Projects and Resource Planning

Transmission Line Projects

Nogales Tap to Kantor Upgrade

The proposed project includes upgrading a 27.5-mile segment of UES’ existing 138-kilovolt (kV) transmission line that serves customers in Santa Cruz County and building a new substation west of Nogales.

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Golden Valley 230 kV

UniSource is developing plans for a double-circuit 230kV transmission line from the Harris Substation to the new Mineral Park Substation to improve reliability, replace aged equipment, and accommodate a projected 5 to 35 megawatt increase in load over the next decade in the north Golden Valley area of Mohave County.

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Resource Planning

Safe, Reliable Power for the Future

UniSource Energy Services (UES) is diversifying its portfolio of resources in response to new environmental regulations, emerging technology and changes in our customers’ energy needs.  To inform regulators, customers and other interested stakeholders about these and other changes, UES and its sister company, Tucson Electric Power ( UES), have developed Integrated Resource Plans (IRPs).   These IRPs present the detailed assumptions and analyses used to develop the companies’ strategies for serving customers’ long-term energy needs.

2020 IRP

UniSource filed its 2019 Preliminary IRP with the Arizona Corporation Commission on August 1, 2019.

UNS Electric 2019 Preliminary Integrated Resource Plan – PDF 2 MB

2017 IRP

UniSource filed its 2017 UNSE IRP with the Arizona Corporation Commission on April 3, 2017.

UES 2017 Integrated Resource Plan – PDF 5 MB