The proposed RioSol to Saguaro Interconnect (also known as the Saguaro Interconnect, or the Project) is a 500-kilovolt transmission line and switchyard that is needed to connect the RioSol transmission line with the existing Arizona Public Service (APS) Saguaro Substation. The Saguaro Substation is located east of I-10 near Red Rock Village, Arizona in South-Central Pinal County. The Saguaro Interconnect only consists of transmission facilities. No solar or battery storage equipment is associated with the Project.

Improving Regional Connectivity

The Saguaro Interconnect enhances power transfer capacity and overall transmission reliability by establishing a direct, extra high voltage link to a major regional transmission line that will extend into Central New Mexico. By providing an additional energy delivery route to utilities such as APS, Tucson Electric Power, and Western Area Power Administration, the Project supports the state’s growing electricity demand—particularly in rapidly expanding regions in Arizona.

Enhancing Grid Reliability

Moreover, the Saguaro Interconnect introduces greater system redundancy and resilience, enabling Arizona to better withstand outages, planned maintenance, and extreme weather events. From a commercial perspective, the interconnection facilitates broader regional energy exchange, supports the integration of new generation resources and industrial load growth.