Self-styled "green" leaders across the country face a conundrum over wind power: Do they alienate part of their constituency by leveling pristine forests to build wind farms, or irritate the other part by rejecting a promising source of renewable energy?

When Gov. Martin O'Malley faced that choice in April , he opted for the latter, and in no uncertain terms.

"In the end, we could not justify the consequences that commercial wind would have on this land, this publicly held land," he said in announcing his decision to block a wind-farm proposal in Western Maryland. He also barred wind turbines from being constructed on any state land.

"I also want to stress what this decision should not be misinterpreted to mean: This is not a rejection of wind power in the state of Maryland," he told a group of wind- farm opponents.

The move scuttled a plan to clear about 400 acres of forest to build more than 100 wind turbines along Backbone Mountain in Garrett County.

At the same time, Mr. O'Malley won approval for his plan to impose new energy standards requiring utilities to double the renewable energy they purchase by 2022.

The wind-farm decision fanned opposition from renewable energy advocates, including developers eyeing wind projects in Western Maryland.

"It has been a struggle for some time now," said Frank Maisano, a spokesman for US Windforce, whose project Mr. O'Malley blocked. "A small cadre of activists are doing whatever they can to stop the industry from moving forward. All in the face of legislative priorities requiring increased renewable energy investment."

Maryland, Alabama and Mississippi are the only three states that have no operational wind turbines.

About 25,000 wind turbines nationwide generate more than 16,600 megawatts of electricity, a little more than 1 percent of the nation's supply, according to the American Wind Energy Association.

An O'Malley spokesman said he sees no conflict in the governor's decision.

"The state has a responsibility to protect public lands as well as promote renewable sources of energy - and the decision to bar wind turbines on state parkland does not affect wind turbines on privately-owned land," said Rick Abbruzzese, Mr. O'Malley's director of communications.

But supporters are still ruffled.

"When it comes to actually building wind farms, Maryland increasingly has a reputation as an anti-wind state," said Mike Tidwell, executive director of Chesapeake Climate Action Network. "This is because a very small but intensely vocal minority of citizens have successfully delayed and killed reasonable and effective wind projects."

Three proposals to build wind farms have already won permission in Maryland, but the developers have been locked in court battles with local opponents since 2004.

One developer, Clipper Windpower, recently dropped the number of turbines it wants to build from 40 to 28, which could fast-track the process because state law allows smaller projects to be approved without a public hearing.

The Public Service Commission is expected to decide on Clipper Windpowers' application for a public-hearing exemption next week.

This is the second time the governor has created fissures among environmental supporters this year.

In April the O'Malley administration crafted a lawsuit settlement with Constellation Energy that granted Baltimore Gas and Electric ratepayers a one-time credit on their electric bills, but also cleared the way for construction of a third nuclear reactor at Calvert Cliffs.

Some environmentalists remain mum on that decision, while others have vocally opposed the new reactor.

Opponents of the US Windforce project on Backbone Mountain say they are not opposed to wind farms, just opposed to private exploitation of public land.

"It has been pointed out in the Maryland Energy Administration's recent report, 'there is no silver bullet' in dealing with Maryland's energy concerns," members of the Western Maryland delegation wrote in a letter to Mr. O'Malley's natural resources secretary in February. "As such, the exploitation of Western Maryland's pristine forests for private gain must not be permitted."

Many of the same opponents have said they would support placing wind farms on private land in Western Maryland, as some developers have already been permitted to do.

But wind energy supporters said that while many Americans support the concept of wind farms, nobody wants them built in their backyards.

"I see no other reason that can be justified, the only thing they use is the visual aspect of this: to me that's not an important enough reason not to build this," said Barbara Hill, executive director of Clean Power Now, which is fighting to build wind turbines off Cape Cod in Massachusetts.

The Cape Wind project, proposed in Nantucket Sound, has become a national "poster child" for the struggles of the wind industry, Mrs. Hill said. Politically-connected opponents, led by U.S. Sen. Edward M. Kennedy, a Massachusetts Democrat whose Hyannis Port home is 8 miles away from the site, have stalled the plan.

Mr. Tidwell and Mrs. Hill both said that constructing wind farms in the Northeast has always been a struggle, and the projects have often have been blocked by wealthy residents who don't want their views ruined.

"They know how the system works, and they know how to fight these things," Mrs. Hill said. "We don't have a lot of time."