Largest Battery Storage System In U.S. Connects To California ISO Grid

July 17, 2020

by Taelor Bentley
Posted July 17, 2020

The California Independent System Operator (ISO) connected the largest battery storage resource in the nation to its power grid last month.

The initial phase of LS Power Group’s Gateway Energy Storage Project in San Diego County came online June 9 and added 62.5 megawatts (MW) of storage interconnection to the ISO grid.

Serving about 80% of California and a small portion of Nevada, the CAISO power grid currently has over 216 MW of storage capacity in commercial operation. If all planned projects in the interconnection queue are completed on schedule, storage capacity will jump to 923 MW by the end of 2020. Making it a six-fold increase from 136 MW at the beginning of the year.

Steve Berberich, ISO president and CEO, predicts that as much as 15,000 MW of battery storage of different duration levels and various technologies will be needed to help the state reach its goal of cutting carbon from power grids by 100% by 2045. The ISO expects large increases in its battery storage resources through 2023 based on the state’s procurement targets.

The Gateway project is a lithium-ion battery system that will have a total capacity of 250 MW when it is in full operation. The company plans for it to be fully online in August 2020, when it will reportedly be the largest operating Battery Energy Storage System (BESS) in the world. The initial 62.5 MW of storage already makes it the largest BESS in the nation. Out of a total of more than 170 BESS facilities of 1 MW or more currently operating in the United States, the two second-largest are 40 MW, one each in California and Alaska.

Larger projects are also in the works in the United States, including plans for a system of more than 400 MW in Florida, and another in Nevada expected to be 380 MW.

Additional battery storage is expected to be added to the ISO market in the new few years, most notably 300 MW of a 400-MW project planned by Vistra Energy Corp. at Moss Landing in Monterey Bay, and the remaining 187.5 MW at the Gateway station.