INSIDE a non-descript gray building tucked in a Torrance industrial park, the costly and still-sputtering hydrogen revolution is underway.

Attention is centered on a critical part, called a "traction inverter," that helps power hydrogen vehicles. Motors that drive fuel cell cars need constant current--not the alternating kind that comes out of an outlet--and the inverter makes that adjustment. It is currently the size of a breadbox--about two-thirds smaller than it used to be--but still too large to suit General Motors Corp. engineers.

"We try to get the size down by a third every generation," said Dave Ouwerkerk, manager of commercial and strategic projects at GM's Advanced Technology Center. "Ultimately we need a fuel cell platform that doesn't compromise performance in something like a pickup truck or a Malibu (sedan)."

The Advanced Technology Center is one of GM's half dozen laboratories that are working to meet the company's ambitious goal of marketing a fuel cell-powered car by 2010. Already, the troubled automaker is spending more than any other company in the world on this technology in the belief that it can make the jump to fuel cells while its competitors focus on hybrid gasoline-electric vehicles.

The financial commitment is so great that the company is winning the praise of environmentalists--even as Wall Street analysts note that the technology could be decades away from being commercially viable.

"From my point of view, they're wasting money," said David Healy, an analyst at Burnham Securities Inc. in New York. "It's a lot of green P.R., but no added value. There's no real economic value to it. The industry is going the way of hybrids, but GM and the other Detroit producers are being dragged kicking and screaming into that market."

Ourwerkerk acknowledges the skepticism, but contends that new technologies are being developed by engineers and accepted by consumers at ever faster rates, making GM's 2010 goal ambitious but not unreasonable.

"It took 55 years from the introduction of the automobile until 25 percent of the population had them," he said. "It only took 13 years after the cell phone was invented to reach that penetration."

Manhattan project

Fuel cell vehicles are basically electric cars. They zipper oxygen from compressed air with hydrogen gas or liquid to create a stream of electrons that powers an electric engine, emitting only pure water.

It's a simple concept that was imagined decades ago. But there are huge technical hurdles to be overcome in fuel storage, efficiency, cost and reliability. The Torrance center is working on a handful of the problems.

Inside the cinderblock walls, engineers and technicians sit hunched over rows of workbenches crowded with high-precision power tools as they work on the traction inverters, now into their fifth generation.

It's no coincidence that the Advanced Technology Center is in the middle of the South Bay aerospace hub, with neighbors such as Alcoa Inc.'s aerospace fastening systems unit and Boeing Co.'s Electronic Dynamic Devices Inc.

The facility had been a defense technology lab for Hughes Electronics Corp. for years when Hughes was acquired by GM in 1985; even now, about half its engineers were trained in aerospace electronics.

The electronic motors and inverters needed to make fuel cell cars operate were developed at the center for GM's EV1 electric car, which was introduced in 1990 and became the first mass-produced electric car. While their ultra-aerodynamic looks and electric propulsion fostered a loyal following, GM was unable to sell enough of them to make production pencil out.

"The EV1 taught us the real need to sell advanced technology in mass numbers," said Ouwerkerk, formerly an engineer working on missile guidance and radar systems at Hughes. "We're a company that has to make a profit, so it has to appeal to a lot of people."

One example of the center's work is developing fuel tanks that can hold the hydrogen gas at 10,000 pounds per square inch, instead of 5,000 psi. Working with Quantum Fuel Systems Technologies Inc., a subsidiary of Cerritos-based Impco Technology Inc., GM has essentially doubled the car's driving range to 250 miles. "The promised land is 300-mile range," Ouwerkerk said.

Making waves

Honda Motor Co. Ltd., Toyota Motor Corp., DaimlerChrysler AG and Bayerische Motoren Werke AG (makers of BMWs) all are working on fuel cell research, but GM spends the most on its program.

It's a strategic decision that got a big boost in 2003 when President Bush announced a five-year, $1.7 billion program to develop hydrogen fuel sources. And it's getting the attention of environmentalists, who have criticized GM for fighting higher federal and California fuel-efficiency standards.

"They're doing good work at GM, pushing the technology forward, investing in fuel storage technology, improving the fuel cell stacks," said David Friedman, research director for the clean vehicles program at the Union of Concerned Scientists. "They're one of the companies pushing to get a fuel system infrastructure out there, with universal standards."