Q: I read years ago that ethanol plants needed to be subsidized in order to make "ends meet." Since then, how much has the efficiency of ethanol-producing technology improved? Is the industry now getting more energy out of the ethanol produced than put in? How dependent is this efficiency on the type of biofuel used (corn, grass, sugar cane)
Asked by Hector Raynal, '76, MS '77, MBA '80, El Paso, Texas
It's harvest time and the Little Red Hen is deciding what to do with her corn. As a rational farmer, she plans to pursue the option that makes her the most money, and thanks in part to the buyers guaranteed by government mandated quotas, ethanol is a very profitable option. A graph of biofuel production in the United States over time makes the point clear: production has shot up over the last decade, largely as a result of these mandates. But as biofuel production increases, so do all the negative impacts associated with growing the corn and processing it into fuel. These "negative externalities" are not accounted for in the cost of the final product, and they're usually borne by people outside the decision making process, including those who deal with local problems such as soil erosion and water pollution, and global issues like deforestation, hunger, carbon emissions and chemical pollution.
One negative externality of U.S. biofuel production is an increase in deforestation rates in the Brazilian Amazon. How does Iowa ethanol lead to Brazilian deforestation? Through our globally connected economy. First, high prices for corn ethanol encourage U.S. farmers to plant more corn and less soy. With a lower soy supply on the international market, prices for soybeans go up. And higher soy prices give Brazilian farmers all the motivation they need to cut and burn more rainforest and expand their soy crops.
Beyond deforestation, ethanol has been blamed for famine by diverting grain from the food supply. As the producer of 40 percent of the world's corn, when the United States diverts a substantial share of its harvest from the international market, it means a big decrease in supply. This pushes up prices and may have been a major driver behind the large commodity price spikes of 2008, which sparked riots in many parts of the developing world, and pushed millions of food-insecure consumers into states of malnutrition or starvation. Thanks in part to continued biofuel production, and poor corn, wheat and rice crops in many parts of the world, food prices are again climbing rapidly in 2011, and may even have contributed to the recent demonstrations and revolts in northern Africa.
Domestic cattle producers also suffer when the Hen decides to sell to biofuel producers, as an increase in corn demand from the fuel sector puts pressure on feed supply. About two-thirds of the U.S. corn crop goes into cattle feed. Cows eat two to five percent of their body weight each day, so feed price spikes can be costly.
There are also the externalities associated with farming itself. Large farm subsidies have a long history in the United States as a way for the government to provide financial support to farmers by paying for some or all of their input costs. Water prices provide one example: irrigation water is often much less expensive than its domestic counterpart. This system, while heavily favored by farmers, allows for wastefulness and inefficiencies in the industry. Beyond wasteful water use, fossil-fuel heavy fertilizers are often over-applied, by farmers seeking to maximize their harvest. Instead of being used as plant food, excess fertilizer runs off of fields into rivers and streams. Those applied in the Midwest and Great Plains often run off into the Mississippi River, from which they travel to the Gulf of Mexico and contribute to the large "dead zone," an area the size of New Jersey that is devoid of the usual fish and other sealife.
While impacts such as deforestation, hunger and fertilizer runoff are visible, attaching numbers and then linking them back to biofuels specifically is difficult. This prevents such externalities from being included in traditional life cycle assessments (LCA), which are used to evaluate the cumulative social and environmental impacts of producing, manufacturing, distributing, using and disposing of a given good or service. Further complicating biofuel analysis is that there is no set formula for an LCA and it is up to the researcher to decide how to account for inputs and their impacts. The result is an often-confusing mix of LCAs with some showing a positive energy balance and others coming out negative. That's why some conclude that biofuel ethanol has a small positive impact on our total energy supply, and why others argue that the impact is negative.
In many LCAs, one common comparison metric is greenhouse gas emissions, which can be calculated by comparing the energy used for production versus the amount of energy available in the resulting bio or fossil fuel. These LCAs have produced a range of results, thanks mostly to differences in the accounting used when evaluating biofuel impacts and inputs. The two papers listed in the Essential Answer serve as an example: while they use similar categories for energy inputs, including fertilizers, gasoline and seed, they use different numbers for each, resulting in drastically different conclusions. An accurate comparison of these results would require evaluating every number used in each paper, which is beyond the scope of even the most motivated consumer—and perhaps even a SAGE answer.
But before we launch into that particular master's thesis, let's take a step back to the bigger questions: why are we interested in biofuels at all? Just because we can make fuel out of corn, does that mean we should? I agree that renewable, or sustainable, fuel sources are needed as alternatives to fossil fuels, but no matter what LCA methods you favor, corn ethanol is clearly not the answer. Producing corn ethanol takes a lot of fossil fuel, the exact input we are trying to consume less of. Further, even if we made all of our corn into fuel we would barely make a dent in the total energy needs of this country. We need a long-term solution with more energy potential and fewer negative externalities.
Changes to the farming system, like increasing yield per acre or decreasing fertilizer use, have the potential to increase the efficiency of biofuels or to at least limit their negative environmental impacts. That said, even the most dramatic changes in production probably won't make corn ethanol into our best alternative fuel option. In most parts of the country, it is not even possible to mix gasoline with much more than 10 percent ethanol. Higher mixes not only can lead to decreases in mileage efficiency, they can cause gasoline to solidify in cold weather. It is likely that cows and cola will always be more efficient converters of corn to energy than biofuel processing ever will be.
Other options do exist, however, even in the biofuels realm, and technology is in the works to turn woody plant material—cellulose—into biofuel. The most abundant organic compound on earth, cellulose is found in plant's cell walls, and "cellulosic biofuel" could be made from native grasses such as switchgrass—which takes few inputs to grow—or farm trimmings and agricultural waste. Even corn stalks. If successful, the energy output from these fuels could be over 30, making battles over whether corn ethanol's is 0.9 or 1.3 pointless. If renewable fuel is really what we want, this is where we should be investing our resources. The Hen can keep her corn where it belongs: on the table.
Gina Lappé plans to receive her master's in earth systems in 2011.
