The developer was TransÉnergie U.S., a subsidiary of Hydro-Québec. The owner is now ARGO Infrastructure Partners.
ABB provided a complete 330 MW ±150 kV HVDC Light transmission system with maximum current of 1,175 amperes. The system is made up of two high-tech extruded (oil- free) cables buried under the seabed, and includes fiber-optic cables for phone and Internet data transfer.
DC allows for precise control of power flow and transfer capability in either direction, helping to improve reliability of power supply in regional grids, and enabling increased sharing of power plant capacity.
Construction began in 2002, and the cable was trenched on the floor of Long Island Sound. Commercial operation began in mid-2003. Cable landfalls and other facilities are located on existing waterfront utility property. On land construction was minimal; impacts to marine and coastal resources were short term and localized.
The Cross-Sound link improves the reliability of power supply in the Connecticut and New England power grids, while providing urgently needed electricity to Long Island. The HVDC Light connection is also designed to promote competition in the New York and New England electricity markets by enabling electricity to be traded among power generators and customers in both regions.