The future is not without detours. For the material researcher Thomas Klassen, this means that on his way from Geesthacht in the south-east of Schleswig-Holstein to Kiel, he must first drive via Hamburg. In Kiel classes should talk about the future: how the emission of greenhouse gases can be reduced with the help of hydrogen. The scientist is researching new tanks for this at the Helmholtz Center in Geesthacht. In political Berlin, the gas is just the stuff of dreams, the federal government is working on a "National Hydrogen Strategy" ( ZEIT No. 8/20). But it is precisely what many are conjuring up in the current euphoria that is preventing classes from getting to their destination this Wednesday in February: a hydrogen car.

Such cars are paradoxical pioneers. Because they are not just ambassadors for the new energy source. You can also see from them why hydrogen is a rather unlikely replacement for petrol or diesel in private transport.

It is around 260 kilometers from Geesthacht to Kiel and back. Thomas Klassen is unsure whether the remaining tank of his hydrogen SUV will suffice. However, it is not possible to fill the tank in Geesthacht or Kiel. And that's why the detour via Hamburg has to be.

The lack of petrol stations is the first of three major disadvantages: there are only around one petrol station with a hydrogen fuel pump per million inhabitants in Germany. The network of ordinary petrol filling stations is much denser, one for almost 6000 people.

The second, higher hurdle is physics. Before the gas can drive green, energy has to be converted in a complicated way, for example like this: from wind power to electricity, which uses hydrogen to generate hydrogen, which is stored under pressure and cooling and has to be transported and ultimately generates electricity in the fuel cell of a car, which ultimately drives the electric motor. "The conversion in each further individual process reduces the overall efficiency," summarize the experts from the Agora Verkehrswende think tank. In the end, hardly a third of the energy originally used arrives on the road - not particularly efficient (after all, it is more than two thirds for a battery-operated electric car).

In general, and that is disadvantage number three, the battery electric car has a clear lead over models with fuel cell and hydrogen: This category is so insignificant that it is not mentioned in the monthly registration statistics of the Federal Motor Transport Authority. The authority refers to a special evaluation according to which only 386 such cars were registered at the beginning of 2019, of which 372 cars.Newer figures are not yet available, but it is unlikely to be more than 500 vehicles. At the beginning of the year, this contrasted with almost 240,000 battery-powered electric vehicles, according to the Association of the Automotive Industry. After all, the government has been providing incentives here for years, not only when buying a car, but also when building charging stations. The fact that the few fuel cell models are currently still unrivaled in price is free - it's an uneven race.

Nevertheless, the draft of the national hydrogen strategy for fuel cells "also shows good prospects in the car sector (...)". Significantly, especially where pure battery cars reach their limits, "for vehicles with a high weight, in continuous operation and in use on long distances". Anyone who has the three major disadvantages of the energy source in mind may be surprised.

However, because greenhouse gas emissions (and air pollution in some places) are unacceptably high in traffic, hydrogen remains at play: it only generates water vapor in the fuel cell. If it was produced using green electricity, it is even climate neutral. At least the CO₂ statistics could be depressed with the gas: This applies both to the average ("fleet emissions") of individual manufacturers who struggle with the EU limits, as well as to the still rising emission curve of the entire German transport sector.

And for that you would, at least in Berlin, also accept a few detours.