Prolonged permitting delays by the Trump administration have thrown Vineyard Wind’s $2.8 billion wind farm south of Martha’s Vineyard further into flux, even as the state continues to take steps to promote the burgeoning offshore wind industry.

On Tuesday, the Bureau of Ocean Energy Management (BOEM), the federal agency of the Department of Interior that oversees permitting for the 84-turbine Vineyard Wind project, announced that a supplement to the project’s environmental impact statement would be delayed until June 12, while a decision on whether to approve or deny the project is now not expected until next December.

Vineyard Wind said in a statement on Tuesday that the most recent delay to the environmental impact statement means the project will not be online by 2022, as previously promised.

“While we need to analyze what a longer permitting timeline will mean for beginning construction, commercial operation in 2022 is no longer expected,” said Lars Pedersen, CEO of Vineyard Wind.

Vineyard Wind is a 50-50 joint renewable energy venture between the American company Avangrid Renewables and European counterpart Copenhagen Infrastructure Projects. The project — the first of its kind and the largest utility scale offshore wind development in the United States — saw a 500-page draft environmental impact statement issued by BOEM in December 2018. But late last summer the federal government announced it would indefinitely delay the final version of the report, suddenly putting crucial federal tax credits and complicated supply chains potentially at risk.

The environmental impact statement and approval by BOEM are mandatory before construction can begin on the wind farm project.

According to BOEM, the delay in the final EIS was in response to concerns from stakeholders and cooperating agencies about the cumulative impacts of offshore wind development along the Eastern seaboard. Agency spokesmen said more comprehensive analysis is intended to better address potential conflicts with other ocean users, including the commercial fishing industry.

In the months since last summer, BOEM has decided to write a supplement to the initial EIS responding to the concerns. While Vineyard Wind was the first utility-scale offshore wind development to ink a contract with the state Department of Public Utilities, the industry has grown substantially in the past three years, with projects in Connecticut, New York, New Jersey gaining traction and substantial local support.

There are five federal offshore wind lease areas in Massachusetts; Vineyard Wind’s area alone totals over 160,000 acres of open ocean.

Last August, BOEM gave an expected date of early 2020 for the new version of the EIS for Vineyard Wind, saying it may be available by March of this year. But BOEM has since expressed concern about changes to turbine sizing and other differences in early Vineyard Wind project proposals, culminating in the announcement Tuesday that the project will be delayed even further. The news had the effect of turning what were once headaches into a full migraine for the project that was expected to kick off the state’s offshore wind industry.

But despite the permitting lethargy at the federal level, enthusiasm for offshore wind remains strong in Massachusetts. On the same day as the announced delays by BOEM, Mayflower Wind, a second developer, sent its final energy pricing contract to the state DPU for approval.

The promised energy price — $58 per megawatt hour — marks the lowest offshore energy costs yet and is approximately 13 per cent lower than the price offered by Vineyard Wind when it signed a power purchasing agreement in 2018.

State Energy and Environmental Affairs secretary Kathleen Theoharides said the proposed pricing from Mayflower Wind will provide rate-payers an average savings of one to 1.8 per cent on their utility bills.

“We are excited about what the project means for the bottom line for Massachusetts rate-payers,” Ms. Theoharides told members of the press in a conference call Tuesday. “We’ve set prices far below what industry experts predicted years ago and really kicked-off the offshore wind industry here on the Northeast coast.”

The initial cap for offshore wind pricing was approximately $83 per megawatt hour.

A cooperative between an arm of Shell Oil and EDP Renewables North America, Mayflower Wind was selected last October to develop the second 800-megawatt offshore wind-farm in the state. Early plans indicate that the project will be located in a federal wind lease area approximately 25 nautical miles south of Martha’s Vineyard, slightly southeast of Vineyard Wind, planned for 15 miles south of the Island. Mayflower spokesmen said in an email that the estimated cost of the project was approximately $3 billion.

Both Vineyard and Mayflower Wind plan to connect their farms to mainland Cape Cod with undersea cables that will pass through the Muskeget Channel off the eastern shore of Chappaquiddick.

Vineyard Wind has cleared the local permitting process, but neither of the projects can begin without approval from BOEM.

There is growing tension in the matter between the Massachusetts congressional delegation and the Trump administration.

Sens. Elizabeth Warren and Ed Markey, along with Cong. Bill Keating and others, recently wrote a letter requesting a government accountability office review of the delay of renewable energy projects, as fossil fuel projects continue to win approvals.

“We are particularly concerned that there is ‘a double standard at play’ in which fossil fuel projects are expedited while renewable energy projects are delayed,” the letter said in part. “Despite seeking expedited environmental reviews for numerous fossil fuel infrastructure projects, Trump administration officials in the Department of the Interior have ordered a sweeping environmental review of the burgeoning offshore wind industry, a move that threatens to stall or even derail this growing industry . . . ”

Speaking to the Gazette by phone Tuesday afternoon, Congressman Keating was even more adamant, characterizing the delays as hypocrisy by the Trump administration that could threaten important offshore wind projects along the East Coast. He said he believed BOEM was ready to release the report by March, or even this past August, but said political pressure from higher-ups in the Department of Interior or executive branch pushed review of the project to December.

He noted the new date is after the 2020 presidential election.

“It’s clear to me that these are political decisions and not guided by wanting to mitigate environmental impacts,” Mr. Keating said. “This is infuriating because of the contradictions. It doesn’t even pass the red face test.”

Despite the setbacks, state energy administration officials expressed enthusiasm, if not optimism, for the industry in the phone conference Tuesday. And they cited Mayflower Wind’s low energy price point as a hopeful sign that shows the strength of the offshore wind industry.

“There certainly has not been a chilling effect on the industry here,” Ms. Theoharides said. “I think there’s a continued growth and momentum in the industry.”

State energy commissioner Patrick Woodcock added that he understood the need for a comprehensive federal review of the projects. He said Mayflower was aware of the issue when it submitted its bid last summer, and that a flexible schedule for that project, which aims to be operational by 2025, reflected federal permitting uncertainties.

“This bid by a sophisticated energy company was a bid that voiced confidence in the long-term industry and the offshore wind regulatory regime,” Mr. Woodcock said. “Make no mistake, doing significant renewable energy projects requires significant federal review from agencies, and it should be robust. But . . . this industry has developed faster than anybody anticipated.”