SAN CARLOS — PG&E will begin construction on a hydrogen fuel station at its San Carlos operations and maintenance yard in the coming days.

Company officials, along with representatives from the city and ZTEK, the company that manufactures the pumping equipment for the station, were on hand Wednesday for a ceremonial groundbreaking. It is hoped that the station will be part of a future skeleton-fueling system to create a "hydrogen fuel highway" between San Francisco and San Jose.

PG&E ultimately plans to use the hydrogen station to gas up a number of vehicles in its fleet. Completion of additional stations, planned for San Francisco International Airport and Menlo Park, are still a couple of years away. San Francisco and San Jose each already have a functioning hydrogen fuel station. None of the stations are currently open to the public.

"This is really like a lab experiment in the real world," PG&E spokesman Jason Alderman said. "This is an attempt to understand how hydrogen-power vehicles refuel and work."

By participating in the program, the company hopes to learn the basics about what is needed to deliver hydrogen fuel, like what kind of gas lines work best and where they should be placed.

PG&E also wants to know if hydrogen will work for its own alternative-fuel vehicle fleet, which at over 850 is the fourth largest in the nation, Alderman said. "We want to kick the tires and look under the hood to see if hydrogen-fuel cell vehicles work for us."

PG&E will pick up $300,000 of the $1.5 million tab for the station. ZTEK will pay the rest, officials said. The station is expected to be operational by the end of March 2006. For now the company will lease one hydrogen-fuel cell A-Class Mercedes, with plans to lease two more within the next couple of months at a cost of $550 each per month.

Without state or federal grants to help, PG&E will depend on customer rate funds to pay its share of the costs. The company anticipates Californians will understand that this relatively small investment could ultimately make it easier for everyone to breathe. "[Cleaner air] has been a pretty clear directive from our elected leaders and our customers," Alderman said. "We know that our car-crazed culture contributes to [air pollution] in a big way."

The more hydrogen-powered cars and stations there are on the road, the sooner the technology will make it to the general public, officials said.