The day Alberta almost went dark

How did Alberta - Alberta! - almost lose power during last week's cold snap?

January 24, 2024

On Thursday, January 11th, Alberta set an all-time record for electricity use. Alberta’s hourly demand peaked at 12,384MW, beating the 12,193MW record set in December of 2022. There were no emergency alerts regarding the electricity market that day. No grid alerts were called, nor were panicked calls made for exports from Saskatchewan or B.C. You probably didn’t even know it had happened.


Because on Thursday afternoon, wind generation provided roughly 1,100MW through that challenging hour, and for much of Thursday. The day was a non-event.

The same cannot be said for last Friday, Saturday or Sunday.

At roughly 6:45pm, an emergency alert was sent out to all Albertans asking that we conserve electricity. You might have thought we’d set another record that day, but we didn’t. System load peaked Saturday at 11,802 MW, which ranks as the sixth highest daily peak in Alberta history.

We should have been covered. Why weren’t we? The simple answer is project delays.

We had higher demand not only on Thursday, but also on Wednesday of last week when we first nearly broke the 2022 record. The biggest change from earlier in teh week was that on Saturday, wind generation barely registered on the Alberta Electric System Operator dashboard: during the time when system reserves plunged perilously close to zero, Alberta’s entire wind fleet generated less than 20 MW.

Basically nothing. And that was the news story. The wind let Alberta down, and don’t get me started on the solar power shutting down at sunset.

Who could have foreseen this?

It turns out that the electric system operator could have foreseen and indeed did foresee this very thing coming like a train on the prairies. We knew the cold snap was coming, and the AESO wind forecast was nearly perfect. It also reveals just how lucky we really were this past week.

Imagine an alternative world where, instead of happening from Wednesday through Monday, the cold snap and the low-wind event had all shifted by two days and happened from Monday through Saturday.

If that had happened, there’s a very good chance some or all of the province would have gone dark on one of the days of the cold snap.


Historically, electricity demand is a little lower on Friday and much lower on the weekends (our grid alerts on Saturday and Sunday happened on the 15th- and 36th-highest electricity demand days we’ve ever seen in Alberta), and that was enough to get us through the crisis. It wouldn’t have taken much to push us over the edge. On Thursday, peak hourly loads on the system were almost 300MW higher than they were on Friday, and 600-700MW higher than they were on Saturday and Sunday. If Thursday’s loads that high had been combined with the low wind and limited import availability that we saw on the weekend, we would have been in a lot of trouble.

Albertans should be asking how we got this close to disaster. Why was our system not capable of providing an appropriate level of reliability during this cold snap? You don’t want an overbuilt system, but last weekend was way too close for comfort.

Let’s start with the cold snap. We saw one of the coldest nights in 50 years in Alberta, so we should have expected demand records to be set. But, the AESO plans for growth in system demand, and it had assumed 2024 peak demand of 12,342MW. That should have meant we had appropriate generation in place to meet last week’s early 2024 peak.

It’s also well-known that wind tends to be low during cold snaps. When the AESO assesses reliability, they don’t assume they can command the sun to shine nor the wind to blow any more than they can capture lightning from the sky to power our houses. When the AESO looks at reliability, they assess it based on whether we have enough firm generation to meet peak demands. And, at least as recently as last spring’s reliability report, they saw no challenges for years even if we built a lot more wind and solar.

So, we should have been covered. Why weren’t we?

The simple answer is project delays. It’s boring, but it’s more accurate than blaming the wind and less politically-motivated than blaming the renewables moratorium or the lack of a capacity market.

The 900MW Cascade combined-cycle natural gas plant was originally proposed to be fully in-service by the end of 2022. That date has been extended at least twice, and last week’s crunch saw the plant still in the commissioning phase. Had this plant been fully operational, all else equal, we’d be talking about the resilience of the Alberta grid this week, not about its vulnerability.

And Cascade wasn’t the only project that was delayed. Capital Power’s Genesee expansion project, slated to add a further 512 MW of capacity to the system, was also initially scheduled to be completed by the end of 2023.

Why does this matter? The AESO has the responsibility to ensure that our system has sufficient generating resources available, but it can’t make them appear overnight. Perhaps, had they known that both Genesee and Cascade would be delayed through this winter, they would have brought on batteries or other capacity on an emergency basis. As it played out, they were left thankful that the wind blew for a couple of days, and left asking Albertans to trim demand for four more.

That was far from ideal.

Hopefully, Cascade is up and running before it gets cold again. And hopefully the AESO will be forthcoming with a full public report so that we can all understand how things got so close to going so badly wrong.

Posted on:
January 24, 2024
5 minute read, 949 words
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