Name and Location
Lower Churchill hydroelectric project, Labrador, Canada.

Client
Nalcor Energy.

Project Description
The hydroelectric potential of Muskrat Falls and Gull Island makes the lower Churchill river, in Labrador, the best undeveloped hydroelectric source in North America. The river has a combined capacity of more than 3 000 MW and will be able to provide 16.7 terawatt hours a year of electricity and significantly reduce greenhouse-gas emissions – which equates to taking 3.2-million vehicles off the road each year.

The Lower Churchill Project will be developed in two phases.

Phase 1 of the project, the Muskrat Falls project, includes an 824 MW hydroelectric generating facility at Muskrat Falls, the Labrador-Island Link (LIL) that will transmit power from Muskrat Falls to Soldiers Pond on the Avalon Peninsula, and the Maritime Link connecting Newfoundland and Nova Scotia.

The construction of the hydroelectric dam will consist of two dams and a powerhouse.

The proposed LIL will transport electricity from the generating facility, at Muskrat Falls, to the island of Newfoundland. It will be a high-voltage direct current (HVdc) transmission system 1 100 km long, with a 60-m-wide right-of-way, which will run from central Labrador, crossing the Strait of Belle Isle, and extending to Newfoundland’s Avalon Peninsula.

The transmission project includes building and operating:
• a converter station at Muskrat Falls (Labrador) to change alternating current (ac) power into dc power;
• a 400-km-long overhead HVdc transmission line from the Muskrat Falls converter station to the Strait of Belle Isle at Forteau Point;
• a 35-km-long underwater cable crossing the Strait of Belle Isle, from Forteau Point, Labrador, to Shoal Cove, in Newfoundland;
• a 700-km-long overhead HVdc transmission line from Shoal Cove to Soldiers Pond, in Newfoundland;
• a converter station at Soldiers Pond to convert the dc power back into ac power for distribution on the island’s electricity grid; and
• electrodes, or grounding systems, at L’Anse au Diable on the Labrador side of the Strait of Belle Isle, and at Dowden’s Point, in Conception Bay, Newfoundland.

The marine cable crossing will include the installation and operation of three marine power cables along the seabed across the Strait of Belle Isle. Using horizontal directional drilling (HDD) technology, two drill rigs will bore three holes from the shoreline under the seabed on both sides of the straits. Cables will be installed through the drilled holes and placed along the sea floor using a cable installation vessel. The cables will be covered by rock berms to protect them against marine traffic and fishing activity.

In addition to the proposed LIL, further transmission lines will be required in Labrador to transmit power between Muskrat Falls and the existing 5 428 MW hydroelectric facility in Churchill Falls. Two 250 km 315 kV high-voltage ac transmission lines will be built between the hydroelectric generating facilities in both locations.

A 480 km HVdc transmission link is planned between the island of Newfoundland and Nova Scotia. Construction of the maritime link will create a new connection from the island of Newfoundland to the North American power grid for the first time in history. This connection will improve the reliability of the province’s electricity system and provide a channel to export surplus power not immediately needed in the province.

Phase Two of the project entails the development of the 2 250 MW Gull Island generation facility and associated transmission to markets.

Value
Not stated.

Duration
The Muskrat Falls project was sanctioned by the government of Newfoundland and Labrador in December 2012 and construction is expected to take five years.

The proposed development of Gull Island will follow at least three years after the sanction of Muskrat Falls.

Latest Developments
In October, Nalco selected Astaldi Canada, a subsidiary of the Astaldi group, as the preferred contractor for the construction of major civil works for the Muskrat Falls hydroelectric generating facility. The contract is valued at C$1-billion.

The civil works package is the largest associated with the development, and the scope of work includes construction of the powerhouse, and the intake and gated spillway. The works are planned to start before the end of the year and last about four years.

Key Contracts and Suppliers
Astaldi Canada (civil works).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Nalcor Energy, tel +1 709 737 1440, fax +1 709 737 1800 or email lowerchurchill@nalcorenergy.com.
Astaldi, Alessandra Onorati, tel +39 06 41766389 or email a.onorati@astaldi.com.