Biofuels are only a stepping stone toward energy efficiency

Cecilia Westbrook Apr 28, 2008
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Recent weeks saw riots break out in developing nations over the rising cost of food worldwide. Although in the U.S. the effect of this rise might seem small (Sam’s Club recently imposed a limit of four sacks of rice per customer), in developing nations — where about 100 million people now face starvation — the impact is much more real.

The reason for the cost increase is complex and multi-factorial, but one major culprit — accounting for 20 to 30 percent of the price rise — is biofuel production. The developed world’s insatiable hunger for energy means that more land is being devoted to crops for biofuel use (notably corn) instead of food. Although plenty of food is still produced, the resulting price increase means that people living on less than a dollar a day can no longer afford to feed their families.

Considering this excessive human cost of biofuel production, it becomes necessary to ask: Is it worth it? What are we getting out of biofuel production, and is it equal to what it’s costing us as a nation and as a planet? When you take a look at the numbers involved, the answer is grim.

Biofuel production has quickly become big business. Currently, the U.S. government spends in the ballpark of $7 billion annually in subsidies for ethanol production, and the European Union does the same. The total market for biofuels was about $20 billion in 2006 and is projected to grow to over $100 billion within the next decade.

The growing demand for biofuel is powered by growing worldwide concern over the threat of global warming, and the consequent search for cleaner alternatives to fossil fuels. Biofuels, such as biodiesel and ethanol, offer the promise of carbon neutrality; plants store carbon as they grow, so releasing this carbon by burning the fuel doesn’t result in a net increase in atmospheric carbon. Thus, in essence, biofuels represent a sort of stored solar energy, which is stored by plants for later use in ethanol or biodiesel.

Sadly, the economic drawbacks of biofuels may outweigh their potential for carbon neutrality. For one, a considerable amount of energy must go into the production of these fuels, and currently, the majority of this energy comes from — you guessed it — fossil fuels. If you count all of the energy needed to harvest, transport, and refine corn into fuel-grade ethanol, you’ve already cut a substantial chunk out of the benefit of the fuel. But (perhaps surprisingly), the largest energy input goes into the production of chemical fertilizers, which are fundamental to commercial farming in the developed world.

One measure commonly used to assess the positive value of biofuels is the so-called energy balance, or the ratio of energy put out by burning biofuels to energy required to produce them. Assuming the corn to be grown in the most nutrient-rich soil using the most efficient farming methods and refined in state-of-the-art facilities, ethanol has an energy balance of between 2:1 and 3:1. Of course, not all ethanol is produced as efficiently as possible, and thus the energy balance for ethanol from different production conditions differs. The most inefficiently produced ethanol has an energy balance of about 0.76:1 — meaning more energy is required to produce it than is harnessed from burning it. Currently, such worst-case-scenario ethanol comprises about 5 percent of the total market for ethanol. However, as the market grows, more of the corn used to produce ethanol is being grown in developing nations where standards for efficiency are much lower.

Much more alarming than energy balance is the question of carbon neutrality, the whole reason for biofuels’ existence in the first place.

Recent reports, including two published in Science magazine this year, have found that biofuels have a much larger carbon impact than originally thought, even though the energy balance looks good overall. The problem is an “accounting error” made in earlier estimates of carbon and energy balance for biofuels, which excluded a large part of the environmental impact.

The biggest problem with biofuel production is that it requires an increase in agricultural production, and that translates to more land being used to cultivate ethanol. In practice, this means large-scale deforestation, particularly as more of these crops are being grown in developing parts of the tropics such as South America. Even regulations imposed on biofuel production by the U.S. and EU, requiring that crops be grown on land that was not clear-cut for that purpose, still indirectly result in deforestation as new land must be found to grow food crops supplanted by ethanol crops.

Deforestation of land results in an increase in carbon emissions as the trees and plants that were storing carbon in biomass decay. This increase will not be offset by use of land for biofuel production for hundreds of years. When this is taken into account, most biofuels are no more carbon neutral than conventional fossil fuels.

It’s clear that biofuels are not a panacea for the global climate problem. However, properly produced, they can be a very useful part. Newer biofuels will be so-called cellulosic fuels — produced from non-food crops such as wood and grass. These second-generation fuels will have a much greater energy balance (around 6:1) and will have the benefit of not competing for use of food crops, and thus will hopefully not cause food price increases like ethanol. However, the land-usage problem must still be satisfactorily solved.

But more important than finding the “right” biofuel is rethinking, as a society, the way we use energy. Initially, the appeal of a technology like biofuels was that it would enable us to go on living our energy-intensive lives with very little change, driving inefficient vehicles and so forth. Likely, any other new forms of “alternative energy” that come on the market in the next few years will have the same appeal — and the same problems.

There is no “silver bullet” that will solve climate change. Any successful plan to cut global carbon emissions must have at its center the ideals of conservation and increased energy efficiency. We need to reduce, reuse, and recycle, and invest in alternative energy production only if it is responsible and truly carbon-neutral.