Largest Battery Energy Storage System in California to Improve Electric Reliability for Customers

By David Kligman

SAN JOSE — PG&E and the California Energy Commission today (May 23) unveiled the single largest battery energy storage system in the state. The pilot project will improve customers’ electric reliability and better balance the needs of California’s power grid during hot summer months when the demand for energy is greatest.

PG&E project manager Dave Fribush points out one of the four 1 megawatt batteries as part of the new Yerba Buena Battery Energy Storage System pilot, which will improve electric reliability for customers. (Photos by David Kligman.)

The 4 megawatt (MW) Yerba Buena Battery Energy Storage System, located on the property of Silicon Valley storage technology company HGST in the San Jose foothills, actually went online earlier this month but was symbolically launched with the flip of a giant light switch.

“It’s appropriate that this pilot project is occurring in a region known throughout the world for innovation and technology,” said Greg Kiraly, senior vice president of distribution operations for PG&E. “PG&E continues to look at the needs of our customers to ensure that we’re providing them safe, reliable and affordable electric service. These pilots are one of many ways in which PG&E is preparing for the future needs of our customers.”

The project is similar to PG&E’s 2MW sodium-sulfur battery pilot at its Vaca Dixon substation. (Click to watch a Currents video on the projects). While the smaller project is primarily intended to test applications of energy storage on the grid, the San Jose battery storage system is at the end of a distribution line so it will improve reliability for customers by stabilizing voltage frequency in the summer when voltage can dip.

When asked what the system will mean for customers, Robert Schainker of the Electric Power Research Institute (EPRI) quickly listed all the benefits: “Power quality, meaning no voltage sags, very firm power, no lights flickering.”

Enough power for seven hours

In the event of a power outage, the battery system can support HGST and neighbors of the company for up to seven hours.

The system charges the four 1MW batteries when demand is low and then sends reserved power to the grid when demand grows. The batteries are kept heated at 300 degrees C and have a life span of 15 years.

Though the project went online earlier this month, a flip of a giant symbolic switch launched the 4 megawatt project.

PG&E helped install and will evaluate the system, thanks to a $3.3 million grant from the Energy Commission. The utility working closely with EPRI to study how sodium-sulfur battery energy storage can improve power quality and reliability while supporting greater integration of intermittent renewable power.

The unveiling was the result of a partnership between many groups. In addition to PG&E, the Energy Commission and EPRI, S&C Electric Company was contracted to supply and install the equipment. Japan-based NGK Insulators, the same company that manufactures spark plugs for cars, produced the sodium sulfur battery system.

Representatives from all the groups attended the celebration, as well as  San Jose council member Rose Herrera and other public officials. And about 50 members of the Electric Storage Association, in town for its national conference in Santa Clara this week, put on fire-protective jumpsuits, hardhats and safety goggles for an up-close tour of the battery system.

Important for Silicon Valley innovation

Members of the Electric Storage Association donned fire-resistant jumpsuits and hard hats to tour the project as part of their national conference in nearby Santa Clara.

Maintaining electric reliability in the region is so important, said Carl Guardino, president and CEO of the Silicon Valley Leadership Group. He said it’s noteworthy that the project is located in the epicenter of technology.

“Thirty-six years ago, when David Packard, the co-founder of Hewlett-Packard, created the Silicon Valley Leadership Group, the defining event that led to our creation was the rolling blackouts of 1977,” Guardino said. “Service disruption, even for an instant, wreaks havoc on the innovation economy. That’s why the work of PG&E and this partnership is so vital.”

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