There is no pure hydrogen car on the market today. Today's hydrogen cars are hybrids. They have fuel cells that produce electricity by combining hydrogen from a tank with oxygen in the air (the waste product is only water vapour), which is partially consumed to power the vehicle during light load periods and the rest is stored in a built-in battery; when more power is required (starting, overtaking), the missing energy is supplied by the battery. It is not worth installing more powerful fuel cells to cover even peak consumption due to their size and weight.
In passenger transport, hydrogen propulsion has not yet made much inroads, with German physicist Patrick Plötz of the Fraunhofer Institute for Systems Research and Innovation even telling Nature Electronics magazine that hydrogen is too late for any road transport. The West's drive to rapidly achieve climate-neutral transport is leading to a preference for existing technologies that promise to achieve this goal within a few decades. In passenger transport, it no longer expects hydrogen technology to catch up with the lead held by electric cars if the Paris Agreement commitments are to be met. If hydrogen trucks are not in series production within a few years, he is also sceptical about freight transport.