June 3 (Reuters) - Power transmission developer PowerBridge LLC said on Monday its $850 million, 660-megawatt (MW) underwater Hudson River transmission line from New Jersey to Manhattan started delivering power to customers in New York City about six weeks ahead of schedule.
The line is capable of providing about 5 percent of New York City's peak demand, privately held PowerBridge, of Fairfield, Connecticut, said in a release. One megawatt powers about 1,000 homes in New York.
The total length of the Hudson cable is about 7.5 miles (12 km), with a line buried under the Hudson River for about 3.5 miles and buried underground for about four miles, starting in Ridgefield, New Jersey.
The line connects the Bergen substation in New Jersey owned by a unit of New Jersey power company Public Service Enterprise Group Inc to the West 49th Street substation in Manhattan owned by New York power company Consolidated Edison Inc.
PowerBridge said its Hudson Transmission Partners affiliate started construction of the project in May 2011.
The state-owned power company New York Power Authority (NYPA) buys electricity from New Jersey over the Hudson line to serve its government customers in the New York City area.
The project uses High Voltage Direct Current (HVDC) technology to convert electricity from alternating current to direct current power, and then back to AC power at a converter station in Ridgefield, New Jersey.
The principal contractors on the project were German engineering firm Siemens AG, which supplied the HVDC equipment, and Italian cable company Prysmian SpA, which supplied and installed the cable.
The line under the Hudson River is PowerBridge's second major underwater project since it completed the 660-MW Neptune project in June of 2007.
Neptune extends 65 miles between New Jersey and Long Island, supplying about 20 percent of Long Island's electric needs since going into service.
Hudson and Neptune provide access to power from the PJM energy grid, the biggest power grid in the United States.
PJM serves 61 million people in 13 mid-Atlantic and Midwest states and the District of Columbia.
PowerBridge is also developing the proposed 1,000-MW West Point Transmission line, an 80-mile cable underneath the Hudson River between Athens and Buchanan, New York that would provide access to less expensive and renewable energy from upstate New York for customers in the New York City area.
Hudson Transmission Partners is managed by PowerBridge. Other partners include Anbaric LLC of Wakefield, Massachusetts and Triton LLC of Portland, Maine.
Principal investors in the Hudson Transmission project are Energy Investors Funds through its United States Power Fund II LP and Starwood Energy Investors LLC, an affiliate of Starwood Energy Group Global LLC.