David Johnson’s truck emits no pollution and is powered with fuel costing about two cents a mile.

But the technology that silently propels his ’97 Chevrolet S-10 is a decade old. Each night, the 51-year-old radiologist parks in his Mankato garage, pulls down his front license plate and connects an oversized plug from the wall to his truck.

“I want to change the discussion here in Mankato,” he said.

The normal-looking pickup doesn’t prompt much discussion, at least without the bumper stickers that read: “Driver buys NO gas. None.” And, for those who still don’t get it: “You are following an electric vehicle.”

That first sticker isn’t strictly true — a small diesel tank heats the truck — but it’s close enough.

Power comes from 26 12-volt batteries mounted under the chassis. It takes up to five hours to fully charge the truck, which is not one of the more-popular hybrid vehicles.

But Johnson knows that his electric-powered truck is only as environmentally friendly as the coal that supplies the electricity. A planned solar panel over his garage will mean a totally guilt-free drive.

“I’d rather burn American coal than foreign oil,” he said.

Even so, he’s got a stopgap measure.

Both of his vehicles carry a small, green sticker on the hood, called a TerraPass. Johnson paid a small fee — about $30 for the truck and more for his gas guzzler — that goes toward the generation of renewable energy.

The idea is that the payment offsets the carbon dioxide that vehicles spew into the atmosphere, a “mini-Kyoto for consumers,” Johnson says, referring to the United Nations’ greenhouse gas reduction effort.

Electric vehicles are far from perfect. His gets 40 to 50 miles per charge, so it’s not practical for long-distance travel. Only a few dozen of the electric S-10s were produced, and major car makers haven’t been able to make the technology viable over long distances.

Locally, there’s been lots of focus on renewable fuels, says Minnesota State University professor Louis Schwartzkopf, who talks about renewable energy during Envision 2020 meetings. Discussion centers on ethanol and biofuels — areas that a rural economy can contribute to.

MSU has been a leader in biofuels research. A bill currently in the legislature would provide $100,000 to the university to convert hybrid vehicles into plug-ins, another strategy that Johnson advocates with bumper stickers.

Clearly, he’s not shy about promoting his truck.