Hybrid Electric Vehicles (HEVs)

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Hybrid electric vehicles (HEVs) combine internal combustion gasoline engines with electric motors. Compared to conventional vehicles, hybrid cars have two to three times the fuel efficiency, greatly decreased pollutant emissions, are lightweight and are able to run on alternative fuels such as methanol, compressed natural gas, hydrogen, or other alternative resources. One way that the hybrid vehicles conserve energy is through regenerative braking. When the driver decelerates, the motor uses the kinetic energy of the vehicle's forward momentum to generate electricity that is then stored in the battery for later use. This is very useful considering about 60% of the total energy spent in urban driving is lost due to overcoming the effects of inertia and up to half of this can be reclaimed in hybrid vehicles. In most hybrid vehicles, such as the Toyota Prius and Honda Insight, the two hybrid vehicles currently available for retail sale in the United States, the internal combustion engine is smaller than normal, and the electric motor provides added power when needed, during low speed driving, acceleration, and uphill driving. An HEV can have either a parallel design or a series design. In a parallel design, the fuel tank supplies gasoline to the engine and set of batteries to supply power to the electric motor, so either one or both can provide propulsion power. In a series design, the gasoline engine is connected to a generator that charges the batteries or powers the electric motor. Both the Toyota Prius and the Honda Insight have parallel designs. Hybrid vehicles offer the extended range and rapid refueling that consumers expect from conventional vehicles, while providing a significant portion of the energy and environmental benefits of an electric vehicle.

Links to Pictures of Hybrid Electric Vehicles

HEV Diagram
How the Insight Works
Honda Insight
Honda Insight Battery
How the Prius Works
Toyota Prius
Toyota Prius Engine

For More Information on Hybrid Electric Vehicles

How Hybrid Cars Work
Hybrid Vehicles: The Best of Both Worlds

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