As we saw with the GM Hy-Wire, hydrogen is the best alternative fuel. The big problem with it is its bad press - thanks to the Hindenberg and other airship disasters, it has an aura of danger about it and people imagine giant fireballs where once there was a car. The fact that hydrogen is less flammable than gasoline stands little chance against such images unless a public re-education program is instituted.

That is exactly what BMW intends with its introduction of the hybrid H7, a normal-looking saloon that runs on both gasoline and hydrogen. The company intends to import 25 H7s this year for loan to people who can advance the cause of hydrogen as a fuel.

For more than fifty years there have been cars that run on hydrogen - but early ones depended upon containing the gas within a pressurized fuel tank, thus allowing us to fear leaks and explosions (although neither has ever happened, as far as I know). BMW have chosen to cool the gas to a liquid, making it easier to handle and allaying our fears.

Hydrogen has so many obvious advantages as an alternative fuel that we cannot afford to ignore it. It has almost the same power to volume ratio as gasoline and the product of burning it is as innocuous as water. In fact, it is water. Rather than considering turning our farms over to ethanol-producing corn and starving ourselves in the process, we should be getting used to the idea of hydrogen as a fuel.

One warning, however: if you want to build an airship, use helium, not hydrogen…