Six years after state lawmakers deregulated electricity to give consumers more choices, residential customers in Western Pennsylvania who want to shop are left with basically the same -- and only -- choice they had before the experiment began.

Green Mountain Energy, one of only two suppliers signing up new residential customers in territory served by Duquesne Light, Allegheny Energy and Penn Power, announced yesterday it will stop selling electricity in Pennsylvania. Duquesne Light and Penn Power residential customers have another choice, Community Energy, which supports wind energy development and charges a much higher price.

Austin, Texas-based Green Mountain said its decision was based on economics. Given the rules of deregulation and current market conditions, the only way it could survive would be to charge residential customers about $30 more a month, spokesman Andy Prince said.

"To me, this pretty much says competition is dead and deregulation is basically a failure," said David Hughes, executive director of consumer advocate Citizen Power.

The story has been the same nationwide. Frightened by the 2000-2001 California energy crisis and the Enron scandal, some states have abandoned deregulation altogether. Others have limited it to industrial customers.

Despite the lack of choices in the state, electric rates have come down, said citizen's group Penn-Future President John Hanger, who championed deregulation as a member of the state Public Utility Commission member. Mr. Hanger said even after a rate increase this year, Duquesne Light customers are paying about 15 percent less for electricity than they did when the process began.

"That's an extraordinary story," he said. "It would be an extraordinary story in the best of energy times. These are the worst of energy times."

Electricity suppliers rushed to the Pennsylvania market after lawmakers voted to deregulate the industry in 1996. The proposal was supposed to lower prices by spawning competition. When the PUC approved plans to let Duquesne Light customers start shopping in 1999, Mr. Hanger promised "the monopoly is ending."

While commercial and industrial customers have choices at competitive prices, Mr. Hanger said, "it's absolutely the case there's too little choice" for residential customers.

For the most part, residential customers have stuck with the supplier they had before deregulation. Only about 23 percent of the residential customers in territory served by Duquesne Light, viewed as having made the most progress toward deregulation, have signed up with alternative suppliers, according to the Pennsylvania Office of Consumer Advocate.

The agency said only 0.1 percent of Allegheny Power's residential customers and 0.3 percent of Penn Power's residential customers have switched.

Mr. Prince said Green Mountain's customer count peaked at 100,000 in 2001 and has declined to about 30,000. About 15,000 customers are in Western Pennsylvania and the same amount are in the Philadelphia region, he said.

Many of those customers switched to Green Mountain not to save money -- its prices generally run significantly higher than other suppliers -- but because it relies on renewable energy purchased largely from companies that generate it from windmills or landfill gases.

Electricity rates for most utilities in the state are still capped as part of deregulation. That makes it difficult for Green Mountain to compete, Mr. Prince said, because wholesale prices for electricity that it must buy to resell to consumers have been on the rise. For example, its price per kilowatt hour currently ranges from 7.55 cents to 7.97 cents, compared with Duquesne Light's 6.69 cents, and its facing further increases in its wholesale costs.

Sonny Popowski, the state's consumer advocate, said the rate caps negotiated as part of deregulation have shielded consumers from those higher costs.

Customers in Duquesne Light's and Penn Power's territories can select Community Energy, which like Green Mountain relies on renewable energy. Community's prices are 2.5 cents per kilowatt hour above whatever Duquesne Light and Penn Power charge for electricity.

Next week, Green Mountain will start alerting customers about the need to find another supplier. Customers in Western Pennsylvania will have 30 days to make arrangements, Mr. Prince said. But since there are no other residential suppliers, customers who do nothing will automatically be switched to either Duquesne Light, Allegheny Power or Penn Power, he said.