The U.S. Army Corps of Engineers this week gave Cape Wind Associates a green light to erect a single 197-foot-tall monitoring station in the shallows of Nantucket Sound.

The permit grants the private energy company permission to build just a single structure for collecting wind and water data - information that will further aid in state and federal environmental review of a proposed offshore wind farm. But the would-be developer of what is potentially the first such farm in the United States interprets permission from the Army Corps as a monumental hurdle.

"This authorization to install a scientific monitoring station represents a significant milestone in developing and evaluating our landmark project," said Cape Wind president James Gordon of his eventual intention to build a wind farm in a relatively shallow part of the sound known as Horseshoe Shoal.

The $2 million data tower, expected to be operational by fall, will log wind speed and direction, ocean currents, wave height and water salinity. It will be supported by steel pilings driven 100 feet into the sea bed.

The Army Corps, which has occupied center stage during wrangling among state, federal and local officials over who has permitting authority for a project just outside state waters, issued the permit after soliciting public concerns across the Cape and Islands last spring.

"Through review by Corps engineers and biologists in consultation with other federal, state and local agency representatives, we have concluded that the proposed project will not impact navigation and have minimal impact on the marine environment," said Christine Godfrey, chief of the Corps' New England district regulatory division. Ms. Godfrey noted that the permit did not imply property rights for Horseshoe Shoal.

The appropriateness of opening public waters to private enterprise has been a central element in debates from Beacon Hill to Capitol Hill, from yachts to commercial fishing boats. A sudden surge in proposals for wind farms in the waters surrounding the Cape and Islands - a clear indication that the region's strong winds, high energy costs and dense population will continue attracting wind energy projects to the Massachusetts coastline - added new energy to the debates.

New York-based Winergy LLC announced this month its intentions to construct a 231-windmill farm five miles off the southeast coast of Nantucket. According to officials, two more potential private wind projects are also being discussed for area waters.

While the developers reveled in Monday's news, critics of the project and a handful of government officials fueled a new wave of public outrage over Cape Wind's application to plant 170 wind turbines across 28 square miles of the sound.

U.S. Rep. William Delahunt held up a stop sign for all offshore wind projects Monday, calling for a comprehensive management plan spearheaded by Congress and the President to determine if and how the outer continental shelf will accommodate alternative energy projects in coming years. He urged a moratorium until Congress signs off on a long-range plan for wind farms in public waters.

U.S. Sen. Ted Kennedy added an amendment to an energy bill earlier this summer that requires the federal secretary of the interior to contract a study from the National Academy of Sciences to evaluate "potential for the development of wind, solar and ocean energy on the outer continental shelf; assess existing federal authorities for the development of such resources, and recommend statutory and regulatory mechanisms for such development."

In addition, the Alliance to Protect Nantucket Sound - a Cape Cod-based opposition group that has led public attacks against Cape Wind throughout the year - said it may challenge the Army Corps' permit in federal court.

But Cape Wind is taking the opposition in stride.

"If we thought we could get everyone comfortable, we'd be kidding ourselves," communications director Mark Rodgers told the Gazette last week. "But the facts are that global warming is here and energy demands are up. In that context, with every passing day, alternative energy becomes more important.

"No one project is going to save the day," he said. "But our only way out is to switch entirely away from fossil fuels."