Electric vehicles (EVs) are hailed as a solution for reducing greenhouse gas emissions and air pollution, but they also face some scepticism and criticism. One of the most common concerns is their safety, especially regarding the risk of fires.
Some online chatters claim that EVs are more likely to catch fire than conventional cars and that their fires are more dangerous and difficult to extinguish. But are these claims based on facts or myths? The Guardian has unveiled a new series of reports, where it has consulted experts and examined hard data where possible to address some of the most common criticisms of electric vehicles.
The report explores the myths, the realities, and the grey areas. The first question it asks is: should we worry more about fires in electric cars?
The allegations about electric car fires can be divided into two main categories. The first is that electric cars are more likely to catch fire, while the second is that they cause more damage when they do.
If electric cars are more hazardous than petrol or diesel cars, that would have serious implications. For instance, it could mean that car parks need larger spaces to prevent fire spread or that EV owners need to pay higher insurance premiums to cover the extra costs to firefighters. Consumer and market scepticism would be the big hurdle.
There are millions of electric cars on the roads around the world, so some data on the frequency of fires is becoming available, though not comprehensively. Several experts have said that data suggests there is no reason to believe EVs are more prone to catching fire. The opposite is the case.
One of the experts who heads the transport at a think tank said that electric cars are much safer than their petrol counterparts and that the many fires in petrol or diesel cars are just not reported.
There are various ways in which fires can occur. In the case of car batteries, energy is stored by the movement of lithium ions within a battery cell. However, if the cells are damaged or there are manufacturing errors that lead to short circuits, chemical reactions can occur, triggering a 'thermal runaway'.
This can cause cells to quickly heat up and release toxic and flammable gas. In contrast, fires in petrol cars may be caused by electrical faults that result in sparks or by engine overheating due to issues with the cooling systems, which can ignite flammable fuel.
In Norway, which has the world’s highest share of electric car sales, there are four to five times more fires in petrol and diesel cars, according to the Directorate for social security and emergency preparedness.
The Swedish Civil Contingencies Agency found this year that there were 3.8 fires per 100,000 electric or hybrid cars in 2022, compared with 68 fires per 100,000 cars for all fuel types. However, the latter figures include arson, which makes comparisons difficult.
Australia’s Department of Defence funded EV FireSafe to investigate the issue. It found a 0.0012% chance of a passenger electric vehicle battery catching fire, compared with a 0.1% chance for internal combustion engine cars.
Elon Musk’s Tesla, the biggest and most prominent EV maker, says that the number of fires on US roads involving Teslas from 2012 to 2021 was 11 times lower per mile than the figure for all vehicles, most of which have petrol or diesel engines.
The reason why some people think that electric cars are more fire-prone becomes clearer when you watch a video of one: they can be furious infernos.
A professor of pure and applied electrochemistry at Newcastle University, who studies batteries and helps to train fire brigades, highlighted the ominous risks of vapour cloud explosions and rocket flames when the gases burst out of cells.
However, he said that their lithium-ion cousins were tarnishing the electric car’s reputation. He had real concerns with electric scooters and bikes that use similar technology but often from unregulated, inexperienced manufacturers or even DIY jobs using internet-sourced parts. (He advised people never to leave scooters charging indoors or unattended.)
Firefighters face a unique challenge when dealing with battery fires in electric vehicles. These fires require more water to extinguish, can burn at much higher temperatures, and are more prone to reigniting compared to traditional fuel-powered vehicles, as noted by EV FireSafe. In response, some fire departments have explored the use of fully submerging electric cars in water tanks as a potential solution.
Based on the data that is currently available, it seems that the likelihood of being involved in an EV fire is lower than that of petrol or diesel cars, despite the higher risk posed once a battery fire is ignited. It is important to note that this may change in the future as more people adopt electric vehicles.
According to a think tank expert, there is a possibility that the frequency of fires in EVs could rise as the batteries on the road become older. However, it seems that they would need to increase significantly to surpass the risk posed by petrol or diesel engines.