A high voltage direct-current undersea transmission line proposed from South Brunswick, N.J. to Huntington, N.Y. has received interconnection approvals from the PJM Interconnection and the New York Independent System Operator, a spokesman for the developer said on March 9.

The line is anticipated to deliver 500 MW of low-cost energy to the downstate New York grid in Long Island that is capable of powering about 500,000 homes.

With NYISO approval on March 6 of the 82-mile line’s reliability impact study, the New York Public Service Commission has begun a formal project review, said developer Poseidon Transmission.

The firm did not release the estimated cost of the project, which is intended to help relieve congestion in the lower New York area.

Poseidon Transmission is a subsidiary of Anbaric, a HVDC transmission developer with headquarters near Boston.

The transmission line will be built underground and under the sea. It is the second such project Anbaric has built between New Jersey and Long Island. The 660-MW Neptune project was completed in 2007. It runs 65 miles between Sayreville, N.J. and New Cassel, N.Y. on Long Island.

“The fact that Poseidon will interconnect seamlessly with both NYISO and PJM demonstrates the project’s superior design,” Clarke Bruno, senior vice president of Poseidon Transmission, said in a statement.

Poseidon claims the project will produce $573 million in direct wholesale energy cost savings and yield $2.5 billion in cost savings for Long Island ratepayers during its first 10 years in service.

The benefits are based on the benefits provided by the Neptune transmission line, the company said.

The Poseidon line will replace power that Long Island typically obtains from the Indian Point nuclear plant on the Hudson River in Westchester County. The Poseidon project will anchor Long Island to PJM’s lower cost, high-efficiency generation portfolio, the company said.