White rectangular battery storage system with TESLA on the front
Lopez Battery Energy Storage System (BESS)

Energy Storage System Installed at Lopez Water Treatment Plant

Author: Public Works
Date: 5/19/2023 10:28 AM

ARROYO GRANDE - County of San Luis Obispo Public Works continues its work in energy savings through the activation of the Battery Energy Storage System (BESS) at the Lopez Water Treatment Plant (LWTP).

The BESS was procured at no cost to the County through the California Public Utilities Commission Self-Generation Incentive Program (SGIP).

SGIP promotes the use of energy storage through prioritizing incentives to install battery storage systems in communities situated in high fire-threat areas and low-income and disadvantaged communities.

Under this program, the County qualified for the Equity Resiliency Program, which covers 100% of the cost of the BESS, including operations and maintenance.

“Lopez WTP coming online represents the third BESS project in less than a year supporting County facilities, all of which were at no cost to the County, thanks to the State’s funding opportunity,” said Annie Secrest, SLO County Energy & Water Coordinator. “I’m grateful to have such a wonderful team at Lopez who supports the technology and is interested in learning how the battery operates.”

The BESS will position the facility to be resilient in both backup power infrastructure and through electricity cost management.

One primary benefit of the BESS is the ability to manage and reduce electricity use and costs.

The BESS can deploy stored energy during peak demand periods when PG&E grid electricity rates are highest and then recharge during off-peak periods when rates are lowest.

The estimated electricity cost savings at LWTP are projected to be approximately $655,158 after 10 years and $1,414,746 after 20 years. The batteries can provide 7-14 hours of emergency backup power depending on charge and load during the outage.

“Having the batteries will help alleviate plant shut-downs and disruptions to service while saving the customers money at the same time – It’s a win-win,” said Water Systems Superintendent Kyle James.

A secondary BESS benefit includes serving as a backup temporary power supply, with an estimated duration to range from six to 12 hours depending on the building’s electricity load.

The project was developed and managed through Tesla. Construction was performed by J.G. Contracting and Electricraft. The project was overseen by the Department of Public Works.