PG&E Celebrates Commissioning of its Moss Landing Elkhorn Battery

By Paul Doherty

At a ribbon-cutting ceremony Monday (June 6), PG&E commissioned its Elkhorn Battery System — the world’s largest Tesla Megapack energy storage installation to date.

Nearly 100 people including PG&E coworkers, Tesla employees, and California and community leaders gathered at PG&E’s Moss Landing substation to learn about the storage system and get an up-close look at the batteries.

PG&E coworkers, Tesla employees and community leaders attended the ribbon cutting for PG&E's Elkhorn Battery System.

Patti Poppe, PG&E Corporation CEO, highlighted the critical role the Elkhorn system and battery energy storage play in integrating renewable energy and supporting state grid reliability.

Patti’s remarks were followed by comments from Mike Snyder, Senior Director of Engineering and Construction, Energy Projects, Tesla; David Hochschild, Chair, California Energy Commission; and Elliot Mainzer, President and CEO, California Independent System Operator.

A Tesla Cybertruck and a PG&E clean vehicle flanked the speakers, with the Megapacks in the background.

Comprised of 256 Tesla Megapack battery units, the energy storage system has the capacity to store and dispatch up to 730 megawatt hours (MWh) of electricity to the grid at a maximum rate of 182.5 megawatts (MW) for up to four hours. That’s enough electricity for the instantaneous demand of nearly 275,000 homes.

The system enables PG&E to charge the batteries during the middle of the day when excess renewable energy — like solar — is available, and then use that stored energy in the evenings when less renewable energy is available. This reduces reliance on power coming from greenhouse gas-emitting resources and helps PG&E meet peak system demand in the evening hours. It’s also cost-effective for customers, as the battery can charge when market prices are lower, and discharge when market prices rise.

A Tesla Cybertruck was on display at the ribbon-cutting ceremony for the Elkhorn Battery System.

The Elkhorn Battery System, located at the mouth of the Elkhorn Slough on Monterey Bay, was designed and constructed and continues to be maintained in collaboration with Tesla. It is owned and operated by PG&E.

PG&E has contracts for large-scale battery energy storage systems totaling more than 3,300 MW of capacity to be deployed throughout its service area – and across California – through 2024.

To date, including the Elkhorn System, PG&E has connected 955.5 MW of battery energy storage capacity to California’s electric grid.