Southline project sponsor begins process of selling capacity on line

A subsidiary of Southline Transmission LLC (Southline), which is developing the transmission line designed to provide 1,000 MW of transmission capacity in southern New Mexico and southern Arizona, on March 31 said that SU FERC LLC has begun an open solicitation process for parties interested in obtaining capacity on the transmission line.

In order to obtain transmission capacity rights on the Southline project, interested parties must register and submit a non-binding Expression of Interest Form through the open solicitation process by June 30.

Southline, a subsidiary of Hunt Power, is the project sponsor, according to the project website. SU FERC is an affiliate of Sharyland Utilities LP, a Texas utility headquartered in Dallas. SU FERC is privately owned by Hunter L. Hunt and other members of the family of Ray L. Hunt, and is managed by Hunter L. Hunt, SU FERC said in a March 31 statement.

On its website, Southline noted that FERC‘s Sept. 17, 2015, order authorized SU FERC to sell transmission capacity on the project at negotiated rates. The order authorized SU FERC to use an open solicitation process to reach potential customers and allocate transmission capacity in a manner that is not unduly discriminatory or preferential.

SU FERC has contracted Energy Strategies LLC to act as the independent third-party administrate of the open solicitation process to ensure a fair and transparent process, Southline said.

Interested parties can learn more about the Southline open solicitation process and how to participate by visiting

With the solicitation process scheduled to end June 30, SU FERC and Energy Strategies intend to identify entities for negotiations during July to reach transmission service agreements.

The Southline project is planning to receive a record of decision from the Western Area Power Administration (Western) during 2016 and begin construction after that, with transmission line operations beginning in 2018.

The project would consist of two sections, a “new build” section that would involve construction of approximately 240 miles of new double-circuit 345-kilovolt (kV) transmission line in a 200-foot ROW between the Afton substation, south of Las Cruces, N.M., and Apache substation, south of Willcox, Ariz.

The second section would entail the upgrade of approximately 120 miles of Western’s existing Saguaro-Tucson and Tucson-Apache 115-kV transmission line in a 100-foot existing ROW to a double-circuit 230-kV transmission line in a 100 to 150-foot ROW. The upgrade section would originate at the Apache substation and terminate at the Saguaro substation northwest of Tucson, Ariz.

The project is designed to connect to up to 14 existing substations and may include development of a new substation in Luna County, N.M., Southline said.

In November 2015, Western and the Bureau of Land Management issued a final environmental impact statement for the project.