Transmission line projects are literally the opposite of backroom deals, built in plain sight through transparent public processes.
That hasn’t stopped opponents of the Copper World mine from trying to stir up controversy around an unrelated transmission line. Recent social media posts from Save the Scenic Santa Ritas claim there’s a “backdoor plan” to power the proposed mine through Tucson Electric Power’s Santa Rita Connection project while slipping the bill to existing customers.
That claim is nonsense. This proposed 138-kilovolt (kV) line has been planned through an extensive public outreach process to support the reliability of TEP’s regional grid. In combination with a new substation, the line will help serve growing energy needs in Sahuarita and Green Valley. Circuits serving 14,000 customers in these communities are already at or near load levels that should not be exceeded, and further growth is expected.
To relieve these conditions, the Santa Rita Connection would link TEP’s Sonoran Substation to the planned Santa Rita Substation three-quarters of a mile south of the intersection of Santa Rita and Country Club Roads. The project will allow the retirement of older infrastructure and support greater resiliency of the regional transmission grid in this area.
TEP representatives discussed this purpose and need in public meetings held in November 2025 and March 2026 in Sahuarita. These objectives also were highlighted in TEP’s public April 2026 application for a Certificate of Environmental Compatibility (CEC) from the Arizona Corporation Commission (ACC). The Arizona Power Plant and Transmission Line Siting Committee approved two potential routes for this line in a May public hearing, and the ACC’s review is expected in another public meeting later this summer.
Meanwhile, TEP has planned and the ACC has approved an entirely separate transmission line that could potentially serve the proposed mine. The 138-kV Rosemont Transmission Line, originally approved in June 2012, would extend approximately 13 miles from the Sahuarita area to the mine site in the Santa Rita Mountains. Rather than originating at a separate switchyard, as envisioned at the time, the line would connect to the planned Santa Rita Substation in that same area.
This line will not be built unless Hudbay, the mining project’s current owner, agrees to take power from TEP and to pay in full for the line and related facilities dedicated to its exclusive use. Hudbay also would pay its proportionate share of any shared costs at the Santa Rita Substation, which will be built regardless of whether the mine moves forward.
So, TEP customers won’t be subsidizing service to the proposed mine. There is no secret deal, just a much needed infrastructure project being reviewed in a public process. And if the mine is someday served by TEP, it will happen through a separate project fully funded by Hudbay in ways that will reduce costs for other TEP customers.
Eric Bronner is Vice President of Energy Management, Planning, and Development for Tucson Electric Power.
