That's kind of the point.

Engineers were aiming for what Robert Stempel calls "acceptability."

"That's what we tried to do, so when you got in, it would be like driving your normal car," said Stempel, chairman and chief executive of Rochester Hills-based Energy Conversion Devices Inc.

But this isn't any other hybrid. There are some who are betting that vehicles like the ECD Prius will deliver the U.S. automotive industry from the quagmire in which it is bogged down, struggling with dwindling petroleum reserves, volatile fuel prices and changing consumer likes and dislikes.

This Prius runs off a battery - and on hydrogen, the most common element in the universe.

"This would be a bridge to promote the hydrogen fueling infrastructure and increase the public's awareness and use of hydrogen," said Jeffrey Schmidt, a systems energy for Ovonic Hydrogen Systems, LLC, one of the companies under the ECD umbrella. "And, in the future, the use of fuel cells."

While hydrogen-powered cars might seem the stuff of science fiction, "this is doable technology today," Schmidt said.

Indeed, Stempel said hydrogen-powered vehicles using internal combustion engines similar to the one in the Prius could be commercially available by 2010.

"What we would probably do is target the fleets where you have the same stopping point every night," he said.

In recently published interviews, high-ranking offi cials at General Motors Corp. said hydrogen-powered vehicles could be available in massproduction volumes by 2011.

The company last month showed off the hydrogen-powered Sequel concept vehicle to journalists in California. It also announced it will test more than 100 hydrogen-powered Equinox vehicles in 2007 in California, as well as in New York City and Washington, D.C.

"The day is getting closer when we would have to consider this as a possible entry into the marketplace," said Byron McCormick, executive director of GM's fuel cell activities.

Fill 'er up?

While the day may be getting closer, hydrogen-powered vehicles face roadblocks, chief among them fueling infrastructure.

Schmidt, who drives the ECD Prius from Southgate most weekdays to the company's headquarters off Auburn Road, fuels at a hydrogen pump on site.

But drivers of hydrogen cars can't just go down to the corner service station. Schmidt, for example, was loading the Prius onto a trailer recently to take it to a demonstration across the state in Muskegon.

"If there were hydrogen fueling stations between here and Muskegon today, I'd hop in the car and drive it," he said. "I would have no qualms about driving this car to Muskegon."

In the early days of the automobile, pioneering motorists had to go to the hardware store to pick up a can of gasoline. The gas station infrastructure grew rapidly, however, once there were enough motorists to make such an operation economically viable.

Developing the hydrogen infrastructure might follow the same route, according to McCormick.

"It's like rural electrifi cation," he said. "We're trying to get enough vehicles out there that use hydrogen so it makes sense to invest in other forms of (making hydrogen)."

And those forms might follow a less traditional route. Richard Thompson, ECD director of communications, likes to show visitors a room stocked with models of the company's products, ranging from solar roof shingles to fuel cells. In one corner is what looks like a child's model of a service station.

"There's a lot of hydrogen produced today industrially, but it's produced from natural gas," he said. "This company thinks the better way of producing hydrogen is the green way."

The roof of the service station is covered with a photovoltaic material that produces electricity from sunlight - and which is manufactured by yet another ECD company, United Solar Ovonic, in Auburn Hills. The current runs to a plate suspended in a small tank of water. When Thompson flips a switch, bubbles form on the plate.

"That's electrolysis," he said. "That's hydrogen being produced.

"This is the company's answer to producing hydrogen the green way, through our solar panels."

The same type of technology could be adapted to home use, McCormick said.

"You could contemplate that, ŒI will take care of a percentage of my transportation costs by putting some solar cells (on the roof) and making hydrogen from electrolysis of water,' " he said.

Hydrogen also is produced by industrial processes such as metal plating, McCormick said. It's currently vented to the atmosphere, but that hydrogen could conceivably be captured.

"When I talk to the person in Japan responsible for the hydrogen program in Japan, they have identified the sources of hydrogen that are byproducts, and they believe they might be able to cover the first 10 million vehicles in Japan (using waste hydrogen)," he said.

Roland Hwang, vehicle policy director for the Natural Resources Defense Council, said that while there's a "lot of excitement" regarding the potential of hydrogen, the jury is still out on making it work and building the infrastructure.

"It's a heck of a challenge to get the hydrogen out there and the fuel cells out there in numbers," he said.

Environmental debate

Surprisingly, perhaps, some environmental groups like the NRDC have cast a jaundiced eye on hydrogen and hydrogen-fueled vehicles.

According to Hwang, "what casts a big shadow or pall over hydrogen work is it's clearly being used by the Bush administration and the auto companies as an excuse not to take meaningful action ... on fuel economy."

Environmentalists believe the administration is holding out the carrot of clean-burning hydrogen in 10 to 20 years in exchange for business as usual right now. They claim reducing emissions and increasing fuel efficiency immediately would do much to reduce global warming as well as reduce dependence on petroleum.

"The problem with the argument is it's much faster to raise the fuel economy of a gasoline vehicle, which we can do right away," Hwang said.

"It's much faster to raise fuel economy ... than it is to try to get tens of thousands of fuel cells out on the road."

Instead of one or the other, Hwang said, car companies need to both develop new technologies and improve fuel economy.

"Our position is we don't have 10 years or 20 years to wait," he said. "Start getting the carbon out of the air and start reducing our petroleum dependency now.

"In a hole, the first rule is to stop digging, and we need to do that."

For their part, companies such as ECD point to the potential benefits for the environment hydrogen holds.

Schmidt said the internal combustion engine in the Prius hybrid emits water vapor and about 1.6 grams of carbon dioxide - mainly due to trace amounts of engine oil burned during the combustion cycle.

"A normal car would be in the thousands," he said. "An ultra low-emissions vehicle (gasoline hybrid) puts out 176 grams."

Burning anything for fuel burns hydrogen, he said - pollution results from the "stuff" that holds the hydrogen.

"We've gone from early man burning wood, to coal to natural gas," Schmidt said. "Eventually you move to hydrogen if you follow the natural progression."

"I might say it slightly differently," McCormick said. "One way to look at it, whether we're talking about petroleum or natural gas or whatever, most of the energy is hydrogen.

"If you look at the history of man, when we started burning wood, started burning petroleum, we have progressively been adding more hydrogen to the carbon," he said.

"That trend continues today. Low sulfur gas or diesel - we add hydrogen to it to get that other junk out of there."

Some environmental groups remain skeptical, however. They prefer a mix of options, including biofuels produced from agricultural crops such as corn and soybeans, as well as hydrogen.

"Hydrogen is not the silver bullet," Hwang said. "We don't have a silver bullet. What we do have are some pretty darn good solutions that can break our dependence on petroleum."

What the future's like

Silver bullet or not, ECD, GM and other manufacturers see concepts like the Prius and other hydrogen-burning vehicles as stepping stones toward the ultimate goal - vehicles powered by fuel cells.

A fuel cell, McCormick said, is essentially a battery that combines hydrogen with oxygen from the air to make water and electricity.

"The advantage is a fuel cell is substantially more effi cient than the burning process," McCormick said. "The amount of energy you can effectively extract is much more effi cient than when you burn (hydrogen)."

Engineers at ECD added a turbocharger to the Prius in order to boost its horsepower back to levels approximating what it would have if it burned gasoline.

Fuel cells, said McCormick, would double the energy output produced by burning the same amount of hydrogen.

"For the same amount of hydrogen, you'd get twice the range," he said. "That extra efficiency is what gives you the ability to get enough hydrogen on board to get the range and utility our customers are looking for."

Hwang, however, said fuel cell technology could be 20 years in the future - something McCormick disputes.

"I think, sort of stay tuned," he said. "Our progress is absolutely huge on fuel cells.

"I'll believe you'll see them well before that."