Arizona Siting Committee Hearing On 500-kV Line Scheduled For November

The Arizona Power Plant and Transmission Line Siting Committee, in an Oct. 8 notice, said that a public hearing will be held before it on Nov. 16 and continue on Nov. 17-19, as necessary, regarding the application of Hashknife Energy Center LLC for certificates of environmental compatibility (CECs) to authorize the Hashknife Energy Center Gen-Tie Project.

The project — to be located in unincorporated Navajo County, Ariz. — consists of a new 500-kV transmission line, rebuilding a short portion of an existing Arizona Public Service (APS) 230-kV line on double-circuit structures to carry the new 500-kV transmission line, and associated facilities interconnecting with the existing APS Cholla 500-kV substation in Navajo County, Ariz.

The committee said that due to the COVID-19 pandemic, the public is strongly encouraged to participate in the hearing by either watching the meeting online or listening to the meeting via telephone, rather than attending in person. Information regarding online and telephone hearing access will be posted on the project website and available by calling 303-557-4502, at least 24 hours in advance of the hearing, the committee said.

According to the Oct. 8 application, Hashknife Energy seeks approval of two separate CECs for the gen-tie and associated substation facilities, as two CECs are required to address ownership of specific portions of the transmission line. Hashknife Energy would own the portion of the line from the generation source to the fence/property line of the Cholla substation (CEC-1), while APS would own the portion of the line inside the fence/property line of the Cholla substation (CEC-2).

The gen-tie project would deliver electricity from Hashknife Energy’s planned Hashknife Solar Project, an up to 400-MW nameplate capacity solar photovoltaic power plant that may be paired with a battery energy storage system, the application added.

The collection substation that is part of the project will step-up electricity generated by the solar facility from 34.5 kV to 500 kV, and the gen-tie would deliver the electricity to the regional transmission grid.

The application added that CEC-1 would originate at the project substation and terminate at the point of ownership change immediately outside of the Cholla substation fence/property line, a distance of about 3.2 miles. CEC-2 would include rebuilding a short portion of an existing APS 230-kV line using double-circuit structures that would also carry the new gen-tie from the Cholla substation fence/property line into the point of interconnection at the APS-owned Cholla substation, a distance of =+/-0.20 miles.

The application also said that the project substation would occupy an area of about four acres and would be located within the solar facility boundary. The preferred gen-tie line would be about 3.4 miles long and require a 200-foot ROW. In total, the application added, the gen-tie would encompass about 82.42 acres, and it would be three-phase 500 kV with three conductors per phase. The project would use up to 18 self-supporting lattice tower or steel monopole structures, which would be about 90 to 195 feet tall and be spaced 800 to 1,800 feet apart.
The filing further noted that depending on final design, the estimated cost for the proposed transmission line, the preferred route, and the project substation is up to $23m.

As noted in the application, Hashknife Energy is a wholly owned subsidiary of Invenergy LLC.