view alternate design

Routed, Planned, & Moving Along

Current 2023

February 2023

Revised Final EIS issued

FutureĀ 2023-2028

April 2023

Amended Federal Record of Decision

Amended Federal Record of Decision Expected.

Mid-to-Late 2023

Start of Line 1 Construction

Pattern Energy expects to start full construction of Line 1.

Late 2025

Line 1 starts Operating

Pattern Energy expects to complete construction and start operation of Line 1.

Late 2025

RioSol/Line 2 starts Construction

SWPG expects to start full construction of RioSol (Line 2).

Early – Mid 2028

RioSol/Line 2 starts Operating

SWPG expects to complete construction and start operation of RioSol (Line 2).

PastĀ 2006-2022

December 2022

Line 2 renamed RioSol

SWPG renames Line 2 RioSol to avoid confusion with Line 1 which is called SunZia.

July 2022

Line 1 is sold to Pattern Energy

SWPG sells SunZia Line 1 to Pattern Energy and keeps Line 2.

May 2022

Revised Draft EIS issued

BLM issues the Draft EIS for the re-routed Project.

April 2021

NMRETA joins SunZia as co-development partner

SunZia and NMRETA sign a joint-development agreement.

December 2020

Federal Permit is re-opened

SunZia submits an amended SF-299 to the BLM to re-start federal permitting for the re-routed portion of the Project.


Line 1 changes to HVDC

SunZia and Pattern Energy agree to change the technical basis for Line 1 from HVAC to HVDCwith 3,000 MW of capacity. Line 2 will now be HVAC with 1,500 MW of capacity.

November 2018

SunZia and US Military agree on re-route

SunZia and the Dept of Defense agree to re-route a portion of the line in NM that avoids the Northern Call-Up area, north of WSMR.

August 2016

SunZia selects Anchor Tenant

The Project selects Pattern Energy as anchor tenant for Line 1.

February 2016

Arizona State Permit is granted

The Arizona Corporation Commission approves a Certificate of Environmental Compatibility for the Project.

January 2015

Federal Permit is granted

The BLM issues the Record of Decision for the Project.

May 2011

FERC approves SunZia cost recovery

FERC approves negotiated rate authority for Line 1.

September 2008

Federal Permitting starts

The Project submits an SF-299 to the BLM to commence federal environmental permitting under NEPA.

April 2008

Joint Development Agreement signed

SWPG and 4 other companies signed a joint development agreement for the SunZia Southwest Transmission Project.

Summer 2006

Start of Project Development

SouthWestern Power Group (SWPG) started planning the development of an interstate transmission project between AZ and NM consisting of two, single-circuit 500kV transmission lines and associated substations.