Crop and forestry waste and dedicated energy crops can sustainably replace nearly a third of gasoline use by the year 2030, according to a study by Sandia National Laboratories and General Motors Corp.

The goal of the 90-Billion-Gallon Biofuel Deployment Study was to assess whether and how a large volume of cellulosic biofuel could be sustainably produced, assuming technical and scientific progress continues at expected rates.

Researchers assessed the feasibility, implications, limitations, and enablers of annually producing 90 billion gallons of ethanol – sufficient to replace more than 60 billion of the estimated 180 billion gallons of gasoline expected to be used annually by 2030. Ninety billion gallons a year exceeds the U.S. Department of Energy's goal for ethanol production established in 2006.

The study assumes that 75 billion gallons of ethanol would be made from nonfood cellulosic feedstocks and 15 billion gallons from corn. The study examined four sources of biofuels: ag residue such as corn stover and wheat straw, forest residue, dedicated energy crops including switchgrass, and short-rotation woody crops such as willow and poplar trees. It examines the costs of producing, harvesting, storing and transporting these sources to newly built biorefineries.

Sandia researchers determined that 21 billion gallons of cellulosic ethanol could be produced per year by 2022 without displacing current crops. The Renewable Fuels Standard calls for ramping up biofuels production to 36 billion gallons a year by 2022.

The study focused only on starch-based and cellulosic ethanol. Other findings:

    • Continued support of research and development and initial commercialization is critical; sustained technological progress and commercial validation are prerequisites to affordably producing the large volumes of ethanol considered in this study.

    • Policy incentives such as a federal cap-and-trade program, carbon taxes, excise tax credits and loan guarantees for cellulosic biofuels are important to mitigate the risk of oil market volatility.

    • The domestic investment for biofuels production is projected to be virtually the same as the investment required to sustain long-term domestic petroleum production.

    • Cellulosic biofuels could compete without incentives with oil priced at $90/barrel, assuming a reduction in total costs as advanced biofuels technologies mature.