Tucson Electric Power (TEP) is developing plans for a new transmission line that will strengthen electric reliability for customers in central Tucson and help satisfy growing energy needs in our community.
TEP is identifying a route for the Kino to DeMoss-Petrie (Kino-DMP) 138-Kilovolt (kV) Transmission Line, which will connect the Kino Substation to the DeMoss-Petrie Substation and interconnect with the planned Vine Substation.
The Arizona Corporation Commission (ACC) must approve the route before the line can be built. In August 2021, TEP filed an application with the ACC for a Certificate of Environmental Compatibility (CEC). To allow ample time for collaboration with the City of Tucson and additional outreach to stakeholders, TEP withdrew its CEC application. TEP anticipates that the line siting hearing to consider its application will be rescheduled for the first quarter of 2023.
TEP will continue to communicate with neighbors and other stakeholders about the project, and public input remains an important part of TEP’s planning process. TEP encourages neighbors and other stakeholders to share their comments using one of the public participation methods listed below.
Please visit this link for information about the Vine Substation Project, which previously was named the UA North Substation.
Application & Exhibits A-I
- Notice of Hearing—signed Aug. 11, 2021
- Transcript of Prehearing Conference to Reschedule Hearing—Sept. 8, 2021
TEP encourages residents, property owners and others to share their input by:
- Mailing a letter with comments to:
P.O. Box 711
Mail Stop RC131
Tucson, AZ 85701-0711
- Sending comments to KINO2DMP@tep.com
- Filling out an online comment form
- Calling 1-833-523-0887 and leaving a voicemail message
- Prevention of power outages and inadequate voltage. By increasing electric capacity, TEP can avoid overload conditions that can damage equipment, causing outages or low voltage for residential and other customers. Some lower-voltage feeder lines in the study area have reached or are approaching their capacity limitations.
- Service for growing energy needs. Increased electrical capacity would allow TEP to better serve customers throughout the study area, even during summer months when customers’ need for power is highest. Peak energy demands throughout TEP’s service territory have increased by about 9 percent since mid-2015. New infrastructure would help meet customers’ current and future energy needs.
- Improved electric reliability. New energy infrastructure will strengthen reliability for homes and businesses in the study area by adding redundancy, allowing TEP to deliver energy from more than one direction.
- Replacement of aging infrastructure. A large transformer, electric switchgear and other substation equipment currently providing service to some area customers are nearing the end of their useful lives and must be replaced within the next five years.
- Support for the University of Arizona and the Banner – University Medical Center Tucson campus and emergency room. The new line will tie into TEP’s 138 kV transmission system to accommodate increased energy demands.
In determining where to locate new energy infrastructure, TEP considers the projected energy needs of nearby residential and commercial customers, anticipated economic development, proximity to existing equipment, project costs, geography, the environment, public input and other factors. Transmission lines link substations that change the voltage of electric facilities for distribution and delivery of electric service to area customers.
TEP is evaluating potential transmission line routes within a defined study area that could interconnect existing and planned substations that include:
- Kino Substation: TEP is building a new substation at the southeast corner of South Kino Parkway and East 36th Street to accommodate growing energy demands and support expected economic development in the area. The substation will occupy about 4.5 acres. Construction began in September 2019. The substation is scheduled to be in service in 2020.
- Vine Substation: This planned substation will tie into TEP’s 138 kV transmission system to accommodate increased energy demands in the area. It also will help maintain reliable service by supporting the eventual retirement of aging, lower capacity 46 kV substations.
- DeMoss-Petrie (DMP) Substation: Located near Interstate 10 and West Grant Road, the substation serves as the point of
interconnection for several high-voltage transmission lines and natural gas generating resources and an energy storage system.
TEP will use input from customers, stakeholders and other members of the public to identify potential alternative transmission line routes within the study area. Members of the community will have additional opportunities to comment on these potential alternative routes in the future.
The Kino to DeMoss-Petrie line will cross private property and utilize road right of way within the City of Tucson. Interconnecting the Kino Substation and planned Vine Substation to the existing DeMoss-Petrie Substation will strengthen reliability by adding redundancy, allowing TEP to deliver energy from more than one direction.
TEP would build the line with self-weathering steel monopoles that stand between 75-110 feet tall. Taller structures may be required at major road or line crossings.
Under state law, TEP must secure a Certificate of Environmental Compatibility (CEC) before building the transmission line. TEP filed a CEC application in August 2021 with the Arizona Power Plant and Transmission Line Siting Committee, which will review the application in a public process that allows neighbors and other stakeholders to provide comments. If the Line Siting Committee grants a CEC, it will be sent to the ACC for final review and approval.
In August 2021, TEP filed an application for a CEC. To allow ample time for collaboration with the City of Tucson and additional outreach to stakeholders, TEP withdrew its CEC application, thus suspending the line siting hearing that was scheduled to begin in February 2022. TEP anticipates that the line siting hearing to consider TEP’s application will be rescheduled for the first quarter of 2023.
TEP must also obtain a Special Exception Land Use Permit from the City of Tucson for the UA North Substation.
TEP is planning to place the Kino-DMP line into service by 2024.
Public Outreach Materials
- Virtual Open House Meeting #3 PPT Presentation
- October Virtual Open House Meeting Questions and Responses
To view a recording of the livestream, click below or view on YouTube.
In September 2020, TEP updated the preliminary alternative routes under consideration. Due to planned development on North Vine Avenue, Route 4, Route 6 and Route C were removed from consideration. Through additional analysis, a new route titled 'Route E,' was identified for consideration.
To view a recording of the livestream, click below or view on YouTube.
Kino to DeMoss Petrie Preliminary Route Videos
To view a video describing preliminary routes, click below or view on YouTube.
- Underground Report Rev0
- Biological Evaluation
- Visual Impacts Assessment
- Historic District Analysis (Built Environment Study)
- Cultural Resources Class I Analysis
- Underground Report Rev1
- Interim Siting Study – Phase 1, 2 & 3 Analysis
- Underground Report Rev 2
- Underground Report Rev 3
- Underground Report Rev 4
- Final Visual Simulation Exhibit 118kb
- Final Siting Study May 2021
- Final Exhibit Simulation, Alternative 5
Although TEP suspended public open house meetings in March 2020 as a precaution to limit unnecessary risk of exposure to the COVID-19 coronavirus, public input remains an important part of the planning process.
This online project update provides details about the multiple potential line route links that could be combined in various ways to form route alternatives, and eventually a final route.
Residents and other stakeholders are encouraged to view the update and share their comments about potential line route links by Friday, May 22, 2020 using one of these methods listed above.
Detailed route link maps also can be found here:
TEP suspended public open house meetings scheduled for Tuesday, March 17 at the Quincie Douglas Center, 1575 E. 36th St., and Wednesday, March 18 at the Dunbar Pavilion, 325 W. 2nd St., as a precaution to limit unnecessary risk of exposure to the COVID-19 coronavirus. These actions were intended to support public health under social distancing guidance from the Centers for Disease Control and Prevention (CDC).
The Kino to DeMoss-Petrie Community Working Group includes representatives of neighborhood groups within the study area, public agencies and other community organizations. Members have submitted more than 100 questions and comments throughout the months-long, ongoing public outreach process. Responses are posted in the document below.
The document also includes loading and service area maps describing demands placed on equipment under summertime peak loads, when customers’ energy needs are highest.
Loading and Service Area Maps
- Transformers, breakers, switchgears and switches are designed and insulated to withstand certain temperatures during operation. Each piece of equipment carries a rated thermal capacity.
- Maps describe the percentage of rated thermal capacity for the most heavily loaded existing and planned equipment during peak energy demands.
- If load (customer energy demand) exceeding 75 percent is placed on a transformer, switchgear or circuit, or if load exceeding 100 percent is placed on other pieces equipment, mitigation measures are required.
- Loads exceeding 100 percent of rated thermal capacity, or ‘overload conditions,’ can gradually damage equipment and cause outages for customers.
- Several major pieces of equipment at eight area substations are nearing the end of their useful life and must be replaced within 3-10 years. New 138 kV substations and facilities may eliminate the need to replace aging 46 kV facilities.
- If 46 kV substations are replaced by 138 kV facilities, poles and wires associated with retired 46 kV substations also may be removed.
- Contingency support describes the ability of one piece of equipment to ‘pick up’ the energy demand from another piece of equipment rendered inoperable during an outage. A contingency support percentage of 100 or higher means the equipment has no capacity to satisfy additional energy demand.
TEP held public open house meetings on
Tuesday, October 22 at the Quincie Douglas Center, 1575 E. 36th St., and on Wednesday, October 23 at the Tucson City Council Ward 6 Office, 3202 E. 1st St. TEP representatives used these materials to describe the study area and need for the project.
The Materials provided on this webpage are the property of TEP and should not be copied or distributed outside of this website without prior permission.
Answers to Questions about Underground Electric Lines
Most of TEP's electrical facilities are installed above ground, but some lower-voltage distribution lines are installed underground. To learn more, please review answers to frequently asked questions about the potential underground installation of transmission lines and distribution lines.