Hydro seeks approval for major improvement to Island transmission system

Newfoundland and Labrador Hydro (Hydro) filed an application today with the Board of Commissioners of Public Utilities (PUB) to approve the construction of a new 230 kilovolt (kV) transmission line from Bay d’Espoir to the Avalon Peninsula.

The proposed Bay d’Espoir – Western Avalon line will reinforce the stability of the interconnected system once the Labrador-Island Link is in full operation. The estimated cost is $291.7 million and the line is proposed to be in service for 2018.

“The development of the 824 megawatt (MW) hydroelectric generating facility at Muskrat Falls and the 1,100 kilometre transmission line between Labrador and the island will significantly change our power system,” said Rob Henderson, Vice President, Newfoundland and Labrador Hydro.

“Upgrading this vital corridor between the Bay d’Espoir and Western Avalon Terminal Stations is essential in terms of providing additional capacity, relieving congestion, and enhancing the resiliency of the current transmission network.”

The primary reason for the new line is to maintain system stability following disruptions or faults on the interconnected power system. It will also improve the transport of energy to major growth areas in the Avalon region and provide capacity to enable the import of electricity over the Maritime Link to Newfoundland and Labrador if needed.

“Hydro completed significant engineering analysis, including hundreds of stability and load flow studies, to confirm that the line is necessary and is the best option to ensure optimal reliability levels once the island is connected with Labrador,” explained Henderson.

During the analysis leading to the decision to construct the Muskrat Falls Project, two primary long-term scenarios were investigated: the Isolated Island and Interconnected Island options. A third transmission line from Bay d’Espoir was required in both scenarios but for different reasons. The Isolated Island scenario would have meant the development of a series of smaller hydro, thermal and wind generating facilities and the new line would have been required to facilitate the delivery of electricity from these developments to the major load centre on the Avalon Peninsula.

This application follows a recent request from Hydro to approve the purchase of a 100MW (megawatt) combustion turbine to be in the service by the end of the year. Both projects have been part of ongoing analysis and included in Hydro’s long term generation planning analysis and capital investment plan for some time.

“We are moving forward with strategic and major capital investments to modernize our assets, build a robust electricity grid, and to ensure Hydro provides the best possible service to our customers over the long term,” said Henderson. “The next five years will see a major transformation of the province’s electrical system.”