The Chevrolet Volt concept is a battery-powered, four-passenger electric vehicle that uses a gas engine to create additional electricity to extend its range. The Volt is powered by the E-flex System, GM’s next-generation electric propulsion system.

 “The Chevrolet Volt is a new type of electric vehicle. It addresses the range problem and has room for passengers and their stuff. You can climb a hill or turn on the air conditioning and not worry about it,” says GM Vice Chairman Robert A. Lutz.

The Volt can be fully charged by plugging it into a 110-volt outlet for approximately six hours a day, and when the lithium-ion battery is fully charged, the Volt can deliver 40 city miles of pure electric vehicle range.

When the battery is depleted, a 1L, three-cylinder turbocharged engine spins at a constant speed, or revolutions per minute (rpm), to create electricity and replenish the battery. According to Lutz, this increases the fuel economy and range.

The Volt is designed to run on E85, so fuel economy of 150 mpg would translate into more than 525 miles per petroleum gallon.

Even if left uncharged, the Volt would still get 50 mpg by using the engine to convert gasoline into electricity and extending its range up to 640 miles, more than double that of today’s conventional vehicles.

A technological breakthrough required to make this concept a reality is a large lithium-ion battery. This type of electric car, which the technical community calls an “EV range-extender,” would require a battery pack that weighs nearly 400 pounds (181 kg). Some experts predict that such a battery – or a similar battery – could be production-ready by 2010 to 2012.

The Volt uses a large battery and a small, 1L turbocharged gasoline engine to produce enough electricity to go up to 640 miles and provide triple-digit fuel economy.

GM will show other variations of the propulsion systems at future auto shows. Future concepts might incorporate diesel generators, bio-diesel and E-100.