Tesla Roadster: an electric car with a diesel generator

The Tesla Roadster doesn't pollute, but you've got to wonder about the generator.

Tesla Motors is currently allowing prospective buyers to test-drive its all-electric sports cars. The test drives are taking place around the intersection of Skyline Boulevard and Highway 84 going toward La Honda.

I saw the company prep for some test drives while I was on a bike ride on Friday. (Thank you for repaving the road to San Gregorio, California Dept. of Transportation.) The company hauls the car up the hill in a trailer. But what does it also bring? A generator, to charge the car's batteries in between test drives. I couldn't tell if it was running gas or diesel, but the generator was making the familiar clug clug clug of a gas engine. It was kind of amusing.

I wanted to talk to someone about it but I think they were all having lunch. All I could find in the parking lot were a bunch of guys on Harleys and I had to get back for first-grade pickup.

Owners will plug in their cars and recharge them from wall sockets and special chargers. Generating electricity for this will spew some carbon emissions, but not nearly as many as running a gas-powered car. The company also plans to set up charging stations along highways and at likely destinations.

But for now, until you can drive home with one of these things, the generator is the refueling station of choice.