Salt River Project turned on two new grid-connected battery projects in the East and West valleys.

SRP and its partner, Plus Power LLC, celebrated the connection of the Sierra Estrella Energy Storage in Avondale and the Superstition Energy Storage in Gilbert on Monday.

Utility officials estimate the storage facilities will add 340 megawatts of power or 1,360 megawatt-hours per day, enough to power 76,000 homes for about four hours.

The Sierra Estrella is SRP’s largest grid-tied batter project at 250 megawatts. It sits on about 9 acres. The 90-megawatt Superstition project is expected to come online this week.

“We appreciate our partnership with Plus Power to develop these resources, which will provide flexibility and resource diversity to help maintain reliable power during Arizona’s hot summers,” said Jim Pratt, SRP chief executive officer, in a press release.

Plus Power designed the facilities in consultation with Avondale and Gilbert first responders and will operate them to national safety codes and standards for battery energy storage.

The facilities feature lithium-ion battery energy storage systems designed and manufactured in the U.S. by Tesla. A majority of the EPC work was performed by union labor. Both facilities were supported by a federal investment tax credit from the Inflation Reduction Act.

“We are proud to partner with SRP to bring the Sierra Estrella and Superstition battery storage projects online to help meet growing summer peak demand, while creating local jobs and tax benefits for Avondale and Gilbert,” said chief executive officer Brandon Keefe at Plus Power in a press release.

SRP is aiming to reduce its carbon intensity by 82% over 2005 levels by 2035, with a goal of being net-zero on carbon by 2050.