Fuel Cells

Fuel cells produce electricity. Similar to a battery, a fuel cell converts the energy released from a chemical reaction directly into electric power. But unlike a battery, a fuel cell has an external fuel source — typically hydrogen gas — and will generate electricity as long as fuel is supplied, so it never needs electrical recharging.

Inside most fuel cells, hydrogen from a fuel tank and oxygen from the air combine to produce electricity and warm water. Fuel is not burned in this simple electrochemical process (see: How Do Fuel Cells Work?), allowing a fuel cell to operate quietly and virtually pollution-free. This unique method of energy-conversion is exceptionally fuel-efficient — while a typical automobile engine captures 15–20% of gasoline's chemical energy; a fuel cell can convert nearly three times that fraction of its fuel's energy into usable power.

Though fuel cells have been widely publicized in recent years, they are not new: the first one debuted in 1839. Fuel cells powered the 1960's Gemini spacecraft, continue to power the Space Shuttle, and have been used by NASA on many other space missions. Today, all major auto companies have fuel-cell powered vehicles in the works, and a nascent fuel cell industry is growing rapidly.

While their operation is simple, fuel cells have historically been expensive to make. Until a few years ago these devices had to be assembled one at a time in the hands of Ph.D.s. Yet extensive research and development over the past few decades have promised the widespread use of fuel cells in the near future. Fuel cells still cost more today than conventional power sources. But more and more companies are choosing fuel cells for their dependability, fuel efficiency, and clean operation.

• How Do Fuel Cells Work?
• Types of Fuel Cells
• Fuel Cell Applications