Harnessing the sun & wind.

• Author: Flavin, Christopher

As alternative sources of energy, these elements can provide the equivalent of nearly 1,000 trillion barrels of oil a year:

Although they have been pursued by scientists, entrepreneurs, and visionaries for two decades, solar and wind energy never have claimed the large share of the market that proponents hoped they would. Many people gave up on the heady promises made in the 1970s and decided that solar and wind were unlikely to find a place in the realm of modem energy.

Yet, 1994 brought a series of developments that suggest the time has come for solar and wind energy to compete directly with fossil fuels. Major wind power projects were announced in India, China, Germany, and Argentina, setting off a boom in wind turbine construction. At the same time, tens of thousands of homes from Sri Lanka to Switzerland were equipped with solar cells for electricity generation. A number of major corporations, including Enron, Westinghouse, and Siemens, improved the credibility of the renewable energy markets when they announced new investments in solar and wind technologies.

With world leaders struggling to cope with problems such as urban air pollution, acid rain, and global climate change, pressure is growing to begin the transition to the planet's two most abundant energy sources--the equivalent of nearly 1,000 trillion barrels of oil--that strike the Earth's atmosphere in the form of sunlight each year and the winds that flow from it.

In the early 1980s, wind machines typically cost $3,000 per kilowatt and produced electricity for more than 20 cents a kilowatt-hour. By the late 1980s, the machines were larger and more efficient, and their capital cost, including installation, had fallen to about $1,000-1,200 per kilowatt. At an aver age wind speed of 13 miles per hour and a maintenance cost of a penny per kilowatt-hour, this yields generating expense of seven to nine cents per kilowatt-hour for U.S. wind turbines installed in the early 1990s.

More than a dozen American and European companies, many with government assistance, are pursuing advanced wind technologies that are believed capable of closing the remaining cost gap with fossil fuel plants. The machines now entering the market generate 300-750 kilowatts per turbine, rather than the 100-kilowatt average of the late 1980s models. They have lighter and more aerodynamic blades made of synthetic materials, improved roto-hub connections and drive trains. new blade controls, and more advanced power electronics, including some that operate at variable speeds, allowing the turbines to run more efficiently in a range of winds. The latest designs are less expensive and can be deployed in more moderate wind regimes. In 1994, wind developers using the new technology signed contracts to sell wind-generated electricity for as low as four to five cents per kilowatt-hour.

As wind power has gained acceptance as a reliable, economical source of power, a number of American utilities have begun to incorporate it into their plans. California, for instance, is poised to move forward with some 1,500 megawatts worth of projects. Sizable wind power projects also are being built or planned in Iowa, Maine, Minnesota, Montana, New York, Oregon, Texas, Vermont, Washington, Wisconsin, and Wyoming.

An even bigger wind rush is under way in Europe. Prompted by environmental concerns, several governments stepped up their efforts to promote carbon- and sulfur-free renewable energy sources in the late 1980s, including increased research and development support and additional subsidies.

Germany and the United Kingdom each hopes to develop at least 1,000 megawatts of wind-generating capacity by 2005. Greece, Spain, and the Netherlands have ambitious plans as well. Altogether, members of the European Community aim to install 4,000 megawatts of wind power capacity by 2000 and 8,000 megawatts by 2005.

Other wind projects are under way in China, Ireland, New Zealand, Switzerland, and even Quebec, Canada, where, despite a longstanding commitment to large hydro projects on James Bay, provincial officials suggested in 1994 that the region's energy future lies in wind power. One of the most intriguing recent developments is in Ukraine, where, despite the skepticism of diplomats and the breakdown of the local economy, the state electric utility Krimenergo and Kenetech Corporation of San Francisco embarked on a 500-megawatt...