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Powering the Future
AUGUST 2005
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Powering the Future

By Michael Parfit
Photographs by Sarah Leen

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There are other challenges. Like sailboats, wind turbines can be becalmed for days. To keep the grid humming, other sources, such as coal-fired power plants, have to stand ready to take up the slack. But when a strong wind dumps power into the grid, the other generators have to be turned down, and plants that burn fuel are not quickly adjustable. A wind-power bonanza can become a glut. Denmark, for example, is sometimes forced to unload power at uneconomic rates to neighbors like Norway and Germany.

What's needed for wind as well as solar is a way to store a large energy surplus. Technology already exists to turn it into fuels such as hydrogen or ethanol or harness it to compress air or spin flywheels, banking energy that can later churn out electricity. But most systems are still decades from becoming economically feasible.

On the plus side, both wind and solar can provide what's called distributed energy: They can make power on a small scale near the user. You can't have a private coal plant, but you can have your own windmill, with batteries for calm days. The more houses or communities make their own wind power, the smaller and cheaper central power plants and transmission lines can be.

In Europe's big push toward wind power, the turbines keep growing. But in Flagstaff, Arizona, Southwest Windpower makes turbines with blades you can pick up in one hand. The company has sold about 60,000 of the little turbines, most of them for off-grid homes, sailboats, and remote sites like lighthouses and weather stations. At 400 watts apiece they can't power more than a few lights.

But David Calley, Southwest's president, whose father built his first wind turbine out of washing machine parts, is testing a new product he calls an energy appliance. It will stand on a tower as tall as a telephone pole, produce up to two kilowatts in a moderate wind, and come with all the electronics needed to plug it into the house.

Many U.S. utilities are required to pay for power that individuals put back into the grid, so anyone in a relatively breezy place could pop up the energy appliance in the yard, use the power when it's needed, and feed it back into the grid when it's not. Except for the heavy loads of heating and air-conditioning, this setup could reduce a home's annual power bill to near zero. If, as Calley hopes, he can ultimately sell the energy appliance for under $3,000, it would pay for itself with energy savings within a few years.

Somewhere in this mix of the grand and the personal, there may be big numbers in wind too.


BIOMASS: FARMING YOUR FUEL

In Germany, driving from the giant wind turbine near Hamburg to Berlin, I regularly got an odd whiff: the sort-of-appetizing scent of fast food. It was a puzzle until a tanker truck passed, emblazoned with the word "biodiesel." The scent was of burning vegetable oil. Germany uses about 450 million gallons (1,700 million liters) of biodiesel a year, about 3 percent of its total diesel consumption.

Biomass energy has ancient roots. The logs in your fire are biomass. But today biomass means ethanol, biogas, and biodiesel—fuels as easy to burn as oil or gas, but made from plants. These technologies are proven. Ethanol produced from corn goes into gasoline blends in the U.S.; ethanol from sugarcane provides 50 percent of automobile fuel in Brazil. In the U.S. and other nations, biodiesel from vegetable oil is burned, pure or mixed with regular diesel, in unmodified engines. "Biofuels are the easiest fuels to slot into the existing fuel system," says Michael Pacheco, the National Bioenergy Center director.

What limits biomass is land. Photosynthesis, the process that captures the sun's energy in plants, is far less efficient per square foot than solar panels, so catching energy in plants gobbles up even more land. Estimates suggest that powering all the world's vehicles with biofuels would mean doubling the amount of land devoted to farming.

At the National Bioenergy Center, scientists are trying to make fuel-farming more efficient. Today's biomass fuels are based on plant starches, oils, and sugars, but the center is testing organisms that can digest woody cellulose, abundant in plants, so that it too could yield liquid fuel. More productive fuel crops could help as well.

One is switchgrass, a plant native to North America's prairies that grows faster and needs less fertilizer than corn, the source of most ethanol fuel made in the U.S. It also thrives on land unfit for other crops and does double duty as a source of animal food, further reducing the pressure on farmland.

"Preliminary results look promising," says Thomas Foust, the center's technology manager. "If you increase automobile efficiency to the level of a hybrid and go with the switchgrass crop mix, you could meet two-thirds of the U.S. transportation fuel demand with no additional land."

But technically possible doesn't mean politically feasible. From corn to sugarcane, all crops have their own lobbyists. "We're looking down a lot of alleys," says Pacheco. "And every alley has its own vested interest group. Frankly, one of the biggest challenges with biomass is that there are so many options."


NUCLEAR: STILL A CONTENDER

Nuclear fission appeared to lead the race as an energy alternative decades ago, as countries began building reactors. Worldwide, about 440 plants now generate 16 percent of the planet's electric power, and some countries have gone heavily nuclear. France, for instance, gets 78 percent of its electricity from fission.

The allure is clear: abundant power, no carbon dioxide emissions, no blots on the landscape except an occasional containment dome and cooling tower. But along with its familiar woes—the accidents at Three Mile Island and Chornobyl, poor economics compared with fossil fuel plants, and the challenge of radioactive waste disposal—nuclear power is far from renewable. The readily available uranium fuel won't last much more than 50 years.

Yet enthusiasm is reviving. China, facing a shortage of electric power, has started to build new reactors at a brisk pace—one or two a year. In the U.S., where some hydrogen-car boosters see nuclear plants as a good source of energy for making hydrogen from water, Vice President Dick Cheney has called for "a fresh look" at nuclear. And Japan, which lacks its own oil, gas, and coal, continues to encourage a fission program. Yumi Akimoto, a Japanese elder statesman of nuclear chemistry, saw the flash of the bomb at Hiroshima as a boy yet describes nuclear fission as "the pillar of the next century."

In the town of Rokkasho at the northernmost tip of Honshu Island, Japan is working to get around the limits of the uranium supply. Inside a new 20-billion-dollar complex, workers wear pale blue work suits and an air of patient haste. I looked in on cylindrical centrifuges for enriching uranium and a pool partly filled with rods of spent nuclear fuel, cooling. Spent fuel is rich in plutonium and leftover uranium—valuable nuclear material that the plant is designed to salvage. It will "reprocess" the spent fuel into a mixture of enriched uranium and plutonium called MOX, for mixed oxide fuel. MOX can be burned in some modern reactors and could stretch the fuel supply for decades or more.

Reprocessing plants in other countries also turn spent fuel into MOX. But those plants originally made plutonium for nuclear weapons, so the Japanese like to say that theirs, due to start up in 2007, is the first such plant built entirely for peaceful use. To assure the world that it will stay that way, the Rokkasho complex includes a building for inspectors from the International Atomic Energy Agency, the United Nations' nuclear watchdog, who will make certain that none of the plutonium is diverted for weapons.

That doesn't satisfy nuclear energy opponents. Opposition has mounted in Japan after fatal accidents at the country's nuclear plants, including one that killed two workers and exposed others to radiation. Shortly after my visit to Rokkasho, about a hundred protesters marched outside the plant in a blizzard.

A bigger controversy would greet what some nuclear proponents think is a crucial next step: a move to breeder reactors. Breeders can make more fuel than they consume, in the form of plutonium that can be extracted by reprocessing the spent fuel. But experimental breeder reactors have proved to be temperamental, and a full-scale breeder program could be an arms-control nightmare because of all the plutonium it would put in circulation.

Akimoto, for one, believes that society has to get comfortable with fuel reprocessing if it wants to count on nuclear energy. He spoke to me through an interpreter, but to emphasize this point he jumped into English: "If we are going to accept nuclear power, we have to accept the total system. Sometimes we want to get the first crop of fruit but forget how to grow the trees."


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