Project Experience
PowerBridge and key members of the Cascade Project development team are directly responsible for the successful development, permitting, financing, construction, and current operation of two major underwater HVDC projects in the northeastern United States. These projects are summarized below, with further detailed information available on individual websites for these projects.
The Neptune Project
The Neptune Project is a 660 MW (500 kV) high-voltage, direct current (HVDC) submarine electric transmission system, completed in 2007, that connects power generation resources in the PJM system to electricity consumers on Long Island. The cable extends from Sayreville, New Jersey to the Long Island Power Authority (LIPA) Newbridge Road substation in Levittown, Long Island, a distance of 67 miles.
Converter stations are located at Sayreville and at Duffy Avenue (community of New Cassel, near Hicksville) on Long Island. The majority of the route – more than 50 miles -- is underwater in the Raritan River, New York Harbor, and Atlantic Ocean; 14 miles are buried in the existing right-of-way of the Wantagh State Parkway.
Neptune’s two converter stations, which are virtually identical, were built under the direction of Siemens and employ Siemens “HVDC Classic” LCC power conversion technology. The converter stations require no fuel or combustion and produce no air emissions or discharges of pollutants. The Neptune cables were manufactured by and installed under the direction of Prysmian Cables and Systems. Three underwater cables are bundled and buried four-to-six feet under the river and sea beds. On land, the cables are buried three-to-four feet below ground in separate conduits. The Neptune project includes no overhead transmission lines.
Neptune Converter Station - Sayreville, NJ
Successful completion of Neptune required permits and approvals from multiple agencies and jurisdictions (some overlapping), including the U.S. Army Corps of Engineers, New York State Public Service Commission, and the New Jersey Department of Environmental Protection, as well as local approvals. Starting in 2005, the PowerBridge team raised more than $650 million in debt and equity financing and oversaw the two-year construction and cable installation process. The project was completed ahead of schedule and within budget in June of 2007. PowerBridge has managed the administration and operation of Neptune since completion. Since 2007, Neptune has provided more than 20 percent of the electricity consumed on Long Island and has averaged more than 98 percent availability.
The Hudson Project
The Hudson Project cable vessel exits New York harbor following the marine cable installation
Like Neptune, the Hudson Transmission Project is a 660 MW HVDC underwater transmission link between New York and PJM Interconnection. While the basic technology for Neptune and Hudson is the same, Hudson features a single “back-to-back” AC-DC-AC converter station in Ridgefield, New Jersey. AC power from PJM is transmitted at 230 kV from the PSE&G Bergen substation in Ridgefield underground for approximately a quarter mile to the converter station, where it is converted to DC power, then back to AC at 345 kV. The power is then transmitted via three miles of cable buried underground and three and a half miles of cable under the Hudson River before making landfall near Pier 92 and under the West Side Highway to West 52nd Street in Manhattan. The cable then proceeds underground to the Con Edison West 49th Street substation.
As with Neptune, the Hudson converter station was designed and built by Siemens, while the underground and underwater cables were manufactured and installed by Prysmian Cables and Systems. The single back-to-back converter station occupies approximately eight acres on the former site of a warehouse facility. The actual AC-DC-AC conversion takes place within the building.
The 345-kV underground cable follows existing railroad rights-of-way to a site in Edgewater, NJ, where it enters the Hudson River and proceeds southward, primarily in New York waters, to the Manhattan landfall.
Like Neptune, Hudson was constructed and is operated under the authority of three major permits, including a New York State Article VII Certificate, a Department of the Army Permit, and a New Jersey DEP Waterfront Development Permit. In addition, the converter station was built under the authority of the New Jersey Meadowlands Commission, which has zoning jurisdiction over the site.
Construction of the project began in May 2011 and was completed ahead of schedule and on budget, in June 2013. The Neptune and Hudson projects are operated and maintained jointly by Siemens under the oversight of PowerBridge employees, with specialized technical expertise available when needed from Siemens and Prysmian.
