A full tank of veggies

UC IRVINE — Riley Hopeman spends most of his life on the road, sleeping in cheap motels or on the couches of sympathetic friends. Most of the time, his home is the vehicle he drives across the country. Every so often, he stops by the back doors of restaurants and begs for food.

If he gets food, he funnels it into his gas tank.

Hopeman is one of the marketing representatives for the National Outdoor Leadership School, a nonprofit that leads classes in wilderness living and environmental responsibility. On Wednesday, the group made a tour stop at UC Irvine and showed off its official transportation: a bus powered entirely by solar energy and vegetable oil.

“A large part of our tour can be defined as leading by example,” said Hopeman, who attended the National Outdoor Leadership School as a teenager. “Our solar panels on the roof cost $30,000, and there’s no way — no matter how much we travel — that we’re going to spend $30,000 on gas. But it comes down to how much you think clean air is worth.”

The vehicle, officially called the Creating a Climate for Change Bus, was built in South Carolina and has been on the road off and on for two years. On Wednesday, it made its first visit to UCI, opening its doors in the late morning and early afternoon for passersby to tour the facilities.

At a distance, the bus looks like an ordinary one — and inside, it has features that regularly go on diesel-fueled buses. The eight solar panels on the roof provide energy for lights, a stereo and television, air conditioning and heating. On Wednesday, the tour guides opened the on-board refrigerators and handed out free smoothies from Stonyfield Farm, an organic food company that sponsors the school.

In traveling to 47 states and logging more than 50,000 miles, the bus has stayed mobile by stopping at restaurants and dining halls and asking for leftover vegetable oil from the kitchen. According to marketing representative Nora Kratz, the main hurdles come when dirty oil clogs the bus’ filters, and when other drivers of vegetable-fueled vehicles work out exclusive deals with restaurants.

“We already have a harder time getting oil because we travel so much,” Kratz said.

Tom Pine, a UCI graduate student in mechanical engineering, was among those stopping by for a tour of the bus. He had converted his 1982 Mercedes Sedan to operate on both diesel and vegetable fuel but said he had doubts about how many drivers would embrace the idea.

“I don’t know about the majority, but I could see a significant minority,” he said. “I’m not sure if there’s enough [vegetable] oil to run the entire traffic fleet of the United States.”