Disaster control: good electric cars as flood savers – the confused internet debate

On the Internet, e-car fans are fighting bitterly with the combustion fraction. The focus is on the question of whether electric models would be useless in a flood disaster. This internet discussion ignores practice.

As soon as the flood rises in Germany, e-car fans and e-car opponents collide. But the discussion is not on a high level. One of the photoshopping “Fuck you Greta” stickers on flooded combustion cars to make flood victims look like climate deniers. The other side sees the flood as proof that electric vehicles are no good.

“Imagine, in the future only e-cars will be used in such disasters. There would be a few sparks for a moment, there would be a short circuit and that’s it. Floods, no electricity and no more operational combustion engines believe the shit of #diegruenen? ” And the posts are similar.

Incidentally, the argument can be easily turned around: In the event of a fire, you shouldn’t feel comfortable with 80 liters of gasoline under the back seat.

E-cars protected from splash water and puddles

The contribution is nonsense in every way, because e-vehicles are of course protected in such a way that they can also drive through deep puddles. Tesla fans proudly point out videos showing a Tesla still making headway in deep water. Basically, this trip is a stupid idea, because the interior of the Tesla is not waterproof and penetrating water is very difficult to get out of the passenger cell with its carpet, foil and insulation materials. Even if the car survives the joyride, the damage will be great unless you only drive a few meters through the flood. Because normal cars are not waterproof amphibious vehicles. Stern special issue Flood The helpers 13.01

Here the electric vehicle benefits from an otherwise rather negative factor. The high weight of the battery pack counteracts floating. At a certain water level, cars take off in the water. The car loses contact with the ground – usually before the engine fails – and then follows the direction of the water. When that happens depends on many factors. The more ground clearance a vehicle has and the higher the center of gravity, the higher the water can rise. But the slope of the subsoil and the flow speed of the water also play a decisive role and not just the water depth.

Combustion vehicles and e-cars end up in the scrap metal

It is estimated that around 40,000 vehicles were destroyed during the flood in Germany. A car that is flooded by the muddy water and only recovered days later is always a total write-off. Whether a combustion or an electric model. Once filled up, the car is hopelessly lost. A car cannot simply be dried out and used again. With a flood like the one we have experienced, clean water does not simply run into the car. Most of the time, the cars are either swept away by the flood or heavy objects hit the car. In addition to the internal problems caused by the water damage, there is also external damage, which is also not economical to repair.

If there are occupants in a car when a tidal wave hits it, their lives are in danger. At a corresponding flow speed, the water pulls the vehicle with it. In the first few minutes there is still air in the passenger cell and trunk, then the vehicle floats up and follows the water uncontrollably. Theoretically, it could now happen that the fuel leaks or the batteries are damaged due to external damage. However, other dangers are much more likely: For example, that the occupants drown when trying to get out of the car or that their car is pushed under water if it gets into a torrent.

Even if it is not true that e-vehicles give off sparks when they drive through a deep puddle, the combination of electricity and water remains dangerous, even in flooded houses or basements.

Heavy emergency vehicles with electric drive?

If there are emergency vehicles with e-drive, the smallest worry would be to protect the electrical system against water damage. A regularly applied spray film is sufficient for this, as is also used on boat engines and electronics. But what is actually meant by an “emergency vehicle”? A large number of cars and small vans are involved in a large-scale deployment by the German armed forces, technical relief organizations or fire services – they can certainly be powered electrically. We’ll answer later whether this is generally useful. Ultimately, they are civil vehicles with special equipment. They already exist or in a few years they will be on the market as an e-vehicle with a sufficient range.

But when you think of “flood rescue” and “evacuation” you first think of other models. Unimogs of the Bundeswehr, who brace themselves against waist-high floods, the all-wheel drive of the fire brigade, the big tractors of the volunteers from the agriculture, mountain or armored personnel carriers and and and. And here the debate comes to nothing because, apart from test models, such vehicles are not even manufactured as an electric variant. And as long as there is no civilian model of a heavy clearance vehicle, there will be none in the fire brigade.

So the whole discussion is highly hypothetical.

These machines do heavy work

Why is that? If you ignore the disaster scenario for the time being, the reason is simple: the battery capacity is insufficient. A car can have 500 hp, but this power is not called up once to determine the standard range. After all, a car with only 80 hp should also be able to cope with the same course. That always leads to a certain amount of distortion, because in reality the 500-hp vehicle is driven a little more sportily than a small car with a mini-engine. But nobody demands the 500 hp permanently in road traffic. To do this, you would have to go to the racetrack.

The situation is completely different with wheel bearings, tractors or clearing vehicles: Here, the power of the engine does not primarily serve to caress the driver’s ego; this is the horsepower that is really used. And the fuel consumption is correspondingly high, or that is how quickly the battery is sucked empty. In addition, there is a factor in agriculture that is also encountered in the event of a disaster: for many days a tractor or combine harvester is not moved at all, but if the weather is right, the machine works 24 hours a day without a break. Longer downtime to recharge is not an option

It is conceivable that these problems will be resolved in the future. But it is not foreseeable. This would require a real breakthrough in battery technology; simply continuing the previous – otherwise very positive – development is not enough.

Very long lifespan in disaster control

But even when the manufacturers present series models of heavy work equipment with battery technology, there is another factor. In the military there is a saying that the vehicles are usually older than the drivers. That is not always true, but it is often the case: The lifespan of vehicles in disaster control is very long – 20 years is more of a lower than an upper limit. The wagons work far fewer hours a year than haulage trucks. Because they are very expensive to purchase because of the special equipment, more complex maintenance is also worthwhile than with an off-the-shelf truck. The Federal Armed Forces are currently decommissioning Unimog from the late 1980s, and the situation is similar for large vehicles from the fire brigade and technical aid organization. In other words, if the appropriate device with electric drive is available at some point, it will be decades before these vehicles are procured in large quantities.

Nobody can say today what the technology will look like then. Also not whether electric batteries will prevail in heavy work vehicles at all, or whether other technologies such as hydrogen will not be used there – the internet controversy is accordingly pointless.

Charging infrastructure at the place of use

Regardless of the question of what the distant future will bring, heavy duty vehicles today would not only have problems with the battery. Then there is the loading time. During the flood disaster, the clearing equipment was refueled on site by mobile tankers of the Bundeswehr so ​​as not to lose any time. Something like that would not be possible with a battery-powered vehicle. Nor could it be possible to concentrate hundreds of vehicles at one operations center because there is no corresponding charging infrastructure there. And even if it were, it would be difficult to get the required amount of electricity from a network that would have been affected by a disaster.

In principle, you can always imagine solutions in an ivory tower. Battery trucks can be hung behind a clearing vehicle to deliver more juice. On site, generators could burn oil in order to generate electricity for mobile use, which can then be used to charge the vehicles. But even the outline of the idea makes it clear that this process would be far more complex than providing a tanker. Assuming that such operations also take place in regions in which the normal power grid is designed for low loads, it becomes clear that the conversion from heavy rescue equipment to electric batteries in disaster control will still be a long time coming. For the Bundeswehr anyway, which should also do its service in countries like Mali.