The Long Island Power Authority is on the cusp of making the most significant decision about generating electricity with noncarbon fuel since it shut down the Shoreham nuclear power plant in 1992.

LIPA wants to green-light the building of 15 large wind turbines in the Atlantic Ocean that will deliver a net of 75 megawatts of power to the South Fork, one of the few spots on the Island where demand is increasing. It’s a small amount of generation, compared with Shoreham, which was projected to deliver 540 megawatts, but the wind farm under contract to LIPA would be the largest in the nation to harness the power of ocean wind.

LIPA being in the lead for anything other than bad news is difficult to comprehend, but adding wind power to its already substantial residential solar program is an impressive achievement.

Despite the postponement of a vote two weeks ago, LIPA trustees are expected within weeks to approve the start of negotiations with developer Deepwater Wind. The turbine project, located 30 miles east of Montauk and 19 miles south of Block Island, will not be visible from land. It already has all federal approvals and is supported by East End officials. An undersea and underground cable would connect to an existing substation in East Hampton, causing little of the usual disruption of building transmission lines.

The Deepwater Wind option was one of 21 submitted in response to a PSEG-Long Island request for proposals to solve the energy deficit on the South Fork.

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Other proposals were simply nonstarters, such as burning biofuels, which would mean frequent deliveries of fuel on large trucks, as well as dirty emissions. A solar farm would have required the purchase of 350 acres, not easy to find or afford in the Hamptons.

While the final contract hasn’t been negotiated, the project is expected to cost all ratepayers $1.20 a month when it comes online. That’s a rate LIPA chief executive Thomas Falcone said was competitive with the cost of power from gas-fueled plants, in part because there are no expensive school taxes or other payments to local governments that come with land-based power plants. The project is considerably cheaper per megawatt than a much-larger proposal by the same developer that LIPA rejected because of the high cost in 2014.

LIPA’s turbines would be built in the vast Rhode Island-Massachusetts wind-energy zone where the nation’s first offshore turbine was mounted on a steel platform only a few days ago. The field’s first project, with five turbines generating 30 megawatts, will deliver power to Block Island and Rhode Island via undersea cables by the end of this year. LIPA estimates a megawatt of wind power is enough to power roughly 465 homes.

It’s the early stage of a massive ocean field leased by Deepwater Wind that is 256 square miles, or 163,840 acres, an area that could eventually host turbines producing about 4,500 megawatts. It’s so large that in theory it could power most of Long Island, where peak use so far this year is 5,400 megawatts.

Meanwhile, LIPA is looking west to Long Island’s South Shore to launch an even bigger wind project. It could generate a sizable amount of megawatts by 2024.

This big push for offshore wind is a major part of Gov. Andrew M. Cuomo’s ambitious energy policy, and if he succeeds, it would be one of his most measurable and consequential legacies.

The state Public Service Commission last week approved a Clean Energy Standard. It calls for 50 percent of all electricity used in the state to come from wind and solar generation, as well as hydroelectricity from Canada, by 2030. Offshore wind is key to reaching that goal.

The standard also supports continued nuclear generation upstate as part of the portfolio. Those plants and the hydropower already generated at Niagara Falls are the reasons why New York already ranks among states with the lowest greenhouse gas emissions.

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In the next few weeks, the New York State Energy Research and Development Authority is expected to release an initial blueprint for offshore wind. LIPA’s South Fork project is already included. NYSERDA will bid later this year for an 81,000-acre site, described as having the potential to be the Saudi Arabia of renewable fuel, along the outer continental shelf, south of Rockaway peninsula.

Should NYSERDA win the lease in the upcoming auction by the federal Bureau of Ocean Energy Management, it will conduct a competition among developers for the construction of wind farms to provide power to LIPA and Consolidated Edison.

This project already has some considerable obstacles. The triangle-shape field, at its tip, is only 12 miles south of Long Beach and visible on the horizon. NYSERDA would be wise to develop areas farther from shore. However, the Coast Guard recommends that the turbines not be built too far away, in busy shipping lanes. Environmental reviews are sure to raise concerns, too.

But those are questions for another day, problems that are, after all, about how to best harness a plentiful and clean natural resource that over time might reduce the future cost of electricity.

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That’s a powerful place for Long Island to be.