When a fire ripped through a car park at Luton Airport a few months ago, speculation quickly pointed to an electric vehicle (EV) as the culprit. However, Bedfordshire Fire and Rescue Service clarified that the fire started in a diesel car. Despite this, the rumour persisted and spread rapidly on social media. Even when debunked, such stories often return as persistent myths.
Electric vehicles may not be a panacea for environmental damage, but international climate forecasters agree that they are essential to the transition away from fossil fuels. Addressing common criticisms of EVs, particularly around the risk of fire, is crucial to public understanding. Claims that EVs are more prone to fire, or that these fires are more severe, have implications. But what about the data?
All the data shows that EVs are simply much, much less likely to catch fire than their petrol equivalents. For example, in Norway, where EV uptake is the highest in the world, there are four to five times more fires in petrol and diesel cars than in EVs. Similarly, Sweden found only 3.8 fires per 100,000 electric or hybrid cars in 2022, compared to 68 fires per 100,000 vehicles overall.
The physics behind car fires helps explain these differences. A typical petrol car contains about 50 liters of highly flammable liquid fuel, which can ignite at just 246°C (475°F). The formula for potential energy release is
E = m × c × ΔTwhere m is fuel mass, c is specific heat capacity, and ΔT is temperature change. This means a full tank of petrol can release up to 445 kWh in a fire, enough to power an average home for 1 week.
Australia’s EV FireSafe project reported only a 0.0012% chance of an EV battery fire, compared to a 0.1% chance for internal combustion engine vehicles. Tesla’s data from 2012 to 2021 shows that its vehicles had 11 times fewer fires per mile driven than the average for all cars in the U.S. These findings highlight that EVs are not inherently more dangerous than conventional vehicles.
However, videos of EV Tesla fires show intense infernos, fueling the belief that these incidents are more dangerous. This perception is partly due to the unique challenges of EV battery fires. Lithium-ion batteries can go into ‘thermal runaway’, releasing flammable gases and creating hazards such as vapour cloud explosions. Such fires burn hotter, require more water to extinguish and are prone to re-ignition.
Despite the dramatic nature of EV Tesla fires, data suggests they are far less common than those involving petrol or diesel vehicles. Statistical analysis of fire incident data from 2018-2023 shows that 76% of EV fires were caused by external damage to the battery pack, 18% by manufacturing defects, and only 6% by charging issues. In comparison, 61% of petrol car fires start in the engine compartment due to fuel system leaks.
As EV adoption increases and batteries age, the prevalence of Tesla fires may change, but current evidence suggests the overall risk is much lower. While not without its challenges, EV technology remains a critical step towards a sustainable future.
