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 278-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 Western Area Power Administration facilities between the Apache and Vail, Arizona substations.

Benefits

  • Southline is fully permitted with NEPA and New Mexico and Arizona state approvals secured. Grid United, an independent transmission company joined the Southline team in 2022 to complete the final stages of development: final engineering, land acquisition, and chimerical arrangements
  • Enhanced grid reliability and resiliency in the Desert Southwest, making the power system less vulnerable to price volatility and extreme weather events
  • Minimized land and resource impacts by routing along existing infrastructure and upgrading existing transmission lines where feasible
  • Providing access to new geographically diverse renewable resources, which will enable more clean power generation, increase reliability, and lower the cost of energy to consumers
  • Creating hundreds of high quality construction-related jobs during construction of the Project
  • Investing approximately $4 million dollars directly in local communities through donations, sponsorships, and partnerships with local organizations

Benefits

New tax revenue for local governments, communities, and schools: $100 million+

Sponsorships and Donations for local communities: $4 million+

Construction Jobs: 800+

Indirect and induced economic benefits across New Mexico and Arizona: $1 billion+

Enhanced grid reliability and resiliency in the Desert Southwest ➔ a power system that is less vulnerable to price volatility and extreme weather events

Improved interregional transmission ➔ development of new energy generation projects in New Mexico driving hundred of millions in new investment

Routing along existing infrastructure and upgrading existing transmission lines where feasible ➔ minimal impacts to land and resources

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 and Western Area Power Administration 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 the Project using a collaborative process and conducting easement negotiations in a manner that is respectful of private property rights.