Biofuel! was one of the stops we made over the weekend on a local organic farm tour. →[More:]They collect used vegetable oil from the mall a few miles away and swap out alcohols, basically. Then they run it in diesel anything (about $1.50/gal): tractors for the farm, a generator, etc.

They make soap and organic compost from the glycerin byproduct, and throw any leftover food chunks into the woods to feed the wildlife.

For some bureaucratic bs gubmint reason they aren't allowed to sell it. They can resell someone else's biofuel for $5.30/gal. And you can bring your own oils there they will process for you at $1.50/gal.