Quick Study: Alternative Energy

With $4-a-gallon gas, global warming, and war in the Middle East, America seems eager (finally) to kick its addiction to oil and other fossil fuels. Here's where we are and where we're going with alternative energy sources.

By Joseph K. Vetter

From Reader's Digest

Images from this article

Chitose Suzuki/AP Images

2006
First sea-based wind farm in U.S. proposed off Cape Cod.

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Chitose Suzuki/AP Images

2006
First sea-based wind farm in U.S. proposed off Cape Cod.

Solar. Enough of the sun's energy reaches the earth's surface to satisfy all our energy needs. The trick is harnessing it in usable form. Solar cells made of silicon convert sunlight into electricity, which is then wired to the power grid. For decades, they've powered calculators, satellites, and homes. Scientists are experimenting with other materials to capture more of the sun's power and cut manufacturing costs. One technique, known as concentrating solar power, uses an array of mirrors, lenses, and liquid-filled tubes to turn the sun's intense heat into steam, which then powers an electric turbine. Advances could one day allow the sun to replace coal and nuclear plants as our main source of electricity.

Wind. It currently accounts for only 1 percent of U.S. electrical production. Yet it's the fastest-growing energy source, representing a third of all new power generation in 2007. The basic technology—a rotor to capture the wind's energy and a shaft to convert it—hasn't changed much since the Dutch used windmills to grind grain. In the modern version, aerodynamic rotor blades grab the wind, and a generator converts the mechanical energy into electricity. The Midwest and Plains states have the highest wind potential, with Texas already leading the way. New York City mayor Michael Bloomberg envisions an offshore wind farm that could supply 10 percent of the city's electricity needs within a decade.

Biofuel. Ethanol, an alcohol produced through the fermentation of corn or other crops, has been touted as a petroleum substitute for decades, particularly in the Midwest, where corn is king. But the dramatic rise in oil prices has triggered a biofuel boom. That, in turn, has led to talk of an ethanol glut as more and more farmers join the new gold rush.

Other plant-based fuels include biodiesel, which can be made from vegetable oil (even restaurant grease).

Flash Points

• Cost has been the main impediment to a large-scale shift to solar. While the sun is free, the hardware that converts it to usable electricity is not. Nor is the labor needed for installation. But technological advances have helped cut costs by some 80 percent since 1980, with further declines expected.
• NIMBY spells trouble for wind. A field of whirring turbines can be loud and unsightly. In some communities, wind farms have pitted residents who lease their land to wind companies against neighbors with ruined views. Generating wind energy is easier than getting it to customers: The infrastructure does not yet exist to bring energy from remote, high-wind regions into large numbers of homes.
• Rising food prices have put biofuel in the hot seat. By diverting crops and land from food to energy production, critics say, the biofuel boom has squeezed the food supply and driven up grain and meat prices. But a Texas A&M study found that the main cause of the food price hike in the U.S. is not biofuel but the spike in oil prices, which affects agricultural production and transport.

Forward Thinking

• Shingles, paints, and pavement could offer new solar options. Shingles containing silicon cells can be used to power homes or buildings. Researchers are developing paints laced with solar cells made of titanium dioxide and other so-called nano materials. They're also working on ways to harness the heat absorbed from the sun by asphalt roads and parking lots.
• Change is definitely in the air when Texas oilman T. Boone Pickens announces he's building a wind farm likely to be the world's largest (it is Texas, after all). Upon completion, in late 2014, Pickens's 4,000-megawatt farm will be able to power 1.3 million homes.
• Cellulosic ethanol made from nonfood plants like switchgrass could be biofuel's future. (It leaves a smaller carbon footprint than corn.) Named for the substance that makes up plant cell walls, cellulosic ethanol could emit one third the greenhouse gas of corn ethanol. These "energy crops" affect food prices less and can be grown outside the farm belt without clearing new land. Other potential nonfood biofuel sources: waste timber, algae, and nuts from the Jatropha tree, which grows throughout Asia, Africa, and South America.

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