There’s been a lot of smoke and little light since a large battery fire in California at the Moss Landing facility, which was, when built, state of the art, but now represents long obsolete technologies.
You may remember that once, long ago, Apple had a problem with MacBooks catching fire on the assembly line. I only wish I had bought 10,000 dollars worth of Apple stock that week.
New York Times, Sept. 16, 1995:
Some of Apple’s newest portable machines have burst into flames, and the company is recalling them.
The setback is one of a series that have plagued Apple, which has been struggling to protect its declining market share against machines that use Microsoft’s operating system software. Yesterday, analysts began slashing their earnings estimates for the company, the second-largest personal computer maker, after Compaq Computer.
The company’s stock price, which fell 5.6 percent on Thursday, plunged 10.3 percent today after the company reported the fires and said that its revenues would be “significantly below” expectations for its fourth quarter. The stock skidded $4.125 in Nasdaq trading, closing at $35.875. Its loss for the week was nearly $9 a share.
All year, Apple has been forgoing sales because of an inadequate supply of machines based on the PowerPC chip. The company had been hoping to get back on track with its eagerly awaited new line of Powerbook portable computers, which are based on the PowerPC.
But on Thursday night Apple announced that it was recalling its new Powerbook 5300 laptop computers, which were introduced in August, after several of the machines caught fire while being recharged at the company’s headquarters in Cupertino, Calif.
Energy storage experts note that the Moss Landing facility was housed indoors and used a type of battery more prone to thermal runaway, among other potential safety issues. Utility-scale lithium-ion battery installations’ overall safety track record is impressive, with just 20 fire-related incidents over the past decade despite a 25,000% increase in installed capacity since 2018, a spokesperson for the American Clean Power Association told Utility Dive last month.
But the Moss Landing incident has nevertheless focused utilities, regulators and lawmakers attention on lithium-ion battery safety. It could also create an opening for non-lithium energy storage technologies to compete, some experts say.
It may sound counterintuitive to think of a storage plant completed in 2020 as outdated. But the grid battery industry has evolved at a rapid pace since then — it’s now the second-biggest source of new U.S. grid capacity, behind solar power.
In that short time, the storage industry has matured through a process of trial and error that has included several high-profile fires. None of these have killed anyone, but a pivotal battery explosion in Arizona in 2019 injured four emergency responders and forced a major reappraisal of grid storage plant design. The industry has also improved the batteries themselves since then, but those upgrades came after construction of Vistra’s landmark battery behemoth.
Moss Landing’s design was “unique, globally, as a facility,” given its vintage and the qualities of the 1950s-era building-turned-battery-vault, battery fire safety expert Nick Warner told Canary Media.
In this case, the lack of exact copycats is very good news: It means that the design elements that allowed Moss Landing to burn so apocalyptically are not present in newer or forthcoming battery plants. The bad news is that a handful of other battery projects built around the same time as Moss Landing are slated to operate for years to come.
Key factors in the Moss Landing battery fire
We don’t know what caused the Moss Landing fire, but we do know two big factors that help explain why the facility burned so spectacularly.
First off, Vistra used batteries manufactured by Korea’s LG (not Tesla batteries, as some news reports incorrectly claimed; a separate Tesla battery array sits next door). The LG batteries used the nickel-manganese-cobalt (NMC) chemistry, developed for electric vehicles because it packs a lot of power. That energy density can turn into a vulnerability; when defects cause these batteries to heat up, they can enter thermal runaway, a chain reaction that can quickly run out of control.
Indeed, many of the most prominent battery fires in the U.S. sprang from LGbatteries in facilities built around a similar time: the Arizona 2019 explosion, the Gateway project fire of 2024, and now Moss Landing. General Motors also ripped out LG batteries in its $2 billion Chevrolet Bolt battery recall, and LGitself recalled some of its residential battery products in late 2020.
NMC was the dominant chemistry for grid storage in the industry’s early days, as a sort of hand-me-down from the much bigger EV industry. Battery manufacturers have improved their technology and added safety features in the years since Moss Landing was installed.
The grid storage market has also moved away from NMC in favor of lithium iron phosphate (LFP), a chemistry with better safety metrics. Major grid battery supplier Tesla, for instance, switched to LFP for its popular Megapack enclosures in 2021.
The other defining factor specific to Moss Landing was the choice to use a large, legacy building to house rows and rows of battery racks.
That decision made sense at the time. California was looking for big batteries to help its shift to clean energy, and Vistra had taken over the old Moss Landing power plant in its acquisition of power producer Dynegy. In hindsight, it seems that the design choice packed too much battery fuel into one enclosed space, creating the conditions for an unstoppable, 100-foot tower of flames.
Nearly all grid batteries installed in the past several years have opted not for one overarching building but for row upon row of modular battery containers. Each box contains batteries, controls, and safety equipment. Projects are designed so that if a fire breaks out at one individual container, it won’t propagate to neighboring units. This limits the amount of fuel a fire could engulf and makes it easier for emergency responders to suppress a fire with water.
Case in point: A fire broke out at the neighboring Tesla project in September 2022, but it never spread beyond one container, and responders quickly put it out.