Offshore Wind Energy Cable Would Be Seen Onshore One Winter Only

If 15 wind turbines, each 600 feet tall, are constructed in the Atlantic Ocean east of Montauk to send enough electricity to power all of the South Fork, the only physical evidence of the project in East Hampton itself would be the installation of an underground 40-mile-long cable.

Engineers said this week that all the on-shore installation work, snaking the approximately 9 miles from northern Amagansett to the LIPA substation in East Hampton Village, would be performed over one winter off-season so as to minimize traffic disruptions.

Clint Plummer, the vice president of development for Deepwater Wind, the company that has the contract with LIPA to supply power from the wind farm, said that the trenching and laying of the power cable could be completed in three to four months, starting in the winter of 2021-22.

“It would be the same as when they put in a new sewer line or water main,” Mr. Plummer said. “We open up 700-foot sections, lay in the conduits, pour concrete around them and fill in the trench. It will be done with maximum sensitivity to the traffic concerns out there.”

The company has released a map of its preferred route for the cable conduits: starting at the East Hampton substation and following the LIRR tracks to Route 114 and then up to Route 27 and east to Amagansett to Abrams Landing Road and then making a left onto Fresh Pond Road and continuing until it reaches the water.

Deepwater has also identified possible alternative routes that would put the conduits under Stephen Hands Path and Cedar Street and then snake through northern back roads to Town Lane and Old Stone Highway, rather than following 27, but the route would be much longer, more expensive and time-consuming to follow.

The company has also identified an alternative potential landing site for the cable near Lazy Point and running under Cranberry Hole Road or possibly Napeague Meadow Road to the highway.

Whichever landing site is chosen, when the cable reaches the edge of Gardiners Bay its underground journey will not end. The tentative plans call for a horizontal drilling machine to bore an underground tunnel a foot or two in diameter through the earth landward of the shoreline, running several feet below the beach and dunes and then through the bay bottom to a point 600 to 1,500 feet out into the bay where it would meet the cable coming from the turbines 40 miles away.

The cable from the turbines has, thus far, been among the most controversial aspects of the project. Fishermen have voiced concerns that the construction of the turbines, which must be anchored to the sea floor, will disrupt fishing and that electromagnetics from the power cable will drive away fish.

The company has countered that the cable is no different than the numerous power transmission cables that already snake across the sea floor between Long Island and Connecticut and New Jersey.

Like the onshore version, the undersea cable will be buried 4 to 6 feet below the surface of the bay bottoms to protect it from damage by fishing gear or wayward ship anchors. The cable will follow a trenching machine that uses either water or a mechanical boring tool to dig a trench in the sea floor and bay bottom, into which the trailing cable is laid and covered as material settles back into the trench.

“Suffolk County, the State Department of Environmental Conservation and local officials will play big roles in the selection of the final route into the bay,” the Deepwater executive said. “We have to take a lot of things into consideration, including the location of shellfish beds and fixed-gear fishing that goes on in those areas.”

The cable itself would be just 8 to 12 inches in diameter.

“It’s like a very big backyard extension cord—if you’ve ever run one over with the lawnmower you see that it’s basically three cables twisted together and wrapped in plastic,” Mr. Plummer said. “This is the same thing, only bigger, and wrapped in steel armoring.”

The survey work for the project will begin this summer, the company says, with detailed mapping and sampling of the bottom of Gardiners Bay, Block Island Sound and the Atlantic to determine the best exact route for the cable.

The project timelines call for three years of surveying and public discussion of the project while permits are secured. If approvals go according to plan, the physical work would commence in 2021 and the turbines would come online in the fall of 2022.

Distributing the 90 megawatts of power from the turbines would require that the existing East Hampton substation be expanded, though Mr. Plummer said by how much is not yet known. LIPA owns 17 acres of land around the substation, though only a small percentage of it is disturbed.

“There’s still a lot of engineering to do on that but right now every summer LIPA has to fire up all four diesel generators there and they’re noisy, they’re dirty and they smell,” Mr. Plummer said. “Our project will mitigate that need by injecting clean power.”