Corn ethanol is way too pricey to save us from our dependence on oil, argues food scientist MANFRED KROGER
Sunday, April 08, 2007
All the buzz about someday using ethanol as a standalone fuel to power cars misses an important point: The cost of producing ethanol depends not only on corn or other plants but also on natural gas. It is natural gas that typically provides the energy used to distill corn into ethanol, and gas prices can be volatile and unpredictable.
With his plan for a mandatory five-fold increase in renewable fuels within 10 years, President Bush has called for a huge increase in ethanol production. It would require making about 35 billion gallons of ethanol and other alternative fuels per year by 2017, up from 5.2 billion gallons this year. This would allow ethanol to displace about 15 percent of the nation’s gasoline use. And this would depend on the availability of an enormous amount of natural gas, which raises problems of its own.
The increasing demand for natural gas in the United States has outpaced supply, and this has led to high prices. Once $2 per million BTUs, prices have been as high as $14, which is the equivalent of $7 a gallon for gasoline. It might bother some people to be reminded, but natural gas prices would be more stable if it weren’t for the not-in-my-backyard attitude that is blocking the siting of liquefied natural gas terminals and oil-and-gas production off the Atlantic and Pacific Coasts.
Like other manufacturers, ethanol producers have tried to insulate themselves from high gas prices by using oil, coal and even nuclear power to provide the energy they need. Because solar and wind energy provide power intermittently and require costly backup energy from other sources, renewables aren’t practical.
At the same time, the price of corn, the main source of ethanol in this country, continues to climb. It trades now above $4 per bushel, up from $2.17 per bushel a year ago. And commodity experts say corn prices are likely to keep rising as ethanol producers demand more corn. This food-for-fuel tradeoff already is affecting food prices at supermarkets, given the nation’s primary use of corn as feed for dairy and beef cattle, pigs and poultry.
Corn itself is one of the most energy-intensive crops. It requires large amounts of fertilizer, an increasing factor in the cost of corn, and natural gas accounts for 90 percent of the cost of ammonia, the building block for nitrogen fertilizers. Pesticides and herbicides also are made from gas-based petrochemicals, and substantial amounts of diesel oil are needed to run farm machinery.
The Congressional Research Service says that ethanol provides slightly more energy than the energy required to produce it. But some agricultural experts disagree. Two researchers – David Pimentel, professor of agriculture and life sciences at Cornell University, and Tad Patzek, a civil and environmental engineer at the University of California-Berkeley – totaled all the energy from fossil fuels that’s needed to make fertilizer and pesticides to grow corn, run farm machinery, ship the corn to distilleries, provide heat for the distilling process and transport ethanol by railroad and truck to the marketplace. They calculated that it takes 29 percent more energy to produce a gallon of corn ethanol than is contained in the ethanol.
The production of corn ethanol is water-intensive, as well. According to Messrs. Pimentel and Patzek, each gallon of ethanol requires 1,700 gallons of water, mostly to grow the corn. In large parts of the Great Plains, where new ethanol plants keep popping up, groundwater is the only source of water. But a prolonged drought has taken its toll on aquifers. In some parts of Nebraska, water tables have dropped about 14 feet in the past decade. Water shortages are a fact of life now in most of the midwestern and south-central states.
To top it all off, ethanol yields one-third less energy than an equivalent amount of gasoline, so you can’t go as far on a gallon of ethanol as you can on a gallon of gasoline. In other words, with ethanol you have to fill up the car more often. Ethanol needs to be cheaper than gasoline to compensate for its poorer fuel efficiency. Instead it’s invariably more expensive due to its high production cost. That’s why ethanol must rely on a federal subsidy of 51 cents a gallon and a renewable-fuels mandate in the Energy Policy Act to remain competitive.
Nationally, nearly half of the gasoline being sold today contains 10 percent ethanol. But the ramp-up in ethanol production has become all too apparent. The Earth Policy Institute warns that ethanol is on track to consume half of the U.S. corn crop by next year. That’s still about 22 billion gallons short of President Bush’s renewable-fuels goal. Yet researchers at the University of Minnesota estimate that if the entire corn crop is used, it would replace only 12 percent of U.S. gasoline. A new corn-ethanol surge could produce more problems than it solves.
Ethanol needs to be a part of America’s energy mix, but only a part. Stepped-up research on other biofuels that require less energy and water to produce – cellulosic ethanol using switchgrass and wood chips, for instance – would be a better use of U.S. tax dollars. Corn should be used mainly for food, not fuel.