AC Transit foresees hydrogen-cell future
$21 million pilot program tests fossil-fuel free buses
09/24/2006 02:42:00 AM PDT
09/24/2006 04:02:02 AM PDT
actransit.org/environment/busdata.php">http://www.actransit.org/environment/busdata.php and watch the buses move about the East Bay in real time, there are questions about whether the technology will ever live up to its publicity as savior of an energy-starved nation on the move.
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Rajesh Paulose, a hydrogen program manager with Chevron, explains how compressors are used in the process of making hydrogen from natural gas at AC Transit's hydrogen bus facilities at its Oakland bus barn.
For a bus company, it's a lofty vision:
"Imagine a world without smog. Imagine clean air and clear blue skies. Imagine your neighborhood without the noise of internal combustion engines.
"Then take away global warming. Then take away dependence on foreign oil."
That's AC Transit's vision for its cutting-edge $21 million pilot program to test hydrogen fuel cell and electric hybrid technology in three of its working buses and five staff cars.
"The laptop computer: Think of where this technology has gone," says the transit agency's marketing and communications director, Jamie Levin, as he leads a breathless tour of the hulking 40-foot buses and the Oakland facilities built to keep them fueled and maintained. "The technology will get smaller, it will get lighter, it will get cheaper."
In a nation desperate not to become an international hostage to fossil fuel, the pitch was enough to capture the imagination of President George Bush.
"Investing in new technologies like hydrogen will enable this economy to be strong, people to be able to afford fuel, this country's national security not dependent on parts of the world that are unstable," Bush said during an April visit to the California Fuel Cell Partnership, where he got to hear Levin's pitch about the threshhold of a new transportation age while standing on the doorstep of an AC Transit fuel-cell bus.
But some would argue that even though anyone can log onto
"We can build one at a high price but can we build lots at a high price?" asked Randy Rentschler, spokesman for the Metropolitan Transportation Commission, which helps decide how federal, state and local transportation funding is spent. "The object is to make thousands that are cheap enough for people to buy."
Right now, there is no actual "Hydrogen Highway" as Gov. Arnold Schwarzenegger dubbed his two-year-old effort to foster hydrogen-fueled transportation through grant programs and other initiatives. The simplest of elements on the Periodic Table is among the most difficult ones to make and store, let alone purchase along a California freeway.
But there is progress, much of which has been witnessed for the first time in AC Transit's fleet of modular test buses as they cart passengers around on actual bus routes, according to Levin.
Starting in 2000, the transit agency has pioneered the use of hybrid fuel cell buses to the point where they not only run on electricity created by stripping electrons from hydrogen stored in roof tanks, but they use energy created by the friction of their brake pads and store it in their batteries.
During a recent demonstration, AC Transit officials treated journalists to a three-hour demonstration of its hydrogen project, including letting the reporters take one of the buses and one of five hydrogen fuel cell staff cars for a spin around the parking lot.
"This vehicle has amazing potential for providing zero emissions in the most densely populated urban areas," Levin said, adding that the fuel cells, which are virtually silent, also make for a far quieter bus than the growling diesels that now patrol the streets of Alameda and Contra Costa counties.
But there are still major problems to be worked out. While hydrogen itself can provide energy in the form of electricity via fuel cells and energy from combustion instead of diesel or gasoline for an emissions-free ride, "it doesn't come from a hole in the ground," Rentschler points out.
Hydrogen has to be made. One technique used by AC Transit at a facility in Richmond, is electrolysis, which uses electricity to separate the H (hydrogen's elemental symbol) from H2O. At the bus barn in the shadow of BART tracks north of the Oakland Coliseum, Chevron has constructed, with more than $3 million of its own money combined with other funds from AC Transit, a hydrogen processing plant that strips the hydrogen from natural gas, whose molecules are made up of four atoms of hydrogen and one of carbon.
Other companies are also heavily invested in the experiment, such as UTC Power of Connecticut, which developed the cells, Belgian bus maker Van Hool NV and Korean carmaker Hyundai, which constructed the Tuscon and Kia Sportage fuel-cell vehicles.
The cinder-block-encased plant is about the size of a convenience store. Inside, natural gas goes through a purifier, then through a compressor. Then it reacts with steam and a catalyist to make hydrogen, which is purified, compressed further to a bone-crunching 900 pounds per square inch for storage.
Using fossil fuel to make hydrogen is not the goal of the program. It's just one way to make hydrogen until some future system can make it cleanly, perhaps with wind power.
"There are multiple feed stocks for hydrogen," Levin explains.
Another problem with hydrogen is that it is highly combustible and kept under high pressure. Inside Chevron's hydrogen plant, there are detectors that sound an alarm whenever any source of sparks or flame threatens the operation. The monitoring devices are so sensitive that they had to be pointed downward so they wouldn't be tripped by sparks dancing off the third rail on the neighboring elevated BART tracks. In the nearby service garage, a special maintenance bay is kept spotless and has special tools and equipment that are spark-free to avoid igniting the hydrogen.
While Levin talks about AC Transit expanding the hydrogen fuel system to its entire fleet someday, hydrogen experts say widespread use of the fuel is a ways off.
"If you look at the history of innovations in automobiles, like hybrids, really the story started about 30 years ago," said Joan Ogden, co-director of the Hydrogen Pathways Program at the University of California, Davis. Development of hydrogen fuel cells really didn't get started until the 1990s, it could be another couple of decades before hydrogen becomes as available as hybrid automobiles, she said.
Transit, however, is another story.
"Buses are kind of a logical place to test alternative fuels because you're garaged in one place and they're fueled in one place," Ogden said.
And while critics believe that hydrogen research money could yield more impact in making internal combustion engine-equipped vehicles more fuel-efficient, Ogden said America's energy needs require both short-term solutions as well as seemingly futuristic solutions such as hydrogen fuel cells.
"We need to be doing things in the near term like fuel economy improvements," she said, "but efficiency alone won't be enough for the long term."