New cars are to be emission-free in the EU from 2035. Electric vehicles are considered emission-free in this context. At this point, we don’t even want to discuss whether this is actually the case, given the environmental pollution caused by the very energy-intensive production of the batteries. But sometimes it helps to do a little math if you want to visualize the dimensions of problems. So let’s abstract from the manufacture of the car and focus on its operation. A normal electric car has a consumption of about 20 KWh per 100 kilometers in real life (not on the test bench in the test cycle).

In Germany, according to the statistics of the Federal Motor Transport Authority, German residents travel about 630 billion kilometers a year in passenger cars. If all passenger cars in Germany were to be operated electrically, this would result in electricity consumption of 126,000 GWh. That is almost exactly how much all wind turbines together fed into the grid in 2020 and almost three times as much as was generated by photovoltaics in the same year. Now let’s assume that we wanted to generate all of this electricity with sustainable wind energy and, for simplicity, assume that the production of the wind turbines is CO2-free. Let’s further assume that for this purpose we would have unlimited access to the most powerful offshore wind turbines in the world, which are concreted into the sea and have a height of about 220 meters at the rotor tip – 63 meters higher than the tip of Cologne Cathedral. Such wind turbines have a capacity of about 12 MW each. Under ideal conditions, such turbines can produce about 67 GWh of electricity per year. Let us further simplify (and somewhat heroically) assume that the power is generated very evenly and that there are no line losses. Even with highly idealized (and thus much too optimistic) assumptions, we would then need just under 2000 of these gigantic wind turbines to operate the German car fleet CO2-free. In reality, it would probably be closer to 4000 plants, since hydrogen would have to be produced as buffer energy for times of low wind, which would entail major efficiency losses. At a distance of 500 meters, these wind turbines would line up on a 2000-kilometer-long string of pearls.