alternative fuel
(1) “alternative fuel” means— (A) methanol; (B) denatured ethanol; (C) other alcohols; (D) except as provided in subsection (b) of this section, a mixture containing at least 85 percent of methanol, denatured ethanol, and other alcohols by volume with gasoline or other fuels; (E) natural gas; (F) liquefied petroleum gas; (G) hydrogen; (H) coal derived liquid fuels; (I) fuels (except alcohol) derived from biological materials; (J) electricity (including electricity from solar energy); and (K) any other fuel the Secretary of Transportation prescribes by regulation that is not substantially petroleum and that would yield substantial energy security and environmental benefits.