Level 3 Reading 7A

Ch.13

Reading 7A POWERING THE PLANET Despite modern society's heavy dependence on fossil fuels for energy, most people are aware that the supply of these fuels is finite. As oil and other fossil fuels become more costly and difficult to find, researchers are looking at alternative energy sources, including solar, wind, and even nuclear power. But which substitute—if any—is the right one? Solar Solar panels catch energy directly from the sun and convert it into electricity. One of the world's largest solar power stations is in the Indian state of Tamil Nadu, where more than 2.5 million solar panels have the capacity to generate enough power for 750,000 people. But unlike the burning of fossil fuels, the process used to create all that solar energy produces no emissions. Today, however, solar power provides less than 2 percent of the world's energy, primarily because the cost of the panels is still very high. But price is only one issue. Clouds and darkness also cause solar panels to produce less energy. This requires that additional power sources (such as batteries) be available. Some scientists think the solution to this problem can be found in space, which is the ideal place to gather energy from the sun. With no clouds and no nighttime, a space-based solar power station could operate constantly. These stations would send the power back to Earth, which could then be turned into electricity for consumption. Advocates of solar space stations say this technology would initially require a lot of money, but eventually it could provide continuous, clean energy that would be cheaper than other fuels. Also, unlike other energy sources, solar power from space would last as long as the sun shines, and would guarantee everyone on Earth all the energy they need. Wind Wind—the fastest-growing alternative energy source—is another way of collecting energy from the sun. Wind is caused by the sun's heat rather than its light. Therefore, unlike solar power, wind power works well even on cloudy days. All over the world, incentives designed to decrease the dependence on oil and coal have led to a steep increase in wind-powered energy. Today, Asia leads the world in wind power, producing around 230,000 megawatts, the equivalent of 230 large coal-powered plants. Europe produces nearly 180,000 megawatts. North America remains a distant third, at 105,000. Despite its successes, some people are protesting wind-power development, saying the turbines are both noisy and ugly. Just outside England's Lake District—a protected national park—a dozen existing wind towers are due to be removed. "This is a high-quality landscape," says one local homeowner. "They shouldn't be putting those things in here." There are other challenges, too. If the wind doesn't blow, the turbines are not able to produce adequate energy. As a result, other power sources are needed. In contrast, a strong wind can create too much power. In cases like this, the energy company must sell the extra power at a much-reduced rate, which is not good for business. What's needed for both wind and solar is a way to store a large energy surplus. However, most systems are still decades away from making this a reality. On the plus side, both wind and solar power enable people to generate their own energy where they live:

People can have their own windmills or solar panels, with batteries for calm days. Nuclear In the 1970s, nuclear power was seen as the main energy alternative. Nuclear power produces vast amounts of electricity more cheaply than gas or coal, with no carbon emissions. For a number of years in the 1980s and '90s, however, use of nuclear power declined due to accidents, concerns about nuclear waste storage and disposal, and high construction costs. Today, times are changing. Worldwide, about 450 plants generate 11 percent of the planet's electric power, and some countries have invested heavily in nuclear energy. France, for instance, gets three-quarters of its electricity from nuclear power, the highest percentage of any country. China has started to build one or two new plants a year, and India has also begun to utilize nuclear energy on a large scale. However, there are still concerns about the safety of nuclear power, as seen, for example, at the Fukushima nuclear power plant in Japan. The country had to close the nuclear reactors at Fukushima when the plant was hit by a tsunami and, as a consequence, began releasing substantial amounts of radioactive materials. Many still believe, however, that nuclear power is one of the future's greenest energy alternatives. In the end, are any of these sources alone the answer to our current energy problems? The short answer is no, but used in some combination—along with other power sources— we may find ways to reduce and eventually eliminate our dependence on fossil fuels.

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