The New England Clean Energy Connect (NECEC) is a cross-border electricity transmission project connecting Quebec, Canada, and Maine, US to deliver Canadian hydroelectricity to the New England grid in the US. The project will supply clean electricity to approximately 1.2 million homes in the New England region.
The cross-border transmission project is being developed through a partnership between Iberdola’s US-based sub-holding company Avangrid and Hydro Quebec, a Canadian public utility that manages electricity generation, transmission, and distribution in the province of Quebec.
The NECEC project, involving the construction of approximately 233km of high-voltage direct current (HVDC) transmission line, will be capable of transmitting 1,200MW of clean renewable electricity from Canada to the US.
The project was granted the final approval by the Maine Department of Environmental Protection (MDEP) in May 2020. The construction works on the £743m ($950m) project are expected to be started by the end of 2020 with the commissioning expected by the end of 2022.
The project will create more than 1,600 jobs during the construction period and reduce annual carbon emissions by approximately 3.1 million metric tonnes (Mt) once operational.
Project route and components
The NECEC transmission project comprises more than 333km of new HVDC transmission line as well as the upgrade of approximately 80km of existing alternating current (AC) transmission lines.
In Québec, the transmission route will stretch for approximately 100km from the Appalaches sub-station in Saint-Adrien-d’Irlande to a connection point on the Québec-Maine border. The new transmission line will run for approximately 75 km from the Appalaches sub-station to the Mégantic substation in Nantes municipality and from there it will further run for 23km to the crossing point at the Canadian-US border.
In the US side, the new HVDC transmission line will run for approximately 85km from Beattie Township in Maine near the Canadian border to merge with an existing transmission line right-of-way (ROW) in The Forks, Maine, for another 151km to Lewiston.
A new DC/AC converter substation will be constructed in Lewiston, Maine from where power will be distributed to the New England power grid. The project also involves a new 345 kilovolt (kV) substation in Pownal, Maine.
New England Clean Energy Connect
Apart from a 320kV HVDC transmission line from the Appalaches sub-station in Saint-Adrien-d’Irlande to the Lewiston sub-station in Maine, the NECEC transmission project will also involve a new 42.6km 345kV alternating current (AC) transmission line from the existing Coopers Mills substation in Windsor to the Maine Yankee substation in Wiscasset.
Approximately 26km of 115-kV AC transmission line between substations at Larrabee Road and Surowiec, a 15km AC line between Crowley Road and Surowiec and a 1.2km AC line outside the Coopers Mills will also be undertaken as part of the project.
The project will use single steel poles standing 30.5m-tall and spaced approximately 305 meters apart for the 320kV portion of the transmission system. The 345-kV and 115-kV lines will utilise a variety of structures including 125ft-tall steel structures, 80ft single-pole structures, 75ft wooden H-frames, and 45ft wooden, single-pole structures.
Hydro Quebec will construct a new AC/DC converter station at the Appalaches substation to supply power to the transmission line. A new DC-to-AC converter station will be built on Merrill Road in Lewiston. A new substation will be constructed on Fickett Road in Pownal to receive the transmission from Lewiston.
Cianbro, Maine’s largest general contractor, in a joint venture with Irby Construction, Sargent Electric, and Northern Clearing was awarded a contract to build, upgrade and provide land clearing for the project in April 2020.
Cianbro and Irby Construction will construct the new high voltage DC transmission (HVDC) line from the Canadian border to a substation in Lewiston, Maine under a joint venture partnership.
The transmission line upgrades will be performed by Sargent Electric, while Northern Clearing will be responsible for all clearing works and access road improvements.