07/13/2006
Source: LOHAS Weekly Newsletter
Author: Vancouver Sun
Soybeans are a vastly better choice than corn as the basis for formulating alternatives to fossil fuel, according to a controversial new study out of the University of Minnesota.
Researchers said soybean biodiesel nets 93 per cent more energy than the amount required to produce it in the first place. Corn-based ethanol nets just 23 per cent more energy.
Findings by the researchers, released Monday afternoon by the U.S. National Academy of Sciences, challenge earlier studies that argued there is a net energy loss in the production of ethanol from corn once the cost of farm equipment, environmental impacts and distillation are factored in.
However, the authors say that regardless of net benefits, neither soybeans nor corn should be the foundation of an alternative fuel industry because they can replace only a fraction of U.S. petroleum consumption -- even if all production in the United States is shifted from food to fuel.
"Neither biofuel can replace much petroleum without impacting food supplies," says the study, noting that global demand for food is expected to double within 50 years while global demand for transportation fuel will double in 32 years at current consumption rates.
"Turning a food crop into energy when we actually need food, when the demand for food is going up around the world, is just not a very wise policy," co-author David Tilman said in an interview.
Tilman holds out hope that more cost-effective methods of producing ethanol may be developed -- such as making it from grass or wood fibre.
The study is the most detailed examination to date of the energy costs associated with production of so-called biofuels, which process plant matter into fuels that can be burned in automobiles and trucks as alternatives to oil, diesel or gasoline.
It arrives just as North American auto industry momentum and public sentiment are shifting toward support for the replacement of fossil fuels with greener alternatives that would lessen dependence on imported oil.
For example, on Monday, Calgary-based Suncor Energy Inc. announced it has begun production of corn ethanol at a new $120-million plant in St. Clair, Ontario.
Suncor expects to produce 200 million litres of ethanol per year -- making it the largest ethanol producer in Canada.
Only last week, the U.S. Energy Information Agency noted that the Big Three U.S. automakers plan to put two million biofuel-capable vehicles on the road in North America by 2010.
The Energy Information Agency describes the production of ethanol from corn as a "mature" industry -- first developed in 1908 -- that has no room to make further gains in net energy.
Its growing popularity is due in part to American politics -- it is laden with economic subsidies for corn farmers.
It is also benefitting from environmental concerns because it is touted as a substitute for MTBE, an octane booster that was recently banned -- leaving the United States without the necessary volume of liquid fuel to replace it.
Soybean biodiesel not only yields more energy, it has lower environmental impacts, according to the study -- leaching 99 per cent less nitrogen, 93 per cent less phosphorus, and 87 per cent less pesticide into drinking water supplies during crop production, compared to corn ethanol.
Greenhouse gas emissions from soybean biodiesel are more than three-times lower than those from corn ethanol.
Tilman said earlier studies which posit a net energy loss from corn ethanol, notably by Cornell University Prof. David Pimentel, were based on out-of-date numbers.
"He was using yields of corn from a decade or more ago, costs for construction factories that were again about a year out of date," Tilman said.
Nonetheless, Tilman said corn ethanol production cannot survive without subsidies.
"I think with current methods of making ethanol, I believe it is the wrong direction to go."