California Grid Operator Adds 62 Megawatts of Battery Storage, Largest in U.S.

The California Independent System Operator Corp. on July 13 announced that the first phase of LS Power Group’s Gateway Energy Storage Project connected to its power grid, adding 62.5 megawatts of storage, the largest in the U.S. The entire project, expected to come online in August, will have a total capacity of 250 megawatts.

The grid operator expects a six-fold increase in storage capacity if projects in the interconnection queue are completed as planned, reaching 923 megawatts by the end of 2020 from just 136 megawatts at the start of the year. The system operator, which serves about 80 percent of California and a small part of Nevada, currently has about 216 megawatts in commercial operation.

The two second-largest facilities have a capacity of 40-megawatt each located in California and Alaska. Currently, 170 battery storage facilities of one-megawatt or more are operating in the U.S., according to the U.S. Energy Information Administration.

More battery storage projects are expected to enter the California grid operator’s wholesale market in the recent future, including 300 megawatts of Vistra Energy Corp.’s 400-megawatt project at Moss Landing in Monterey Bay. Other large projects underway in the U.S. include plans for 400 megawatts in Florida and 380 megawatts in Nevada.

Technological advancement is paving the way for batteries with longer discharge duration, which is cost-effective for commercial applications and more efficient for grid operations. Given their ability to charge and discharge for different durations and power levels, batteries serve versatile functions depending on the market circumstances. The grid operator underscored recent test results, which showed that solar and wind installations paired with batteries can offer ancillary services required for grid reliability, make intermittent renewable generation more cost-effective.