by Ira Flatow
Plants like switchgrass don’t need to grow on high-priced farmland but can thrive on marginal lands. They don’t need expensive, energy-intensive fertilizer or pesticides. They thrive in dry soil and their roots can reach deep down for a drink. Like willows, switchgrass grows quickly; it can stand 10 feet tall after one season. It processes sunlight efficiently, and turns photons and CO2 into rugged cellulose.
And because it’s been around for millions of years, switchgrass has learned how to live in just about any soil and in harsh climates. It can be grown in fields and harvested and baled like cotton, needing to be replanted only once every 10 years or so. Many plants deplete the soil as they grow, but not switchgrass. It adds organic material to the soil as it grows, and its extensive root system fights winter erosion.
And “buffer strips of switchgrass, planted along stream banks and around wetlands,” says ORNL, “could remove soil particles, pesticides, and fertilizer residues from surface water before it reaches groundwater or streams—and could also provide energy.”
Test plots of switchgrass at Auburn University, says ORNL, have produced up to 15 tons per acre, equivalent to 1,150 gallons of ethanol per acre per year. And researchers are genetically engineering the plant to become even better, making it even more adaptable to a wider range of growing conditions. So not only is the yield better per acre but also the plant will be able to grow under more adverse conditions. I could go on singing the praises of switchgrass, but you can read about it yourself at http://bioenergy.ornl.gov/papers/misc/switgrs.html.
Why not have farmers change crops, from, let’s say, tobacco—the crop of yesterday—to switchgrass, the crop of tomorrow? “I’ll grow anything,” a farmer once told me, “as long as I can make a profit.”
“The reason corn has become so popular is because it’s there and we’re producing it in huge quantities,” says Brown, “and there’s strong support from farmers to convert part of that crop into ethanol. But the willow trees and the fast-growing hybrid poplars are two of the strongest candidates for cellulosic ethanol production, along with switchgrass.”
Here’s my vision of our energy future: fields of switchgrass, forests of willows and poplars, and planted among them, rows and rows of wind turbines, all creating a future of clean energy independence. But that vision may have to wait a bit because the technology for turning cellulose into fuel is not quite ready for prime time, says Brown. “We’re probably at least five years away from technologies to convert either willow trees or switchgrass into ethanol on an economically competitive basis.”
In addition, other alternatives to ethanol may be more productive, says Brown, such as a move toward plug-in electric cars powered by electricity produced by wind turbines. “If you take a car like a Toyota Prius, which is the most widely sold gas–electric hybrid, and if you add a second storage battery and a plug-in capacity, then we can do most of our short-distance driving—commuting, grocery shopping, and so forth—almost entirely with electricity. And the idea that we now have the technologies and an abundance of wind resources that would permit us to run our cars largely on wind energy is, I think, very exciting. Especially when you realize that the costs of the wind-electricity equivalent of a gallon of gasoline is less than a dollar a gallon. There will be no source of ethanol, even cellulosic ethanol, that’ll be able to compete with the equivalent of a dollar-a-gallon wind energy.” Wind turbines can produce electricity at under five cents per kilowatt-hour, making your plug-in auto cheaper to run than a gas-powered model. And as turbine technology progresses and the number of installed wind turbines grow, the costs can come down even more.
ALCOHOL VERSUS DIESEL: A COMPARISON
Given the headlong rush to build ethanol plants, some of the world’s top economists and agriculture experts are wondering if it makes any sense to grow crops just to turn them into alcohol. For example, one study shows that when you take into account the economic, environmental, and energy costs and benefits, biodiesel is a better choice than corn ethanol as a fuel.
Research teams at the University of Minnesota and St. Olaf College studied alternative biofuels—that is, fuels made from plants as opposed to oil, coal, and natural gas. To be a viable alternative energy source, they wrote in the Proceedings of the National Academy of Sciences, a biofuel should produce more energy than it takes to grow and process, it should have “environmental benefits,” be able to compete economically with other fuels, and “be producible in large quantities without reducing food supplies.” Using those criteria, they compared the life cycle of corn used to make ethanol with the life cycle of soybeans used to make biodiesel.
Their results were startling. Ethanol returns 25 percent more energy than it takes to put into it. So if you put 100 units of energy into growing, harvesting, and turning corn into alcohol, you get a yield of 125 units of energy. But biodiesel yields 93 percent more. Put 100 units of energy into growing, harvesting, and turning soybeans into diesel and you get 193 percent of energy out of it. That’s a tremendous energy-saving advantage over corn.
What about the environmental impact of each one? If biofuels are used instead of fossil fuels, “greenhouse gas emissions are reduced twelve percent by the production and combustion of ethanol and forty-one percent by biodiesel,” according to the research teams. Wow. “And pollution-wise, biodiesel also releases less air pollutants per net energy gain than ethanol.”
Why the big difference? The advantage of biodiesel is that it takes less energy to grow soybeans than it does to grow corn. And it’s a lot more efficient to convert soybean feedstocks to create biodiesel than it is to convert corn to ethanol.
On the other hand (and there always is another hand), even if you were to dedicate all the corn and soybean production in the United States to making biofuels, they “would meet only eleven percent of gasoline demand and eight-point-seven percent of diesel demand,” the researchers wrote. Clearly energy conservation and alternative energies have to be part of the solution.
Switchgrass could be one of those energy alternatives. It compares much more favorably with soy. But soy is already an established crop, the second largest in the United States, right after wheat. On the other (third?) hand, growing soy for fuel raises the same problem that comes with growing corn for fuel: You drive up the price of food. Which might be politically unacceptable. By growing switchgrass, you do not face a choice between food or fuel.
CHAPTER THIRTEEN
THE NUCLEAR OPTION
It is not too much to expect that our children will enjoy in their homes electrical energy too cheap to meter…
—LEWIS STRAUSS, CHAIRMAN OF THE U.S. ATOMIC ENERGY COMMISSION, 1954, SPEAKING ABOUT THE FUTURE OF NUCLEAR ENERGY
It wasn’t too long ago, after World War II, that the U.S. government had such high hopes for nuclear energy that it thought nuclear power would be so plentiful and cheap that it would be given away. Of course, that never happened. Nuclear power did get a foothold in this country, but the meltdown of nuclear fuel at the Three Mile Island power plant in Middletown, Pennsylvania, in 1979 put the lid on nuclear power development in this country.
But not in Europe. France gets about 75 percent of its electricity from nuclear power. Here in the United States, nuclear power usage is less than a third of that. France has brought 58 nuclear plants online since the 1970s. The United States hasn’t ordered any new plants since the Three Mile Island accident.
But that may all be changing. President George W. Bush has said that he wants to see an increased emphasis on nuclear power in the United States, including starting construction on new plants by 2010. But is this country ready for nuclear power? Has the technology improved to the point where concerns over issues such as safety and waste disposal can be addressed? In the land where the phrase “Not in my backyard” strikes fear in the heart of politicians, is there a political will to build new plants?
But ironically, we are seeing some environmentalists who once were rigidly opposed to nuclear power now saying that
compared with global warming, nuclear energy poses a much smaller threat. Take the ultimate tree hugger, Dr. Patrick Moore, cofounder and former leader of Greenpeace. He has helped create CASEnergy Coalition, a group devoted to helping promote nuclear power. “There is a great deal of scientific evidence showing nuclear power to be an environmentally sound and safe choice. A doubling of nuclear energy production would make it possible to significantly reduce greenhouse gas emissions while increasing our energy supply.”
Other environmentalists are not convinced. But interestingly enough, where they used to argue that nuclear power was risky because of the threat of a meltdown, as happened at the reactor at Three Mile Island or in the explosion and fire at Chernobyl, they no longer present those arguments. Rather, they argue three other points. The first is economics.
“The rub for nuclear power today, particularly in the United States, is that it’s uneconomical compared to alternative energy sources for producing electricity.” That’s Dr. Tom Cochran’s argument against nuclear power. He’s director of a nuclear program at the National Resources Defense Council.
“Wall Street has no confidence in nuclear power, and although a lot of people are talking about it, nobody’s really ordered a reactor yet. And I hope the government doesn’t get into the business.” That’s Dr. Arjun Makhijani, president of the Institute for Energy and Environmental Research in Takoma Park, Maryland.
The second problem is waste storage. Where will we put all the spent nuclear fuel rods that nuclear plants leave behind? “The real issue is what do you do with this material over the long term, over the tens of thousands and hundreds of thousands of years that it will remain radioactive?” That’s Dr. Kevin Crowley, a geologist and director of the Nuclear and Radiation Studies Board at the National Academy of Sciences.
The third is terrorism and nuclear proliferation. In a nuclear society that relies on large quantities of nuclear materials, there is always the threat that terrorists might get their hands on radioactive materials and make a crude nuclear bomb or even a nonnuclear but deadly “dirty” bomb.
“They’re into ‘Will it explode?’ And they don’t care if it’s one kiloton or ten kilotons,” says Makhijani.
There is also the possibility that “peaceful” countries, when faced with newly nuclear hostile nations, may find a way of turning their nuclear power reactors into breeding grounds for nuclear weapons.
THE FRENCH CONNECTION
Searching for answers to these problems, technologists look for similar scenarios where nuclear power appears to be working well: France. France is the poster child for nuclear energy. The vast majority of the electricity in that country comes from nuclear power. Why can’t we just do what the French do and build more nuclear reactors?
“In order to address it to the level of France, we need about seven hundred or eight hundred nuclear power plants here in the next fifty years, if you want seventy-five to eighty-five percent in this country,” says Makhijani. “It’s much bigger than France with a much bigger electricity sector. That’s about maybe two a month, or three every two months, for the next forty years. Not an achievable level.” And even if you could build that many plants and run them for the rest of the century, says Cochran, where would you put all those spent, highly radioactive nuclear fuel rods? “You would need something like another fourteen or so Yucca Mountain–size repositories,” says a skeptical Cochran, referring to a site in Nevada that is being studied as a place to store the spent nuclear fuel rods.
THE STORAGE PROBLEM
Even if you build only one new nuclear reactor, you’re faced with a problem that has not been solved since the first reactor was patented in the 1950s: where to store the highly radioactive, highly lethal, nuclear waste—the used-up fuel rods that are taken out of the reactor?
“The nuclear waste disposal issue has been characterized by some as the elephant in the living room,” says Crowley. “We’ve had a waste disposal problem since the late 1950s when the first commercial nuclear reactors began operating. We do have a short-term solution to the problem, and that is basically to store it at the sites at which it’s generated. So since the late 1950s, the spent fuel that has been produced by operating nuclear reactors has been stored in the large water-filled pools called spent fuel pools at the nuclear reactor sites.
“And as those pools have begun to reach capacity, at some sites, nuclear power plant operators have taken some of the older fuel out of the pools and put that into large, heavily shielded structures called dry casks. And dry cask storage facilities are now beginning to be built at many plants.”
Crowley says there’s a general scientific consensus that the storage at plant sites can be carried out safely for decades if appropriate attention is paid to managing the waste. “The real issue is what do you do with this material over the long term, over the tens of thousands and hundreds of thousands of years that it will remain radioactive?”
A solution was proposed back in 1957, by the National Academy of Sciences: bury the wastes deep underground. The place currently under consideration as a deep burial site is Yucca Mountain, a ridge line in Nevada. It’s been selected from a handful of potential sites to be the final resting place for high-level nuclear waste, the by-products of nuclear power and nuclear bombs, that are stored now in those casks and pools at 126 sites around the country. The U.S. Department of Energy has been studying the site since 1978. Various political, legal, and scientific controversies have flared up over the decades. Some claim that the site is not suitable—read: not safe—for the storage of nuclear wastes for tens of thousands of years. Other efforts come from the state of Nevada, trying to get the storage site moved elsewhere. The Department of Energy, in 2006, asked Oak Ridge Associated Universities to analyze the scientific basis for storing the wastes there, and to arrive at a judgment about the safety of Yucca Mountain as a storage site.
“The current plan is to submit a license application to the Nuclear Regulatory Commission by the end of 2008,” says Crowley, “and then to begin operation of the repository no later than 2020. At this point, we’re still waiting for the Environmental Protection Agency to issue health and safety standards for Yucca Mountain. And until they do that, the Department of Energy cannot complete its license application.”
Once again, scientists are wading into unfamiliar territory, trying to make decisions about events they can’t possibly foresee thousands of years into the future. Crowley continues, “This is a first-of-a-kind endeavor, and it’s a very technically difficult endeavor, because the Department of Energy has to demonstrate with a high degree of confidence that the repository that they would build and eventually close at Yucca Mountain could contain the radioactive material for very long periods of time. And it’s really establishing that long-term confidence in the performance of the repository that is the challenging technical issue.”
Has is been established? “It has not been established yet,” says Crowley. But…“I think that there’s a strong consensus in the scientific community that it’s possible to establish that basis.”
The debate over the future of Yucca Mountain and the disposal of nuclear waste can get as heated as the nuclear fuel itself. Even some people who believe in the technology believe that the waste can and should be buried, deeply underground, do not believe that Yucca Mountain is that place.
“Yucca Mountain just happens to be the worst single site that has been selected or studied in the United States,” says Dr. Makhijani, who says he has studied the repository problem for the past 25 years. “I say this as a supporter of a repository as a least-worst solution to a very big problem that we’ve created.” He is most vocal about the potential problem for drinking water being contaminated thousands of years from now.
“In 1983, the Department of Energy-commissioned study from the National Academy of Sciences projected drinking-water doses. The department’s own studies, its own contractors, have published graphs and charts” showing that according to the standards that the
National Academy of Sciences has advocated for more than twenty years, “Yucca Mountain would not meet existing repository standards. In fact, rules have been changed four different times to accommodate Yucca Mountain because Yucca Mountain simply can’t meet the standards. And I say this—unlike many environmentalists who don’t support repositories, I do think we need one. I think we’ve rushed into site selection.”
Rushed? It’s been studied for decades!
“Unfortunately—and here I sympathize with the utilities and even with the Nuclear Energy Institute—the government has wasted most of this money. It’s wasted it on a site that it knew could not really meet the standards. Instead of going to a new repository, we created another standard. I call it the double standard.”
Even if Yucca Mountain were certified as a repository, certainly somewhere down the road another Yucca Mountain would need to be opened; more sites would need to be considered. How many more would we need? Crowley says the jury is still out on this one. “If we proceed down the path that we’re going down now, which is to simply put the spent fuel into a repository, Yucca Mountain, the currently legislated limit is about seventy thousand metric tons. At present, we have about fifty-five thousand metric tons of commercial spent fuel in the United States. So we will soon fill up Yucca Mountain at the present rate of generation of commercial spent fuel, about two thousand metric tons a year. However, the capacity at Yucca Mountain is a legislated limit, and Yucca Mountain can be expanded if Congress would choose to do that. Some studies suggest that it could be expanded by a factor of five to ten in capacity.”
Another possibility is shrinking the size of the nuclear waste. Scientists are looking into the future to do that by technologies that remove the “unburned” nuclear material that is normally thrown out with the spent fuel rods.