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The rise of electric vehicles—preparing an emergency response plan
PHOTO: SHUTTERSTOCK
Electric vehicles (EVs) are no longer the future, but an ever-growing part of the transport environment. The science behind them helps to reduce greenhouse gas emissions, responding to climate change concerns, but electric vehicles also create new fire risks for emergency responders and the public. So how should we prepare for, and deal with, EV fires?
HAJNAL NAGY and PAUL WATERHOUSE
FPA Australia
The push to respond to climate change has put renewable energy and rechargeable battery technology front and centre of measures to combat climate change. And a big part of ongoing plans is expected to be a reliance on electric vehicles (EVs).
It is expected that this form of transport will represent 48% of all new cars sold globally in 2030. In some places such as California, they will—by law—be the only allowable option by that date.
But with increasing attention being paid by the fire protection sector to the risks of battery technologies, there is also growing discussion about the potential dangers EVs may pose to the public and to those called upon to respond to these fires.
So how should we prepare for a larger fleet of EVs? And what do we know about the fire risks they represent?
The current political climate
Government policy on EVs differs from state to state. Currently, there is no federal strategy, but at state and territory level there has been some action.
The ACT has a Zero Emissions Vehicles Strategy, as part of its goal to reach net zero emissions by 2045, which encourages the uptake of EVs by private purchasers.
The NSW Government’s Electric Vehicle Strategy is offering $500 million of investment to facilitate EV uptake, setting a goal of 52% of all new-car sales being EVs by 2030–31.
Victoria has set a similar goal of 50% by 2030, while in Queensland the target is every new car to be electric by 2036.
As yet, other states have not locked in specific targets, but it is expected that this will occur.
What are the risks?
It is expected that 58 EV models will be available in Australia by the end of 2022, compared to the 31 available in 2021. These have different technologies, battery types, and chemistries, creating variety for the consumer, but complexity for the emergency responder.
When an EV has a collision, or its battery has been abused or damaged in some other way, there can be a risk of ‘thermal runaway’.
Thermal runaway is an unstable chemical process that begins when the heat generated within a battery exceeds the amount of heat that is dissipated to its surroundings.
If the cause of excessive heat creation is not remedied, the condition will worsen and the internal battery temperature will continue to rise. This in turn will cause the battery current to rise, creating a domino effect. The rise in temperature in a single battery cell will begin to affect other cells in close proximity, and the pattern will continue—hence the term ‘runaway’.
If a battery catches fire when it has been abused (for example, by being damaged in an accident), it carries further risk for secondary ignition. This is when multiple abused battery cells go into thermal runaway at different times. So, an emergency responder may extinguish one fire, only to have another arise in its place.
EV battery fires also tend to put out toxic fumes, creating significant personal risk to the driver, nearby members of the public, and, of course, first responders.
Perhaps more concerning is the differing chemistry being used for batteries may require unique strategies to deal with future fires.
Training first and second responders
EV battery fires have been relatively rare to date, with only 72 verified so far in 2022. This means that many firefighters have not been exposed to them and would not be familiar with risks.
PHOTO: 123RF
—Emma Sutcliffe, Director of EV FireSafe
EV FireSafe, a private Australian company, was awarded seed funding from the Department of Defence in 2021 to research EV fires and emergency response, particularly around EV charging units, and develop information and presentations to support various stakeholders.
According to Emma Sutcliffe, EV FireSafe’s Director, there are new and different challenges for firefighters when dealing with EVs involved in any incident, including road traffic collisions, battery fires, and submersion in flood waters.
“It’s important for firefighters to understand battery pack construction and the concept of thermal runaway. Once we learn that the seat of an EV fire is an exothermic chemical reaction, firefighters can understand that cooling the battery can be the most efficient way to slow and then stop the fire.
“It’s a different way of managing an incident and can be a long process, using far more water and personnel than we’re used to,” she said.
More research is needed to understand what brigades in Australia should do to manage EV incidents. For example, other countries have techniques such as using water baths to submerge the vehicle until microbubbling stops. This may be an option in Australia, but it might be difficult to get the bath to the site in time. Instead, a storage and takeaway process might be more achievable.
A key issue is ‘stranded energy’— energy that remains in the cells, meaning that the battery pack is still carrying voltage inside but has no way of discharging it.
In other words, an emergency responder who comes across an EV fire may think that the battery is no longer live, and thus risks being electrocuted.
Not all EVs are the same
An increasing area of concern is with e-bikes or e-scooters, as fires in these light EVs are becoming alarmingly common.
Part of the risk is how they are obtained and managed. Light EVs are not always purchased from reputable manufacturers and their construction may be of lesser quality; they are often sold second-hand, meaning that they do not come with the manufacturer’s cable; and they can be charged indoors, rather than in a garage.
If a fire breaks out in a light EV, it can not only spread to an owner’s home and possessions but can also generate toxic fumes that make the area untenable for people. The only real solution is for the building occupants to evacuate.
This year, Australia saw its first death due to a lithium-ion battery fire, which occurred in a caravan in Queensland. In this incident, an e-scooter, which was charging at the time, caught fire. A man died from burns incurred while protecting his partner and unborn son from the blaze.
This case has shown the increased need for authorities to develop strategies to deal with fires and to educate the public about the risks of light EVs.
So, what do all responders need to learn?
When it comes to incidents, it is important to know the early warning signs that an EV battery is about to catch fire.
In road traffic collisions, even minor ones, Ms Sutcliffe advises firefighters and road rescuers to monitor for popping and hissing noises from the underside of an EV, where the battery is located. In the event of thermal runaway leading to fire, the resulting blaze should be managed using the relevant agency’s standard operating procedure.
It is difficult to predict when EVs will take over completely, and it is not clear how big the risks may ultimately be.
It may be that they are generally safer than other vehicles and that, with careful strategies, most risks can be contained.
Alternatively, it could be that, because EVs tend to be more expensive to purchase and (arguably) their owners tend to take more care of them than with other vehicles, we have not seen how big this could get. If so, more common usage of these vehicles could lead to an uptick in EV fires and different chemistries could complicate firefighting.
Whatever turns out to be the case, both firefighters and the public need to be informed about how to identify the risks and what to do if an EV fire breaks out.
In this way we can keep everyone safe, while still saving the planet.
