Driving on Sunshine

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Driving on Sunshine
Ethanol: Starve While You Drive
Sarah S. Mosko, Ph.D.

From President Bush on down, it seems everyone is talking up “biofuels”, especially corn-grain ethanol and soy-diesel, as the panacea to the country’s energy woes . . . global warming, air pollution, increasing prices at the pump and dependence on foreign oil.

Automakers are promoting flex-fuel cars that run on either E85, a gasoline mixture that is 85% ethanol, or straight gasoline. Agribusiness giants like Cargill and Archer Daniels Midland are trumpeting their ethanol, fermented and distilled from corn, as they boost production to meet rising domestic demand. Even some environmentalists are tipping their hats to so-called “green fuels.” Wondrous indeed is the process whereby plants capture and store the energy in sunlight. However, just because a fuel can be made from plants doesn’t make it inherently “green” or ever plentiful enough to replace gasoline.

Consider the findings of a 2006 study from the University of Minnesota. If all U.S. corn and soybean crops were used for biofuels instead of food, the amount produced would suffice to replace only 12% of gasoline demand and 6% of diesel demand countrywide.1Another reputable analysis concluded that conversion of all U.S. cropland to corn production, strictly for ethanol, would not suffice to fuel the current fleet of American autos.2 Shouldn’t such statistics compel us to take a long, sober look at biofuels? Let’s start with the simple but critical mathematical concept of net energy balance and apply it to corn-grain ethanol, currently the hands-down leader in domestic biofuel production.

Net Energy Balance is Key

Net energy balance (NEB) denotes energy return relative to energy invested. It is a ratio, analogous to a financial investment, where anything above 1.0 indicates a positive energy return and a value below 1.0 means you put more energy in than you got out. Petroleum, for example, once enjoyed an extremely favorable NEB in the range of 30.0-40.0, but this ratio has been falling as easily extractable stores are being depleted or have become geopolitically too dangerous to pursue.2

Estimates of the NEB for corn-grain ethanol have varied somewhat, depending on who is doing the math. Scientists from the University of Minnesota, for example, calculated a NEB of 1.25, a positive yield of 25%.1 Notably, almost all of the savings stemmed from the leftover grain byproducts that are used for livestock feed, rather than from energy inherent in the ethanol itself. In contrast, a most recent analysis from Cornell University experts that incorporated an extremely detailed accounting of energy inputs, gave corn-grain ethanol a poor NEB of 0.70 – 0.78, indicating a net energy loss of 22% – 30%.3

In general, the more favorable NEB ratios tend to come from corn ethanol advocates whose computations are criticized by opponents for ignoring significant energy inputs. Pinning down the truest NEB for corn-based ethanol could be near impossible because of the many variables that have to be taken into account. Most estimates, however, hover not too far from 1.0, indicating, at best, a fairly meager energy yield.4 A chief reason is that ethanol production is heavily dependent on fossil fuels.

Modern corn farming uses copious amounts of inorganic fertilizers and pesticides manufactured from natural gas or oil. Fossil fuels also provide the energy to drive irrigation, to manufacture and operate field machinery, to distill fermented corn into ethanol and to provide transportation from points of manufacture to neighborhood gas stations. There is also the oft-overlooked energy required to sustain farmers, distillery plant workers and their households. Unless substantially more energy can be derived from ethanol than is sunk into its production, it is hard to rationalize all the fanfare surrounding it.

Indisputably, there are some pluses to ethanol. It is renewable and can be produced domestically. Conversion of gasoline cars to flex-fuel vehicles is relatively inexpensive. Plus, compared to gasoline, emissions of greenhouse gases are reduced somewhere between 10% and 30%. Whether other problem emissions are reduced, including carbon monoxide, acid-rain causing sulfur dioxide, VOCs (volatile organic chemicals) and inhalable particulates, apparently varies with how much ethanol is blended in with gasoline and is the subject of controversy. But even allowing for such tangible benefits, corn-grain ethanol has additional downsides well beyond its questionable NEB that often are overlooked.

More Ethanol Drawbacks

  • Cost at the pump: Compared to gasoline, ethanol supplies 30% less energy, which means poorer fuel economy and more frequent trips to gas up. So even if ethanol is sometimes priced lower, the overall driving cost goes up.5 Also, ethanol can add to the price of vehicle maintenance since it is more corrosive to the engine.
  • Hidden taxpayer-supported corn subsidies: Uncle Sam shells out $4 billion/yr to subsidize domestic ethanol production, much of it going to agribusiness cartels. Gallon for gallon, this subsidy is 45 times the subsidy for gasoline. 3According to the U.S. Congressional Budget Office, oil refiners get a 51-cent tax credit for every gallon of ethanol blended into gasoline, costing taxpayers more than $7 billion over five years.6
  • Smog: Because ethanol is more volatile than gasoline, adding it to gasoline can increase smog, especially in summer months. The California Air Resources Board has confirmed that mixing in ethanol can increase smog-forming compounds, such as nitrogen oxides, and that cancer-causing chemicals like acetaldehyde are emitted too when ethanol is combusted.
  • Availability: Far fewer than 1 in 100 gas stations nationwide provide E85. As of late 2006, CA had only three. Major car manufacturers, however, have put many E85-capable vehicles on the road to profit from a federal law that allows them to take mileage credits for such cars toward meeting the CAFE requirements, even though those vehicles’ gas mileage might be very poor. (Note: E85 must be distinguished from the small amounts of ethanol currently blended into all gas sold in CA to replace MTBE, the toxic octane booster that was found to be contaminating drinking water).
  • Environmental Impacts: Applying industrial farming methods to grow massive amounts of corn certainly would accelerate soil contamination & erosion and groundwater depletion. Heavy use of fertilizers could foster oxygen-depleting algal blooms and dead zones in fresh and marine bodies of water that are downstream of the agricultural run-off.
  • Expansion of a corn “monoculture”: Corn agribusiness giants generally rely on genetically-modified seed lines supported by liberal application of pesticides/herbicides. The result is a distorted ecosystem lacking in normal biodiversity – naturally occurring insects and the birds that feed on them are suppressed. Already, much of Iowa’s corn-belt can be characterized as such a monoculture.

A Question of Morality

Historically, the US has been an exporter of grains on which countless peoples around the globe depend for basic survival. Many Americans of conscience question the morality of diverting cropland to fuel U.S. transportation when so much of the world is underfed already. According to the World Health Organization, the number of humans that are malnourished, 3.7 billion, is at a record high. Furthermore, global food requirements are expected to double in the next half century as world population continues its rise.7

Collateral Damage

In the U.S., demand for ethanol fuel grew 30% just in the last year – ethanol production gobbled up one-fifth of the entire domestic corn crop. Based on the rate at which new ethanol distilleries are going up around the nation, agricultural economists at the Washington D.C.-based Earth Policy Institute project that one-half of the domestic corn harvest will go into making ethanol by the year 2008. Already, America’s thirst for ethanol is driving up the price of corn at home and abroad. Some vegetable farmers in CA are switching to corn to cash in on the profits. The upshot could well be higher prices for fresh or processed vegetable products as yields shrink. Meat prices could jump too as corn-fed livestock become costlier to raise.

Even bigger effects might be felt elsewhere around the world. Mexico, for example, has relied historically on cheaper U.S. government-subsidized corn to feed its cattle, hogs and chickens. As more U.S. corn is diverted to ethanol, Mexican livestock farmers will be left in the lurch to find affordable feed. Mexico’s poor already are suffering a tortilla crisis because the local price of tortillas follows rising international corn prices. Dating back to the time of the ancient Mayans, the poor in this region have relied on corn tortillas for nearly half of their dietary protein.8 World prices for other grains, including rice and wheat, are expected to rise too as corn supplies are shifted away from food and livestock feed.

Weaning off Fossil Fuels

As we begin the painful process of weaning ourselves off fossil fuels, the idea of “driving on sunshine” sounds so nice. After all, sunlight will be the ultimate source of whatever new methods we employ to propel our cars. Remember that even fossil fuels originated from sunlight captured by plants eons ago. But in choosing among energy alternatives, the devil is definitely in the details. An honest accounting of the NEB for any alternative is imperative. Otherwise we will invest enormous resources and hope into solutions that might sound comforting on the surface but really get us nowhere in combating global warming and also have unintended, detrimental effects on other peoples and the environment.

Cellulosic ethanol, made from non-food plant sources such as prairie switchgrass, wood chips or vegetable waste, is being explored as a solution to at least some of the problems with corn-based ethanol. The attributes could include much lower inputs of energy, water, pesticides and fertilizers, plus a substantially improved NEB estimated at 4.0 or even higher.1,4 Even soy-diesel, with a measured NEB of 1.93, comes out on top of corn-grain ethanol,1 although both share the problem of pitting human hunger against transportation. Certainly any honest efforts to explore truly sustainable biofuels from non-food substrates should be applauded. For example, experiments by ecologists at the Univ. of Minnesota suggest that ethanol derived from mixtures of native grassland perennials could deliver a NEB over 17 times that for corn-grain ethanol.9

Do we really have to gas up?

It is hard to envision a world where liquid fuels of some type are not necessary. But in our rush to replace fossil fuels with biofuels, let’s not fail to seek parallel solutions of a totally different ilk. Consider solar energy, or more specifically photovoltaics (PV), where sunlight is converted directly into electricity. The basic technology is the same as has been used for decades to power satellites and calculators. Current mainstream solar panels use semiconductor wafers made of crystalline silicon. Electricity is generated when sunlight knocks electrons on one side of the wafer to the other. A box called an inverter converts the electricity from DC to AC, making it usable by household appliances. Modern inverters lose no more than 10% of the energy in the incident sunlight in this conversion process.

The amount of sunlight reaching the earth’s surface in the U.S. averages 1,800 kWhr/m2 per year, more than enough to meet the entire world’s energy needs many times over. For example, the U.S. Dept. of Energy calculated that a PV system covering a 100-mile swatch of sunny Nevada could supply the whole of the nation’s electrical needs. One beauty of PV is that no one could monopolize the source since sunlight is everywhere. Energy production could be spread out on literally millions of rooftops across the nation, each functioning as a mini-solar electric plant contributing to the grid.

The idea of energy in versus energy out is usually handled a bit differently for PV since the energy input is a one-time affair (energy required to produce and install the panels), whereas the energy output spans the 30+ yrs lifetime of the panels. So, generally, the concept of Energy Payback (how long it takes to repay the initial energy input) is used to figure the energy efficiency of PV. The U.S. Department of Energy calculates an Energy Payback of 3 or 4 years for PV systems in use as of 2004, declining to 1-2 years by 2009 with expected advances in technology.10 Applying these figures to calculate a NEB ratio, PV earns a NEB of 7.5 for a four-year payback and 30.0 for a 1-year payback (a net energy gain of 750-3,000%). Once installed, the energy generated is clean, homegrown and pollution free. Literally, no CO2 is released for the life of the panels. Taking into account the fossil fuels that went into their construction, the Department of Energy estimated that 87% to 97% of the energy generated by a PV system would be free of greenhouse gas emissions, pollution, or resource depletion.

Squeezing the Most out of Sunlight

Since sunlight will be powering transportation, one way or another, shouldn’t we be focused on how to capture and utilize it most efficiently and with the least pollution? If you’ve seen the 2006 documentary “Who Killed the Electric Car,” you know that the technology for zero emission all-electric vehicles has been with us for years, even though major automakers no longer offer them to the public. Their removal from the market seems odd, if you’re looking for energy efficiency, since electric cars would surely seem the way to go. Consider a few well-established facts. The electricity equivalent of one gallon of gasoline is 34 kWh. Overall, the American fleet of gasoline vehicles averages 20 mpg. Historically, all-electric car models travel between 3 and 6 miles on one kWh of electricity, the gasoline equivalent of 102-204 mpg.11 This is fully five to ten times the efficiency of gasoline cars.

Hybrid gasoline-electric cars, averaging 40 mpg or more, were introduced in the U.S. in 2001 and have made a big splash with the public, to say the least. Yet, plenty of us hybrid drivers are wondering already why we can’t plug them in at home to wring even better mileage out of a gallon of gas. Indeed a few innovative owners of the Toyota Prius model have figured out how to convert it to a plug-in version (that averages at least 100 mpg11) and are waiting for Toyota and other big auto industry players to run with the idea. However, even some hardcore hybrid buffs are hesitant to endorse plug-in technology at first glance because a sizable percentage of the electricity on the grid typically derives from burning coal, another polluting fossil fuel.

So imagine instead that the electricity is generated from a PV system on the car driver’s own home roof. Not only would driving costs plummet, but so would home electricity bills. Naysayers of all income brackets reply that the costs of both home PV systems and plug-in electric cars would be prohibitive. Certainly this argument rings hollow for those with enough discretionary income to, say, remodel already functional kitchens or to upgrade to pricey luxury autos without so much as a flinch. For those truly living on limited incomes, driving on electricity is far cheaper than driving on gasoline, 11 and money saved on gasoline could go toward paying off the solar system. Furthermore, the cost issue would be moot if our government made a serious move to subsidize solar power instead of oil and ethanol: home PV systems and plug-in cars could become affordable to most everyone. Take Germany and Japan, where government sponsored PV subsidies & incentive programs allowed both countries to meet ambitious goals that were set for homeowner rooftop installations. Perhaps Calif.’s new Million Solar Rooftops initiative, aimed at driving down the costs of PV systems through a $3 billion, 10-yr subsidy, will get the ball rolling here at home.

I wish some expert would calculate a realistic NEB for two scenarios: all-electric plug in vehicles and plug-in hybrid electric vehicles, both powered by home solar panels. A sustainable biofuel with a high NEB would be chosen for the hybrid’s additional liquid fuel needs. Surely, we could expect NEBs of hefty double and maybe even triple digits. Given that the technology behind both scenarios is ready to go, not just a pipe dream, one has to question why so much political and corporate handclapping is directed to pursuing corn-grain ethanol when the energy gains seem so paltry and the threats to the environment and food supply so severe. I suspect the old adage “follow the money” would lead us to the answer. Who is positioned to profit, either monetarily or politically? Certainly it’s neither the public nor the planet.

My guess is that powerful corporate forces out there, supported by their political allies, just want us to keep gassing up with whatever best ups their profit margins, no matter how little progress is made in battling global warming and environmental pollution. The last thing they would want us to do is reap the gift of sunlight ourselves on our own rooftops to power our own cars and homes and then pocket the money we save in the long run. If we did, we might discover that we don’t need them as much as we’d thought. Wouldn’t that be just grand.


1) J. Hill et al, 2006. Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels.Proceed Natl Acad Sci USA 103:11206-10.

2). R. Heinberg, 2006. The Party’s Over: Oil, War and the Fate of Industrial Societies. New Society Publishers, BC, Canada.

3) D. Pimentel et al, 2007. Ethanol production: energy, economic, and environmental losses. .Rev Environ Contam Toxicol 189:25-41.

4) R. Hammerschlag, 2006. Ethanol’s energy return on investment: a survey of the literature 1990-present. Environ Sci Technol 40:1744-50.

5) Consumer Reports, 2006 (Oct). The ethanol myth.

6) A Lashinsky, ND Schwartz, 2006 (Jan). How to beat the high cost of gasoline forever! FORTUNE Magazine.

7) N.V. Fedoroff, J.E. Cohen, 1999. Plants and population: is there time? Proc Natl Acad Sci USA 96:5903-07.

8. M. Roig-Franzia., 2007 (Jan 27). A culinary and cultural staple in crisis. Mexico grapples with soaring prices for corn – and tortillas. Washington Post Foreign Service.

9) D. Tillman et al, 2006. Carbon-negative biofuels from low-input high-diversity grassland biomass. Science 314:1598-600.

10) U.S. Dept. Energy, 2004(Dec). PV FAQs: What is the energy payback for PV <www.nrel.gov/docs/fy05osti/37322.pdf>

11) Boschert S, 2006. Plug-in Hybrids: The Cars That Will Recharge America. New Society Publishers, BC, Canada.

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