Neptune Regional Transmission System

Neptune Regional Transmission System

The Neptune Regional Transmission System is a high-voltage power cable network connecting New Jersey and Long Island, New York, delivering up to 660 MW of electricity to the Long Island Power Authority and serving more than 600,000 homes. Spanning approximately 65 miles—50 miles underwater and underground and 15 miles alongside parkways—the system ensures a reliable and largely invisible power link between regional grids.

Neptune is a prominent project utilizing high-voltage direct current (HVDC) technology, featuring a 500 kV DC cable and advanced HVDC converter stations, with Siemens supplying the HVDC equipment. The project exemplifies HVDC’s role in efficiently transmitting bulk power over long distances, especially through underground and submarine applications.