WestConnect’s 2012 transmission expansion plan includes more than 7,000 miles of new transmission

West Connect RegionWestConnect’s annual 10-year transmission plan for 2012 lists nearly 300 planned and conceptual transmission expansion projects across the group’s eight-state footprint.

The plan, which is the fifth subregional transmission plan coordinated and produced on behalf of the group’s subregional planning participants and stakeholders, was approved by the WestConnect Planning Management Committee on Feb. 16.

The plan lists a total of 215 planned transmission projects with a combined length of 7,109 miles. Planned projects include 110 new, rebuilt, or upgraded transmission line projects totaling 6,305 miles that require a total capital investment of $10.6bn.

In addition, planned projects include 65 substations, 12 transmission line and substation projects, 23 transformers, and five other planned projects. Total capital investment is estimated in excess of $13.1bn.

Combining the planned and conceptual projects, the 2012 plan includes 13,193 miles of new/upgraded transmission lines, and other facilities, that require a total capital investment of more than $27.5bn.

Planned projects include two 500-kV DC projects, 16 AC projects at 500-kV, 21 at 345-kV, 60 at 230-kV, and 114 below 230-kV.

Multi-state projects account for 3,049 miles of new transmission, including:

  • The Centennial West Clean Line, an HVDC line that will connect wind energy produced in eastern New Mexico to communities in southern California or southern Nevada.
  • The Chinook Project, a 500-kV HVDC line from south central Montana to the Eldorado Valley south of Las Vegas.
  • The Las Vegas to Los Angeles Project, a proposed double-circuit 500-kV AC line from the Eldorado Valley area in southern Nevada toward the load centers of Los Angeles.
  • The North Gila – Imperial Valley #2 project, a double-circuit 500/230-kV AC line from the North Gila substation near Yuma, Ariz., to the Imperial Valley substation near El Centro, Calif.
  • The Southline Transmission Project, a high-voltage electric transmission line in southern New Mexico and Arizona consisting of the Afton-Apache segment connecting New Mexico and Arizona and the Apache-Saguaro segment near Tucson, Ariz.
  • The Southwest Intertie Project, a 500-kV interstate transmission line connecting southern Idaho and southern Nevada.
  • The SunZia Southwest Transmission Project, a 500-kV interstate transmission lines between Arizona and New Mexico.
  • The TransWest Express Transmission Project, a 600-kV DC transmission line from Wyoming to the Eldorado Valley in southern Nevada.
  • The Wyoming-Colorado Intertie project, a 345-kV transmission line between southeast Wyoming and northeastern Colorado.
  • The Zephyr Project, a 500-kV HVDC transmission line from southeast Wyoming to the Eldorado Valley south of Las Vegas to deliver renewable power into the California and Arizona markets.

Utilities in Arizona are responsible for the largest number of planned projects and the most miles of new transmission in a single state: 1,405 additional miles of new transmission will be constructed in 92 projects. Colorado has the second-largest number: 39 new projects creating 1,205 miles of new transmission. Texas has 23 planned projects resulting in 41 miles of new transmission; Wyoming has 15 projects at 280 miles; New Mexico has 14 projects and 132 new miles; Nevada has 13 new projects and 781 new miles; and California has 9 projects adding 217 new miles of transmission.

Additionally, there are 71 total conceptual transmission projects including 43 new or rebuilt/upgraded transmission line projects with a combined length of 6,084 miles. Six substations, four transmission line and substation projects, seven transformers, and 11 other conceptual projects complete the list of conceptual projects. Capital investment data, which was submitted for slightly more than 50% of the conceptual projects, estimates an outlay of at least $14.4bn.

The plan also lists 35 projects that were placed in service since publication of the 2011 plan.

The 2012 plan encompasses three subregional planning areas covering portions of eight states. The intent of the plan is to provide a comprehensive overview of the large number of planned and conceptual transmission projects proposed within the planning area for the ten-year horizon, from 2012 to 2021.