Steven Brown, editor in chief
On a damp, overcast October morning, I was invited to attend the dedication of a facility that promises a bright energy future for Long Island, N.Y., residents. It was an occasion that might also mark the beginning of a flurry of activity in the high-voltage direct current (HVDC) transmission business.
More than 350 people gathered at the Duffy Ave. converter station to formally dedicate a new undersea HVDC transmission link between Sayreville, N.J., and Long Island dubbed the “Neptune Project.” It is the largest underwater system in the United States and gives the Long Island Power Authority access to 660 MW of reliable, competitively priced electricity from the 13-state PJM energy grid. The project includes more than 50 miles of underwater and 14 miles of underground high-voltage cable supplied by Italy’s Prysmian Cables & Systems. On either end of the cable, 30,000-square-foot converter stations were built in Sayreville, N.J., and at Duffy Ave. in New Cassel, N.Y., where the dedication ceremony took place. Siemens Power T&D was awarded the contract to build the HVDC interconnection in July 2005 and successfully commissioned the cable at the end of June 2007.
Speaking at the dedication ceremony, former LIPA chairman and CEO Richard Kessel, called Neptune the “most important power project ever in Long Island” and noted that it gives LIPA customers access to an “energy supermarket,” referring to the access the link provides to power generated in PJM. Kessel further noted that with the commissioning of the Neptune HVDC system, LIPA goes from “the most unreliable utility in New York to the most reliable.”
FERC commissioner Philip Moeller agreed when he addressed those gathered at the dedication, saying: “This is a big day in the history of Long Island. For essentially the first time ever, Long Island is connected to the national grid.”
Long Island is in a situation where it’s not feasible, mainly for environmental reasons, to build new power plants on Long Island or near the city to cover the city’s power demands. The HVDC link to New Jersey provides an unobtrusive, cost-effective conduit to PJM’s rich and varied generation sources. The end result is more power supplied to Long Island without building additional power generating facilities. LIPA has estimated that in its first 100 days of operation, the Neptune HVDC link has saved LIPA $20 million, in large part due to the lower cost of power generated in PJM.
During information sessions after the dedication ceremony, it was reported that Siemens Power T&D has been contracted to construct a similar undersea HVDC link between San Francisco’s electrical power grid and a substation near Pittsburg, Calif. This new project—the Trans Bay cable project—will employ Prysmian cable, just like in the Neptune Project, but will mark the first use of Siemen’s new “HVDC Plus” technology. Siemens says the main advantages of its new HVDC Plus over traditional HVDC are increased network security and reliability and reduced system losses. There was also discussion during the Neptune dedication ceremony of a proposed 140-mile underwater HVDC link which would connect Maine to South Boston. This proposed HVDC project is dubbed Green Line because of its ability to delivery “green power” (mainly wind and hydro) from Maine into the Boston area.
The now-functional Neptune project and the future Trans Bay and Green Line projects are demonstrating HVDC’s ability to supply power to congested urban areas where building new generating facilities isn’t feasible. With the dedication of Neptune, the future looks brighter for Long Island and for power transmission in general.