Transmission

Electric Transmission

Hotstick lineman apprentice Brandon Guinane, left, works on the Apache-Hayden 115-kilovolt structure changeout under the supervision of hotstick lineman Henry Patricio.

AEPCO transmits wholesale electric power from Apache Generating Station in Cochise, Arizona, to our six Member distribution co-ops, which serve members in Arizona, California, and New Mexico. AEPCO operates and maintains:

  • 841 miles of transmission line owned all or in part by AEPCO
  • 33 substations reaching out from Apache Station across Arizona to the northwestern corner of the state
  • 30 telecommunications towers and an extensive fiber network used to communicate between AEPCO operations centers and substations, and Member cooperatives and customers

It takes a solid, reliable system to transmit power from our plant to our Member distribution electric co-ops, and on to their 420,000 member-consumers at the end of the line.

We continue to boost system reliability and service by partnering with other utilities on transmission projects.

  • We are interconnecting the Valencia Substation in southwest Tucson with the Central Arizona Water Conservation District (CAWCD) and its Central Arizona Project (CAP), which powers pumps that deliver water to southern Arizona. Scheduled for completion in 2020, the new 2.7-mile transmission line and Valencia Substation upgrades will provide mutual backup for AEPCO and CAP.
  • We are developing an interconnect between AEPCO’s Kartchner Substation and the Tucson Electric Power (TEP) substation at the Fort Huachuca U.S. Army Post. Scheduled for completion in 2021, the cost of the 5-mile transmission line and substation would be shared between TEP, Fort Huachuca and AEPCO.
  • We are working with Arizona Public Service (APS) on a new 1-mile transmission line near Bagdad, Arizona, connecting the Bagdad Substation to an APS line. This will provide backup for APS’s Bagdad townsite and Mohave Electric Cooperative loads in the Wikieup area.
  • We are working with APS on another project north of Tombstone, Arizona, that will include an interconnect between Sulphur Springs Valley Electric Cooperative and APS in the Hereford/Palominas area. This is projected to be in service in 2021.
We do extensive maintenance and perform upgrades to enhance system reliability whenever and wherever possible. Here, crews replace a component of one of the wooden structures that supports the Apache – Hayden 115 kV line, in a remote area east of San Manuel, Arizona.