WHAT IS BIODIESEL? Oil exploration engineer Pete Bethune built "Earthrace" to prove that biodiesel is the fuel of the future, but do most boaters even know what this energy source is? According to the National Biodiesel Board, biodiesel is the name of a clean-burning alternative fuel produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic and essentially free of sulfur and aromatics.