Building America’s Next Generation Infrastructure to Power Our Future

The Department of Energy has chosen the Southline Transmission Project as one of three recipients of the Transportation Facilitation Program’s $1.3 billion commitment to improve the electric grid. Secretary Granholm, Governor Hobbs, and others joined us at the Apache Substation in Cochise, Arizona to celebrate the announcement.

Watch the highlight reel of the event

Southline Transmission Project

Grid United and Black Forest Partners are co-developing the Southline Transmission Project (“Southline” or “the Project”), a 280-mile, double-circuit, high voltage transmission line and associated substation facilities. The design provides the capability to transport power bi-directionally and will enable wind and solar resources from the Desert Southwest to reach key markets while improving the grid reliability of the border region. Southline will connect the electrical transmission systems of the El Paso and Tucson metropolitan areas and includes new facilities between the Afton, New Mexico and Apache, Arizona substations, as well as upgrade WAPA facilities between the Apache and Vail, Arizona substations. 

Benefits

  • Southline will enhance grid reliability and resiliency in the Desert Southwest, making the power system less vulnerable to price volatility and extreme weather events
  • Southline will minimize land and resource impacts by routing along existing infrastructure and upgrading existing transmission lines where feasible
  • Southline will allow new energy generation projects to be built via improved intra and inter-regional transmission, providing access to geographically diverse renewable resources, which will enable more clean power generation, increase reliability, and lower the cost of energy to consumers
  • Southline will enhance the potential for improved connection between Western and Texas electrical grids
  • Southline will create high-quality jobs and provide increased tax revenues for six counties in the border region of New Mexico and Arizona

Project Location

Southline will be up to 280 miles long, connecting the electrical systems of the El Paso and Tucson metropolitan areas via the Afton, New Mexico, Apache, Arizona, and Vail, Arizona substations. The Project will enable substantial renewable development opportunities and be an outlet for abundant generation by providing access to new markets.

Project Schedule

Southline has already successfully completed a highly complex, multi-year federal and state regulatory process through which all major state and Federal permits have been obtained. Southline’s Final Environmental Impact Statement was published in October 2015. Bureau of Land Management (BLM) and Western Area Power Administration (WAPA) Records of Decision were published in April 2016. The Arizona and New Mexico state siting processes were completed in February 2017 and August 2017 respectively. The Project is in the final stages of development, which includes completing engineering, concluding land acquisition, and finalizing commercial arrangements.

Southline expects to begin construction in 2025. The first phase of the Project could be operational by 2027, with the full Project online by 2028.

  • Phase 1: Hidalgo to Vail 
  • Phase 2: Afton to Hidalgo
2021

64 miles of Southline sold to Tucson Electric Power

2021
2022

Grid United’s Investment in Southline’s remaining 280 miles

2022
2023

Finalize Engineering Design, Private Land Acquired, BLM Notice to Proceed

2023
2024

Procurement

2024
2025

Construction: Staging, ROW Prep and Construction

2025
2027

Commercial Operations of Phase One by end of 2027

2027
2028

Commercial Operations of Phase Two by end of 2028

2028

Landowner Relations

Our relationships with landowners and communities is at the core of everything we do. We are committed to developing Southline using a collaborative process and conducting easement negotiations in a manner that is fair and respectful of private property rights.