ATT QuickStart - A Student's Guide to Alternative Fuel Vehicles...

"Alternative fuels" are vehicle fuels that aren't made from petroleum. There are many kinds of fuels that vehicles can run on that aren't made from petroleum. The United States Department of Energy officially recognizes this list of alternative fuels:

• Alcohols - ethanol and methanol.
• Compressed natural gas (CNG) - natural gas under high pressure.
• Electricity - stored in batteries.
• Hydrogen - a very special type of gas.
• Liquefied natural gas (LNG) - natural gas that is very, very cold.
• Liquefied petroleum gas (LPG) (also called propane) - hydrocarbon gases under low pressure.
• Liquids made from coal - gasoline and diesel fuel that doesn't come from petroleum.
• Biodiesel - a lot like diesel fuel, but made from plant oil or animal fat.

For more information:
http://www.energyquest.ca.gov/transportation/index.html