Today, nearly 85 percent of cars sold in Brazil are flex: small, sporty designs that zip around the lumbering, diesel-belching trucks in São Paulo. You can even get a flex Transporter–the beloved loaf-shaped VW van, still made here. With a liter of alcohol running an average of one Brazilian real cheaper than gasoline at the pump, most flex cars haven't burned gas in years.
Sugarcane, not engine technology, is the real key to Brazil's ethanol boom. The sweet, fast-growing tropical grass has been a staple export for the country since the 1500s. Unlike corn, in which the starch in the kernel has to be broken down into sugars with expensive enzymes before it can be fermented, the entire sugarcane stalk is already 20 percent sugar–and it starts to
ferment almost as soon as it's cut. Cane yields 600 to 800 gallons (2,300 to 3,000 liters) of ethanol an acre, more than twice as much as corn.
Usina São Martinho, one of the largest sugar mills and ethanol distilleries in the world, sits in the heart of the emerald desert, as one São Paulo columnist has dubbed Brazil's prime sugarcane region in central São Paulo state. The rolling fields are carpeted with cane for as far as the
eye can see. Each year the mammoth plant turns seven million tons of cane into 300 million liters of ethanol for Brazilian cars and 500,000 tons of sugar, bound mainly for Saudi Arabia. To meet growing demand for ethanol both here and abroad, the company is also building a three-million-ton unit–exclusively for ethanol–in the rapidly expanding cane fields of Goiás state.
Growers in the emerald desert can get seven harvests from their fields before replanting, and the distilleries recycle their wastewater into
fertilizer. Like most of Brazil's usinas, São Martinho consumes no fossil fuel or electricity from the grid; for heat and power it burns cane waste, known as bagasse, typically generating a slight surplus of power. Even the cane trucks and
agricultural machinery burn a blend of diesel and ethanol, while the favorite crop duster, a hot little plane called the Ipanema, is the first fixed-wing aircraft built to burn pure alcohol. "We're obsessed with efficiency," says plant director Agenor Cunha Pavan.
While corn ethanol's energy ratio hovers around breakeven, "we get eight units of ethanol for every one unit of fossil fuel," says Isaias Macedo, one of Brazil's leading sugarcane researchers. Experts estimate that producing and burning cane ethanol generates anywhere from 55 to 90 percent less carbon dioxide than gasoline. And Macedo envisions even greater efficiencies. "We can do the same thing with two-thirds or half of the bagasse, better manage tractors in the field, and approach levels of 12 or 13."
Even sugarcane isn't without its problems. While nearly all of São Martinho's cane is
machine harvested, most Brazilian cane is cut by hand; the work, though well paid, is hot, dirty, and backbreaking. Cutters die of exhaustion
every year, say leaders of their union. And to kill snakes and make the cane easier to cut by hand, the fields are usually burned before harvest, filling the air with soot while releasing methane and
nitrous oxide, two potent greenhouse gases.
The expansion of Brazil's cane acreage–set to nearly double over the next decade–may also be contributing to deforestation. By displacing ranching in existing agricultural areas, sugar may be adding to the pressures that send cattlemen deeper into frontier territory like the Amazon and the biologically diverse savannas known as the cerrado. "If alcohol is now considered a 'clean' fuel, the process of making it
is very dirty," says Marcelo Pedroso Goulart, a prosecutor for the Public Ministry of São Paulo. "Especially the burning of cane and the exploitation of the cane workers."
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