Cross-Sound Cable

Cross-Sound Cable
Name	Cross-Sound Cable
Country	United States
Start	New Haven, Connecticut
Finish	Shoreham, New York
Length	25.6 miles
Capacity	330 MW
Voltage	345 kV HVDC
Operator	Anbaric (formerly)
Construction	2002
Commissioning	2002

Cross-Sound Cable The Cross-Sound Cable is a submarine high-voltage direct current transmission link between New Haven, Connecticut and Shoreham, New York that connects the New England Independent System Operator area with the New York Independent System Operator. It was constructed to increase electricity transfer capacity across the Long Island Sound and to integrate generation and load centers in Connecticut, Rhode Island, Massachusetts, and New York. The project has intersected with regulatory bodies such as the Federal Energy Regulatory Commission, state agencies like the Connecticut Department of Energy and Environmental Protection and the New York State Energy Research and Development Authority, and stakeholders including utilities and environmental organizations.

Overview

The Cross-Sound Cable is a 345 kV HVDC submarine cable designed to transmit approximately 330 megawatts of power across the Long Island Sound between New Haven and Shoreham. It links the ISO New England footprint with the NYISO control area, enabling power transfers that affect regional transmission planning overseen by the North American Electric Reliability Corporation and market settlements under the Federal Energy Regulatory Commission. The facility’s converter stations interface with the alternating-current networks of utilities such as United Illuminating, Eversource Energy, PSEG Long Island, and formerly connected with merchant projects seeking capacity exports to Long Island and New York City.

History and Development

Planning for a submarine interconnection emerged in the 1990s as restructuring of the Public Utility Regulatory Policies Act era markets and the advent of regional transmission organizations encouraged cross-state transfers. Proposals engaged state actors including the Connecticut Public Utilities Regulatory Authority and the New York State Public Service Commission, along with federal review by the United States Army Corps of Engineers for marine permits. Construction commenced in the early 2000s amid debate involving environmental groups such as the Sierra Club and local municipalities including the Town of Brookhaven and the City of New Haven. The line was completed and entered service in 2002, during a period of substantial investment in transmission similar to projects like the Hudson Transmission Project and interconnects to the Millstone Nuclear Power Plant and other generation resources.

Route and Technical Specifications

The submarine route crosses the Long Island Sound along a corridor from New Haven to Shoreham near Long Island. The system uses a buried high-voltage direct current cable assembled with multiple layers of insulation, armoring, and a metallic return buried beneath seabed sediments regulated by the National Marine Fisheries Service and the National Oceanic and Atmospheric Administration. At each landfall, converter stations transform AC to DC and back using thyristor-based converters comparable to technology deployed in the Neptune Regional Transmission System and the other regional links. The capacity of roughly 330 MW at 345 kV nominal voltage permits firm transfer capability used for energy arbitrage, congestion relief, and reliability support under NERC standards and FERC interconnection rules.

Environmental and Legal Issues

Environmental review considered impacts on marine habitats including concerns raised under the Marine Mammal Protection Act and the Endangered Species Act for species in Long Island Sound waters. Litigation and permit disputes involved parties such as the Town of North Haven and advocacy by the Natural Resources Defense Council about cable burial, electromagnetic fields, and fisheries interactions affecting stakeholders including the Commercial Fishermen’s Association and recreational anglers. Legal processes invoked the National Environmental Policy Act and federal permitting by the Army Corps of Engineers, with mitigation measures coordinated with the Connecticut Department of Energy and Environmental Protection and the New York State Department of Environmental Conservation.

Ownership and Operations

Originally developed by private developers and utility consortia, ownership and operational responsibilities have changed through sales, contracts, and asset management agreements involving entities such as merchant transmission firms and regional utilities including PSEG and third-party operators. Day-to-day operations are coordinated with ISO New England and NYISO for scheduling, congestion management, and reliability dispatch following rules set by FERC and performance standards from the North American Electric Reliability Corporation. Maintenance and emergency response planning coordinate with maritime authorities like the United States Coast Guard and local harbor masters for New Haven Harbor and Long Island Sound ports.

Economic and Energy Impact

The Cross-Sound Cable affects wholesale markets by enabling energy transfers that influence locational marginal prices in New England and New York City, supporting resource adequacy in both regions and providing alternative supply paths during outages at facilities such as the Indian Point Energy Center prior to its retirement. The link supports merchant participation, transmission investment signals overseen by FERC and state commissions, and integration of diverse generation including natural gas-fired plants, renewables such as offshore wind planned off Rhode Island and New England coasts, and imports from neighboring market areas. Economic analyses by regional planning bodies have weighed its effects on congestion rents, capacity market dynamics like those administered by ISO New England and NYISO, and the broader resilience of the Northeast power grid.

Category:Electric power transmission systems in the United States Category:Submarine power cables Category:Energy infrastructure in Connecticut Category:Energy infrastructure in New York (state)