There is no way to completely eliminate the risk of battery fire. The industry has focused on preventing them as much as possible and limiting the damage when they do occur.
The recent Tesla fire demonstrates the success of damage control protocols: no one was injured and the fire did not spread. In practice, all the factory owner needs to do is clean the burnt-out unit and drop off a replacement battery pack on site.
3. Even a limited fire is a bad look for the industry
The fact that no one was injured does not erase the disruption for the surrounding Moss Landing community.
Residents faced a day of lockdown and ominous warnings that toxic air could be floating around until authorities gave the go-ahead that evening. Local news reported how a neighbor VR park lost tourism business. Anyone trying to get down the Pacific Coast Highway for their daily commute or a transcendent Big Sur retreat has found their way blocked.
Batteries are generally better neighbors than fossil fuel power plants. They do not systematically emit local pollutants into the air that their neighbors breathe, nor gases that warm the planet. They make virtually no noise and have little visual impact on their surroundings. But these benefits could be overlooked if these battery facilities routinely impose shutdowns on surrounding communities or threaten to emit noxious gases during a fire and its response.
4. Tesla is not invulnerable, but he learns quickly
Tesla is a leading supplier of batteries for power plants, in addition to its better-known lines of electric vehicles and home batteries. It has a strong reputation for its products, backed by tons of cell performance data in its many on-road vehicles and stationary batteries. For the large-scale Megapack, Tesla adopted liquid cooling systems early on to keep the batteries from overheating, back when other companies were still doing it with fans.
All the technological pizzazz hasn’t stopped a few fires from breaking out at power plants using the company’s batteries. Before the last fire at Moss Landing, a Tesla battery caught fire during testing at the Victorian Big Battery site in Australia in July 2021. This incident also did not injure anyone, and the fire only spread to a single adjacent Megapack.
A independent report on this incident noted that the battery “failed safely,” and he pinned the root cause on “a leak in the liquid cooling system” which caused an electric arc in the battery power electronics. Notably, it is not a failure of the battery cells themselves, but of the surrounding systems that turn these cells into a powerhouse in their own right.
Tesla’s thermal insulation in the walls of the enclosure prevented the fire from spreading to the neighboring unit, just 15 centimeters away. But 20– at 30Nodal winds pushed the flames onto the roof of the nearby Megapack, where they ignited plastic components that eventually allowed the flames to reach the batteries.
By the time the investigation was concluded, Tesla had already designed a new roof shield to prevent a repeat of this particular form of spread. This was to modernize this on previously installed projects and incorporate it into future designs, alongside software updates to avoid repetition.
It’s too early to know what caused the latest blaze, though something to do with errant moisture would be a logical theory to consider, given recent history.
And Tesla’s Megapack design has already evolved from the generation installed at Elkhorn. This version used nickel manganese cobalt (NMC) chemistry, the long preferred high energy density formula for electric vehicles. Since then, Tesla bloggers have spotted signs of the Megapack switching to lithium iron phosphate (LFP) chemistryknown in the industry for its greater fire resistance.
During an early September visit to the Kapolei Energy Storage Plant under construction on the island of Oahu, Hawaii, Canary Media confirmed with developer Plus Power that the incoming new Megapacks contained LFP Battery. In other words, the Megapacks installed today already have new security features added since Project Elkhorn, which began construction in July. 2020.
5. The storage industry is still learning, but it can be done safely
It is clear from these case studies that the grid battery industry is still young compared to other power plants, which means that there are failure modes that have not yet been identified.
Although it is crucial to ensure that the batteries themselves are manufactured without defects (see GMit’s huge and embarrassing Chevy Bolt Recall), components other than the battery can also cause problems. Tesla’s coolant failure in Australia reads similarly to Vistra’s Moss Landing incidents, where it was not the batteries but the cooling system and hoses that were the culprits. Presumably, the storage facility will include more rigorous stress testing of plumbing systems in the future.
But even with these direct errors, it is possible to fail safely. Responders to the fire in Australia blew through lake water trying to quench the insatiable thirst of a roaring battery fire. Instead, they heeded Tesla’s recommended response: sit back and let the Megapacks burn out while making sure the flames don’t jump anywhere else. Then replace the pack afterwards.
Anxious neighbors might not be calmed by claims of, “Don’t worry, we’ll just let the fire take its course. But this strategy is significantly different from an approach that puts responders at risk, requires obscene amounts of water, and potentially results in dangerous runoff, to achieve the same result.
There’s a long history of fossil gas infrastructure blowing up and killing people. That hasn’t stopped utilities from running gas to major population centers. But no one alive today remembers the difficult early years of adopting gas power. As battery storage matures in real time, its social license depends on its ability to fail without hurting people.