Arizona committee to hold public hearing on April 18 on proposed 230-kV project

The Arizona Power Plant and Transmission Line Siting Committee on April 18 will hold a public meeting/hearing regarding Pinal Central Energy Center LLC’s application involving a proposed 230-kV alternating current generation transmission tie-in line (Gen-tie) and associated substation facilities (project substation).

The meeting/hearing will continue each weekday on April 19 through April 25, as necessary, unless a tour is taken, the committee added in its March 20 filing. Public comment will be taken in a special evening session on April 18, and may be taken at the start of each hearing day or at other times during the hearing, as designated, the committee said.

Pinal Central, in its March 15 application filed with the Arizona Corporation Commission, said that it is seeking a certificate of environmental compatibility (CEC) for the Gen-tie and project substation in order to deliver electricity generated by a solar facility to the regional electric transmission grid.

The proposed CEC-covered facilities are designed to deliver power from the solar facility, which is an adjacent 20-MW alternating current solar photovoltaic plant with a 10-MW/40-hour advanced energy storage system. The solar facility, Pinal Central added, is the subject of pending negotiations for a 20-year power purchase agreement (PPA) between Pinal Central and an entity with an obligation to deliver power to Arizona residents.

The new 230-kV substation would be dedicated exclusively to serve the solar facility, and the Gen-tie would be an approximately 0.40-mile, 230-kV transmission line from the project substation to the existing Pinal Central 230/500-kV substation.

The estimated cost for the proposed Gen-tie and project substation is $4m – that is, $1m for the Gen-tie and $3m for the project substation.

Pinal Central also said that the project substation would occupy about .34 acre, while the Gen-tie would occupy about five acres in total, with 2.5 acres within the existing Pinal Central substation and the remaining 2.5 acres formed by a 100-foot right of way (ROW) centered around the Gen-tie structures. The Gen-tie is expected to require four roughly 80-110-foot-tall wood or steel poles spaced about 500 feet apart; two static lines; and three power conductors.

Pinal Central also noted that the proposed Gen-tie would originate at the project substation within the solar facility boundary, located in unincorporated Pinal County, near 11-Mile Corner, Ariz. The proposed Gen-tie route would travel south and west about 0.40 mile across private land from the project substation, where it then would connect to the Pinal Central substation. About 0.20 mile of the Gen-tie is situated on private land owned by Pinal Central and generally runs parallel to the fence line of the Pinal Central substation, which is less than 150 feet to the north; the other 0.20 mile is situated within the existing Pinal Central substation.

The proposed Gen-tie would cross over one Bureau of Indian Affairs (BIA)/San Carlos Irrigation Project canal lateral. The BIA ROW would be crossed overhead and no ground disturbance would occur within that ROW, Pinal Central added.

The project substation would be located within the solar facility boundary on a 100-foot x 150-foot tract. Pinal Central also said that it is anticipated that the project substation would include a power transformer, one 230-kV main breaker, two 35-kV feeder breakers, switches, a control house, and a substation superstructure within an approximately seven-foot-tall fence enclosure.

The project has been identified as an optimal location based on the recognized need to interconnect renewable energy sources to local electrical utilities; the existence of compatible adjacent and nearby land uses; and the proximity to the existing Pinal Central substation, Pinal Central said. The location removes the need for a long generation tie line or costly system upgrades, Pinal Central said.

Among other things, Pinal Central said that overall, the vicinity of the project is a semi-developed rural area with existing utility infrastructure, as well as scattered agricultural and residential uses. Land uses in the immediate vicinity of the project include utilities such as the adjacent Pinal Central substation, the Pinal Central to Tortolita 500-kV transmission line, the Pinal Central to Browning 500-kV transmission line, the ED2 115-kV substation, as well as the Florence-Casa Grande Canal and associated laterals; agricultural operations; and residences.  

Pinal Central is a wholly owned indirect subsidiary of NextEra Energy Resources, which is a principal subsidiary of NextEra Energy (NYSE:NEE).

About Corina Rivera-Linares 2807 Articles
Corina Rivera-Linares, chief editor for TransmissionHub, has covered the U.S. power industry for the past 13 years. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial. She has also covered such topics as health, politics and education for weekly newspapers and national magazines. She can be reached at corinar@pennwell.com.