Battery storage projects advance in West Valley as data center demand surges
A handful of new battery energy storage system facilities are on tap around metro Phoenix as demand swells for power needed to operate future data centers while ensuring grid reliability.
Right now, Arizona is leading the country for battery storage capacity growth, with 6.2 gigawatt-hours added in the second quarter of this year, according to a U.S. Energy Storage Market Outlook report by the Solar Energy Industries Association and Benchmark Mineral Intelligence.
Two projects in the West Valley that already have interconnection plans with utilities Salt River Project and Arizona Public Service recently cleared initial city approvals, while another city just codified an updated zoning ordinance specifically targeting battery energy storage system, or BESS, projects.
Barrel Cactus Energy Storage in Peoria
The Barrel Cactus Energy Storage is being proposed in Peoria on a 14-acre site adjacent to a planned Aligned Data Center campus. It’s located at 75th and Olive Avenues, and the new facility would have 120 megawatts of battery storage capacity across 328 battery units.
It would also include an electrical interconnection line to SRP’s Agua Fria Substation southeast of the site.
Peoria’s Planning and Zoning Commission recommended approval at an Aug. 20 meeting.
The site is owned by Van Tuyl Companies, and Plus Power – a private firm that develops, owns and operates BESS projects – is the proposed developer.
Plus Power currently has two BESS facilities in Arizona – its Sierra Estrella project in Avondale, which is a 250 MW capacity facility on an 11-acre site that started operating in 2024. It connects to nearby Salt River Project line but will also directly support the future Prime Data Centers campus next door.
Plus Power’s other project – Superstition Energy Storage – is in Gilbert and holds up to 90 megawatts of battery energy capacity.
Larkspur Energy Storage in Glendale
Larkspur Energy Storage is being proposed in Glendale and just got approval from planning and zoning on August 27.
The project site spans about 37 acres at the northwest corner of the Loop 303 and Olive Avenue and is owned by Suburban Land Reserve Inc. – a real estate arm of the Church of Jesus Christ of Latter-day Saints. A two-phase, 500-megawatt BESS facility is being planned there.
Like the BESS project in Peoria, the proposed developer is esVolta – a firm that develops, owns and operates utility-scale BESS projects across North America. The facility would include an on-site private electric substation connecting directly to an existing APS substation next door.
According to a project narrative document, esVolta would essentially lease the project once built out to APS, which would then use it to store and release electricity back to its electrical grid.
“APS has an urgent need for new BESS facilities as their electrical loads continue to skyrocket, fossil fuels are being retired, and additional renewable energy sources are creating a need to store power and provide firm capacity,” the narrative states.
Surprise passes BESS projects ordinance
Over the past few years, more Arizona municipalities have passed their own zoning rules covering data centers, and now they’re doing the same with BESS facilities.
Surprise’s City Council passed a new zoning text amendment at a September 1 meeting regarding the development of BESS facilities, requiring a variable separation distance of 100 to 500 feet from any “existing dwelling unit.”
It comes several years after APS’s McMicken BESS facility in Surprise experienced a thermal runaway event causing an explosion that sent four firefighters to the hospital.
Goodyear also passed a new zoning ordinance covering both data centers and BESS facilities in July.