Projects

Project Highlights

• Designed substation, BESS, and transmission in service of large-scale Arizona solar project.
• Required extensive station coordination for new BESS technology.

The Pinal Central Project is a 20-megawatt solar photovoltaic generation facility located in Pinal County, Arizona. At the time, this site was Arizona’s largest utility-scale solar energy center paired with a battery storage system, generating enough solar energy to power 5,000 Arizona homes. An additional 10 megawatts of energy are stored in Pinal’s lithium-ion battery energy storage system (BESS).

ECI provided designs to the Pinal Central 34.5-230 kV Solar Collection Substation, the Pinal Central Battery Energy Storage Facility (BESS), and the Pinal Central 230 kV Transmission Line.

The substation build is an “open air” solar collector station with a 34.5-230 kV (33/44/55 MVA) main power transformer (MPT). This substation was designed to connect approximately 40 megawatts of solar generation to the 230 kV system. Initially, only 20 megawatts of solar generation were connected to the system, with provisions for an additional 20 megawatts of future generation. Additionally, the station was designed to connect approximately 10 megawatts from Pinal Central’s Battery Energy Storage System (BESS) that ECI also designed. The BESS is located adjacent to the Pinal Central Collector Substation and connects via a 34.5 kV feeder to the 34.5 kV bus. Lastly, ECI designed approximately 0.4 miles of overhead 230 kV transmission line interconnect the new substation and BESS to the existing Salt River Project (SRP) Pinal 230 kV Switchyard.