Strengthening the Power Grid With Large-Scale Batteries

SCE’s new utility-owned energy storage project provides reliability and resilience to the grid, especially during high heat.
Skip to content
Stories : The Grid
Stories : The Grid

Strengthening the Power Grid With Large-Scale Batteries

SCE’s new utility-owned energy storage project provides reliability and resilience to the grid, especially during high heat.
Contributors
Photo Credit: Ernesto Sanchez
Video Credit: Joseph Foulk, Ernesto Sanchez and Roberto Lazarte
 

On a scorching day in September 2020, California experienced an unprecedented shortage of electricity due to a heat wave, increasing air conditioning use and driving demand for electricity in Southern California and across the West. This led to the call for rotating outages in California — the first for Southern California Edison customers since 2006.

This incident prompted a reevaluation of how to achieve the state’s goal of 100% clean energy by 2045 while maintaining reliable power. While the state had aggressive goals to invest in large-scale energy storage systems, it doubled down on the strategy in 2021 to reinforce supply fluctuations and lessen reliance on fossil fuels.

The governor issued an emergency order to add more resources to the grid, and in response, SCE used its Reliability Utility Owned Energy Storage (RUOES) program to launch a new installation project in 2021.

SCE's Reliability Utility Owned Energy Storage (RUOES) program is strengthening the grid with large-scale batteries.

The project aimed to install three battery energy storage systems at locations across SCE’s service area, with a total capacity of 537.5 megawatts, enough to power over 400,000 homes. The three sites, named Separator, Cathode and Anode, are located near existing substations in Rancho Cucamonga, Long Beach and Porterville.

The project uses lithium-ion batteries, the same technology that powers most cellphones, laptops or electric vehicles, but on a much larger scale.

“You can think of these in a way just like the small battery packs that most people have now at home to keep their cellphones charged during the day when no outlet is available,” said Scott Lacy, an SCE senior project manager who started at the company as a distribution field engineer. “You have to continually recharge them.”

The batteries at the three sites can power over 400,000 homes in SCE’s service area.
The batteries are housed in containers that look like large shipping containers, arranged in rows on the ground. Each facility has hundreds of containers. The plants vary in size, from 112.5 megawatts at Separator to 200 megawatts at Cathode and 225 megawatts at Anode, and are intended to provide full power output for up to four hours, when fully charged.

One of the most important benefits is that each site can help integrate more renewable energy into the grid by storing electricity from solar and wind when supply exceeds demand and discharging it when they are producing less, such as in the evening or when the weather is cloudy or calm.

“This provides that buffer to allow clean energy to serve customers even if the sun does not shine or the wind does not blow,” said Lacy.

Each facility can provide up to four hours of power when fully charged with the hundreds of large shipping containers that store 112.5 to 225 megawatts.
That helps the electric grid provide more reliable power when it is needed most, along with more resilient power that can better endure extended heat waves, storms or other emergencies.

“Although the projects did come with some challenges, they exemplify what can be accomplished to support grid capacity during periods of high demand and help mitigate the risk of future rotating outages — which we are all proud of,” said Lacy.

Learn more about energy storage at edison.com/innovation.