What New Developments in Energy?

WIND:

▪ Mankind has long harnessed the power of the wind to propel sailing ships, turn grinding mills, and pump water. In recent years, though, enthusiasm for wind power has swept the globe. High-tech windmills now generate enough nonpolluting, renewable power worldwide to provide electricity for 35 million people. Denmark already generates 20 percent of its electricity from wind power alone. Germany, Spain, and India are rapidly adopting wind power, with India claiming the fifth-largest wind power capacity in the world. The United States currently has 13,000 windmills generating electricity. And some analysts claim that if all the suitable sites in the United States were developed, that country could generate more than 20 percent of its current electric needs from the wind.

SUN:

▪ Man-made photovoltaic cells convert sunlight into electricity when the sun’s rays excite electrons in the cells. Worldwide, nearly 500 million watts of electricity are produced by this method, and the market for solar cells is growing at 30 percent per year. At present, though, photovoltaic cells are relatively inefficient, and the electricity produced from the cells is expensive when compared with that produced from fossil fuels. In addition, toxic chemicals, such as cadmium sulfide and gallium arsenide, are used in the cells’ manufacture. Because such chemicals persist in the environment for centuries, notes Bioscience, “disposal and recycling of the materials in inoperative cells could become a major problem.”

 GEOTHERMAL ENERGY:

▪ If a person were to dig a hole in the earth’s crust toward its hot core, which is an estimated 7,000 degrees Fahrenheit [4,000°C], the temperature would increase, on average, by about 90 degrees Fahrenheit for every mile [30 degrees Celsius for every kilometer] dug. However, for people who live close to thermal springs or volcanic fissures, the earth’s heat is more readily available. Hot water or steam produced by hot spots in the earth’s crust is used in 58 countries to heat homes or generate electricity. Iceland satisfies about half its energy needs by harnessing geothermal power. Other countries, such as Australia, are looking into tapping the energy trapped in large areas of hot, dry rock buried just a few miles beneath the earth’s surface. Australian Geographic reports: “Some researchers believe that by pumping water down to that trapped heat and then using the hot water to turn turbines as it returns to the surface under very high pressure, we could generate power for decades​—even centuries.”

WATER:

▪ Hydroelectric power plants already supply over 6 percent of the world’s energy needs. According to the International Energy Outlook 2003 report, over the next two decades, “much of the growth in renewable energy sources will result from large-scale hydroelectric power projects in the developing world, particularly among the nations of developing Asia.” However, Bioscience warns: “The impounded water frequently covers valuable, agriculturally productive, alluvial bottomland. Furthermore, dams alter the existing plants, animals, and microbes in the ecosystem.”

 HYDROGEN:

▪ Hydrogen is a colorless, odorless, combustible gas and is the most abundant element in the universe. On earth, hydrogen is an integral part of plant and animal tissue, is bound up in fossil fuels, and is one of the two components that form water. In addition, hydrogen burns more cleanly and more efficiently than fossil fuels.

The journal Science News Online states that water “can [be] split into hydrogen and oxygen when electricity passes through it.” While this method could produce abundant amounts of hydrogen, the journal notes that “this seemingly straightforward process isn’t yet economical.” Factories already produce some 45 million tons of hydrogen globally, mainly for use in fertilizers and cleaning agents. But this hydrogen is extracted in a process involving fossil fuels​—a process that also gives off the poisonous gas carbon monoxide and the greenhouse gas carbon dioxide.

Still, many see hydrogen as the most promising of the alternative fuels and feel it is capable of satisfying mankind’s future energy needs. This optimism is based on recent dramatic improvements in a device known as the fuel cell.

FUEL-CELL POWER:

▪ A fuel cell is a device that produces electricity from hydrogen​—not by burning it, but by combining it with oxygen during a controlled chemical reaction. When pure hydrogen is used rather than a hydrogen-rich fossil fuel, the only by-products of the reaction are heat and water.

In 1839, Sir William Grove, a British judge and physicist, developed the first fuel cell. However, fuel cells were expensive to build, and the fuel and components were awkward to obtain. Thus, the technology lay dormant until the mid-20th century when fuel cells were developed to provide power for American spaceships. Modern spacecraft still use fuel cells to provide onboard power, but the technology is now being refined for more down-to-earth uses.

Today, fuel cells are being developed to replace the internal combustion engine in motor vehicles, to provide electricity for commercial and domestic buildings, and to power small electric devices, such as mobile phones and computers. Even so, at the time of writing, the power generated from existing stationary fuel-cell plants is more than four times as expensive as that from fossil fuel sources. Still, hundreds of millions of dollars are being invested in developing this emerging technology.

The environmental benefits of adopting cleaner energy sources are obvious. However, the cost of doing so on a large scale is likely to remain prohibitive. The IEO2003 report says: “Much of the increment in future energy demand . . . is projected to be for fossil fuels (oil, natural gas, and coal), because it is expected that fossil fuel prices will remain relatively low, and that the cost of generating energy from other fuels will not be competitive.”

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Fuel-cell vehicle, 2004

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Mercedes-Benz USA

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DOE Photo