway / Midpoint West / 2487 / 3000 / 5487

Table 1 – Gateway West Transmission Segments and Proposed Transfer Levels

The Gateway West Transmission Project will conform to the NERC/WECC “Reliability Criteria for Transmission System Planning”, and the WECC “Procedures for Regional Project Review and Rating Transmission Facilities.” A Gateway West Transmission Project Comprehensive Progress Report (Phase I) was released for comment in November 2008 and Phase II status was requested and granted in February 2009.

Please direct all questions or concerns regarding these proposed projects to:

Mark D. Hanson
Idaho Power Company
1221 W Idaho
P.O. Box 70
Boise, Idaho 83707-0070

Tel. (208) 388-2253
Fax (208) 388-6647
E-mail

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