Biofuels could sustainably replace nearly one-third of the petrol used by US motorists by 2030, according to a new study from Sandia National Laboratories and General Motors Corporation. However, those findings come with several big “ifs.”

The paper, titled “The 90-Billion Gallon Biofuel Deployment Study,” included both energy crops and plant/forestry waste in its calculations.

The study’s authors set out to assess how much ethanol the US could sustainably produce, assuming that technological advances and understanding continue to advance at today’s pace. The 90-billion-gallon goal, which exceeds US Department of Energy targets, was set to reduce the estimated 180 billion gallons of gas the nation’s drivers are expected to consume by 2030.

Of the 90 billion gallons of biofuel the US could produce, 75 billion gallons would be cellulosic ethanol and 15 billion gallon would be corn-based ethanol.

The study’s findings, however, do come with several caveats. For example, research, development and commercialisation efforts would have to continue receiving sustained support. Also, incentives such as a cap-and-trade programme or carbon tax would be needed to protect cellulosic biofuel development from oil market volatility. Without incentives, cellulosic ethanol would be competitive if oil was priced a $90 a barrel (US) or more, the study found.

Of course, oil at the moment is at about $40 a barrel, so there goes that assumption.

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