Doubling down on its commitment to renewable energy, the Massachusetts Legislature overwhelmingly passed a new energy measure that would create the nation’s most ambitious offshore wind energy target.

The bill, approved in the final hours of the legislative session Sunday night, would require local utilities to get 1,600 megawatts of their combined electricity from wind farms far offshore—roughly equivalent to three average-sized coal-fired power plants. The law requires the utilities to line up contracts for that energy by 2027. They also would have to arrange for even more clean energy from other sources, including hydropower, by 2022. Gov. Charlie Baker, a Republican, is expected to sign it.

There’s about 1,800 megawatts of renewable energy (mostly solar) currently installed in Massachusetts.

The bill would contribute to the state’s broader effort to reduce greenhouse gas emissions by 80 percent by 2050—a target that effectively requires the state to rely almost entirely on renewables for electricity. And it could also have broader implications for the nation’s offshore wind industry, which has yet to make its first splash.

The new measure doesn’t require that all new clean energy come from within the state—at least some of the electricity will likely come from Canadian hydropower plants. But experts say the legislation sends a signal to the clean energy industries, especially offshore wind developers, that New England’s waters are open for business.

“This new state policy is head and shoulders above the other [offshore wind] procurement requirements in the nation and I think we are going to see real movement and real momentum coming from this legislation,” said Nancy Sopko, advocacy and federal legislative affairs manager with the American Wind Energy Association.

Despite a few proposed projects, the East Coast doesn’t yet have a single energy-generating turbine in its waters. Federal regulatory uncertainty, permitting snags, high infrastructure costs and local resistance have left some projects in limbo for more than decade, including the 130-turbine Cape Wind off Massachusetts’ Cape Cod.

The nation’s first offshore wind farm, a 30-megawatt demonstration project off Rhode Island’s coast, is nearing completion. When it goes online by the year’s end, it will have five turbines anchored to the ocean floor, with enough capacity to power about 17,200 homes.

So far four companies have won federal offshore wind leases for Massachusetts’ waters, and several more have been granted leases along the East Coast, from New York to North Carolina. The federal government is also planning to open up sections of the Pacific Ocean for offshore wind development.

One of the companies angling to build a utility-scale wind farm off Massachusetts, the Denmark-based Dong Energy, hailed the new bill as a “landmark moment for Massachusetts’ clean energy future.”  

“With world-class wind speeds and ideal water depths of between 130-165 feet, Massachusetts will be able to garner the economic benefits and supply chain development of being the first mover to site utility-scale offshore wind energy on the East Coast of the United States,” the company said.

The state Senate voted unanimously for the bill H.4568  and the House voted 157-1; both chambers have Democratic majorities.

According to the bill, companies will have to solicit bids for getting power from offshore wind projects by June 30, 2027 and those proposals can only be for projects with a capacity of at least 400 megawatts. That means each project will be able to power hundreds of thousands of homes.

Based on back-of-the-envelope calculations, the 1,600 megawatt wind target would provide about 5.6 million megawatt-hours (MWh) of electricity per year. (This assumes the wind farms produce about 40 percent of their capacity, about what European offshore wind farms achieve.) The bill also specifically calls for utilities to get an additional 9.45 million MWh of clean energy annually from sources such as hydro. Massachusetts currently uses about 55 million MWh of electricity per year, meaning the clean energy resources used to hit the targets in this bill could provide about 27 percent of the state’s electricity needs.

Beyond the offshore wind goal, environmentalists, clean energy advocates and workers cheered the bill’s creation of a property-assessed clean energy (PACE) program to help finance energy efficiency upgrades and clean energy for commercial buildings. The measure also calls for partnerships between Massachusetts and its New England neighbors on  energy projects. But those same supporters have also noted that the fight to expand clean energy in Massachusetts is far from over.

“We are certainly happy to see the offshore wind piece of the bill move forward,” said Ben Hellerstein, director of the green nonprofit Environment Massachusetts. But, he added, “we need an energy policy that’s going to get us to 100 percent renewable as fast as possible. [This bill is] a step in that direction but it’s not as big a step as we actually need.”

The Global Warming Solutions Act, passed in 2008, mandates that the state reduce its greenhouse gas emissions 25 percent by 2020 (compared to the state’s 1990 emissions levels) and 80 percent by 2050. It is one of the most ambitious climate goals in the country.

The state also has a renewable energy standard that requires Massachusetts to increase the amount of electricity it gets from clean energy sources by 1 percent a year. For 2016, the state is on target for its goal of 11 percent, according to the Massachusetts Department of Energy Resources

An earlier version of the energy bill out of the Senate had called for a doubling of the rate to 2 percent a year, but it didn’t make it past the negotiations that shaped the final measure.

“That was the final give on the Senate’s part, and it was no small give,” said State Sen. Ben Downing (D-Pittsfield), according to MassLive.

Also taken out of the final bill was a prohibition on funding pipeline projects through electricity rate increases. State utility regulators are currently reviewing proposals for three natural gas pipelines; at least one of them calls for increasing customer electricity rates to help pay for the project, a proposal that has outraged environmental and community activists, and is opposed by the state’s attorney general.

The day after Massachusetts passed its energy bill, New York energy regulators announced they had updated the state’s clean energy target to 50 percent by 2030. This new goal puts New York on par with California, and is among the boldest clean energy goals in the nation. But unlike in California, New York’s goal includes dramatically increasing the state’s reliance on nuclear energy, a controversial form of carbon-free energy.

Between Massachusetts and New York, the amount of new clean energy demand “that’s been created in a 24-hour period is a real watershed moment for the region,” said Andrew Gohn, a state policy director at AWEA. “It’s never going to be the same.”

Correction: A previous version of this story incorrectly described New York’s new energy goal as a “renewable energy target” instead of a “clean energy” one. This story was also updated to include more detail about New York’s plan, which involves increasing the state’s reliance on nuclear energy.