The Arizona Corporation Commission (ACC) has approved a route for a new transmission line to help Tucson Electric Power (TEP) meet increasing energy demands in central Tucson.
TEP’s Midtown Reliability Project will involve the installation of a 138-kV transmission line, a substation, and other upgrades, replacing older, lower-voltage equipment to improve grid reliability.
With growing energy needs nearly exceeding the capacity of current infrastructure, the project is expected to be completed by the summer of 2027.
The ACC’s decision follows a recommendation by the Arizona Power Plant and Transmission Line Siting Committee, which issued a Certificate of Environmental Compatibility for the above-ground construction of the project. This decision came after public hearings, during which calls for underground construction were rejected due to the higher costs associated with such an approach. The approved above-ground project is expected to cost approximately $22 million.
The new transmission line will primarily follow West Grant Road, North Park Avenue, Euclid Avenue, and East 36th Street, connecting two TEP substations to the planned Vine Substation near the University of Arizona. TEP plans to relocate existing lower-voltage distribution lines underground along the route, and the completion of the project will allow the retirement of up to eight substations and 19 miles of lower-voltage power lines within a decade.
Although the ACC approved an alternative route, TEP intends to build along its preferred route and seek an exception from the City of Tucson for overhead construction where the preferred route crosses designated Gateway Corridors. Public meetings will be held as part of this waiver request process. If no agreement is reached within six months, TEP may proceed with above-ground construction.
Additionally, TEP plans to request approval for the construction of the Vine Substation after a previous application was denied.
