After many false starts, hydrogen power might now bear fruit

CONVENTIONAL WISDOM holds that battery-powered cars are the future of motoring. But Hyundai, a big South Korean vehicle-maker, is not so sure. Over the past few months it has been running a worldwide public-relations campaign extolling the virtues of an alternative source of electrical power—fuel cells. Instead of storing and then releasing electricity gathered from the mains in the way that a battery does, a fuel cell generates current from a chemical reaction between hydrogen and oxygen. The oxygen comes from the air. The hydrogen, suitably compressed, is stored in a tank on board the vehicle, and is replenished at a filling station, like petrol. Unlike a battery, a fuel cell does create exhaust. But that exhaust is simply the reaction product of hydrogen and oxygen, namely water.

Hyundai’s campaign features members of BTS, a mop-topped South Korean boy-band, staring dreamily into the middle distance amid backdrops of natural beauty. As a reminder of fuel cells’ environmental advantages, water is everywhere. It falls as snow. It roils in oceans. It floats gently through forests as mist. “For rest,” writes Park Ji-min, one of BTS’s members, in a misguided quest for profundity, “our rest comes from for-rests”.

The marketing may be silly, but Hyundai is serious. The firm already sells battery-powered vehicles, but it is...