WAPA » Transmission » Transmission Infrastructure Program » Electrical district no. 5 - Palo Verde hub project

Electrical district no. 5 - Palo Verde hub project

WAPA's Media Line: 720-962-7411

​WAPA’s Transmission Infrastructure Program and a group of electricity providers in Arizona committed to build a large-scale transmission project in Arizona’s Maricopa and Pinal counties. The project will connect a renewable-rich zone south of Phoenix, Ariz., with the Palo Verde market hub, a major electrical trading hub in the Western United States. Financed through WAPA’s authority to borrow funds from the U.S. Treasury, the project will increase transmission capacity to deliver renewable energy, primarily solar, to consumers in Arizona, southern Nevada and southern California.

About the project


WAPA’s Electrical District 5 – Palo Verde Hub project is an about 109-mile transmission project in Arizona, starting at the Palo Verde market hub near Wintersburg in Maricopa County, Ariz., and running southeast to the Electrical District 5 substation south of Casa Grande and near Picacho Peak in Pinal County, Ariz.

Developed in coordination with the Southwest Public Power Resource group, a collection of public power companies that include several WAPA firm electric and transmission service customers of the Parker-Davis Project, ED5-PVH will add up to 410 megawatts of bi-directional capacity, primarily renewable energy, to the electric grid, which includes 254 MWs connecting to the vital Palo Verde market hub that serves consumers in Arizona and southern California and Nevada.

ED5-PVH includes portions of two other existing projects plus adding new 230-kilovolt circuits to existing and planned transmission lines. To complete the ED5-PVH project, WAPA will:

  • Purchase transmission capacity rights on the 500-kilovolt Southeast Valley Project transmission line between WAPA’s Test Track substation and the Palo Verde market, a distance of 64 miles.
  • Add 45 miles of new 230-kV transmission line from the Test Track substation to WAPA’s Electrical District No. 5 substation south of Phoenix. This part consists of:
    • Adding a new 230-kV circuit to an existing WAPA 115-kV transmission line running from ED5 to Casa Grande substation, which is already scheduled for an upgrade

    • Attaching a 230-kV circuit to a planned SEV Project 500-kV line from WAPA’s Test Track substation to where it intersects with the existing line

Project schedule

The project schedule includes upgrades to three substations; and building and upgrading transmission lines, specifically:

  • January 2015 - Project energization
  • November 2012 - Expanded ED5 Substation
  • May 2013 - Expanded Test Track Substation
  • June 2013 - Completed ED5-to-Thornton Road line
  • January 2014 - Completed Thornton Road-to-Test Track line
  • January 2015 - Energized transmission line

See the construction timeline for more details.

News and updates:


 ED-PVH logo


​Timeline and project history

Environmental review (completed)


Public Affairs
Western Area Power Administration
P.O. Box 281213
Lakewood, CO 80228
phone: 720-962-7050

Page Last Updated: 12/10/2019 1:33 PM