A new report shows the burgeoning offshore wind industry could collectively save New England electricity ratepayers hundreds of millions annually.

If already-in-place plans between Massachusetts, Rhode Island, and Connecticut for several offshore wind projects become reality, it will save ratepayers between $2.79 and $4.61 a month on their electrical bills, according to a report produced by Synapse Energy Economics on behalf of the Sierra Club released on Tuesday.

That may not seem like much at first, but when you multiply it out among the region’s many residences and businesses, it works out to be a savings of $630 million annually.

“Offshore wind is New England’s greatest shot at curbing the impacts of the climate crisis and getting our communities off the gas roller coaster for good,” Sierra Club Northeast Deputy Regional Field Director Andrea Callan said in a statement.

The report, titled “Charting the Wind,” shows that savings could grow to more than $1.3 billion in some years, depending on natural gas prices, and that 9 gigawatts of offshore wind power could result in a 42% reduction in CO2 emissions from New England power production plants.

More wind power could, the report shows, halve the amount of natural gas that’s burned to produce power in New England, resulting in more than $362 million in “annual public health benefits by avoiding 3,700 short tons of NOX emissions, 824 tons of SO2 emissions, and 641 tons of PM2.5 emissions annually.”

Not spending $3 billion for gas would also mean, according to the report, that the region would “retain approximately $1.57 billion that would have otherwise flowed out of the region for natural gas fuel.”

Kate Sinding Daly, Senior Vice President of Law and Policy at the Conservation Law Foundation, said the report demonstrates there is a way to protect the climate and the health of New England’s residents while looking after their wallets.

“This study demonstrates just how much offshore wind can save our families and businesses from costly electricity bills and devastating climate impacts. It reaffirms that this clean energy resource is a win for us and every generation moving forward,” she said.

The report comes as Massachusetts, Rhode Island, and Connecticut each work toward individual climate and renewable energy goals, which Sierra estimates should result in 9 GW of wind-driven energy hitting the New England electrical grid by 2030.

It also comes after the April announcement by U.S. Department of the Interior that they would open offshore regions of the Gulf of Maine to bids from anyone willing to provide up to 15 GW of power.

Last year, Gov. Maura Healey announced Massachusetts would join it’s southern New England neighbors in seeking bids for the generation of 6 MW of offshore wind power. In March, Vineyard Offshore, Avangrid Renewables, and SouthCoast Wind submitted bids to produce some of that power.

Paul Craney, a spokesman for the Massachusetts Fiscal Alliance, cast doubt on the report’s findings.

“Offshore wind is so expensive to the ratepayers that during the last round of bids, the state redacted the costs from the public. It’s so expensive, that even the offshore wind companies paid to cancel their previous contracts in order to bid again at higher prices,” he said.

“The reality is, there’s never been an attempted industrialization of our ocean at this scale and the unknowns are potentially extreme costs immediately and in the future,” he said. “The one constant is that prices have only gone up.”