Sometimes in conversation about the bus I’ll frequently make the mistake of referring to biodiesel and the veggie oil we use to power it interchangeably. But there’s an important distinction, there; biodiesel is processed to run inside your average diesel engine, while straight vegetable oil (SVO) is exactly what it sounds like: straight-up french fry grease that can only be used in a specially modified engine. The modifying itself wasn’t easy (more on that later), but regular vegetable oil is a lot easier to get ahold of on the road than biodiesel.

That’s because any restaurant that uses veggie oil in bulk is super eager to get whatever’s left over off their hands anyway. Places like McDonald’s, or Chinese restaurants that use a lot of the oil generally pay people to take it off their hands. We’re offering to take it for free, filter it, and use it to power Anne Marie. Not only is this a hell of a lot cheaper than having to pay to fill up the tank with diesel wherever we go, but it goes without saying that it’s infinitely more environmentally sound.

Perversely, we have a pretty strong incentive to hope that the vast majority of people stick to fossil fuels, at least for the duration of the trip: The more people run their vehicles on veggie oil, the more restaurants will catch on and start charging people for their waste. So you’ll just have to take my word for it when I say that’s not why I’m ambivalent over SVO as a one-size-fits-all alternative to fossil fuels.

I’m just not convinced there’s enough veggie oil to go around were there to be a large-scale conversion to people running on the stuff. So while it might be tempting for the environmentally conscious to see an SVO-powered bus as representing things to come, I’d wager that these souped-up greasemobiles are going to continue to be isolated cases with very little large-scale application.

Photo by Flickr user jamesjyu used under a Creative Commons license.