Certificate of Environmental Compatibility

Avantus has received a Certificate of Environmental Compatibility (CEC) to allow for the construction, operation, and maintenance of its proposed Catclaw Solar 230 kV gen-tie transmission line.


Catclaw Solar CEC

The Catclaw Solar Project involves a new 230 kV gen-tie transmission line and associated substation facilities to connect the Catclaw Solar Project to the regional electrical grid via the existing APS Sun Valley Substation.

A Certificate of Environmental Compatibility (CEC) from the Arizona Corporation Commission and the Arizona Power Plant and Transmission Line Siting Committee (Line Siting Committee) is required to allow for the construction, operation, and maintenance of the project gen-tie. Avantus submitted a CEC application on April 24, 2023, and received a CEC on August 8, 2023.

As part of the CEC process, Avantus studied the environmental setting of the proposed route for the project gen-tie, solicited public input, and presented the project to the Arizona Power Plant and Transmission Line Siting Committee during a public hearing on June 7 and 8, 2023.

CEC Requirements and Permitting Authority

A CEC is required for new transmission lines that operate at or above 115 kV and have “a series of structures.” The Arizona Corporation Commission and Line Siting Committee are the state permitting authorities for CECs.

The Line Siting Committee held a public hearing for the CEC application on June 7 and 8, 2023. During the public hearing, the Line Siting Committee heard evidence from 311SV 8me LLC, deliberated, and voted to approve a CEC for the project gen-tie. In voting to approve the CEC, the Committee recommended that the Arizona Corporation Commission issue a final approval for the CEC. On August 8, 2023, the Arizona Corporation Commission approved the CEC.

Key documents related to the CEC process, including the final CEC, are available on this webpage.