Cater Water Treatment Plant Battery Energy Storage Project

In 2023, the City’s Energy and Climate Division (Sustainability & Resilience Department) and Water Resources Division (Public Works Department) partnered to install a battery energy storage system at the Cater Water Treatment Plant. The Tesla battery array has the capacity to hold 3,727 kilowatt-hours of electricity (enough energy to power 300 Santa Barbara homes for a day).

The batteries provide resilience and additional energy assurance at Cater, which serves a critical role in treating surface water (from Lake Cachuma, the State Water Project, and Gibraltar Reservoir) for residents of Santa Barbara, Carpinteria, Montecito, and Hope Ranch. In addition to providing a backup power benefit, this system will also allow the facility to "load shift," charging the battery with grid power when electricity is abundant and cheapest in the middle of the day, and discharging the battery during peak evening times when electricity is in short demand and most expensive. The ability to load shift will provide an estimated $790,000 in energy savings to the City over the projected 20-year life of the batteries. 

The project is part of the City’s ongoing effort to increase community resilience and leverage the carbon-free electricity provided by Santa Barbara Clean Energy, the City’s community choice aggregation program. Other resilience projects are currently in process at Fire Station 1, the Eastside Library, Santa Barbara Harbor, and the Granada Garage, with many more on the horizon. A future project will include the installation of solar panels to charge the batteries, further reducing the impacts to the local electrical grid and leading to more savings. 

The City worked with Tesla to secure a Self-Generation Incentive Program grant from the State which covered the entire cost of the batteries and was able to install the system and maintain it over a 10-year term, at no cost to the City or water ratepayers.