Scatter Wash Energy Storage

Mortenson was selected as the EPC contractor for this fully operational 255 megawatt / 1,020 megawatt-hour battery storage and power delivery project in Phoenix, Arizona, one of the largest battery storage projects in the state. The project’s batteries can store enough electricity to power more than 250,000 homes for four hours on each charge for 30 years. 

Scatter Wash provides Arizona Public Service (APS) customers with reliable energy, supports increased power demand, and stores significant amounts of renewable energy from solar power plants on its grid to use when it is needed, particularly in the summertime when extreme heat and electricity demand is high in Arizona. 

Tesla’s Megapack 2XL, a fully integrated battery system featuring advanced battery technology, software, and power conversion systems, was used throughout the project. These battery systems efficiently store and dispatch electrical energy to and from the grid during optimal periods. 

Connecting the project to the power grid are two Mortenson-built substations that include two GSU transformers with MV breakers feeding the collection system. The substations are connected to a nearby APS switchyard by a transmission line which spans the Central Arizona Project canal.

APS entered into a 20-year tolling agreement for the Scatter Wash battery storage complex in 2023. This award was a result of the All-Source RFP APS conducted, which was initiated to meet the growing needs of residential and business customers with affordable, reliable, and clean electricity. CIP now owns and operates the Scatter Wash battery storage complex as part of the firm’s growing portfolio of energy infrastructure assets.