http://www.wired.com/news/autotech/0,2554,69529,00.html

and no, the hydrogen is not stored in a fuel cell, or in a tank. it's GENERATED ON THE FLY using electrolysis.

and the amounts of hydrogen involved is quite small; the purpose of the hydrogen is to act as a fuel enhancer (since it burns more readily and hotter than diesel or gasoline) to prevent knock and to promote more complete combustion (kinda like what honda's two spark plugs in the 1.3 i-DSI does.. altough in a different way). the more complete combustion also lowers the particulate output.

granted the device is quite expensive $4000 minimum. but based on the same general principle, what's stopping anyone from constructing their own version? it's moderately within the realm of the doable by the handy DIY'er.


HFI is a bolt-on, aftermarket part that injects small amounts of hydrogen into the engine air intake, said Canadian Hydrogen Energy's Steve Gilchrist. Fuel efficiency and horsepower are improved because hydrogen burns faster and hotter than diesel, dramatically boosting combustion efficiency.

"You get more work from the same amount of fuel," said Gilchrist.

This is not a new idea. The Jet Propulsion Laboratory at the California Institute of Technology published research on the uses of hydrogen as a combustion-enhancing agent in the early 1970s. But the ability to make hydrogen on the go is novel.

The sticking point for hydrogen has always been getting it. Unlike crude oil, natural gas, wind or solar energy, hydrogen doesn't exist freely in nature. It costs $5 a gallon to make hydrogen from natural gas.

But the HFI system uses electricity from an engine's alternator to power the electrolysis of water to produce hydrogen as needed from small amounts of distilled water.

"That's a big advantage and a bit of a novelty," said Venki Raman, an expert on hydrogen-energy applications who started Protium Energy Technologies.

HFI's manufacturer guarantees 10 percent fuel savings, which likely won't interest car companies or consumers, Raman said. But a reduction of pollution emissions could spur broader use.

Trucks with the HFI system produce half the amount of particulates -- microscopic, unburned bits of diesel. The system also reduces nitrogen-oxide emissions, which are major contributors to harmful air pollution, by up to 14 percent, according to Canada's Environmental Technology Verification Program.

The HFI units are relatively small and cost between $4,000 and $14,000, depending on the size of the vehicle.