Massachusetts and Rhode Island have announced offshore wind projects aimed at delivering a combined 1,200 megawatts of energy - or enough to power 600,000 homes.
The Vineyard Wind project will be Massachusetts' first offshore wind farm and is expected to generate 800 megawatts of energy. That's about 5.5 to 6 percent of the state's total annual electric load.
Massachusetts officials said that represents the largest single procurement of offshore wind by any state in the nation. Vineyard Wind was selected by Massachusetts over two other offshore wind proposals: Bay State Wind and Deepwater Wind.
Also Wednesday, Democratic Rhode Island Gov. Gina Raimondo said that the state had selected the same Providence, Rhode Island-based Deepwater Wind project that had been proposed for Massachusetts - a 400-megawatt offshore wind farm Revolution Wind.
Both projects, which the states described as a collaborative effort, will be located south of Martha's Vineyard.
Massachusetts' Republican Gov. Charlie Baker said the announcement brings the state "one step closer to achieving our administration's goals of creating a clean, reliable and cost-effective energy future for Massachusetts residents, and significantly reducing greenhouse gas emissions to combat climate change."
The announcement is the result of a 2016 bill Baker signed authorizing the largest procurement of renewable energy generation in Massachusetts' history, including approximately 1,600 megawatts of offshore wind energy. The remaining 800 megawatts will be awarded at a separate time.
Vineyard Wind said it hopes to begin delivering renewable energy to Massachusetts residents and businesses in 2021. The final acceptance of the bid and award of the contract is conditional on successful contract negotiations.
Lars Thaaning Pedersen, CEO of Vineyard Wind and the decision "reflects the strong commitment to clean energy" by Baker and Massachusetts lawmakers.
According to Vineyard Wind, the project consists of an array of wind turbines, spaced at least eight-tenths of a mile apart, that are each capable of generating over 8 MW of power. Vineyard Wind is a joint venture of Avangrid Renewables and Copenhagen Infrastructure Partners.
The team that reviewed the proposals in Massachusetts was made up of representatives from the state Department of Energy Resources and three utilities: Eversource, National Grid, and Unitil.
Deepwater Wind CEO Jeff Grybowski called the joint Massachusetts and Rhode Island announcements "the first really large-scale procurement ever for offshore wind in the United States."
"It means that offshore wind is no longer a growing industry, it really is an industry that's maturing," he said.
Local construction on the Revolution Wind project could start in Rhode Island in 2020 with commercial operations by 2023 with up to 50 turbines. Deepwater Wind already owns the nation's first offshore wind farm, a five-turbine farm off Block Island, Rhode Island.
The projects are part of a wider push for proposed offshore wind power along the East Coast, with other states - including New Jersey, Connecticut, Virginia and New York - pressing ahead with the goal of transforming the electric grid and providing energy to power millions of homes.
West Coast states are also looking to turn their offshore winds into energy.
U.S. Interior Secretary Ryan Zinke has said he hopes to help streamline the push for offshore wind power.
Emily Norton of the Massachusetts Sierra Club applauded the projects saying the state should try to procure the remaining 800 megawatts of offshore wind to help the state move toward a 100-percent renewable future.
The Massachusetts Clean Energy Center, a state economic development agency, said the creation of 1,600 megawatts of offshore wind power should create over 3,000 "job years" over the next 10 years.
A job year is defined as one person working full-time for one year.
This story has been corrected to show the number of homes that would be powered by 1,200 megawatts of energy is 600,000 not 400,000
Associated Press writer Jennifer McDermott contributed to this report.