As crowds gather today at David L. Lawrence Convention Center for the nation's largest-ever conference on wind power, they do so against the backdrop of one big question: Have increases in the price of energy from traditional sources made wind power a significant player in America's energy picture? The unofficial answer: Not yet -- but give it time.

	Chart: U.S. wind power capacity

Officially, Christine Real de Azua, a spokeswoman for the American Wind Energy Association (AWEA), notes that while wind energy still represents a tiny fraction of overall U.S. electrical supply, it became the second-largest source of new power that came on line last year, trailing only natural gas. There are now more than $3 billion in power-generating stations operating in 22 states, bringing the nation's wind capacity up to 9,000 megawatts, more than triple the national capacity in 2000 and enough to provide electricity to more than 3.5 million homes.

The growth in wind power has been driven by several factors, the most obvious of which has been the pricing of natural gas. From January 2002 to December 2005, the contract price for natural gas on the New York Mercantile Exchange increased more than sixfold, reaching nearly $16 per 10,000 million British thermal units (mmBtu). With natural gas becoming the primary source for electric power plants, rising natural gas prices have resulted in higher electricity prices, making wind-based electricity more attractive.

The federal government also has played a part by enacting a tax credit in the early 1990s that provides a 1.8-cent per kilowatt-hour credit (adjusted periodically for inflation) for electricity produced from a wind farm during the first 10 years of its operation. The Production Tax Credit, or PTC, originally expired in 1999 but has been periodically extended and is now slated to expire in 2007.

Besides the PTC, the federal government is backing wind with $44 million in the 2007 budget for wind energy research to help improve the efficiency and lower the costs of new wind technologies for use in low-speed wind environments.

Government and market factors aside, many are attracted to wind as an energy source simply because of its inherent characteristics: It requires no fuel, it generates no emissions and it is virtually infinite.

"There's a lot of wind out there. The United States has more wind potential than the Saudi Arabians have oil," said AWEA Executive Director Randall Swisher. "It is an enormous resource and it is not depleted over time."

Mr. Swisher, citing U.S. Department of Energy estimates, said the nation's wind resource could generate more than 10,000 billion kilowatts of electricity annually, or three times the amount the country uses today. While that potential may never be fully utilized, he said, "it is realistic to believe that at some point decades from now, wind power could be providing 20 percent of the country's electricity," compared with the half of percent it generates now.

Getting to that 20 percent presents a challenge for a number of reasons, the biggest being "limited transmission capacity," Mr. Swisher said, a concern that wind energy producers share with the rest of the electric industry. The need for increased transmission capacity is one of the reasons for a $500 million overhaul of the Pittsburgh area's electric infrastructure by Duquesne Light Co.

A second significant inhibiting factor is cost. Proponents of wind point out that the costs for wind-generated electricity are stable because they do not depend on fluctuating commodity prices. But the cost to build a wind facility -- $1 million to $1.3 million per generated megawatt -- is significantly more than the $700,000 per generated megawatt that it costs to build a natural gas-fired power plant, and the costs to the consumer are higher than with other traditional sources.

A third obstacle is the intermittent nature of wind. Because wind goes in fits and starts, fluctuating from hour to hour, the actual output of wind generators is typically about 25 to 35 percent of their rated capacity.

Finally, there is the opposition of those who say wind farms ruin skylines, endanger wildlife and encroach on property. Several environmental groups, including Save Our Allegheny Ridges and Friends of the Allegheny Front have fought plans to build commercial wind energy facilities in the state.

All of those challenges will be topics of discussion in the conference, which runs through Wednesday and is geared toward energy professionals and government leaders. There also will be product demonstrations by more than 290 companies from 4 p.m. to 6 p.m. Tuesday for an admission price of $5.

The landscape for wind has changed a lot since Mr. Swisher became executive director of AWEA in 1989. "It was a very different industry at that point," Mr. Swisher said. "The vision was for small wind turbines serving rural homes, rather than big ones serving utility plants."

That was true even though California had begun paving the way with the nation's first power plant wind farm, built in 1981. But then, that facility contained turbines generating 50 kilowatts of electricity, or enough to serve about 15 homes. Today's turbines generate 300 times as much power, or 1.5 megawatts.

In Pennsylvania, wind energy has been promoted most heavily by FPL Energy, a Florida-based company that is the nation's largest builder and owner of wind farms. FPL has built five such facilities in the state since 2000. Together, the wind farms produce enough electricity to supply the energy needs of about 40,000 households.

Locally, that means that consumers can choose to purchase electricity generated by wind energy rather than by traditional power plants. One way to do this would be by visiting the Web site for the state's Public Utility Commission Utility Choice program, www.puc.state.pa.us/utilitychoice, and following the prompts to lists of electricity suppliers.

One of the suppliers for Duquesne Light customers that provides wind energy is Community Energy Inc. of Wayne, Delaware County. Spokesman Paul Copleman said consumers who choose their energy pay a premium of 2.5 cents per kWh above their regular Duquesne Light bill.

But because a consumer can choose how much of their energy they want to be drawn from wind power, in 100 kWh increments, the extra amount they pay can vary, with the minimum being $5 a month. If a typical household using 10,000 kWh a year, or 833 kWh a month, made maximum use of wind energy, it would pay an additional $20 a month for 800 kWh.

The premium will go away when enough people choose wind energy, Mr. Copleman said. "A greater economy of scale will continue to bring the price of wind generation down," he said.