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Power Shock: The Next Energy
Revolution (Continued) |
by Christopher Flavin |
STORING POWERJust as buildings of the future are likely to generate their own electricity, they may also be able to store it. During the past five years, at least five companies have begun developing flywheels, which function like mechanical batteries. Operating on the same principle as a potter's wheel, a flywheel disc is set to spinning at high speed by an integrated electric motor/generator. It is contained inside an airless case, almost eliminating resistance so that the ensuing long duration of the spin serves as a means of storing kinetic energy which can then be converted to electricity by the generator as needed. Although invented over a century ago, the flywheel only became practical with the development of strong, lightweight composite materials in the 1970s and 1980s. Modern composites can spin in a vacuum at up to 200,000 revolutions per minute, with the potential to store and release energy at an efficiency of more than 90 percent. Because they have virtually frictionless electromagnetic bearings, flywheels can store electricity for weeks, and last years before wearing out. Flywheels would last much longer than chemical batteries, and would not require toxic substances. The materials needed to manufacture them are not expensive, and their design readily lends them to mass production, which will yield much lower costs. Because they could be used as storage devices in electric cars as well as in buildings, the ultimate market for flywheels could add up to millions of units. It will probably be 10 to 15 years before flywheels are widely available commercially, but after that, their use could grow as fast as that of cellular phones has in the early 1990s. |
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WINDS OF CHANGE
Another modular power technology, the wind turbine, has begun to change the electric power landscape from the northern coasts of Europe to the plains of southern India. The world had more than 25,000 wind turbines operating at the end of 1995, producing nearly 5,000 megawatts of power. California has 1,700 megawatts, generating enough electricity to supply all of San Francisco's residents, and Germany has more than 1,000 megawatts, supplying over five percent of the electricity in the state of Schleswig-Holstein.
After a slow period in the late 1980s, the world market for wind turbines has exploded since 1990. Following the laws of technological progress and large-scale manufacturing, the cost of wind-generated electricity has fallen by more than two-thirds over the past decade, to the point where it is lower than that of new coal plants in many regions. Within the next decade, it is projected to fall to three to four cents per kilowatt-hour, making wind the least expensive power source that can be developed on a large scale worldwide.
The new wind turbines aren't the quaint old "wind mills" we remember from past generations; they are sleek, high-tech fiberglass models with gearless, variable speed transmissions and advanced electronic controls. The larger machines have blade spans of 50 meters (160 feet) and more. Unlike large conventional power plants, new wind turbine models enter the market as frequently as new laptop computers do. And, like laptops, they deliver services in small units; the latest wind machines generate 300 to 750 kilowatts per turbine--one-thousandth the size of a typical coal plant.
Europe is now the world's hottest wind power market. Its wind boom is led by Germany, which now has thousands of gleaming white wind turbines sprinkled across the flat farmland of Lower Saxony and other coastal states. The tenfold rise in wind power in Germany since 1990 resulted from an investment boom stirred up by generous tax credits and the 1991 "electricity infeed law" for renewables.
Not far behind are several other European nations, including Denmark, Great Britain, the Netherlands, and Spain. If development continues at the recent frenzied pace, wind power could become a major source of European electricity within the next decade.
In India, a wind energy rush began in 1994 as the government opened up the power grid to independent developers and offered tax incentives for renewable energy development. Indeed, India is now second only to Germany in the number of annual wind power installations. By early 1995, some 300 megawatts of wind power were in place, much of it resulting from joint ventures with European and U.S. manufacturers, some of whom are building assembly plants in India.
Already, land values in windy regions have jumped dramatically. Other countries with sizable wind power projects underway include Brazil, China, Greece, and Mexico. Although l wind power provides less than 0.1 percent of the world's electricity today, it is fast becoming a proven power option that is reliable enough for routine use by electric utilities.
Two decades from now, millions of turbines could be spread across windy areas of the world, providing 20 or 30 percent of the electricity in some areas. In the United States, the Great Plains states could in theory supply all the country's electricity, and for China, the same can be said of Inner Mongolia, which is located within a few hundred kilometers of Beijing.
The formula used for wind energy--independent developers installing collections of small generators in resource-rich areas--is proving viable for solar energy as well. In the Mojave Desert, some 350 megawatts of parabolic dish solar collectors already provide power for Southern California Edison's power grid, and similar projects are being eyed in Australia and the Middle East. Similarly, the Houston-based Enron Corporation announced in late 1994 that it plans to build large collections of grid-connected solar photovoltaic generators in the desert regions of China, India, and the United States. As costs fall, these could become a leading source of electricity.
FORCES OF CHANGE
From some perspectives, the mid-1990s are a dark time for the world energy system. Oil consumption is approaching the record levels of the late 1970s, with demand in some countries growing at rates as high as 10 percent per year. Even the use of coal is still expanding in many nations, pushing emissions or carbon dioxide--the leading greenhouse gas--to more than six billion tons per year. Emissions are growing particularly rapidly in China and India, but even the United States and Canada are failing to hold carbon dioxide emissions steady as they are supposed to under the Rio climate convention.
Although most energy analysts view such trends as convincing evidence that the world energy system won't change anytime soon, the reverse may be true. As Stephen Jay Gould's theory suggests, evolutionary bursts are usually precipitated by strong pressures. Today, three major forces of change are bearing down on the world energy economy: new technologies, industry restructuring, and tougher environmental policies all of which are likely to be intensified by incipient climate change.
1) New technologies are the most obvious. As noted earlier, advanced electronics, new materials, and biotechnology are now being put to use in energy systems. The modern automobile, for example, has become virtually a computer on wheels with electronic controls that provide fuel economy and lower emissions.
2) Industry restructuring is also spawning change. In the past, most electric power systems have been operated as government-owned or controlled monopolies that manage everything from constructing power plants to reading the meters attached to customers' homes. These monopolies have been drawn to giant plants and inefficient, entrenched technologies, and have had little incentive to pursue innovation.
But today, all that is changing. In Brazil, India, Poland, Great Britain, Japan, and the United States, utility systems are being broken up and sold to private investors. In many nations, the generation of electricity is increasingly provided by independent power producers that have no monopoly franchise on the business. Local distribution utilities and industrial users buy power from those producers, using the electricity transmission system as a common carrier, in the same way that railroads and telephone lines are used.
This restructuring has led to an unprecedented wave of innovation, as independent producers find that in order to be competitive, they have to build ever more efficient and less expensive plants. Such producers are pursuing smaller and less environmentally damaging energy sources than did their utility brethren. In the United States, for example, a power plant built in the early l990s has a capacity of 100 megawatts on average, compared to 600 megawatts less than a decade earlier. Most of the latest plants now are fueled with natural gas rather than coal or nuclear power.
India provides a particularly strong example of the impact of restructuring. As the state utility monopolies were broken in the early l990s, independent power generation blossomed. Scores of projects are now underway, in a competitive rush to reduce the country's chronic power shortages. Although many of the new plants are coal and gas-fired, dozens of wind and solar energy projects are also underway, attracting foreign investment and creating a manufacturing boom.
The third force driving rapid change is the growing reach of policies intended to protect the earth' s embattled environment. In many countries, emissions and waste-disposal laws have greatly added to the cost of building coal-fired power plants, and nuclear generators have essentially been ruled out as having unacceptably high costs and risks. These changes have boosted the market prospects for efficient natural gas and renewable energy generators.
To help protect the environment, some governments have changed tax and utility laws to level the playing field between dirty and clean technologies. India, for example, allows a full income tax deduction for renewable energy investments, and the United States offers a 1.5 cents per kilowatt-hour subsidy to renewable power. In Germany, renewable power generators have been granted the right to sell power to utilities at a rate of 0.17 DM (12 cents) per kilowatt-hour--about what Germans pay for coal and nuclear power, but well above current prices for the latest natural gas-based power systems--thereby priming the pump for renewables.
THE HYDROGEN AGE
In elaborate studies churned out by governments and corporations each year, powerful computers are used to project future energy trends. Although the results of such studies are received by many policy-makers as gospel, they are generally based on a narrow band of oil price and economic growth assumptions. Indeed, what passes for energy analysis today is dominated by a preoccupation with econometrics and the geopolitics of the Persian Gulf, leaving unquestioned the assumption that we will stay hooked on oil until it is gone, and that coal's role must expand simply because coal is abundant.
Hydrogen is the simplest of the chemical fuels, and unlike methane--the cleanest fuel used today--entirely carbon-free. Hydrogen is the lightest of the elements as well as the most abundant. Three-quarters of the mass of the universe consists of hydrogen, which of course is also a principal constituent of water. When the time comes to use the hydrogen as fuel, it is combined with oxygen to produce water, releasing energy but no pollution.
Scientists have foreseen the possibility of a transition to hydrogen for more than a century, and today it is seen as the logical "third wave" fuel--hydrogen gas following liquid oil, just as oil replaced coal decades earlier. The required technology using electricity to split water molecules through electrolysis is already being used commercially. (All the world's current energy needs could be met with less than 1 percent of today's fresh water supply, and hydrogen can also be produced from seawater.) Although many people worry that hydrogen is dangerous, if properly handled, it will probably be safer than fuels like gasoline that are widely used today.
The challenge now holding up the transition to hydrogen is finding inexpensive sources of energy to split water. This may seem circular--the need to find cheap energy in order to produce an affordable fuel. But the key to the puzzle lies in the possibility of storage and transportation. Wind and solar energy can be used to feed the electricity grid when power demand is high, and to produce storable hydrogen when it is not.
In fact, hydrogen may provide the ideal means of storing and distributing these intermittent power sources. Additional hydrogen can be produced in homes and commercial buildings using rooftop solar cells. The hydrogen can then either be stored in a basement tank for later use in a fuel cell or conventional boiler, or be piped into a local hydrogen distribution system.
Over time, solar and wind-derived hydrogen could transform the way energy is produced and used virtually everywhere. All of the world's major population centers are within reach of sunny and wind-rich areas. The Great Plains of North America, for instance, could supply much of Canada and the United States with electricity and hydrogen fuel. For Europe, solar power plants could be built in North Africa, with hydrogen transported along existing gas pipeline routes. In China, hydrogen could be produced in the country's vast western deserts and shipped to population centers on the coastal plain.
Many people assume that producing sufficient hydrogen from solar and wind energy requires huge swaths of land, but these technologies actually use less than one-fifth as much land to produce a given amount of energy as does hydropower, which now supplies nearly a third of the world's electricity.Moreover, while much of the land used for hydropower has to be condemned for flooding (often of prime cropland), the tracts used for wind farms can still be used for crops and grazing.
What then would a solar-hydrogen energy system look like? One of its chief advantages is that it would be largely invisible. Fuel cells and flywheels would be hidden in peoples' basements; solar rooftops would be nearly indistinguishable from conventional rooftops; and hydrogen pipelines would be buried underground, as are today's natural gas pipelines. Some rural farming areas may be sprinkled with wind turbines, but most of the larger wind and solar power plants are likely to be located in remote areas such as India's Thar Desert or Mexico's La Ventosa, where people rarely visit.
On first reflection, such an energy system may seem fanciful. But two decades ago, the idea of desktop computers and information superhighways would have seemed equally far-fetched. And arguably, what is most inconceivable is that an information-age economy will be powered by a primitive industrial age energy system.
As corporate and government decision makers begin to understand just how economical and practical a zero-emission, carbon-free energy system can be, and just how inefficient and dirty the current system is, they may finally summon the sort of effort that made the last great energy transition possible a hundred years ago.
Christopher Flavin is Vice-President for Research at Worldwatch Institute and co-author with Nicholas Lenssen of Power Surge: Guide to the Coming Energy Revolution (W. W. Norton: 1994), on which this article is based.
which of these new technologies is most significant to you?
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