SRP’s Largest Energy Storage Facility Now Online

Oct. 18, 2021
The bolster substation battery system is capable of supplying 25 MW of power over a four-hour period.

Salt River Project has placed into service a 25-MW battery storage facility at its Bolster Substation, which is adjacent to its Agua Fria Generating Station, located in Peoria. 25 MW is enough energy to power about 5600 typical residential homes.

The battery system consists of a series of Tesla Megapacks that are connected directly to SRP’s energy grid and is the largest stand-alone battery storage system in Arizona. The batteries can be recharged overnight when power is abundant and less expensive and then discharged during peak energy periods to help meet high customer demand.

The storage solution is efficient, making use of renewable energy when there is a surplus. The system’s renewable-charging capability will also increase over time as SRP continues to add more solar energy resources to its power grid. This summer the utility announced an expanded commitment to add 2025 MW of utility-scale solar energy by the year 2025.

“Battery storage is an extremely important and growing component of SRP’s 2035 Sustainability Goals to reduce our carbon footprint,” said Kelly Barr, SRP’s chief strategy, corporate services and sustainability executive. “The Bolster Substation Battery System adds to our already considerable investment in battery storage and further allows us to offset carbon-emitting resources by storing energy and providing it to our customers when they need it most.”

SRP also recently contracted for the output from the Sonoran Energy Center, which will be the largest solar-charged battery project in the state, giving SRP one of the largest commitments to energy storage in the nation. The utility has also contracted for an additional large-scale solar and battery storage project called the Storey Energy Center to be built south of Coolidge. Both projects are scheduled to become operational in June 2023.

In addition to the new Bolster Substation Battery System in Peoria, SRP receives power and collects data from two pilot battery storage projects. These include the Pinal Central Solar Energy Center, a 20 MW, integrated solar energy and battery storage plant in Casa Grande and the Dorman battery storage system a 10 MW, 40 MWh stand-alone battery storage system in Chandler.