The key to being a successful inventor, thought Jeffrey Bentley, is to invent something that people will want to buy. As obvious as this old saw sounds, Bentley struggled for years to reconcile it with his growing conviction that fuel cells would someday replace the internal combustion engine in automobiles. Fuel cells work by combining hydrogen and oxygen to create electricity, without the noise and pollution of conventional engines. Since engineers have not found a safe and acceptable way to store hydrogen fuel in cars, Bentley made a prototype fuel cell that could operate on methanol or ethanol, using a chemical process known as partial oxidation to break these hydrocarbons down into hydrogen plus carbon dioxide. Then he realized his folly. His local service station was offering neither methanol nor ethanol at its pumps. So who would buy a fuel-cell car?
"I came to the conclusion," says Bentley, "that you've ...
