Temperatures plummeted on January 10, beginning an extreme cold snap that lasted almost a week. Albertans set a new peak demand record of 12,384 MW between 5 and 6 pm on January 11, beating the previous record by almost 200 MW.
Already a winter peaking province, extreme cold weather creates a challenge for the grid. During an extended time of record peak and near-peak demand, supply is also stretched as temperatures can exceed the cut of point of winterization packages. Further, lengthy periods of extreme cold in Alberta are often accompanied by a lack of wind.
The emergency alert text messages
On January 13, 2024 at 3:30pm, the AESO declared EEA3. This is step 16 in the AESO’s 22 step plan to manage supply shortfall that ends with distribution system load shed.
The AESO worked with the government and issued an emergency text message alert to Albertans at 6:44pm on January 13 (shown in red in the graph below). The alert noted that “extreme cold resulting in high power demand has placed the Alberta grid at a high risk of rotating power outages in the evening” and requested Albertans to immediately limit their electricity use to essential needs only. Suggestions on the alert included turn off unnecessary lights, minimize the use of space heaters, cook with a microwave instead of an electric stove, and delay charging their electric vehicles.
The alert was effective. The AESO saw an immediate drop of 100 MW in demand and a total reduction of approximately 200 MW within minutes. EEA3 was declared ended at 8:40pm. Demand, as shown in the graph below, continued at lower levels for the remainder of the evening following the alert. Comparing the demand on January 12 and 14 to January 13 also clearly shows the impact of the grid alert.
Note that while the emergency text message alert to Albertans only went out on January 13, there were EEA3 events on each of January 12-15, inclusive.
Drivers of the emergency event
At the time of the event, the Alberta grid had an installed capacity of 20,777 MW. Of this, 11,832 MW are gas generation and another 6,131 MW are wind and solar combined, making up more than 86% of the total installed capacity.
On January 13, thermal generation outages increased as the day wore on, with around 3,000 MW either fully offline or derated at the time of the event. What thermal generation remained in the merit order was dispatched as the solar generation came offline with the setting sun. There was also a de minimis amount of wind available throughout the day. Overall, 9,000 MW of installed capacity were unavailable by sunset.
In addition to local generation, Alberta was importing between 280 and 370 MW from B.C. and Saskatchewan and between 10 and 30 MW from Montana around the time of the EEA3 events. The WECC import transfer capability was between 400 MW and 500 MW indicating that while there was more room for imports, there weren’t enough resources from neighbouring jurisdictions to maximize energy flow. For comparison purposes, during the load shed event in Alberta on July 9, 2012, imports from BC were between 500 and 600 MW.