LIPA and PSEG on Thursday completed negotiations with Deepwater Wind for a 15-turbine wind farm 30 miles from Montauk Point, paving the way for LIPA trustees to vote on the nation’s first large-scale offshore wind contract.

LIPA spokesman Sid Nathan confirmed contract negotiations “successfully concluded” Thursday night, but declined to comment further. Gov. Andrew M. Cuomo last week telegraphed the contract’s completion and urged LIPA board members to approve it.

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Newsday has previously reported the project would produce 90 megawatts of power and raise average residential customer bills by around $1.20 a month. The project will also require $513 million in grid upgrades on the South Fork that will add $2.48 more to average customer bills when all the work is completed by 2026, for a total average monthly bill hike of $3.67.

LIPA has previously said it expects the project to be completed by December 2022, an ambitious six-year schedule given the many environmental studies, permits and approvals required.

The South Fork upgrade also includes 10 megawatts of large battery storage, eight megawatts of demand reduction initiatives, including remotely adjustable thermostats to shave power needs, and short-term use of emergency generators in Montauk and East Hampton. The 15 turbines would be located due south of the Rhode Island coast between Block Island and Martha’s Vineyard, and require a transmission line more than 30 miles long to bring the energy back to the South Fork.

Transmission line limitations on the South Fork could limit the total amount of power from the project to around 75 megawatts, Newsday has previously reported.

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A megawatt of offshore wind power can provide enough energy for about 320 homes, according to the American Wind Energy Association, an industry group in Washington, D.C.