The meaning of "alternative fuel" depends on the context in which it is used. For example, an alternative fuel for a large energy plant could be anything from waste cooking oil to outdated candy or grain products. Under the Energy Policy Act of 1992, alternative fuels for vehicles include methanol ("wood alcohol"), denatured ethanol (non-potable or undrinkable "grain alcohol") and other alcohols, natural gas and propane, hydrogen and electricity among others.