Biodiesel.  Many have heard of it in passing, but not everyone really knows what it is. Well, March 18th is National Biodiesel Day, so what better time to clear the air and talk about biodiesel?

Biodiesel is a renewable fuel made of vegetable oils or animal fats. It can be produced from new oils such as soy or used vegetable oils like restaurant grease. Manufacturers take these oils, filter them, and then chemically react them with an alcohol to form biodiesel. Distributors then blend this new chemical compound with regular diesel fuel. B20, which is 20% bio-based compound and 80% diesel fuel, is the most common blend in the U.S. B20 can be used in nearly all diesel vehicles so long as it meets ASTM International Standards, which ensure that the fuel is consistent. Drivers can also use B5 (5% biodiesel), which is a lower blend and supported by nearly all manufacturers. In contrast, straight vegetable oil that is not chemically reacted is different from biodiesel, does not meet necessary standards, and will harm diesel engines.

Running a vehicle on biodiesel has a number of benefits. Most light-duty diesel vehicles already have better fuel economies than their gasoline counterparts. Using biodiesel further reduces a vehicle's petroleum consumption, as well as its smog-forming and greenhouse gas emissions. Biodiesel can also be made locally, from sustainably grown crops or used vegetable cooking oil. Some local projects have even taken kitchen waste, transformed it into biodiesel, and used it to power local vehicles.

Fortunately, the Department of Energy has made it easy to find any of the 736 stations pumping B20. Using the Alternative Fuel Station Locator, drivers can type in their address and search for nearby stations. Drivers using a mobile device can use the tool's mobile version to find the five closest stations.

Using renewable biodiesel produces fewer emissions and reduces the country's dependence on petroleum. So if you have a diesel vehicle, the next time your tank is empty, consider filling up with a biodiesel blend.  For more information on biodiesel check out the Energy Saver Consumer Guide to Biodiesel fact sheet.