Nova Scotia

Suspended Muskrat Falls deliveries expected to resume soon after software failure

The power interruption is the result of the latest software problem in the Labrador Island Link transmission system.

Labrador Island Link transmission system has been plagued by problems since its launch

The Muskrat Falls dam seen from overhead while under construction. The dam holds a large body of water in the top left of the photo, while water shoots out into a river at the bottom right. There's construction equipment on a dirt lot at the bottom left.
The Muskrat Falls hydro dam in Labrador has suffered many delays and is billions over budget. (CBC)

Deliveries of Muskrat Falls hydroelectricity to Nova Scotia are expected to resume soon after a software failure disrupted flow weeks ago, said Nova Scotia Power on Tuesday.

The power interruption was the result of the latest software problem in the Labrador Island Link (LIL) transmission system.

Jacqueline Foster, a spokesperson for Nova Scotia Power, said the utility was told by its Newfoundland and Labrador partner in the project that the problem would be resolved shortly.

"We have been advised by Nalcor that the LIL will be back up within the next week," Foster said in a statement.

The 1,100-kilometre Labrador Island Link carries electricity from the big hydro dam in Labrador to Newfoundland, where it connects with Emera's transmission system and is sent across the Cabot Strait into Nova Scotia via the Maritime Link.

But deliveries of the so-called Nova Scotia Block stopped after a fire sensor tripped one of the lines in February.

The software did not respond correctly and once again supplier GE Canada is searching for the cause of a deficiency with the Labrador link, which has suffered repeated setbacks.

Newfoundland Labrador Hydro told provincial regulators the link would "remain off line while these incidents are investigated."

Earlier on Tuesday, Foster said further testing was expected in April on the Labrador link.

A long history of problems

"It certainly is concerning," said consumer advocate Bill Mahody, who represents Nova Scotia Power's 400,000 residential customers in rate hearings.

"There's a relatively long history here of this portion of the project causing problems. But they're the types of problems that Nova Scotia Power Maritime Link has represented to the [Nova Scotia Utility and Review Board] were on their way to being resolved."

Ratepayers have been paying the Emera subsidiary Nova Scotia Power Maritime Link for the Maritime Link since 2018 and only recently started receiving full amounts of the Nova Scotia Block — supplying about 10 per cent of the province's electricity.

Full delivery arrived as the Nova Scotia Utility and Review Board considered Emera's application to recover $1.7 billion from Nova Scotia Power customers over the next 35 years.

Approval was given on Feb. 9, just two weeks before the Labrador Island Link was shut down by the latest software deficiencies.

Ratepayers protected in case of interruption   

Because of repeated delays, regulators built in some protection for ratepayers in their approval decision.

Nova Scotia Power has been ordered to hold back $2 million a month it collects to pay for the Maritime Link. The holdback is only released if 90 per cent of the energy for the Nova Scotia Block is received.

"That $2 million can be used to defray those costs, the cost for the energy that ratepayers would have to be paying for to replace the undelivered Nova Scotia Block," said Mahody.

The holdback doesn't kick in until April.

NL Hydro says shortfall will be made up   

Newfoundland Labrador Hydro confirmed Muskrat Falls deliveries have been suspended. Spokesperson Jill Pitcher said in a statement the Nova Scotia Block commitment "has not changed."

"Any deficit in deliveries resulting from this outage will be delivered at a later date," Pitcher said.

The Labrador Island Link still has not received final commissioning. GE had pushed completion of trial operations back to May 31.

On March 3, Newfoundland Labrador Hydro told the province's Public Utilities Board in St. John's that it "is not possible to predict the extent of any possible delay at this point in time."

Foster said deliveries of Muskrat Falls hydro flowed for most of February and stopped in March. 

Neither Nova Scotia Power nor Nova Scotia Power Maritime Link were required to disclose the disruption until the next quarterly report to regulators expected in mid-April.

The Maritime Link and Nova Scotia Block are critical to meeting Nova Scotia's goal of an 80 per cent renewable electricity supply by 2030.

Foster noted that when the Nova Scotia Block is interrupted, the company's Newfoundland partner will replace the energy in co-ordination with Nova Scotia Power at a later date.

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