Maricopa & Pinal Counties, Arizona

Booth Hills Transmission Project

The Booth Hills Transmission Project (Project) consists of two parallel generation intertie (gen-tie) transmission lines. The Project would connect two proposed solar photovoltaic and energy storage system facilities – Pinyon Solar and Caballero Solar – to the regional electrical grid at the existing Pinal West Substation in Pinal County, Arizona.

WELCOME

This website was created to serve as a place for nearby residents and others interested in the Project to find accurate, up-to-date information, and to provide comments on the Project. We look forward to working with the community to build a successful Project that boosts the local economy and helps Arizona meet its clean energy goals.

Pinyon CEC Approval

Caballero CEC Approval

 

Project Snapshot

LOCATION

Approximately 8 miles west of the City of Maricopa in unincorporated Maricopa and Pinal counties, Arizona.
View the site map here

PROJECT CAPACITY

The Project would distribute up to a combined 500 megawatts (MW) of solar capacity generated by the proposed Pinyon Solar Project and Caballero Solar Project.

PROJECT COMPONENTS

The Project consists of two components: the Pinyon Gen-tie and Caballero Gen-tie.

PINYON GEN-TIE

The Pinyon Gen-tie component consists of a 345 kV transmission line that would extend 2.8 miles from the proposed Pinyon substation to the Tucson Electric Power (TEP) interconnection at the existing Pinal West Substation.

CABALLERO GEN-TIE

The Caballero Gen-tie component consists of a 500 kV transmission line that would extend 5.3 miles from the Caballero substation to the Salt River Project (SRP) interconnection at the existing Pinal West Substation.

DEVELOPER

The Project is being developed by Avantus (formerly 8minute), a leading solar and energy storage developer with more than a decade of success across the Western United States. 315PC 8me LLC, a subsidiary of Avantus, will be the CEC applicant.

Project Overview

Avantus is developing the Project to transmit renewable energy from the proposed Pinyon Solar Project and Caballero Solar Project to the existing Pinal West Substation. The Project includes the construction of a substation at each proposed solar field and a transmission line corridor containing two generation-interconnect (gen-tie) transmission lines – the Pinyon Gen-tie and Caballero Gen-tie – extending from the new substations to the Pinal West Substation.

The Booth Hills Transmission corridor extends a total of 5.5 miles. The 345 kV Pinyon Gen-tie line extends for 2.8 miles, while the 500 kV Caballero Gen-tie line extends 5.2 miles, with the Pinyon Gen-tie route overlapping almost entirely with the Caballero placement. Colocating the transmission lines within the same corridor limits the Project’s disturbance area and reduces potential visual and environmental impacts.

Gen-tie Transmission Lines

Booth Hills Transmission has two gen-tie transmission lines that would be colocated within the same 200-ft-wide transmission corridor.

Pinyon Gen-tie

  • 345 kV

  • Located primarily on privately-owned land

  • 2.8 miles long

Caballero Gen-tie

  • 500 kV

  • Located on BLM and privately-owned land

  • 5.2 miles long

Gen-tie Structures

Structures used for the Booth Hills Transmission Project would be monopoles. Compared to more traditional lattice transmission structures, monopoles offer:

  • A smaller footprint

  • Less ground disturbance

  • Smaller visual impact

  • Increased wind resistance

  • Greater structural integrity

Pinyon Gen-tie

The structures supporting the 345 kV line would be 100-140 foot tall monopoles and would typically be spaced between 500 to 1,000 feet apart (center to center), depending on the topographic, hydrologic, and geologic conditions of the underlying lands.

Caballero Gen-tie

The structures supporting the 500 kV line would be 120-180 feet tall and would typically be spaced between 500 to 1,000 feet apart (center to center), depending on the topographic, hydrologic, and geologic conditions of the underlying lands.

This is an example of a monopole structure and may not be representative of what is selected for the Project during final design.

Substations

The two substations proposed for the Project would contain several components such as power transformers, distribution cabinets, revenue metering systems, telecommunications equipment, switch gear, and a control building. The substations would each occupy an area of approximately 0.4 acre within the overall footprint of each respective solar project and would be surrounded by a chain-link fence to limit access and promote safe and secure operation.

Minimizing Environmental Effects

The Project is being designed to minimize potential environmental effects through the following measures:

  • Colocating the Pinyon gen-tie and Caballero gen-tie within a common transmission corridor to minimize cultural, biological, aesthetic, and future use impacts on the surrounding area

  • Conducting preconstruction surveys for sensitive resources

  • Implementing best management practices during construction

Project Virtual Flyover

This simulation of the proposed design shows what the Project is expected to look like once built.

Siting & Environmental Considerations

Please see our FAQs page for additional information and resources.

  • Avantus has a positive track record with local, state, and federal wildlife agencies as well as with environmental organizations. In addition to requiring a Certificate of Environmental Compatibility from the ACC, because Booth Hills Transmission crosses BLM-managed land, the Project is also subject to federal agency review and approval under the National Environmental Policy Act (NEPA). Our past projects have garnered support from respected groups including the Sierra Club, Audubon California, Defenders of Wildlife, and the Natural Resources Defense Council.
    We design each project to avoid or minimize potential impacts to threatened or endangered species and ensure proper mitigation measures are provided as appropriate. Booth Hills Transmission is not anticipated to impact any species protected under the Endangered Species Act.

  • No, impacts to historic and archaeological features will be avoided. A cultural resources inventory is being conducted within the areas of temporary and permanent disturbance. If historically-relevant features are found, the Project design will be adjusted to avoid impacts to these features.

  • No, Booth Hills Transmission will use minimal water. The biggest use of water over the life of the Project occurs during construction to suppress any dust. After construction, no water use is necessary for the operation and maintenance of the transmission lines.

  • During construction, we expect our crew will generate some noise and add cars/trucks to certain roads, and we will aim to minimize those potential impacts.
    As always, we aim to be respectful of our neighbors and aim to keep construction noise to a minimum. All site activity is subject to and will comply with Maricopa County and Pinal County noise ordinances.

  • Dust suppression will be used throughout the construction period to control dust and minimize the potential impacts on construction workers and the surrounding community, as mandated by Maricopa County, Pinal County, and Arizona regulations.