The moment is years in the making and at the same time a modest advance in what experts say needs to be a major buildout of this type of clean electricity to address climate change.

Danish wind energy developer Ørsted and the utility Eversource announced Wednesday the first electricity from what will be a 12-turbine wind farm called South Fork Wind 35 miles (56 kilometers) east of Montauk Point, New York. It will be New York’s first offshore wind farm.

Ørsted and Eversource met Wednesday with New York officials to celebrate this “first power” milestone, in East Hampton, New York, where the wind farm connects to the onshore electric grid. They say the achievement builds a foundation for other large U.S. offshore wind farms that will follow.

So far, two of the 11-megawatt turbines are up. The second is undergoing testing, then it can begin producing power too. When the other ten are spinning and South Fork opens by early next year, it will be able to generate 132 megawatts of offshore wind energy to power more than 70,000 homes.

The first power announcement is “an incredible moment in the American clean energy story,” said Stephanie McClellan, executive director of the nonprofit Turn Forward, which advocates for offshore wind. She said South Fork will be a source of clean, reliable, domestically-produced energy.

“This is just the beginning of what offshore wind can do,” she said in a statement.

Offshore wind is central to New York’s plan to transition to a carbon-free electricity system by 2040. The state aims to install 9 gigawatts of offshore wind by 2035.

“New York’s nation-leading efforts to generate reliable, renewable clean energy have reached a major milestone,” New York Gov. Governor Kathy Hochul said in a statement Wednesday. “South Fork Wind will power thousands of homes, create good-paying union jobs and demonstrate to all that offshore wind is a viable resource New York can harness for generations to come.”

Some Long Island residents at first objected on both environmental and aesthetic grounds to the transmission line running through their community. In a lawsuit four alleged that trenching under roads would spread contaminated groundwater. A judge dismissed their complaint in July.

The project has also overcome objections from fishermen and some environmentalists. Fishermen said they were not adequately compensated for their loss of fishing grounds. The group Save The Bay said the energy project shouldn’t be placed near such a rich diversity of fish.

Business groups and construction unions backed the project.

Large offshore wind farms have been making electricity for three decades in Europe, and more recently in Asia. The first U.S. offshore wind farm was supposed to be a project off the coast of Massachusetts known as Cape Wind. The application was submitted to the federal government in 2001. It failed after years of local opposition and litigation.

Turbines began turning off Rhode Island’s Block Island in 2016. But with just five of them, it’s not a commercial-scale wind farm.

Currently there are two commercial offshore wind farms under construction in the United States, South Fork Wind and Vineyard Wind. Vineyard Wind will be a 62-turbine wind farm 15 miles (24 kilometers) off the coast of Massachusetts. It has not started generating power yet, the developer said Monday. They’re installing and testing five turbines first.

At State Pier in New London, Connecticut, blades and massive tower sections for South Fork are lined up, ready to leave port for the sea where they’ll be erected in the coming weeks. The nacelles that house the generator for each wind turbine are there, too.

On Monday, a barge carrying three blades and a nacelle for the third turbine left port. As Jeff Martin, of Eversource, watched, he said it was a “joy” to see the industry finally move from concept to fruition in the United States, to help reduce the nation’s dependence on fossil fuels.

“Finally we’re taking this step to catch up with the rest of the world and do our part to collectively address climate change,” said Martin, Eversource’s director of business development for the offshore wind group.

Large, ocean-based wind farms are a linchpin of government plans to shift to renewable energy in populous East Coast states with limited land for wind turbines or solar arrays. The Biden administration aims to power 10 million homes with offshore wind by 2030 and establish a carbon-free electric grid five years later.

But the industry has had hard times recently. Ørsted announced it’s cancelling two large offshore wind projects in New Jersey due to problems with supply chains, higher interest rates and a failure to obtain the amount of tax credits the company wanted. Developers in New England recently canceled power contacts too, saying their projects were no longer financially feasible. The series of setbacks for the nascent U.S. offshore wind industry jeopardizes the clean energy goals.

Other projects though, are advancing. Ørsted is moving forward with Eversource on construction of Revolution Wind, Rhode Island and Connecticut’s first utility-scale offshore wind farm. The 704-megawatt project will power roughly 400,000 homes. Tower sections, blades and nacelles are expected to begin arriving in New London as early as this spring.

South Fork and Revolution Wind are a “bright spot for a challenged industry,” said David Hardy, group executive vice president and CEO Americas at Ørsted.

“As we demonstrate that we can build this project and build Revolution, then people will realize the real opportunity of offshore wind,” he said.