They were spectacular shots from an underground car park in Shanghai: Without external influences, a Tesla Model S suddenly started to smoke in April 2019 and detonated a few moments later with a huge flame. Battery fires in electric cars have often been in the headlines in recent years. If you follow the media reports – also at Golem.de – you could get the impression that electric cars are a kind Galaxy Note 7 are on four wheelsthat ignite at every opportunity and explode,
What would happen if several electric cars caught fire in a garage or parking garage? How could such a fire be extinguished? And could the strong heat development endanger the statics of the building? According to the Association for the Promotion of German Fire Protection (VFDB), such fires can be found “considerable risk potential” and need to be researched better. In the end, it could possibly be determined that parking electric cars in certain underground garages is too dangerous.
39 cars go up in flames every day
However, as often as the media reports suggest, electric cars do not go up in flames. Rather, fires of combustion cars are probably not reported in as much detail because they occur so often. According to the Association of the German Insurance Industry (GDV), more than 14,000 vehicle fires were handled by insurance companies in 2018. That’s an average of just under 39 a day. In 2011 there were even 19,000 fires. The Twitter account @autobraende has listed significantly more than 100 internal combustion vehicle fires under the keyword “No Tesla” since November 2019. Because this is so common, it is usually only worth reporting to the regional media.
That is obviously different with electric vehicles. In addition: The new technology presents the fire departments with other challenges. One reason for this is that the fire of a large lithium-ion battery is not so easy to extinguish. In the event of a fire “mostly only ‘fire under control’ is determined by the fire brigade, since a ‘chemical fire’ can take days or weeks to complete a chemical process”, is it[calledin a technical recommendation for handling lithium-ion batteriespublished by the German Fire Brigade Association (DFV) and the Association of Heads of Professional Fire Brigades in Germany (AGBF).
A lot of extinguishing water required
It is also important to use a lot of water. Because the cooling should prevent the thermal runaway of the batteries (“thermal runaway”). “In order to avoid reignitions, the battery area must be cooled with water for a sufficiently long time before it is handed over to the towing service”, recommends the AGBF. That means: Not every fire of an electric car has the consequence that the battery ignites or burns completely.
However, if an electric car burns in an underground car park, there is an important factor that affects almost all vehicles. According to the Munich fire director Peter Bachmeier, the so-called fire load caused by vehicle fires has increased significantly in recent years. “The vehicles became much heavier and a significant part of them are made of flammable materials. We expect the energy release to have tripled in the past 15 years.”said the chairman of the Preventive Fire and Hazard Protection Committee of the German fire brigades at Golem.de’s request.
Risk of collapse for buildings
In recent years there have been more fires in which several vehicles were already burning when the fire department arrived, says Bachmeier. If the fire cannot be stopped by the fire department, “there is a risk of structural loss”, The garage or the building above it would then collapse.
VFDB President Dirk Aschenbrenner, full-time director of the Dortmund fire brigade, makes a similar statement. “The spread of fire can take place very quickly because plastics and fuels can burn. The fact that there are relatively few fires means that an above-average number of them develop critically”said Aschenbrenner in conversation with Golem.de.
Recently there have been several spectacular large fires in parking garages, in which electric cars are said to have played a role.