Philip Augustin P.O. Box 52025 | MS POB100 Phoenix, 85072-2025 (602) 236-8788 [email protected]

February 17, 2021

Peter Mackin Chair, WECC Studies Subcommittee GridBright, Inc. [email protected]

Doug Tucker WECC Technical Staff Western Electricity Coordinating Council 155 North 400 West, Suite 200 Salt Lake City, 84103-1114

Mr. Mackin and Mr. Tucker,

Attached is Project’s 2021 Annual Progress Report to WECC in accordance with WECC Progress Report Policies and Procedures. If there are any questions, please contact me at [email protected].

Sincerely,

Philip Augustin Principal Engineer, Transmission Analysis StS Representative

cc: Bryce Nielsen, SRP Eric Tang, SRP WECC RAC StS

1

2021 Annual Progress Report to WECC Salt River Project

Transmission Additions and Changes

The following projects will be reported in the 2021 “Existing Generation and Significant Additions and Changes to System Facilities” report in accordance with section five of the WECC “Project Coordination, Path Rating and Progress Report Processes” guideline.

Transmission Additions and Changes - Waiver of “Significant Transmission Project” Status Request

As of February 18 SRP does not have any new projects seeking a waiver of “Significant Transmission Project” status.

Transmission Additions and Changes – Projects Granted a Waiver of “Significant Transmission Project” Status

The following transmission additions and changes have received a waiver of “Significant Transmission Project” status as of 2020.

1. Price Road Corridor 230 kV Estimated date of operation: 2021

Point of Origin Knox 230 kV Substation Point of Termination New Henshaw 230 kV Substation Length Approximately 5 miles

The purpose of this project is to serve growing industrial and commercial customer loads adjacent to Price Road in Chandler, AZ. The final line route was determined through the Certificate of Environmental Compatibility (CEC) process. The project consists of a new double circuit 230 kV line from the existing Knox Substation to the new Henshaw 230 kV Substation, which will be located at the intersection of Price Road and Germann Road.

2

2. Red Hawk 230 kV Estimated date of operation: 2022

Point of Origin Section of Santan – Browning 230 kV Line Point of Termination New SY-33 230 kV Switchyard Length Less than 1 mile

This is a single customer requested project and is not triggered by system load growth. Studies were performed and showed no impact to other systems, nor any WECC transfer paths. The final line route was determined through the CEC process. The project consists of bisecting the existing Santan – Browning 230 kV transmission line in order to connect a new 230 kV Switchyard (SY-33) that will be located near the northwest corner of Elliot Road and Sossaman Road in Mesa, AZ, adjacent to the existing Santan – Browning 230 kV transmission corridor. It also includes new high voltage distribution lines from the switchyard to new load serving transformers. Several options are under consideration for the number of load serving transformers and for the length of new high voltage distribution lines for serving them.

3. Abel – Pfister – Ball 230 kV line Estimated date of operation: 2023

Point of Origin Santan – Schrader 230 kV line Intermediate point New Ball (RS-17) 230 kV Substation Intermediate point New Pfister (RS-24) 230 kV Substation Point of Termination Abel 230 kV Substation Length Approximately 20 miles

Estimated in-service dates are: 2023 — Abel – Santan & Abel – Schrader 230 kV lines TBD — Pfister Substation (RS-24) & Ball Substation (RS-17)

This project was originally proposed to serve long-term load growth in the southeast valley. The current timeline reflects two roles; a near-term reliability need driven by new generation resources connecting near Abel Substation and as the southern termination for the Southeast Power Link project needed to serve load in the southeast valley. This project is a double circuit 230 kV line that bisects and connects the existing Santan – Schrader 230 kV line #2 to Abel 230 kV Substation. The new double circuit 230 kV line will be routed generally south and east from a point on the Santan – Schrader 230 kV line near the existing Moody 69 kV Substation and future Ball (RS-17) 230 kV Substation to the new Pfister (RS-24) 230 kV Substation in the southeastern portion of the town of Queen Creek, AZ. From the Pfister 230 kV Substation, the 230 kV line will continue south and east to the Abel 230 kV Substation.

3

4. Southeast Power Link 230 kV Estimated date of operation: 2023

Point of Origin Section of Santan – Browning 230 kV Line Intermediate Point New Scott (RS-31) 230 kV Substation Point of Termination Section of Abel – Pfister – Ball 230 kV Line Length Approximately 7 miles

The purpose of this project is to serve growing industrial and commercial customers in the southeast valley. Studies were performed and showed no impact to other systems, nor any WECC transfer paths. The final line route was determined through the CEC process. The project consists of approximately seven miles of new 230 kV double-circuit transmission lines from the existing Santan – Browning 230 kV line to a new Scott (RS-31) 230 kV Substation, located east of the Loop 202/SR-24 interchange, and terminating at the future Abel – Pfister – Ball 230 kV line.

5. Silver King – New Oak Flat – New Superior 230 kV line Estimated date of operation: 2029

Point of Origin Silver King 230 kV Substation Intermediate Point New Oak Flat 230 kV Substation Point of Termination New Superior 230 kV Substation Point of Termination New RS-34 230 kV Substation Length Approximately 19.5 miles

This is a single customer requested project and is not triggered by system load growth. The alignment of the first 230 kV single-circuit line will closely follow an existing 115 kV circuit. The line starts at the Silver King 230 kV Substation, runs southwest into the New Oak Flat 230 kV Substation, and then will traverse west to the New Superior 230 kV Substation. In addition, the existing Goldfield – Silver King 230 kV line will loop into the New Superior 230 kV Substation. The length is about 7.5 miles. A second 230 kV double-circuit line will follow the customer’s pipeline to a Tailings Storage Facility (TSF). The line will start at the Silver King 230 kV Substation and run southeast to the new RS-34 230 kV Substation located at the TSF. The length is about 12 miles. The locations of the New Oak Flat, New Superior, and RS-34 Substations are still being determined.

4

6. Hassayampa – Pinal West #2 500 kV line Estimated date of operation: TBD

Point of Origin Hassayampa 500 kV Switchyard Intermediate Point Jojoba 500 kV Switchyard Point of Termination Pinal West 500 kV Switchyard Length Approximately 51 miles

The Central Arizona Transmission System study identified system additions to provide access to new generation in western or central Arizona. This project can accommodate increased access to existing and potentially new load growth; however, future load growth was not identified as a driver. This is a reliability driven project not triggered by system load forecasts within the next ten years. The route is south and east of the Hassayampa 500 kV Switchyard along the existing Palo Verde – Kyrene 500 kV line to a point where the gas pipeline splits from the transmission line, then generally along the pipeline (except in the Maricopa County Mobile Planning Area) to the Pinal West 500 kV Switchyard.

5