Photo Credit: US Department of Interior

Biden-Harris Administration Advances SunZia Southwest Transmission Project

The U.S. Department of the Interior recently announced their decision to proceed with a 520-mile, multibillion-dollar transmission line to transport renewable energy from New Mexico to Arizona and California.

The proposed SunZia Southwest Transmission Project involves two 500-kilovolt transmission lines across federal, state and private lands.

The lines cross Graham, Greenlee, Cochise, Pinal and Pima counties in Arizona and Lincoln, Socorro, Sierra, Luna, Grant, Hidalgo, Valencia and Torrance counties in New Mexico are said wll provide 4,500 megawatts of primarily wind-generated electricity.


This project represents is an effort  in the Biden-Harris administration’s to accelerate transmission buildout to lower consumers’ energy costs, prevent power outages in the face of extreme weather, create good-paying union jobs, and make progress towards achieving President Biden’s goal of a 100% clean electricity grid by 2035.

“The Department of the Interior is committed to expanding clean energy development to address climate change, enhance America’s energy security and provide for good-paying union jobs,” said Principal Deputy Assistant Secretary for Land and Minerals Management Laura Daniel-Davis. “Through robust engagement with states, cities and Tribes, we are proud of the part we play in the all-of-government efforts to diversify the nation’s renewable energy portfolio while at the same time combatting climate change and investing in communities.”

The SunZia Southwest Transmission Project is composed of two planned 500-kilovolt transmission lines located across approximately 520 miles of federal, state and private lands between central New Mexico and central Arizona. The permitted route originates at a planned substation in Torrance County, New Mexico, and terminates at the existing Pinal Central Substation in Pinal County, Arizona. The project traverses Lincoln, Socorro, Sierra, Luna, Grant, Hidalgo, Valencia, and Torrance counties in New Mexico and Graham, Greenlee, Cochise, Pinal, and Pima counties in Arizona.

The BLM completed the review period for this project – from the Notice of Intent to Record of Decision – in less than two years. This is one of the final steps the BLM needs to take before the project proponent can formally break ground.

Since 2021, the BLM has approved 35 projects (10 solar, 8 geothermal, and 17 gen-ties) on approximately 23,396 acres of BLM-managed lands. These projects are expected to produce 8,160 megawatts of electricity — enough to power more than 2.6 million homes.

The BLM is currently processing 74 utility-scale onshore clean energy projects proposed on public lands in the western United States. This includes solar, wind and geothermal projects, as well as interconnected gen-tie lines that are vital to clean energy projects proposed on non-federal land. These projects have the combined potential to add over 37,000 megawatts of renewable energy to the western electric grid. The BLM is also undertaking the preliminary review of over 150 applications for solar and wind development, as well as 51 applications for wind and solar energy testing.

The BLM manages vast stretches of public lands that are making significant contributions to the nation’s renewable energy portfolio. To promote the development of these energy sources, the BLM provides sites for environmentally sound development of renewable energy on public lands. The efficient permitting of renewable energy and transmission from our nation’s public lands is crucial in achieving the Biden-Harris administration’s goal of a carbon pollution-free power sector by 2035, as well as Congress’ direction in the Energy Act of 2020 to permit 25 gigawatts of solar, wind, and geothermal production on public lands no later than 2025.