Nalcor Energy is proposing to develop the Labrador - Island Transmission Link, a High Voltage direct current (HVdc) transmission system within and between Labrador and the island of Newfoundland.

The Project will include the construction and operation of an approximately 1,100 km long transmission line from Gull Island, in the central region of Labrador, down to Soldiers Pond on Newfoundland's Avalon Peninsula.

Purpose and Rationale

A key purpose and rationale for the proposed Transmission Link is to put in place infrastructure to further interconnect Newfoundland and Labrador with the North American electricity system, and thus, set the stage for further development and growth in the province's energy sector and overall economy.

As currently planned, the ± 450 kV HVdc transmission system will include the following key components:

Gull Island Converter Station: A facility on the north side of the Churchill River to convert a portion of the ac (alternating current) electricity from the Lower Churchill Hydroelectric Generation Project into dc (direct current) form.

Transmission Line - Gull Island to Strait of Belle Isle: An overhead HVdc transmission line, consisting of single galvanized steel lattice towers (averaging 43 m in height) along a cleared right of way approximately 407 km long and averaging 60 m wide.

Strait of Belle Isle Cable Crossings: The placement of three to five submarine cables within two 27-36 km long corridors across the Strait, installed beneath the seabed through tunneling, trenching, rock placement and/or other means to provide the required cable protection.

Transmission Line - Strait of Belle Isle to Avalon Peninsula: An overhead HVdc transmission line, up to approximately 760 km long with similar characteristics to that described in the Gull Island to Strait of Belle Isle section.

Soldiers Pond Converter Station: A facility to convert the dc electricity transmitted across the HVdc system back into ac form, for distribution to and through the island grid.

Electrodes: A high-capacity grounding system at each end of the HVdc line to assist in system stability and to provide an alternate return path in a fault condition event whereby a conductor becomes temporarily out of service. The link will be connected to their respective converter stations via overhead wood pole lines.

Project planning and design are currently at a stage of having identified a two km wide corridor for most of the on-land portions of the proposed HVdc transmission line and 500 m wide corridors for the proposed Strait of Belle Isle cable crossings, as well as various alternative corridor segments in particular areas. Potential on-land corridors and study areas have also been identified for the proposed electrodes.

The size of these corridors will be reduced where specific transmission line routes will eventually be selected within these corridors on the basis of technical, environmental and socioeconomic considerations and after consultation with the public.

The Transmission Link presents an opportunity to transmit 800 megawatts (MW) of power from the proposed Lower Churchill Hydroelectric Generation Project to the island, and can therefore also play an important part in ongoing efforts towards securing an adequate, reliable and sustainable electricity supply to address the current and future needs of the province's residents and industries.

It will also be designed to accommodate for future developments or market decisions that require additional power be transported over the HVdc system for use and/or export. For example, the link design provides an option to be extended and deliver up to an additional 1,000 MW to the Maritime Provinces through a potential Maritime Link with no changes to the operating voltage or the overland transmission lines.

The proposed Transmission Link is in keeping with, and represents a key component of, the provincial Energy Plan which was released by the Government of Newfoundland and Labrador in September 2007.