You probably don't know it, but the answer to America's gasoline addiction could be under the hood of your car. More than five million Tauruses, Explorers, Stratuses, Suburbans, and other vehicles are already equipped with engines that can run on an energy source that costs less than gasoline, produces almost none of the emissions that cause global warming, and comes from the Midwest, not the Middle East.

These lucky drivers need never pay for gasoline again--if only they could find this elusive fuel, called ethanol. Chemically, ethanol is identical to the grain alcohol you may have spiked the punch with in college. It also went into gasohol, that 1970s  concoction that brings back memories of Jimmy Carter in a cardigan and outrageous subsidies from Washington. But while the chemistry is the same, the economics, technology, and politics of ethanol are profoundly different.

Instead of coming exclusively from corn or sugar cane as it has up to now, thanks to biotech breakthroughs, the fuel can be made out of everything from prairie switchgrass and wood chips to corn husks and other agricultural waste. This  biomass-derived fuel is known as cellulosic ethanol. Whatever the source, burning ethanol instead of gasoline reduces carbon emissions by more than 80% while eliminating entirely the release of acid-rain-causing sulfur dioxide. Even the cautious  Department of Energy predicts that ethanol could put a 30% dent in America's gasoline consumption by 2030.

We may not have to wait that long. After decades of being merely an additive to gasoline, ethanol suddenly looks to be the stuff of a fuel revolution--and a pipe dream for futurists. An unlikely alliance of venture capitalists, Wall Streeters, automakers, environmentalists, farmers, and, yes, politicians is doing more than just talk about ethanol's potential. They're putting real money into biorefineries, car engines that switch effortlessly between gasoline and biofuels, and R&D to churn out ethanol more cheaply. (By the way, the reason motorists don't know about the five-million- plus ethanol-ready cars and trucks on the road is that until now Detroit never felt the need to tell them. Automakers quietly added the flex-fuel feature to get a break from fuel-economy standards.)

What's more, powerful political lobbies in Washington that never used to concern themselves with botanical affairs are suddenly focusing on ethanol. "Energy dependence is America's economic, environmental, and security Achilles' heel," says Nathanael Greene of the Natural Resources Defense Council, a mainstream environmental group. National- security hawks agree. Says former CIA chief James Woolsey: "We've got a coalition of tree huggers, do-gooders, sodbusters, hawks, and evangelicals." (Yes, he did say "evangelicals"--some have found common ground with greens in the notion of environmental stewardship.)

The next five years could see ethanol go from a mere sliver of the fuel pie to a major energy solution in a world where the cost of relying on a finite supply of oil is way too high. As that happens, says Vinod Khosla, a Silicon Valley venture capitalist who has become one of the nation's most influential ethanol advocates, "I'm absolutely convinced that without putting any more land under agriculture and without changing our food production, we can introduce enough ethanol in the U.S. to replace themajority of our petroleum use in cars and light trucks."

Filling up on ethanol isn't new. Henry Ford's Model Ts ran on it. What's changing is  the cost of distilling ethanol and the advantages it brings over rival fuels. Energy  visionaries like to dream about hydrogen as the ultimate replacement for fossil fuels, but switching to it would mean a trillion-dollar upheaval--for new production and
distribution systems, new fuel stations, and new cars. Not so with ethanol--today's  gas stations can handle the most common mixture of 85% ethanol and 15% gasoline, called E85, with minimal retrofitting. It takes about 30% more ethanol than gasoline to drive a mile, and the stuff is more corrosive, but building a car that's E85-ready adds  only about $200 to the cost. Ethanol has already transformed one major economy: In Brazil nearly three-quarters of new cars can burn either ethanol or gasoline, whichever happens to be cheaper at the pump, and the nation has weaned itself off imported oil.

Excerpted from CNNMoney.com FORTUNE by Adam Lashinsky and Nelson D. Schwartz 01-24-06
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