Why the province's electricity operator issued 2 grid alerts this week

Alberta experienced two grid alerts this week, leading the province's electricity operator to dip into emergency reserves and urge industries and residents to lower their electrical consumption.

The alerts were issued at 6:14 p.m. on Tuesday and at 4:18 p.m. on Wednesday, lasting for about two hours each.

The Alberta Electric System Operator (AESO) says a grid alert is issued when the power system is under stress. It notifies customers, both industrial and residential, in hopes of avoiding the use of more serious measures, such as rolling blackouts.

"It got all the way up to Emergency Alert 3, which is the highest level alert. And at that point, what you're doing is you're chewing through the emergency reserves," said Blake Schaffer, assistant professor in the department of economics at the University of Calgary, in an interview on the Calgary Eyeopener.

Schaffer, who specializes in studying the province's power grid, says these dips into emergency reserves don't happen often. The AESO says the last grid alert happened in January, and rolling blackouts haven't happened for a decade.

But the perfect storm of events combined this week to add a significant strain to the province's power supply. 

Add to that some warmer weather than normal for this time of year — and demand spiked.

"We were never in any risk of having rotating blackouts or brownouts, anything like that," said Leif Sollid, manager of communications and stakeholder relations with the AESO.

"We just kind of had a number of things that came together."

To remedy the situation, Sollid says they eventually asked AltaLink, the energy transmission company that operates the intertie, to defer the maintenance. AltaLink agreed, but another shutdown will happen at a later date.

The AESO is always required to have backup power supplies at the ready, Sollid says. 

In exceptional circumstances, if the organization has depleted those emergency supplies, they can take a number of steps, including suspending energy exports or sales, implementing voluntary curtailment programs or initiating rotating power outages across communities.

Schaffer says he's confident in the province's ability to meet electricity demands over time, but he's worried about managing peak periods of use as the province continues its shift toward electrification.

"It's not like other commodities where the time you produce it and the time you want to use it isn't a big deal.… You produce and use electricity instantaneously," he said.