Tesla’s world’s largest battery is moving ahead with expansion

Update: PG&E now says that the Tesla Megapacks are not part of the investigation. The project has now been turned on.

Tesla has deployed what many believe will become the world’s largest battery system for PG&E at the Moss Landing station in California. However, the Tesla Megapack system has been shut down for months due to a fire investigation.

But the company is still planning to move forward with the expansion of the energy storage system this summer.

We first learned of the project at PG&E’s Moss Landing substation when it submitted it to CPUC and the company was in talks with Tesla in 2017.

It involves four separate energy storage projects, and two of them should become the world’s largest battery systems.

Dynegy is going to deploy a 300MW/1,200MWh project on PG&E’s grid while the Tesla project will be 182.5MW/730MWh, which could eventually go up to 1.1GWh.

In 2018, we obtained Tesla’s proposal for the project, and it shows that the company plans to use “Megapack” instead of its usual Powerpack for large utility-scale projects.

In 2020, the project was officially approved, and Tesla started construction on the first phase of the project in July.

Last year, Tesla deployed Megapacks with a capacity of 100 MW/ 300 MWh at the site, and Vistra Corp, the operator of the site for PG&E, started operating the system.

However, there were two incidents related to smoke and fire at the site in September 2021 and February 2022 that prompted a shutdown of the Tesla Megapack system for a full investigation.

Months later, there’s no clear timetable to power the system back on, but local newspaper Monterey County Weekly reports that the companies are aiming for this summer.

Both PG&E and Vistra appear confident that Tesla’s batteries were not related to the incidents:

Vistra spokesperson Meranda Cohn says the Sept. 4, 2021 and Feb. 13, 2022 incidents will not impact their push to move forward. PG&E spokesperson Paul Doherty says the same, adding the utility has “full confidence” in the project and that analysis so far has shown the batteries were not to blame for the two incidents.

At least one of the incidents reportedly was related to the Dynergy system, but not much information is currently available until the investigation is completed.

Even though the Megapacks remain shut down, the company plans to move ahead with the expansion of the energy storage systems with the next phase that aims to double it in size.

All parties involved expect the CPUC to approve the expansion.