A company that made its name in camping lanterns hopes a portable generator it has begun manufacturing here will help shine the way to a future powered by clean energy.

The Coleman Powermate generators combine hydrogen and oxygen to produce up to 1,000 watts of electricity. Pure water is the only waste product of this fuel cell technology, giving it tremendous appeal to promoters of clean energy.

A small number of companies are banking on hydrogen as the fuel of the future. Boosters see in it an incipient boom; skeptics suggest it could end in bust.

"This is the early stages of a profound revolution taking place," said Jeremy Rifkin, author of "The Hydrogen Economy."

Even President Bush touted fuel-cell technology in his recent State of the Union address, pledging that it could routinely power automobiles 20 years from now. Only a handful of prototypes are now on the road.

"With a new national commitment, our scientists and engineers will overcome obstacles to taking these cars from laboratory to showroom so that the first car driven by a child born today could be powered by hydrogen, and pollution-free," Bush told Congress.

Fuel-cell company stocks shot up Wednesday as news that Bush intended to plug the technology leaked out. Prices have since settled.

Despite the hope — and the hype — for a fuel-cell future, the technology is decades away from widespread use. The major stumbling block is cost.

That's something even the Coleman engineer who developed the company's $6,000 AirGen acknowledges.

"I know it works," said Ken Frank, senior research and development engineer at Coleman Powermate. "I guess the jury's out on whether people will buy it."

The company has sold "some" of the units, but it won't say how many or to whom. It hopes to roll out a version for home use in March.

Other manufacturers include United Technologies Corp. of Hartford, Conn. It has sold more than 250 fuel cells that produce 200 kilowatts and according to company spokesman Peter Dalpe, end up costing 16 cents per kilowatt hour over a 20-year period. The average cost of electricity from the grid in the United States is 8 cents per kilowatt hour.

Those 40,000-pound United Technology generators are being used to complement the electrical grid in places like the First National Bank in Omaha, where two of the units ensure its mainframe computer uninterrupted performance.

The $3.4 million that the bank sank into four such units, though steep, ensures that credit card and other transactions can be processed even in a blackout, said Brenda Dooley, president of bank subsidiary First National Buildings. A loss of power could cost the bank $2 million an hour, Dooley said.

But such fuel cells remain anomalies.

Using current technologies, it is too expensive to produce, store, transport and distribute hydrogen fuel to make it commonplace today, according to the U.S. Department of Energy.

For most customers, it is still far cheaper to run a diesel generator as a source of backup power.

Plus, generating hydrogen typically produces the very greenhouse gases fuel cell power is supposed to reduce or eliminate. Eventually, backers hope to produce "clean" hydrogen using water and electricity generated from the sun or wind. For now, natural gas remains the main source.

That's not stopping companies from are sinking hundreds of millions into fuel-cell research, bolstered by increased federal spending on research and development.

Backers of the technology pledge that investment will drive down costs and make the technology competitive in as little as a decade's time. Whether that will occur remains unclear.

"The question is, will discoveries to bring costs down come first, or will the money run out first?" asks Nabil Nasr, assistant provost and director of the Center for Integrated Manufacturing Studies at the Rochester Institute of Technology in Rochester, N.Y.

The uses for which the technology is best suited is also unclear. It's an elegant solution for NASA, which has quietly used fuel cells in space for decades, if only for lack of safe options. But that's a niche use.

Companies like MTI Micro Fuel Cells Inc., Motorola and Casio are designing miniaturized fuel cells for cell phones and laptop computers.

The application could replace the often short-lived batteries that are the scourge of portable electronic devices.

Experts say that and other uses are so attractive they leave no doubt whether hydrogen will play a greater role as an energy source in the future; it's just how soon.

"It's not a matter of 'if,' but a matter of when," said Edward Hensel, head of RIT's mechanical engineering department.