Geoffrey Ballard, 76; Developed Hydrogen Fuel Cells

Geoffrey Ballard risked bankruptcy and his professional reputation to get the internal combustion engine off the streets and its smog out of the skies.

He knew alternative energy could work -- he had a doctorate in geophysics and had been the head of a federal energy conservation office in the early 1970s. Without outside backers, he cashed in his pension and, for $2,000, bought a run-down Arizona motel to use as a laboratory. He first tried to make a high-energy lithium battery, a research project that put him in bankruptcy.

Dr. Ballard, 76, who died Aug. 2 of complications from liver disease at Lions Gate Hospital in North Vancouver, B.C., eventually developed hydrogen fuel cells and, with them, built an emissions-free transit bus that stunned the transportation industry when it was introduced in 1993.

"My goal from the very beginning was replacing the internal combustion engine -- just getting that off the streets," he told Discover magazine in 2002.

Although that goal has not yet been achieved, and Dr. Ballard dubbed skeptics "piston-heads," his work accelerated the drive to replace fossil fuels. He became known as the father of fuel-cell industry. The magazines Discover and the Economist gave him their innovation awards in 2002 and 2003, and Time magazine named him one of its "Heroes for the Planet" in 1999.

One of his three sons told the Vancouver Sun that Dr. Ballard was a proponent of solar and nuclear power as well, but hydrogen offered the best and quickest prospect for upending the surface transportation world.

It seemed to be lucrative; the company he founded, Ballard Power Systems, sold its fuel-cell division to Daimler and Ford Motor earlier this year for a reported $96.6 million.

A small fleet of buses powered by hydrogen fuel cells now plies the streets of Hamburg, as well as streets in the United States, Japan and Singapore, discharging only water and water vapor.

Instead of burning fossil fuel, a vehicle powered by a fuel cell relies on a chemical reaction that isolates hydrogen, then combines it with oxygen to produce electricity.

The idea was not new. High school science students do the reverse when they use electricity to separate hydrogen and oxygen. And the technology was used in the Gemini space program to supply electricity and drinking water, but it was expensive.

Dr. Ballard found a way to vastly increase the amount of power produced while also using a lighter, smaller and cheaper fuel cell.

He was born near a huge source of hydroelectric power, Niagara Falls, in Ontario, and he studied geological engineering at Queen's University in Ontario. He received a doctorate in earth and planetary sciences from Washington University in St. Louis in 1963.