Partnership Brings New Battery Storage System to Help Meet Growing Energy Demand

Salt River Project and Aypa Power have entered into an agreement to provide 250 megawatts (MW) / 1,000 megawatt-hours (MWh) of new energy storage to the Arizona grid.

The Signal Butte energy storage project will be a 250 MW, four-hour battery energy storage system located in the Elliot Road Technology Corridor in Mesa, AZ. The project will utilize lithium-ion technology and will have the capacity to power over 50,000 average-sized residential homes over a four-hour period. The project is scheduled to be operational by mid-year 2026.

“SRP is proud of our continued efforts to deploy battery storage, which will help us maximize use of renewable resources and decarbonize our portfolio in the coming years,” said Bobby Olsen, SRP Associate General Manager and Chief Planning, Strategy and Sustainability Executive. “The Signal Butte project will also help us meet the growing capacity needs of the Phoenix metropolitan area.”

“We are proud to announce our first energy storage project in Arizona, marking a significant milestone in our efforts to support one of the nation’s fastest growing markets,” said Moe Hajabed, CEO of Aypa Power. “The Signal Butte project builds on SRP’s sustainability commitments and helps maintain the reliability needs of its customers.”

Signal Butte was selected from SRP’s 2023 All-Source Request for Proposals process. The project was jointly bid by Eolian, L.P., the original developer of the project, and Aypa Power. The project will be owned and operated by Aypa Power, who purchased this late-stage battery energy storage project from Eolian, taking over the remaining development and construction required to bring this project into operation. Once online, SRP will have full dispatch control of the storage system and will decide when to deploy the energy output onto its grid. The project will typically be charged when energy costs are lowest and will be discharged in the early evening timeframe when demand is highest.

“Signal Butte’s siting adjacent to a substation serving multiple operating and under-construction data centers was no coincidence when we began development of the project in 2018. The continued growth of our economy now depends more than ever on deploying fast-responding and flexible resources in the right locations to provide critical instantaneous capacity, and battery energy storage projects like Signal Butte can be built at a speed that matches and enables continued rapid growth in electricity demand,” added Aaron Zubaty, CEO of Eolian, L.P.

SRP was an early adopter of battery storage technology, which can help SRP meet growing peak demand and complement firm resources like flexible natural gas to maintain reliable and affordable power for customers.

SRP currently has nearly 1,300 MW of batteries and pumped hydro and 2,300 megawatts of carbon-free resources serving its customers. SRP also has significantly more solar energy and storage capacity under development that when operational by the end of 2027, will make nearly half of SRP’s generation carbon free.