The World After Oil
As the planet warms up, eco-friendly fuels can't get here fast enough
- By Eric Jaffe
- Smithsonian.com, April 01, 2007, Subscribe
(Page 2 of 4)
If people wish to control the greenhouse gases that harm the environment they must reduce the amount of carbon they release when producing energy. Biofuel does just that. As plants grow, they collect energy from the sun. Sugars from these plants can then be converted into heat energy. Burning this energy as fuel releases carbon dioxide into the atmosphere, but the gas is soaked up by plants at the beginning of the growing cycle. This give-and-take cancels out harmful carbon emissions, which is why biofuel is often referred to as a "carbon neutral" form of energy.
Right now, the most widely used biofuel is ethanol produced from corn—a process that involves breaking down sugars in the plant's grain and fermenting them into ethanol. Nearly all five or six billion gallons of the fuel made in 2006 were made this way. Perhaps unknown to the East Coast urbanites paying $3 a gallon for petroleum, some 150 corn-to-ethanol factories are already in operation in the United States, mostly in the Midwest.
Still, experts almost unanimously see corn-based ethanol as the beta version of biofuel—an early phase of alternative fuel use that, while necessary, must be improved before realizing success. For starters, making biofuel from corn isn't entirely eco-friendly. Because corn is an annual crop—meaning its life cycle is a single season—farming it can release nitrous oxide, a greenhouse gas more potent than carbon dioxide, Dale's research has shown.
Done correctly, though, corn can be grown in a way that won't release a damaging amount of nitrous oxide. The bigger problem with corn has to do with meeting the presidential benchmarks: it takes a lot of energy to produce fuel from the grain of corn. A prohibitive amount, some feel. "We can't make enough ethanol from corn to change our liquid fuel dependence," says Dale. If you were to add up all the energy it takes to create a bushel of corn—from making the farm machinery to tilling the land—you get only about 1.3 times more energy out of the resulting biofuel, says Somerville. A good energy return would be around 10 times that figure.
However flawed, corn-based biofuel's initial promise—it has resurrected the country's agricultural industry—might have paved the way for a more efficient alternative to enter the market. Experts call this next-generation fuel "cellulosic ethanol." The term is intimidating, but the idea is relatively simple: biofuel producers can convert more sugar into energy if they use the whole plant instead of simply the grain.
In addition to diminishing reliance on petroleum, cellulosic ethanol will neutralize more greenhouse gases than corn. "There's a limit on corn-based biofuel," says energy and environmental scholar David Sandalow of the Brookings Institution in Washington. "But if we can break through technical barriers on cellulosic forces, then the potential is much, much higher."
Overcoming these technical barriers won't require a miracle, just a few research advances and lots of money. In the meantime, scientists and producers continue searching for plants that naturally yield more energy than crops like corn and soybeans do. Most of this focus has been on perennial crops such as switchgrass. Because perennials last several seasons, they don't allow nitrous oxide to escape from the soil into the atmosphere; they are both carbon and nitrous neutral. More importantly, the energy return on these crops is some 15 to 20 times what's used to produce them. The star of this group is Miscanthus giganteus, a wild plant native to tropical regions in Africa and Asia. In addition to its high energy output, Miscanthus requires less water than typical crops and stores more carbon in the soil, says Somerville. The trick for biofuel developers will be domesticating this species and sustaining it over long periods of time.
"I think the industry's going to happen more quickly than most people realize," says Dale. "Once we recognize that we can make ethanol from grass grown to purpose, for something in the neighborhood of $1.50 or $1.20 a gallon, then it's going to explode." This recognition might happen more quickly than even Dale would have imagined. Just five days after his meeting with Bush, the Department of Energy announced that over the next several years it will invest nearly $400 million in six cellulosic ethanol plants across the country.
Single Page « Previous 1 2 3 4 Next »
Subscribe now for more of Smithsonian's coverage on history, science and nature.









Comments (5)
Yes the future is here.
The gas and petroleum is getting expensive at the level that other energy sources are cheaper.
We also can make the cars working with normal oil as showed in
http://vegeoil.com
Posted by Vegeoil on March 18,2010 | 08:38 PM
whats even funnier is that back in 1920 or 1930 i cant remembr which, we used to use HEMP (marijuana) for paper, OIL, and many other things untill the jelous oil compaanies spent millions of dollars lobbying to make it illegal... now look... we are trying to get rid of oil. why not use HEMP which is... grown... green... COMMON SENSE PEOPLE WAKE UP!!!!
Posted by UNKNOWN on March 18,2010 | 06:38 PM
Good article, unfortunately it is too short to address the problem of net energy produced by a fuel and it's relationship to our current oil based world economy and culture and climate change. Don't forget that we are probably at peak oil around now and may soon be on the downslope of Hubbert's curve for world oil production. If you really are interested, and not afraid, in learning what the future has a good chance of being like I would suggest reading John Michael Greer's books. He has incredible insight and rigorous discipline in his logic. Peace be with you all, jesubmar
Posted by Jesubmar on March 18,2010 | 05:39 PM
I'd like to see more detailed coverage about battery electric cars. They are already proving to be a better solution, everything can be run off the grid, or powered at home. People don't understand this potential because not enough media institutions write about it, and if they do, it's usually not fact-based or intelligently covered. I know Smithsonian can do that though!
Posted by meanderingthemaze on March 18,2010 | 01:33 PM
I believe this article is truely interesting. I never even knew half of the things, both pros and cons about oil, and our future if what is happenning to it keeps going on. It was fun to learn somthing new. Thank you, Smithsonian!
Posted by yamilette on March 18,2008 | 12:14 PM