Nogales Interconnection Project

The Nogales Interconnection Project is a proposed direct current interconnection, commonly known as a DC tie, which will allow for an asynchronous interconnection between the electric grids in southern Arizona and the northwest region of Mexico. The project will support the reliability of the electric system, including providing bidirectional power flow and voltage support, as well as emergency assistance, as needed, for the electric system both north and south of the border.

The first phase would consist of a new 150 megawatt (MW) DC tie located on property currently owned by Tucson Electric Power; a new 3-mile 138 kilovolt (kV) transmission line that would originate at UNSE's Valencia Substation in Nogales, Arizona and extend to the west and south to the new Gateway Substation; and a new approximately 2-mile 230 kV transmission line that would extend south from the Gateway Substation to the U.S.-Mexico border where it would interconnect with a transmission line to be constructed in Mexico. The second phase would expand the DC Tie capacity to 300 MW. The timing of the second phase is not yet certain.

For more information, see the links below:

Project Map (Oct. 2015) Download  
FAQs (July 2016) English | Español
Fact Sheet (July 2016) English | Español
Permitting Documents
Notice of Application for a Presidential Permit Download
Presidential Permit Application Download

Agency and Non-Governmental Organization Meeting – September 2015
Informational Posters (Sept. 2015) English | Español  
Pre-NEPA Public Meeting – February 2015
Informational Posters (Feb. 2015) English | Español  
Public Notice (Feb. 2015) Download