Cielo Azul Switchyard

Project Description

The 500-kV Cielo Azul Switchyard in southwest Arizona is designed to support the region’s potential for large-scale solar energy development by creating an interconnection to the bulk electric grid. The interconnection project encompasses approximately 55 acres of right of way (ROW) and will help Arizona and California reach their renewable energy standards and carbon reduction goals. In the first phase, Cielo Azul will be built as a three-bay breaker-and-a-half switchyard with a transmission line interconnection to the Ten West Link transmission line. It is being designed to facilitate a six-bay ultimate configuration. The initial build out will facilitate the interconnection of 2700 megawatts of solar and battery energy storage system (BESS) power to connect into the bulk electric grid. 

The network upgrade project on behalf of Lotus Infrastructure Partners was studied by the California Independent System Operator (CAISO) in the interconnection queue; received its certification of compliance from the Arizona Corporation Commission (ACC); and was approved by the Bureau of Land Management (BLM), Environmental Protection Agency (EPA), Federal Aviation Administration (FAA), Federal Communications Commission (FCC), La Paz County, and Maricopa County.

Project Scope

Sargent & Lundy is the project’s engineer of record (EOR), selected to provide services for environmental permitting, procurement, transmission line and substation design, and telecommunications. As EOR, the firm has prepared drawings, specifications, calculations for substation design, transmission line design, substation SCADA & network design, telecommunication design, environmental permitting, and worked in collaboration with Lotus Infrastructure Partners, and their partners, in construction, operations and maintenance organizations.

Sargent & Lundy provided the following services for each of these areas:  

Switchyard

• Assisting in providing exhibits, descriptions, and schedules for the large generator interconnection agreement (LGIA).
• Project design criteria.
• Design drawings for 30%, 60%, 90% and issued for construction.
• Electrical studies for grounding, insulation coordination, AC/DC calculations, line impedance, arc flash, relay settings, and transient recovery voltage.
• SCADA & network configuration for remote terminal unit, human-machine interface, ethernet switch, router, and intelligent electronic device configuration.
• Disturbance monitoring configuration and integration for automated collection and storage of sequential event recorder, fault records, and synchro phasor data.
• Onsite SCADA integration and testing for point-to-point testing to connect Southern California Edison, Arizona Public Service, Interconnection Customer with Delaney Colorado River Transmission SCADA interfaces.
• Civil storm water calculations and design.
• Site grading and drainage.
• Site fencing.
• Structural steel calculations and design.
• Structural steel and equipment foundation calculations and design.
• Project technical specifications for breakers, capacitor coupled voltage transformers, current transformers/potential transformer metering units, control enclosure, geotechnical support, topography support and construction specifications.
• Factory acceptance testing, quality, and expediting.

Transmission

• Routing studies performed for generation interconnections.
• Provided constraints for land survey collection and permitting exhibits.
• Transmission line design using PLS-CADD software.
• Transmission line foundation design.
• Hardware and assembly design.
• Project technical specifications for transmission structures, geotechnical support and construction specifications.

Telecommunication

• Performed path profile analysis for new microwave system.
• Performed detailed engineering design for three diverse telecommunication paths interfacing three CAISO utilities, inclusive of microwave and fiber optic paths.
• Lead vendor selection for telecommunication equipment.
• Supported co-location application process.
• Radio frequency evaluation.

Permitting

• ACC written and oral testimony by lead expert.
• Preparation of building permits for switchyard and telecommunication towers.
• FAA filing for towers (Form 7460).
• FCC filing for telecommunication towers (Form 854, Forms 620/621, Form 601, etc.).
• EPA underground injection control Class V well registration.
• Preparation of project plans of development (PODs) and SF-299s to support BLM ROW applications.
• Coordination of environmental assessment preparation (by subcontractor).
• Preparation of POD to support La Paz County ROW application.
• Coordination with U.S. Fish and Wildlife Service, Colorado River Indian Tribes (CRIT), and California Department of Fish and Wildlife (CDFW).
• Arizona Department of Agriculture native plant removal permits.
• Section 106 consultation.
• Coordination of biological resource surveys, wetland delineation, and cultural resources surveys.
• Temporary erosion and sediment control plans and details to support stormwater pollution prevention plan.

Procurement

• Work with Lotus Infrastructure Partners to establish acceptable commercial terms and conditions.
• Bid evaluation.
• Participate in contract negotiations.
• Contract administration.
• Review of milestone payments.
• Delivery status and tracking.

Read more about our substation and transmission line services.