Sam Kraft recently discovered Frontier Energy in South China while commuting to classes at the Maine Maritime Academy in Castine.

The 23-year-old Portland man owns a Volkswagen Jetta TDI, which has a diesel engine and can run on biodiesel. He fills up once a week.

“Everybody gets this perception that it’s a hippie thing, but it’s not,” he said, making reference to the common association of biodiesel with environmentalists.

Kraft thinks diesel engines are the way to go – he gets about 50 miles to the gallon – and he believes buying alternative fuel is a way to curb the country’s dependence on overseas oil.

But one problem in Maine is that clean emissions standards prohibit the sale of new diesel vehicles in the state. You can’t go to a Maine Volkswagen dealer to buy a new TDI.

That may change soon.

Steven Linnell, clean cities coordinator for the Maine Clean Communities Coalition, which promotes alternative fuel for transportation, believes “ultralow sulfur” diesel may be available here by 2006. That would pave the way for the sale of new diesel vehicles and could broaden the appeal of biodiesel.

The towns of Biddeford and Yarmouth already use the cleaner form of diesel in vehicles, Linnell said.

He noted that it is illegal to make biodiesel at home for use in vehicles that will be driven on state roads and highways because state and federal taxes would not be paid on the fuel.

Linnell added that work also is under way to make ethanol-based fuel more readily available to consumers. The fuel, often made from corn or wheat, is typically blended with gasoline and can be used in high concentration in what are known as flex-fuel vehicles.

There were 125,000 flex-fuel vehicles on the road in Maine as of two or three years ago, Linnell said, but “most people don’t even know that they’re driving that vehicle.” Soon, flex-fuel vehicles are expected to have special gas caps so consumers can be better informed.