The Pros and Cons of Biofuels

Can biofuels cure America's addiction to oil?

farmer checks his feed corn crop being harvested for biofuel
Dave Reede/All Canada Photos/Getty Images

There are many environmental benefits to replacing oil with plant-based biofuels like ethanol and biodiesel. For one, since such fuels are derived from agricultural crops, they are inherently renewable—and our own farmers typically produce them domestically, reducing our dependence on unstable foreign sources of oil. Additionally, ethanol and biodiesel emit less particulate pollution than traditional petroleum-based gasoline and diesel fuels.

They also do not have much of a net contribution of greenhouse gases to the global climate change problem, since they only emit back to the environment the carbon dioxide that their source plants absorbed out of the atmosphere in the first place.

Biofuels Are Easy to Use, but Not Always Easy to Find

And unlike other forms of renewable energy (like hydrogen, solar or wind), biofuels are easy for people and businesses to transition to without special apparatus or a change in vehicle or home heating infrastructure—you can just fill your existing car, truck or home oil tank with it. Those looking to replace gasoline with ethanol in their car, however, must have a “flex-fuel” model that can run on either fuel. Otherwise, most regular diesel engines can handle biodiesel as readily as regular diesel.

Despite the upsides, however, experts point out that biofuels are far from a cure for our addiction to petroleum.

A wholesale societal shift from gasoline to biofuels, given the number of gas-only cars already on the road and the lack of ethanol or biodiesel pumps at existing filling stations, would take some time.

Are There Enough Farms and Crops to Support a Switch to Biofuels?

Another major hurdle for widespread adoption of biofuels is the challenge of growing enough crops to meet demand, something skeptics say might well require converting just about all of the world’s remaining forests and open spaces over to agricultural land.

“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.” Of course, soy is now much more likely to be grown as an industrial commodity than as an ingredient for tofu! 

In addition, the intensive cultivation of crops for biofuels is done with the help of large amounts of pesticides, herbicides, and synthetic fertilizers.

Does Producing Biofuels Use More Energy than They Can Generate?

Another dark cloud looming over biofuels is whether producing them actually requires more energy than they can generate. After factoring in the energy needed to grow crops and then convert them into biofuels, Cornell University researcher David Pimental concludes that the numbers just don’t add up. His 2005 study found that producing ethanol from corn required 29 percent more energy than the end product itself is capable of generating. He found similarly troubling numbers in the process used to make biodiesel from soybeans. “There is just no energy benefit to using plant biomass for liquid fuel,” Pimentel says.

The numbers might look quite different, though, for biofuel derived from agriculture waste products which would otherwise end up in a landfill. Biodiesel has been manufactured from poultry processing waste, for example. Once fossil fuel prices rise back up, those types of waste-based fuels might present favorable economics and will likely be developed further. 

Conservation is a Key Strategy for Reducing Dependence on Fossil Fuels

There is no one quick-fix for weaning ourselves off of fossil fuels and the future will likely see a combination of sources--from wind and ocean currents to hydrogen, solar and, yes, some use of biofuels--powering our energy needs. The “elephant in the living room” that is often ignored when considering energy options, however, is the hard reality that we must reduce our consumption, not just replace it with something else.

Indeed, conservation is probably the largest single “alternative fuel” available to us.

 

Edited by Frederic Beaudry.