Corn has become a major source of conventional biofuels.
Credit: U.S. Department of Agriculture
The United States is unlikely to produce enough biofuel by 2022 to meet some congressionally mandated targets, according to an analysis released today by a National Research Council (NRC) committee. And even if the
goals are met, there's no guarantee that using liquid fuels produced from crops, grasses, and trees will reduce the country's overall greenhouse gas
emissions. One member of the panel, however, says the analysis may be overly pessimistic, because it was not able to tap into some of the most recent
data, or information about new technologies that companies may be protecting as trade secrets.
In 2005 and 2007, Congress established aggressive targets designed to boost the production and use of biofuels. By 2022, for instance, drivers are
supposed to be pumping 15 billion gallons of "conventional" biofuels—mostly made from corn—into their fuel tanks. Other targets for renewable
fuel standards (RFS) in 2022 include 1 billion gallons of diesel biofuel, 4 billion gallons of "advanced" biofuels made from feedstocks that reduce
greenhouse gas emissions by 50% compared with petroleum, and 16 billion gallons of "cellulosic" biofuels made from wood, grasses, and inedible plant
parts, such as corn stalks.
At Congress's request, the National Academies' panel looked at how likely the United States is to meet those goals. After crunching the numbers, it
concluded that the United States is already close to meeting the 15-billion-gallon goal for conventional biofuels, and has the capacity to exceed the
When it comes to cellulosic fuels, however, the mandate "will likely not be met." One major problem is that although there is plenty of available plant
material, the panel found that "there are no commercially viable biorefineries to convert such plant matter into fuel." Several companies, including
DuPont, have announced plans to build commercial-scale plants, but many investors remain cautious because producing cellulosic fuel has been much more
expensive than alternatives, the report finds. And it's not clear if newer, cheaper technologies will mature fast enough to help meet the mandate.
"It costs a lot to produce cellulosic biofuel," said Wallace Tyner, a co-chair of the panel and an agricultural economist at Purdue University in West
Lafayette, Indiana. Models used in the study, he said, predicted that making the fuels economically competitive would require a "major" increase in oil
prices, big technical leaps, or government action to require emitters of carbon dioxide to pay about $120 per ton for producing the gas. Some investors
are wary of putting money into cellulosic technologies, he says, because "there is a lot of economic, technological, and policy uncertainties." It's
not clear, for instance, if Congress will maintain tax breaks and subsidies designed to help the biofuels industry.
The panel also found that boosting biofuel production is likely to have economic and environmental ripple effects. An additional 30 million to 60
million acres of land will be needed to produce biofuel foodstocks, the panel notes, and that demand could increase competition for desirable plots,
boosting land prices. That, in turn, could help raise food prices. And fuel crops can have positive or negative effects on biodiversity and the
production of greenhouse gases depending on how they are grown, the panel found.
Plowing up wet, heavily-fertilized soils to grow biofuel crops, for example, could actually increase greenhouse gas emissions, said Ingrid Burke, the
other co-chair and a plant ecologist at the University of Wyoming, Laramie. In contrast, she said "you can achieve benefits"—such as increased
carbon storage and reduced erosion—by planting perennial grasses, such as switchgrass, that don't require annual plowing.
The panel stopped short of making any recommendations on what, if anything, Congress should do to revise the renewable fuel standards. But Tyner and
Burke said it's clear there are plenty of areas that are ripe for research—including developing better cellulosic technologies, and studies that
tease out the economic and environmental tradeoffs of growing different kinds of fuel crops in different regions. Although the report doesn't set out a
research agenda, Tyner said the message should be clear: "More is better."
One member of the panel, meanwhile, says she believes the future of U.S. biofuels "is much brighter" than the report suggests—and worries its
findings could undermine political support for biofuels. Virginia Dale, an ecologist at the U.S. Department of Energy's (DOE's) Oak Ridge National
Laboratory in Tennessee, says that "after much anguish," she decided to keep her name on the report even though she worries it could be "misleading if
the assumptions of the analysis are not considered."
She urges readers to "read the details with care." One of her concerns is that models used by the panel to try to forecast land-use changes resulting
from biofuel production aren't detailed enough to account for differences among farming regions and crops. Another is that "the report is not based on
the most current information." For example, it doesn't include numbers from the
Billion-Ton Update, a DOE report released last August that estimates the amount of biomass available in the United States. The committee also lacked information on new
biofuel technologies developed by companies that are jockeying for a market advantage—and reluctant to share valuable secrets. "Some of those things
could make a big difference," Dale says, "but we don't know about them."