Although they are not expected to reach the mass market before 2010, fuel cell vehicles (FCVs) may someday revolutionize on-road transportation. This emerging technology has the potential to significantly reduce energy use and harmful emissions, as well as our dependence on foreign oil. FCVs will have other benefits as well.

A Radical Departure

FCVs represent a radical departure from vehicles with conventional internal combustion engines. Like battery-electric vehicles, FCVs are propelled by electric motors. But while battery electric vehicles use electricity from an external source (and store it in a battery), FCVs create their own electricity. Fuel cells onboard the vehicle create electricity through a chemical process using hydrogen fuel and oxygen from the air.

FCVs can be fueled with pure hydrogen gas stored onboard in high-pressure tanks. They also can be fueled with hydrogen-rich fuels; such as methanol, natural gas, or even gasoline; but these fuels must first be converted into hydrogen gas by an onboard device called a "reformer."

FCVs fueled with pure hydrogen emit no pollutants; only water and heat; while those using hydrogen-rich fuels and a reformer produce only small amounts of air pollutants. In addition, FCVs can be twice as efficient as similarly sized conventional vehicles and may also incorporate other advanced technologies to increase efficiency.

Benefits:

• No Greenhouse Gases Burning fossil fuels such as gasoline or diesel adds greenhouse gases to the earth's atmosphere. Greenhouse gases trap heat and thus warm the earth because they prevent a significant proportion of infrared radiation from escaping into space. FCVs powered by pure hydrogen emit no greenhouse gases. If the hydrogen is generated by reforming fossil fuels, some greenhouse gases are released, but much less than the amount produced by conventional vehicles.
• No Air Pollutants Highway vehicles account for a significant share of the air pollutants that contribute to smog and harmful particulates. FCVs powered by pure hydrogen emit no harmful pollutants. FCVs that use a reformer to convert fuels such as natural gas, methanol, or gasoline to hydrogen do emit small amounts of air pollutants such as carbon monoxide (CO).
• More Energy Efficient Internal combustion engines in automobiles convert less than 20% of the energy in gasoline into power that moves the vehicle. Vehicles using electric motors powered by hydrogen fuel cells are much more energy efficient, utilitizing 40-60% of the fuel's energy. Even FCVs that reform hydrogen from gasoline can use about 40% of the energy in the gasoline.
• Design Flexibility The use of fuel cell stacks and electric motors affords automobile manufacturers a great deal of flexibility in designing vehicles. Fuel cell systems can be designed to fit almost any shape or body style. For example, the prototype on the right houses all of the vehicle's drivetrain components on a skateboard-shaped chassis. Also, instead of one large electric motor, it uses four smaller motors connected directly to each wheel. Fuel cells can provide much more electric power than the 12 volt batteries in conventional automobiles. Therefore, FCVs can be equipped with more sophisticated and powerful electronic systems than those found in conventional gasoline vehicles. For example, some vehicle manufacturers are designing vehicles that use electronic steering and braking. Eliminating the steering column and wheel may make these vehicles safer.
• Quieter Fuel cell vehicles are much quieter than internal combustion engines although wind and road noise will still be present at higher speeds.

-FuelEconomy.gov-

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