When the US government cut funding for hydrogen-fuelled cars last May, Energy Secretary Steven Chu said such vehicles would not be practical for another decade or two.
Dr Lim Tae-won thinks he can prove Chu wrong.
Lim runs the team at Hyundai-Kia Motors that is developing hydrogen fuel cell technology. And they are on course, he says, to mass produce hydrogen cars in six years.
If they fail, Lim says, the firm's future is bleak.
"In order to survive, we have to be a front runner in the field of eco-friendly vehicles" he says. "It's a question of our sustainability."
It's a bit of a gamble. Kia is banking on the South Korean government fronting the money to build hydrogen refuelling stations around the country. And at the moment researchers are getting their hydrogen supplies from oil refineries - the antithesis of green.
But the government in Seoul is big enough on fuel cell technology to seem willing to help, and Kia engineers say hydrogen could come from zero-carbon nuclear power stations or natural renewable energy sources in the future.
Certainly, Kia's latest fuel cell electric vehicle, the Borrego SUV, feels pretty futuristic to drive. Idling, the whir of the fan sucking in air to mix with the hydrogen to make electricity is almost too faint to detect. Only the occasional pneumatic "phhht" as the system purges itself of water, tells you that anything is working at all.
Driving the car is a little disconcerting. When all you can hear is the sound of the tyres on the tarmac, with no engine noise to judge by, it is hard at first to gauge how fast you are going. Any driving experience less like the 20-year-old, Chinese-built Jeep Cherokee that I use at home in Beijing would be difficult to imagine.
At the end of the test-drive (the Borrego has a top speed of 160km/h, a tank range of 760km and goes from 0-100km/h in 12.7 seconds), switching off the ignition elicits an apologetic gurgling burp from the car's mid-section and a dribble of water onto the pavement.
Is this the future? Sceptics may doubt the feasibility of transporting large quantities of hydrogen, or the likelihood that fuel cells will ever be cheap enough to tempt consumers. But it sure beats the internal combustion engine.
Christian Science Monitor