Possibly the most significant change in the energy transition of 2008 was the broadening of production and use of biofuels. In 2006, when President George W Bush castigated Americans for their addiction to oil, he called for the use of alternatives to produce biofuels, including switchgrass. Most experts expect that in the first decade of the 21st century there will appear a mad rush to biofuels, homegrown gasoline, and diesel substitutes made from crops like corn, soybeans, and sugarcane. These technologies had been around for a century, but now were thrust forward as the most effective transitional energy source as humans considered other ways to power transportation. Although most were never intended for use on a massive scale, biofuels became major players in the energy sector with high gas prices.
The image is enticing to many Americans: not only liberating Americans from Middle East oil but also pumping that revenue into the declining rural economy of the United States. The entire industry, though, remains based in speculation and uncertainty. Biofuels as currently rendered in the United States are doing great things for some farmers and for agricultural corporations, including Archer Daniels Midland and Cargill. Most Americans see ethanol as a green alternative, ethanol plants burn natural gas or, increasingly, coal, to create the steam that drives the distillation. Additionally, diesel farm machinery is used to tend the fields, and natural gas-based fertilizers and herbicides are used to maximize the crop yield, leading to substantial use of fossil fuels to make ethanol. “Biofuels are a total waste and are misleading us from getting at what we really need to do: conservation,” says Cornell University’s David Pimentel, who is one of ethanol’s harshest critics. “This is a threat, not a service. Many people are seeing this as a boondoggle” (National Geographic).
Fortunately, with improvements in technology, the ethanol yield has improved and is now approaching 500 gallons per acre for corn, and the energy content of that yield is approaching a 50 percent increase over the total fossil energy required to produce the ethanol. Perhaps even more important is that most of the fossil energy put into ethanol production is in the form of natural gas and coal. Thus, ethanol effectively serves as a method of converting natural gas and coal into a somewhat larger amount of liquid fuel for transportation.
Three factors came together in the early 2000s to make ethanol less an alternative fuel and to move it into the mainstream, which included record high prices for petroleum, the phaseout of the MTBE gasoline additive, and society’s desire to become more energy independent. Ethanol production has responded to these factors, going from 50 million barrels in 2002 to over 200 million barrels in 2008. Continued increases in production will be limited by the ability to grow suitable feedstock for biofuels. For instance, experts estimate that even if we turned our entire corn and soybean crop into biofuels, together they would replace only 12 percent of our gasoline and 6 percent of our diesel. And getting just to this point would require replacing each of these crops in their other roles as feed to various animals (including pork, beef, and poultry).
The push to produce more ethanol has quickly revealed some of the problems associated with biofuels. The growth in ethanol production has pushed corn demand to heights not seen in years, affecting food prices and spurring U. S. growers to plant the largest crops since World War II. Around a fifth of the harvest will be brewed into ethanol—more than double the amount only five years ago. Corn is not the only crop that is problematically being made into fuel. From an environmental perspective, biodiesel from soybeans fares only slightly better. Rising prices for both crops pushed farmers to plow up more land than in previous years—approximately 35 million acres of marginal farmland now set aside for soil and wildlife conservation and in areas too arid for farming without depleting subsurface aquifers. But most disturbing of all is the impact upon global trade as the United States exports less corn and soybeans. This lack of U. S. food exports has led to increased crop production elsewhere in the world, namely Brazil and Indonesia, where rainforests were clear-cut and plowed into new farmland. The carbon footprint of an acre of rainforest being turned into cropland, effectively for biofuel production, is much worse than if fossil fuels had been used in the first place.
These considerations have led pilot projects in the United States to experiment with making ethanol from cellulose acquired from non-crop biomass (switchgrass, wood). One ton can be converted into 70 gallons of ethanol in about a week. Overall, the current process is about half as efficient as that of deriving the energy from crude oil. If the technology is improved, non-crop biomass feedstock can be grown on land without displacing current crops. Furthermore, switchgrass and fast-growing trees can also be grown with a much lower environmental impact when the actual planting, tending, and harvesting procedures are taken into account. Another potential plant that scientists are experimenting with as a biofuel feedstock is one that is much simpler: algae—single-celled pond scum.
Since the plant does not require farmable land resources and can instead be grown even in wastewater, many experts believe algae-based fuels are the only feedstock with the potential to reach the supply levels required to make a significant impact on our energy use.