When hearth broke out on the international’s greatest battery power garage facility in January 2025, its thick smoke blanketed surrounding wetlands, farms and within reach communities at the central California coast.
Highways closed, citizens evacuated and firefighters may just do little however watch as particles and ash rained down. Folks residing within the house reported complications and breathing issues, and a few pets and cattle fell sick.
Two days later, officers introduced that the air high quality met federal protection requirements. However the preliminary all-clear resolution neglected one thing vital – heavy steel fallout at the flooring.
A piece of charred battery particles discovered close to fowl tracks within the dust, with a putty knife to turn the scale. The encompassing marshes are in style stopovers for migrating seabirds. Scientists discovered a skinny layer of a lot smaller particles around the wetlands.
Ivano Aiello, et al, 2025
When battery power garage amenities burn, the make-up of the chemical fallout is usually a thriller for surrounding communities. But, those batteries continuously comprise metals which are poisonous to people and flora and fauna.
The smoke plume from the hearth in Vistra’s battery power garage facility at Moss Touchdown launched now not simply hazardous gases comparable to hydrogen fluoride but in addition soot and charred fragments of burned batteries that landed for miles round.
I’m a marine geologist who has been monitoring soil adjustments in marshes adjoining to the Vistra facility for over a decade as a part of a wetland-restoration mission. In a brand new find out about printed within the magazine Medical Reviews, my colleagues and I had been ready to turn via detailed before-and-after samples from the marshes what was once within the battery hearth’s particles and what took place to the heavy metals.
The batteries’ steel fragments, continuously too tiny to peer with the bare eye, didn’t disappear. They remain remobilized within the atmosphere as of late.
The Vistra battery power garage facility – the huge grey construction within the decrease left, close to Monterey Bay – is surrounded via farmland and marshes. The smoke plume from the hearth rained ash at the house and reached 4 counties.
Google Earth, with knowledge from Google, Airbus, MBARI, CSUMB, CC BY
What’s within the batteries
Moss Touchdown, on the fringe of Monterey Bay, has lengthy been formed via business – a mixture of energy era and extensive agriculture at the fringe of a gentle coastal ecosystem.
The Vistra battery garage facility rose at the website online of an outdated Duke Power and PG&E fuel energy plant, which was once as soon as full of generators and oil tanks. When Vistra introduced it was once changing the website online into the sector’s greatest lithium-ion battery facility, the plan was once hailed as a blank power milestone. Section 1 by myself housed batteries with 300 megawatts of capability, sufficient to energy about 225,000 houses for 4 hours.
The power in rechargeable batteries comes from the float of electrons launched via lithium atoms within the anode transferring towards the cathode.
In the kind of batteries on the Moss Touchdown facility, the cathode was once wealthy in 3 metals: nickel, manganese and cobalt. Those batteries are prized for his or her excessive power density and reasonably low price, however they’re additionally susceptible to thermal runaway.
Lab experiments have proven that burning batteries can eject steel debris like confetti.
Metals present in wetlands matched batteries
When my workforce and I returned to the marsh 3 days after the hearth, ash and burned particles coated the bottom. Weeks later on, charred fragments nonetheless clung to the plants.
Our measurements with transportable X-ray fluorescence confirmed sharp will increase in nickel, manganese and cobalt when put next with knowledge from earlier than the hearth. Once we noticed the numbers, we alerted officers in 4 counties in regards to the chance.
Marine geologist Ivano Aiello measures marsh soils instantly after the hearth the usage of a conveyable X-ray fluorescence detector. The smokestacks of the outdated Moss Touchdown energy plant, the place the battery power garage facility was once positioned, are within the background.
John Haskins
We estimate that about 25 metric heaps (55,000 kilos) of heavy metals had been deposited throughout more or less part a sq. mile (1.2 sq. kilometers) of wetland round Elkorn Slough, and that was once handiest a part of the world that noticed fallout.
To position this in viewpoint, the a part of the Vistra battery facility that burned was once website hosting 300 megawatts of batteries, which equates to more or less 1,900 metric heaps of cathode subject material. Estimates of the volume of batteries that burned vary from 55% to 80%. In keeping with the ones estimates, more or less 1,000 to at least one,400 metric heaps of cathode subject material will have been carried into the smoke plume. What we discovered within the marsh represents about 2% of what will have been launched.
Those contour maps display how metals from the Moss Touchdown battery hearth settled throughout within reach wetlands. Every colour represents how a lot of a steel – nickel, manganese or cobalt – was once present in floor soils. Darker colours imply upper concentrations. The absolute best ranges had been measured about two weeks after the hearth, then declined as rain and tides dispersed the deposits.
Charlie Endris
We took samples at masses of places and tested millimeter-thin soil slices with a scanning electron microscope. The ones slices printed metal debris smaller than one-tenth the width of a human hair – sufficiently small to go back and forth lengthy distances and resort deep within the lungs.
The ratio of nickel to cobalt in those debris matched that of nickel, manganese and cobalt battery cathodes, obviously linking the contamination to the hearth.
Over the next months, we discovered that floor concentrations of the metals dropped sharply after main rain and tidal occasions, however the metals didn’t disappear. They had been remobilized. Some migrated to the principle channel of the estuary and will have been flushed out into the sea. Probably the most metals that settled within the estuary may just input the meals chain on this flora and fauna sizzling spot, continuously populated with sea otters, harbor seals, pelicans and herons.
A high-magnification symbol of a leaf of bristly oxtongue, noticed beneath a scanning electron microscope, presentations a tiny steel particle usually utilized in cathode subject material in lithium-ion batteries, a stark reminder that a lot of the fallout from the hearth landed on plants and croplands. The picture’s scale is in microns: 1 micron is 0.001 millimeters.
Ivano Aiello
Making battery garage more secure because it expands
The fireplace at Moss Touchdown and its fallout dangle courses for different communities, first responders and the design of long run lithium-ion battery programs, which might be proliferating as utilities search to steadiness renewable energy and insist peaks.
When fires escape, emergency responders want to know what they’re coping with. A California regulation handed after the hearth is helping cope with this via requiring strengthening containment and tracking at huge battery installations and conferences with native hearth officers earlier than new amenities open.
How lithium-ion batteries paintings, and why they may be able to be susceptible to thermal runaway.
More recent lithium-ion batteries that use iron phosphate cathodes also are regarded as more secure from hearth chance. Those are changing into extra commonplace for utility-scale power garage than batteries with nickel, manganese and cobalt, despite the fact that they retailer much less power.
How soil is examined may be vital. At Moss Touchdown, one of the executive’s sampling became up low concentrations of the metals, most likely since the samples got here from large, blended layers that diluted the focus of metals slightly than the skinny floor deposits the place contaminants settled.
Proceeding dangers to marine lifestyles
Metals from the Moss Touchdown battery hearth nonetheless linger within the area’s sediments and meals webs.
Those metals bioaccumulate, build up throughout the meals chain: The metals in marsh soils will also be taken up via worms and small invertebrates, which might be eaten via fish, crabs or shorebirds, and in the end via most sensible predators comparable to sea otters or harbor seals.
Our analysis workforce is now monitoring the bioaccumulation in Elkhorn Slough’s shellfish, crabs and fish. As a result of uptake varies amongst species and seasons, the impact of the metals on ecosystems will take months or years to emerge.
