The U.S. Fuel Cell Seminar, Nov. 1-4 at the Convention Center, will promote fuel cell research through exhibits, speakers and paper presentations. 

The event is the largest of its kind, said Bob Rose, the executive director of the U.S. Fuel Cell Council, an advocacy group. 

"We're pleased to have it in San Antonio because there's a lot of fuel cell work going on," committee member Robert Wichert said. 

Fuel cells use chemical reactions to generate electricity for applications ranging from buildings to automobiles. 

Stationary fuel cells served practical uses in San Antonio the past few years through research projects at Brooks City-Base and a Texas Department of Transportation Transguide facility. 

Some of the projects were sponsored in part by the Southwest Research Institute, which has been doing nonprofit research on fuel cells in San Antonio for 10 years, researcher Joe Redfield said. 

The institute and other research groups have been increasing fuel cell interests in Texas. 

"I think you will see Texas become a leader in new technologies as we were in wind technologies," said Patrice Parsons, a San Antonio hydrogen fuel-cell researcher and possible seminar speaker. 

In the Brooks project, three cells, each able to power a single household, were hooked into the power grid for housing. 

A fourth helped power an education facility at the base, doubling as a water heater. 

The Transguide cell powered part of a bank of monitors in the control room to examine traffic conditions around the city. 

Stationary fuel cells, the type used in San Antonio, use natural gas or propane to produce hydrogen. The cell then processes it into electricity. 

Most of the emissions are in the form of water vapor but include a small amount of carbon dioxide, Parsons said. 

Fuel cells require much less natural gas than a conventionally powered generator, and experts believe future applications include environment-friendly automobiles. 

Valero Energy Corp. said its research indicates hydrogen won't have a significant impact on refined product demand for at least 15 years, according to Mary Rose Brown, senior vice president for communications.