Neptune

THE PROJECT
The Neptune is a high-voltage direct-current (HVDC) transmission link between New Jersey and Long Island, New York, consisting of a 65 mile electric transmission line from Sayreville, New Jersey to Nassau County on Long Island via undersea and underground cables. Built using state-of-the-art undersea transmission technology, the Interconnection represents an environmentally friendly solution for Long Island to access competitively priced power resources on the US mainland without building new "on-island" power generation facilities.
ROUTE LENGTH
82 km submarine portion
20 km land portion
TRANSMITTED POWER
660 MW
VOLTAGE
500 kV DC
CABLES
Submarine and Land
HVDC (M. I.) 2100 mm2
MV Metallic Return (XLPE) 2000 mm2
2 F. O.
Land only
1x1600 mm2 XLPE 345 kV AC
1x2500 mm2 XLPE 230 kV AC
INSTALLATION
Submarine
Barge Prysmian I and C/S Giulio Verne
Land
HDD (Horizontal Directional Drilling) in conduit