Thousands lose power after Muskrat Falls transmission lines malfunction again

The outages lasted up to 55 minutes, according to Newfoundland and Labrador Hydro. (Nalcor Energy - image credit)
The outages lasted up to 55 minutes, according to Newfoundland and Labrador Hydro. (Nalcor Energy - image credit)
Nalcor Energy
Nalcor Energy

About 31,000 people across Newfoundland lost power Monday evening in the latest of a series of failures for two transmission lines connected to the Muskrat Falls megaproject.

Customers in multiple locations, including St. John's, Corner Brook, Stephenville and the Burin Peninsula, lost electricity for up to 55 minutes.

In a statement issued Tuesday morning, a spokesperson for Newfoundland and Labrador Hydro said the power outages stemmed from a trip of a transmission line near Stephenville and the Maritime Link, the transmission line connecting Newfoundland to Nova Scotia.

That event affected Newfoundland Power customers in the Stephenville area.

According to Hydro, the Maritime Link tripped again while it was brought back into service. The Labrador-Island Link, also known as the LIL, did not trip during that event, but power flow decreased from 450 megawatts to 175 megawatts, causing power outages in other parts of the island.

"These trips are designed to protect the system from further equipment issues, but in the process, customers may be disconnected from the electricity grid for a brief time, usually less than 30 minutes," reads the statement.

The LIL was brought back up to 422 megawatts, and power was restored.

Hydro did not identify the cause of the malfunction but said an investigation into the event is ongoing.

A series of setbacks

The outages are the latest in a series of setbacks for the Muskrat Falls megaproject and its transmission lines.

Hydro has repeatedly delayed commissioning the LIL, which cost $4 billion and runs 1,100 kilometres from Muskrat Falls to the Avalon Peninsula, due to software problems.

In mid-November, 57,000 Newfoundland Power customers lost power when the Maritime Link malfunctioned. That power outage was caused by what officials referred to as an "under-frequency load-shedding event." It's unclear if the same problem led to Monday's outage.

On Nov. 24, the LIL failed a major test, causing widespread outages and forcing officials to cancel subsequent testing while they searched for answers.

In December and early January some sections of the LIL fell to the ground during freezing rainfall. Hydro is attempting to determine the cause of the failure.

Read more from CBC Newfoundland and Labrador