Rotating brownouts leave thousands of Albertans without power Friday

Tens of thousands of Alberta households lost power Friday morning as a shortage of electrical generation prompted the province’s electrical system operator to temporarily cut usage.

At least seven major power plants were generating little to no electricity early Friday afternoon, according to information on the Alberta Electric System Operator website.

AESO issued a grid alert at 6:49 a.m., meaning the province’s electricity consumption was at risk of exceeding supply.

When the Keephills 2 natural gas plant west of Edmonton tripped offline two hours later, AESO asked power distribution companies, including Edmonton’s Epcor and Calgary’s Enmax, to “undertake rotating outages,” AESO spokesperson Diane Kossman said in an emailed statement.

Enmax turned off power to about 25,000 Calgary customers for about 14 minutes, a spokesperson said in an email.

Epcor shut off power to about 20,000 customers across Edmonton for less than 30 minutes, a spokesperson said.

Although wind speeds were lower than forecast, limiting available wind power, the sun had not yet risen to generate solar power by the time AESO issued the grid alert.

At 1:30 p.m., AESO’s website showed Alberta continued to import power from B.C., Saskatchewan and Montana, as demand outstripped generation. The operator is holding a news conference at 2 p.m. MT.

AESO also issued a grid alert on Wednesday evening this week.

Blake Shaffer, an associate professor of economics at the University of Calgary specializing in electricity, called the brownouts a “far more serious situation” than the power demand crisis Alberta experienced in January.

A combination of record cold, surging power demand and some gas plants offline led Alberta to issue an emergency alert Jan 12, 2024, pleading with the public to turn off appliances and lights to relieve an overtaxed grid.

Friday’s challenge was a result of numerous plants being simultaneously offline with little help from solar and wind power, Shaffer said. Any rapid loss of power from major plants is difficult for an electric system operator to manage, he said.

“People like to assign blame on power system woes to their least favourite generation technology,” Shaffer said. “And the reality is, all generation technologies have reliability challenges.”

Rolling brownouts help protect essential equipment from losing power, he said.

“It avoids that catastrophic sudden blackout by just reducing load — involuntarily, mind you — but in a controlled manner,” Shaffer said.

The operator released data in January showing the alerts are becoming more frequent.

Shaffer said there are steps the province could take to make the system more flexible, including allowing more power exchange with adjacent provinces and states, and building a second intertie with B.C. between the northern portions of the provinces.

He said Alberta could embrace smart metering and flexible demand, incentivizing customers to use more power at times outside peak demand. The province could also encourage the construction of “peaker plants” that can generate or distribute a lot of power, quickly, on short notice.