Interior Secretary Ken Salazar on Wednesday approved the construction of a controversial wind farm off the coast of Cape Cod that puts the Obama administration at odds with one of the president's biggest supporters: the Kennedy family.

Salazar's decision will affect thousands of residents, local businesses and tourists who flock to the seashore paradise each summer -- and sets the course for the building of other such offshore wind farms in states from New York to Michigan.

The Cape Wind project, which will be the first in the nation, had created a bipartisan jumble that pit environmentalists and lawmakers against each other on both sides of the dispute over the 130 planned turbines -- whose windmill arms would extend over 400 feet above the water.

Salazar said the decision marks a "new direction in our nation's energy future," claiming the wind farm will be "one of the largest greenhouse gas reduction initiatives in the nation," cutting carbon dioxide emissions from conventional power plants by 700,000 tons annually.

Click here for more on the controversial project from Molly Line.

An artist's rendering of what the Cape Wind Project in Nantucket Sound would look like.

The offshore wind farm, to be built five miles off the Massachusetts coast, has been blasted by critics like the Kennedy clansmen as an "economic boondoggle" that will cost taxpayers billions, hurt commercial fishing and pose a danger to wildlife along a pristine stretch of the Nantucket Sound.

"It's a boondoggle of the worst kind," Robert F. Kennedy Jr., an environmental lawyer and the son of the late Bobby Kennedy, said in an interview Tuesday with FoxNews.com. "It's going to cost the people of Massachusetts $4 billion over the next 20 years in extra costs."

The late Sen. Ted Kennedy, D-Mass., an avid sailor who had been a leading opponent of the project, contested the project up until his death last August. He claimed that taxpayers already hit with the highest energy costs in the nation will be forced to pay double the price of a land-based wind system. 

"We're the windiest country on earth and we have lots and lots of land" on which to build wind farms, the younger Kennedy said. "Americans don’t want to pay 27 cents a kilowatt hour for energy."

Kennedy's opposition is also shared by Sen. Scott Brown, R-Mass., and Rep. Bill Delahunt, D-Mass., whose district includes the Cape. The two penned a joint letter last week to Salazar, asking him to bring together all "stakeholders" of the project to reach a consensus decision on the project. An "up or down" decision, they wrote, would result in years of legal battles over its development.

"It is the American people who are providing the public space for this project and it is the American people who are being asked to provide hundreds of millions of dollars in subsidies to the developers," wrote Brown and Delahunt. "The people most affected should have a seat at the table on this project."

Critics, like Delahunt and Brown, say they are not opposed to offshore wind farms but favor building them in deeper waters, like in Germany and Scotland. 

On Wednesday, Salazar addressed many of the criticisms, saying the government will demand that developers "minimize and mitigate" any potential adverse impacts on the environment.  He also said the project has been scaled back from 170 turbines to 130, and that he will require the developers to make the them less visible from the shore. 

The offshore wind farm, which would cost an estimated $1 billion to construct, has been heralded by several environmental agencies and six East Coast governors as a breakthrough in alternative energy production.

Massachusetts Gov. Deval Patrick as well as governors in Rhode Island, New York, New Jersey, Maryland, and Delaware each support the project. Rep. Ed Markey, D-Mass., praised the project on Wednesday as a "cleaner way to power America."

"With this historic decision, the answer to America’s energy future is blowing in the wind," Markey said in a statement.  "The same winds that delivered the Mayflower to Massachusetts and created the Perfect Storm will now deliver a clean energy future to Massachusetts and create new jobs."

The ocean winds along the eastern sea board are among the strongest in North America, proponents say, and the project would be a critical step in developing clean sources of energy and reducing emissions of greenhouse gases.

"It’s the Saudi Arabia of wind," said Amy Kempe, press secretary for Rhode Island Gov. Donald Carcieri. "So long as due diligence is done, something tells me that fish can swim around [turbines] just as cattle can move around them on the plains."

Some environmental groups have also expressed a plethora of concerns over the project -- from effects on marine life and the local economy to potential public safety hazards and risks to air traffic control and a disturbance to sacred tribal land.

Audra Parker, president and CEO of the Alliance to Protect Nantucket Sound, said at least three endangered species inhabit the waters eyed for development, including North Atlantic right whales and two bird species, which could be adversely affected by the building.

Parker also claimed that fishing boats and commuter ferries in the sound -- one of the busiest waterways in the country -- could come dangerously close to the turbines’ spinning blades, particularly during stormy weather conditions.

The Humane Society of the United States is calling for a more adequate review of Cape Wind's impact on the environment, according to Sharon Young, the society's marine issues field director. And the Advisory Council on Historic Preservation, an independent government agency, has also said the department should "not approve the project," claiming that the "indirect and direct effects" of the turbines would "be pervasive, destructive, and, in the instance of seabed construction, permanent."

Officials at Cape Wind, which is headed by Energy Management Co., told FoxNews.com that the plan has been subjected to nine years of thorough regulatory review on the state and federal level.

"This project has undergone the closest scrutiny and by all measures has shown the benefits outweigh the [negative] impacts," added Robert Keough, spokesman for the Massachusetts Office of Energy and Environment Affairs.

Supporters of the wind farm continually cite a February study conducted by the Charles River Associates, employed by the project's developers, which suggests Cape Wind could save $4.6 billion in energy costs over the next 25 years.

Cape Wind spokesman Mark Rogers said the "visual impact is driving most of the opposition to the project" -- a claim Kennedy and others say they reject.

"Some people like the way wind turbines look, others do not," Rogers said in an interview.