NYPA cable between LI, Westchester has been 'unreliable' for months, LIPA chief says

Another major power cable to Long Island has been experiencing problems for the past half year, but the problems could be fixed before month’s end.

The so-called Y-49 cable, a 26-mile line that provides 637-megawatts of capacity from Westchester to Long Island, has "not been reliable for the last six months," said LIPA chief executive Tom Falcone. The cable’s owner, the New York Power Authority, had made repairs to address the problems in December and February, but the problems with land-based equipment persisted, he said.

"These [problems] are supposed to be rare," Falcone said, adding the cable hasn’t been as reliable as LIPA would expect for a 30-year-old cable. "It clearly has an issue." The Y-49 cable runs under Hempstead Harbor and the Long Island Sound, but its underwater portions aren’t the problem.

NYPA in a statement said the cable has "had a few recent internal faults."

"Repair work on the recent fault is nearly complete and we are expediting the restoration work to put the line back in service as soon as possible," perhaps by April 19, the agency said.

Meanwhile, NYPA said it is working with PSEG Long Island "to assess the overall health of the transmission asset and implement a long-term strategy for its reliability and resiliency going forward."

It's not the only undersea-cable snafu impacting Long Island.

There are similar land-based equipment problems with the 660-megawatt Neptune Cable, after a giant transformer failed last fall and December, taking half of the line out of commission. The Neptune cable itself, traversing 65 miles under the Atlantic from Sayreville, New Jersey, did not experience problems. Falcone said the transformer won't be replaced until year's end.

Long Island is fed by five undersea power lines that provide around 40% of the grid’s power, through links to generally lower-cost power sources, including the mid-Atlantic PJM and the New England grids. Falcone said he’s expecting the Y-49 cable problems to be fixed well before the peak summer season, when air conditioning use pushes Long Island capacity to its highest point of the year. He noted cable outages could reduce the wide margin of excess capacity in the region, but said they aren’t cause for major concern.

"It will certainly be tighter but we’re planning for that tightness," Falcone said. "PSEG is reviewing it and has contingency plans."

He added that the Long Island grid "appears to have adequate capacity. We’re very focused on it. But we clearly would like the infrastructure to function as it’s been designed for."

A possible expansion or upgrade of Y-49 is being contemplated as Long Island becomes a major jumping off point for offshore wind energy for the state. An upgrade would allow the greener power to flow back and forth from Long Island to the upstate grid. "It’s being evaluated," Falcone said.

In 2014 a barge damaged the Y-49 cable after it dropped anchor over the line in Hempstead Harbor, causing over 6,600 gallons of cable insulator fluid to leak out and requiring a $35 million repair. The Cross-Sound Cable had also been out for around six months last year, but was restored in January. That 24-mile cable connects to Long Island at Shoreham from New Haven, Connecticut.

Another cable connects at Northport to the power grid in Norwalk, Connecticut. A fifth connects Glen Cove to a power substation in Westchester.

By Mark Harrington

mark.harrington@newsday.comMHarringtonNews

Mark Harrington, a Newsday reporter since 1999, covers energy, wineries, Indian affairs and fisheries.