Everyone gets the seeds of their actions. For me in the case of biodiesel, it was the summer of '01 and I had a friend, Lindsay, who just wouldn't shut up about biodiesel. Every other word was biodiesel this, biodiesel that. "We can drive our cars on it! Rudolph Diesel made the engine with that in mind!"

It took about two years to sink in. Friends of mine were by that time driving on straight vegetable oil, or SVO, which requires a conversion to your engine (to heat the veggie oil and make sure it doesn't coagulate; *biodiesel doesn't require any modifcations). But I finally sucked it up and bought a biodiesel-ready car. In other words, I bought a diesel. Now I'm five years in, and while the road has got some potholes, I'm enjoying the ride.

Biodiesel is a non-petroluem based fuel, that is a mixture of methanol (wood alcohol; ethanol can also be used), vegetable oil (or animal fat), and lye. The vegetable oil usually comes from soy or canola oil, but also frequently is made from palm, hemp, sunflower, and even algae. In fact, Rudolph Diesel originally invented the diesel engine to run on all kinds of oils, and at the Paris World's Fair received many waving baguettes for his demonstration of the engine running on peanut oil.

The catch is this: I began to learn a few years ago that as the early prospects of the fuel started to come up, forests were beginning to come down for palm plantations and mega-soy fields (read, Amazon)...and now ethanol is on the push and we're looking right at this decision between fuel and food.

So while we get our fuel from a place (www.biofueloasis.com) that sources biodiesel only from recycled oils (these days it's a potato chip factory), I've stopped waving the biodiesel flag. We put our car in the garage, drive it as seldom as we possibly can, and recognize the cold hard reality that the solutions that are coming up now are just small steps towards sustainability and we have to model innovations very carefully.