Are Biofuels Renewable?

Features

• Renewable energy sources replenish regularly through naturally occurring processes. The natural plant sources that supply ethanol are replenished through a regular crop cycle similar to that of food production. In the United States, most ethanol derives from corn; other sources include switchgrass and sugar cane. The other most commonly used biofuel -- biodiesel -- derives from vegetable oil sources such as soybeans and also from animal fat.

Benefits

• One benefit of biofuels over fossil fuels involves sustainability. A finite amount of fossil fuels exists underground. When that supply runs out, it will not replenish. In contrast, as long as the plants ethanol derives from continue to be grown, biofuel supplies will not exhaust. Additionally, biofuels burn cleaner than fossil fuels and reduce the amount of greenhouse gasses released into the environment.

Considerations

• Biofuels present some environmental concerns. Vehicles using ethanol blends or biodiesel emit lower amounts of most greenhouse gases, but they emit higher amounts of the ozone-destroying greenhouse gas nitrous oxide. Also, some studies indicate that when the resources used in the production of biofuels are factored in, biofuels present little or no improvement over fossil fuels.