Grid alert results in temporary outages for thousands of Edmontonians

Thousands of Edmonton residents were briefly left in the dark on Friday morning as a result of rotating outages.

Epcor said it had implemented the rotating outages on the request of the Alberta Electric System Operator, after a grid alert was issued shortly before 7 a.m. due to "tight supply."

"The AESO has directed Epcor to help manage power consumption in the province," Epcor wrote in a post on social media at 9:11 a.m. MT. "Rotating outages are now in effect in Edmonton."

The outages impacted about 30 neighbourhoods, primarily in north and south Edmonton.

A total of 19,412 customers were without power, according to Epcor.

However, by 9:34 a.m. the outages had ceased.

"Rotating outages have now stopped as the AESO has ended its directive for Epcor to reduce power consumption across Edmonton," Epcor said in a new social media post. "A grid alert is still in place for the province. Please take steps to conserve power where you can."

At 11:18 a.m., AESO sent out an update that the grid alert had ended.

This is the second time in this week AESO has issued a grid alert.

On Wednesday, AESO issued an alert at 7:26 p.m. that ended at 8:40 p.m.

The AESO's vice president of grid reliability addressed the situation on Friday afternoon.

"Although our studies the evening prior indicated that we would have 800 megawatts of extra supply available. The wind generation that materialized was 900 megawatts below forecast," Marie-France Samaroden told reporters about the Friday alert.

"At 8:49 a.m., we had a thermal generator trip offline, which resulted in a loss of 400 megawatts. The AESO then directed our transmission and distribution partners to shed 250 megawatts of load."

Samaroden said additionally, other generators were offline for planned outages, and getting generators back online can take time.

"Some of the older units can take upwards of eight to 12 hours to ramp up to full capacity," she said.

"Some have shorter time frames of four hours. And so you really get quite the gamut of time for these units to ramp up."

Samaroden says the AESO provides a 24-month forecast outlook to operators, which helps them determine how to plan for outages.

"We are looking to improve our forecasts as best as we can, however, the reality is that we can't control the wind and the sun. And so we do our best to forecast and have mitigation measures in place."

Alberta's premier was asked about the AESO alert on Friday morning.

Danielle Smith says the province is looking at incentivizing power producers to ensure there's a consistent power baseload available in the province.

"The minister has talked about having a day-ahead market so that we know who is going to be down, who is going to be on so that we can actually plan the reliability."

But one expert says that his main concern is with the Friday claims from AESO.

"The AESO presented this as a confluence, perfect storm, a nice analogy they always like to use in this," Blake Shaffer told CTV News Edmonton.

Shaffer says the public numbers provided by AESO for Friday morning don't match up with Samaroden's numbers.

"I'm just pulling up the data here, because you can see 12 hour ahead forecast data from the AESO. They post this publicly."

"We shouldn't be missing by 900 megawatts on wind forecasts. Like I said to you, the data shows that 12 hours ahead they missed the actual by 37 megawatts, so I’m not sure where 900 is coming from."

With files from CTV News Edmonton's Jeremy Thompson