Students at West Philadelphia High School are entering their third Tour de Sol competition. The team has taken a Jeep and a Saturn and converted them into alternative-fuel vehicles. The Jeep runs on clean-burning vegetable oil and animal fat. Math teacher Simon Hauger says the Saturn runs entirely on battery power.

"It's been converted to pure electric power. 336 volts, 28 batteries, and it has a top speed of 75 miles per hour," says Hauger. "Its performance is similar to the Saturn that it was before it was converted. So it's not a speedster, but it can lay rubber."

Automotive teacher Ron Price says the hands-on experience students gain will help them build all kinds of vehicles.

"The students build all this stuff," he says. "And they learn every aspect of the vehicle. As well as learning about electric cars and alternative fuels, they learn the basics as far as braking and suspension and basic propulsion."

But not all of the cars in the Tour are educational tools. John Murphy entered his homemade electric car in last year's race.

"My purpose in building this was to build an electric car to show that they really can be fun," says Murphy. "It is a lot of fun to drive, it's fast, you can drive it on the turnpike."

And, says Murphy, it's a completely pollution-free vehicle, since he purchases electricity for his home from wind power. That means no emissions are generated by his car, not even when he charges the battery overnight.