- Creating plant-based biofuels requires too much farmland to be practical or sustainable—land that would be better used to grow food.
- Producing ethanol and other biofuels takes more energy than the fuel can generate.
“Replacing only five percent of the nation’s diesel consumption with biodiesel would require diverting approximately 60 percent of today’s soy crops to biodiesel production,” says Matthew Brown, an energy consultant and former energy program director at the National Conference of State Legislatures. “That’s bad news for tofu lovers.”
In a 2005 study, Cornell University researcher David Pimental factored in the energy needed to grow crops and convert them to biofuels and concluded that producing ethanol from corn required 29 percent more energy than ethanol is capable of generating. Pimental found similar problems with making biodiesel from soybeans.
“There is just no energy benefit to using plant biomass for liquid fuel,” Pimentel says.
Ethanol: Frequently Asked Questions