Green Line

Converter Sites And Cable Routing

Green Line will include two new HVDC converter stations, one in Maine at the northern end of the DC line, and one in Massachusetts at the southern end of the DC line. HVDC converter stations convert between AC and DC power, thus enabling direct current power to flow through the new DC transmission line and alternating current power to synchronize with the existing AC grid.

Converter stations have a footprint of 5 to 20 acres. The building structure is similar in appearance to a medium scale industrial building with an adjacent electric switchyard and can be designed to be compatible with the character of the surrounding built or natural environment.

TERRESTRIAL AND SUBMARINE ROUTING

The terrestrial segment of the Green Line within the state of Maine will be installed primarily within an existing railroad right of way in which NEITC has acquired the exclusive right to transmit electricity.  Use of the existing railroad corridor minimizes the amount of new greenfield right of way and will reduce the overall environmental impact by using already disturbed land.  Further, DC transmission lines require less right of way width than comparable AC lines that would transmit equivalent amounts of energy. Electro-magnetic fields associated with DC transmission lines are far less expansive than those associated with AC transmission lines.

In the marine environment, the transmission line will be in the form of a cable beneath the Gulf of Maine between Maine and Massachusetts. Water depths in the Gulf range from zero feet in shoreline areas to 900 feet in an area known as Murray Basin, which is 36 nautical miles east of Rockport, Massachusetts. Water depths are generally 480 feet or less within 12 nautical miles of the shoreline. The cable length and water depths are well within the design and construction parameters of existing submarine cables installed and operating around the world.

Industry News

The New England States Committee on Electricity (NESCOE) sent a letter to ISO-NE on January 21st announcing an agreement of the six New England States to issue “one or more requests for proposals…to advance the development of transmission infrastructure that would enable delivery of at least 1200 MW and as much as 3600 MW of clean energy into the New England electric system from no and/or low carbon emission resources.”… (Read the full letter.)

Benefits

Green Line will strengthen the transmission grid in New England and help provide greater access to competitively priced non-carbon emitting resources in Maine and eastern Canada. Read more…

Media Coverage

Governor LePage (ME) and Governor Patrick (MA) issue press releases announcing agreement on moving ahead with new regional infrastructure.  (See releases here…)



New England Independent Transmission Company, LLC | 401 Edgewater Place, Suite 640, Wakefield, MA 01880 | 781-246-9851