This tiny car is more than just a toy: It's the Horizon Fuel Cell H-Racer, the smallest hydrogen-powered car in the world, and the first mass-produced fuel-cell-technology product to reach consumers. It's also a great tool for learning and teaching about alternate fuel technologies.

The H-Racer (just 16 centimeters long, about 6.5 inches) runs on a 0.3-watt hydrogen fuel-cell motor and comes with its own refueling system. The fueling station derives hydrogen from water via electrolysis, which splits the hydrogen and oxygen molecules and feeds the free hydrogen through a pump into the car, filling up the proton exchange membrane (PEM) sac; the car's only emission is water. The refueling system is powered by a small solar panel (or batteries, on a cloudy day).

The car is simple enough for a child to put together, and runs for about 3 minutes before refueling is necessary. Fortunately, refueling is part of the fun; the car's designers made most pieces transparent, so you can watch the hydrogen filling up the PEM sac.

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According to Horizon Fuel Cell's vice president Taras Wankewycz, the company eventually plans to develop full-size hydrogen cars. Meanwhile, the H-Racer provides a working, tangible example what clean fuel-cell technology has to offer.

While Horizon is not a toy company, toy makers have expressed interest in integrating fuel-cell technology into there products so fuel-cell-powered remote-control cars, boats, and other toy vehicles may be offered in the future. The H-Racer is available now on the Horizon Fuel Cells Web site for $80, and should hit other retail outlets in the U.S. in August.