Biofuels Miss the Mark—So Far

portrait of Wallace Tyner

Meeting U.S. goals for biofuels will require new land-use and incentive policies.

To securely meet its future energy needs, the United States passed in 2007 the Energy Independence & Security Act (EISA), setting benchmarks for sustainable, renewable energy production through biofuels development. But biofuels benchmarks are flying past unmet, and bioenergy’s development is being delayed by sticker shock. Meeting those targets and securing the energy supply in the United States will require rethinking of the current energy market.

“America’s addiction to foreign oil has had a significant impact on our economy and our national security,” says Bob Dinneen, president and chief executive officer of the Renewable Fuels Association, an ethanol fuel trade group. “The only effective strategy for improving U.S. energy security has been the Renewable Fuels Standard” of 2005, which was updated by EISA. Since the RFS was enacted, Dinneen says, the long-term trend of increasing dependence on oil imports has reversed in the United States.

Ethanol fuel has made headway in establishing better energy security for the nation, but it still must be blended with conventional oil fuels. So other home-grown fuel options are needed to help secure the energy future.

EISA has set a goal for U.S. biofuels production at 36 billion gallons by 2022, two-thirds of which should be non-cornstarch-derived biofuels made primarily from cellulosic materials such as harvest residue. But, five years after the policy was put into place, there are no commercially viable biorefineries to convert cellulosic feedstock into fuel, which will make it challenging to meet EISA’s 2012 production benchmark of 500 million gallons. The production goal of 250 million gallons in 2011 similarly slipped by unmet.

A recent article in the American Chemical Society’s journal Environmental Science & Technology looked at the goals set by EISA to determine the amount of harvestable land that would realistically be needed to meet those biofuels production goals.

“Most previous studies have overestimated the bioenergy potential of the U.S. by using only a handful of field-measured yield values to calculate average yield potential, which is then applied over large regions,” says William Smith of the University of Montana, the article’s lead author. The EISA benchmarks are based on assumptions of maximum yield potential over all land considered to be available for bioenergy production.

Smith and his colleagues analyzed satellite data that integrates climate and vegetation dynamics to quantify terrestrial biomass growth capacity—land’s ability to grow plants—of the contiguous United States. They took a best-case-scenario approach, conservatively accounting for unavailable land such as protected land and wetland to maximize their estimate of land available for biofuels production.

Even with that best-case-scenario approach, the researchers determined that potential yields are much lower than the estimates used by EISA. To meet the policy’s bioenergy goals, extensive redistribution of currently managed land or massive expansion of farmland would be needed: 80% of current agricultural land would have to be directed toward biofuels, or 60% of current rangeland would have to be converted for biofuel agriculture. That conversion would incur significant fossil-fuel inputs, reduced productivity and greenhouse-gas-sequestering abilities of the land, and additional strain on already stressed waterways and aquifers used for irrigation.

Even if land were converted for use in biofuels production to meet EISA targets, “large-scale cellulosic ethanol production remains unavailable due to the difficulties associated with converting cellulose to a usable form,” Smith says. “This removes a very large pool of biomass from consideration—for example, crop and forestry residues—and places the entire EISA biofuel target on starch ethanol, which is mainly derived from corn grains in the United States.”

To succeed, the cellulosic biofuels industry needs incentives to cover the gap between what biorefineries can afford and what biomass suppliers can accept, suggests the 2011 National Academy of Sciences (NAS) report “Renewable Fuel Standard: Potential Economic and Environmental Effects of U.S. Biofuel Policy.” Until a barrel of oil reaches almost $200, the cellulosic market won’t be economically feasible without subsidies or other government support, the report says. And without that economic incentive to build a market, the technological advances needed will be slow in coming.

“The major barrier to biofuels is that the uncertainty is too high for most investors,” says Purdue University agricultural economist Wallace E. Tyner, co-chair of the committee that wrote the NAS report. The government can play a role in mitigating that economic uncertainty through certain incentives, but “biofuels alone will not provide energy security,” he says. “We can be independent of OPEC oil if we want, but we will have to pay the price. Renewables, at least in the medium term, will be more expensive than crude oil.”—Kenneth J. Moore

Sources: Bob Dinneen, Renewable Fuels Association, www.ethanolrfa.org.

William Smith, University of Montana, www.umt.edu. The paper “Bioenergy Potential of the United States Constrained by Satellite Observations of Existing Productivity” was published in Environmental Science & Technology, 46, 2012.

Wallace E. Tyner, Purdue University, Department of Agricultural Economics, www.ag.purdue.edu.