Company Unveils Plans for 200-MW Energy Storage Project in Southern California

by Peter Maloney
APPA News
September 14, 2023

LS Energy Solutions plans to deploy a 200-megawatt, 400-megawatt hour energy storage project in Southern California.

Gore Street Energy Storage Fund plans to use the electrical output of the storage project to provide resource adequacy and ancillary services to the California Independent System Operator market.

Avantus, which originally developed the Big Rock storage project in Imperial County, in February sold it to London-based Gore Street Energy Storage Fund, which is managed by Gore Street Capital.

Big Rock will be operated at 100 MW of deliverability to supply 400 MWh and meet the four-hour discharge needs of a resource adequacy contract, contributing to the available capacity and reserves needed by CAISO to maintain supply and demand in real time, LS Energy Solutions said in a statement.

“The remaining 100 MW not immediately reserved for RA will be directed towards the growing ancillary services and wholesale trading opportunities available to energy storage systems in California,” said David Pratt, communications officer for Gore Street Capital.  

LS Energy Solutions said construction on the Big Rock project is expected to begin soon with the facility coming online in the second half of 2024.

The Big Rock project calls for the deployment of 137 AiON-ESS energy storage units that are being provided by LS Energy Solutions. Each AiON-ESS container has a power rating of 1.5 MW and can store 3.5 MWh. Along with tier-1 lithium-ion batteries, the 137 containers also include over 1,300 of LS Energy Solutions’ modular 140-kilovolt amp AiON-SIS string inverters.

In addition to supplying the AiON-ESS energy storage containers, LS Energy Solutions said it would also provide commissioning support and operational services, including extended warranty, preventative maintenance, capacity maintenance and system remote monitoring for the life of the project.

The Big Rock project will be one of the largest energy storage projects in Imperial County, LS Energy Solutions said.

In July, the California Independent System Operator said total battery storage on its grid had increased to 5,600 MW from about 500 MW three years ago. CAISO attributed to the rapid increase in energy storage to a series of storage procurement orders authorized by the California Public Utilities Commission requiring regulated utilities to add storage to their portfolios.

The increase in energy storage capability “has significantly improved our ability to manage through challenging grid conditions,” Elliot Mainzer, CAISO’s president and CEO, said at the time.