Continuing a series of utility deals in Arizona, Salt River Project (SRP) and EDP Renewables North America (EDPR NA) have announced a 200MW/800MWh battery energy storage system (BESS) in the US state.
The agreement was announced by EDPR NA and SRP, 18 November. EDPR NA’s Flatland Energy Storage Project will be built near the Arizona city of Coolidge, using lithium-ion technology designed and manufactured in the US by Tesla, which CEO Elon Musk recently stated as having an energy storage business “growing like wildfire.”
The project, scheduled to be operational sometime in 2025, will take in surplus energy from the grid when demand is low, discharging it for peak usage hours.
SRP serves Pinal County, Arizona, where Coolidge is located, as well as part of Maricopa County, where Phoenix, the Southwestern US state’s capital, is located.
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Electric load in the Phoenix Metropolitan area is growing and is forecast to continue growing rapidly. According to the Arizona Corporation Commission, the state set a record high for peak energy demand in early August and July during heatwaves, with fellow public utility Arizona Public Service Company (APS) reaching 8,212MW, and SRP reaching 8,219MW on 4 August this year, up from record highs in 2023 of 8,162MW and 8,163MW respectively.
The Flatland Energy Storage Project will help with SRP’s Integrated System Plan (ISP), a shift from an Integrated Resource Plan, which looks to address stakeholder concerns while planning for regulatory and supply chain changes, to achieve net zero carbon emissions by 2050.
Bobby Olsen, SRP Associate General Manager and Chief Planning, Strategy and Sustainability Executive, said of the deal “Battery energy storage is an essential piece of SRP’s plan to decarbonise our portfolio and maximise the amount of renewable energy delivered to our customers,” adding, “The Flatland Energy Storage Project will help us meet the increasing energy demand of one of the fastest growing areas of the nation.”
The project’s overall cost was a capital investment of US$271 million, with what SRP says to be an added US$7 million for tax payments to regional governments. Millions are also reported to be spent in support of construction jobs and permanent operations positions over the course of the project’s life. SRP claims that nearly half of its total electric generation will be carbon free in 2028, when its additional solar and storage projects are set to be operational.
EDPR NA is the North American subsidiary of Spanish company EDP Renewables (EDPR). The company operates more than 10,200MW of onshore utility-scale renewable energy projects, with recent deals in Virgina for a 340MWh BESS, and a 200MW/40MW solar-plus-storage project in California.
Pinal County is also home to Arizona’s biggest BESS, Ørsted and SRP’s 300MW/1,200MWh Eleven Mile Solar Center, which will be used primarily at a data centre for Meta. This follows market research firm Wood Mackenzie’s US Energy Storage Monitor quarterly report placing Arizona in the top three states for grid-scale storage deployments in Q2 of 2024.
SRP and APS, Arizona’s two biggest utilities, have made multiple energy storage agreements this year. Earlier this month, APS signed a tolling agreement with Strata Clean Energy for a large-scale standalone BESS project. In July, SRP signed an agreement for full dispatch rights to a new 250MW/1,000MWh BESS project with developer Aypa Power, set to begin commercial operation by mid-2026.
