corn ethanol fuel and fuel made from switch grass are two of the most promising alternative fuels or biofuels biofuels are fuels that are comprised of biological ingredients like plant material. one advantage of corn ethanol biofuel is that it burns hotter than gasoline. switch grass grows all year long and it is oneof the most efficient biofuels yet developed. switch grass has a very high net energy yield, much better than corn ethanol, but it is not widely used at present.