Runway 230kV

Person and their pet dog laying on the couch.


Voltage - 230kV
Estimated completion date - 1st quarter 2023
Location - East Goodyear and west Avondale, AZ

Project need
The West Valley region of the Phoenix metropolitan area is currently experiencing high growth, and additional growth is anticipated in the future. We continually monitor our electrical system and, when necessary, add or upgrade facilities to enhance reliability and help ensure that an adequate supply of electric power is available to our customers.

This project involves the construction of a new double circuit 230 kilovolt (230kV) power line to support the service and redundancy needs of the new STACK Infrastructure data center in Avondale and the Microsoft data center in Goodyear.

Project description
The project involves building a new double circuit 230kV power line from the existing 230kV power line located on the north side of Buckeye Road and the Agua Fria River, to the planned Diamond Substation, which will serve the new STACK Infrastructure data center in Avondale. From Diamond Substation, the 230kV line will continue west to connect into the Runway Substation, which serves the Microsoft data center in Goodyear, as shown in the project map.

Project planning
In Jan. 2022, we announced the need for a new double circuit 230kV power line to serve the Microsoft data center. The new 230kV line would connect the APS Runway Substation, located on the Microsoft site in Goodyear, to existing transmission lines along the Agua Fria River in Avondale. It would also allow for a future connection of the planned Diamond Substation located to the east of the Microsoft data center. As of Sept. 2022, we have conducted environmental studies and held multiple meetings with representatives from the cities of Goodyear and Avondale, Maricopa County, and other jurisdictions in the study area.

On Jan. 10, 2022, we launched a virtual public open house to provide project information and seek your input. The virtual open house was updated on June 14, 2022, in coordination with our in-person open houses held on two nights during that same week.

Community feedback during this process has helped us identify a preferred route and subroute alternatives, as shown on the Preferred Route Map.

Project features
Monopole (single pole) structures are typically used for new 230kV transmission lines but may include a variety of steel structure types ranging in height from approximately 115 feet to 195 feet depending on routing, terrain, and crossing of existing structures, including elevated roads and other power lines. 

Any opportunity to utilize existing power line routes for the new 230kV structures will be considered. However, new rights-of-way and/or easements (approximately 60 feet each side of the structure totaling 120 feet) will be needed. 

Public Hearing Information

September 27, 2022: A CEC Prefiling Conference was held with the Chairman of the Arizona Power Plant and Transmission Line Siting Committee to discuss the application, public hearing agenda, and ensure proper notifications and filing requirements will be met. PDF copies of the prefiling conference transcripts, prefiling exhibits, and notice of hearing can be viewed within the Evidentiary Hearing documents below.


September 29, 2022: An application for a Certificate of Environmental Compatibility (CEC) was filed at the ACC Docket Control. The docket number for this Project is L-00000D-22-0253-00209. A PDF copy of this CEC (CEC-209) application can be viewed within the Evidentiary Hearing documents below.


November 2, 2022: A Prehearing conference was held with the Chairman of the Arizona Power Plant and Transmission Line Siting Committee to ensure notification requirements were met and discuss evidentiary hearing protocol and expectations. A PDF copy of the prehearing conference transcripts can be viewed within the Evidentiary Hearing documents below.


November 14, 2022: The Arizona Power Plant and Transmission Line Siting Committee (Committee) held hearings on this project beginning at 1 PM on November 14th at the Hilton Garden Inn, 11460 West Hilton Way, Avondale, AZ 85323. A Public Comment Period was also held that same day at 5:30 pm. Notification was sent to the public before the hearings to provide information for attendance in person or on-line. The Committee completed the evidentiary hearings on November 15th 2022, and voted unanimously to grant CEC-209 to APS for their Preferred Route.


November 23, 2022: The Committee Chairman submitted CEC-209 to the Arizona Corporation Commission (ACC) for their consideration. The ACC can either grant the CEC as proposed, modify, or deny the CEC at an open meeting in January 2023. 


January 10, 2023:The case for CEC-200 was presented during the ACC Open Meeting and received a unanimous vote of approval.   

Next Steps
With the completion of the siting efforts, and the acquisition of the CEC, the construction phase of this project is expected to begin in 2023. This includes engineering and design, acquiring the easements and rights-of-way, and finally the construction of the line. 

Public input
Although the public siting process is now complete, comments or questions can be submitted by email to:

Siting Consultant

Related documents and Links
Newsletter #1
Newsletter #2
Newsletter #3
Newsletter #4
Open House #1 Materials & Maps
Refined Preliminary Links Map
Route Alternatives Map

Evidentiary Hearing documents
CEC Application
Notice of Hearing
Prefiling Conference Exhibits
Prehearing Transcripts
Notice of Filing CEC-209
Power line siting projects
A look at the current siting projects, as well as some completed siting projects.
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