It’s Deja vu all over again.The Alberta Electric System Operator (AESO) on Monday morning issued the third Grid Alert in as many days due to the effects of lingering cold temperatures and several power facility outages, and urged Albertans to reduce electricity use.The declaration is the second in a series of steps the AESO takes when it notices surging demand for power that could potentially knock the system out of whack.The first is a curtailment of energy sales and exports through various inter-ties. The second is a public notification and plea for conservation measures via social media outlets such as Twitter (“X”) — which went out at 8:15 am..As of 9:21 am that alert was rescinded as the sun came up but it still illustrates the fragility of the overall system..If steps to reduce demand and increase supply are unsuccessful, AESO will then escalate the grid alert and may implement rolling blackouts to keep the grid from crashing. It also sends out emergency alerts on broadcast and print media to underscore the urgency of conservation measures.That’s what happened on Saturday night after wind and solar generation fell to essentially zero as temperatures plunged below -40 C in some parts of the province.If it weren’t for conservation measures and a kickstart from Saskatchewan, which fired up idle coal generation, the grid would have almost surely crashed.As of 8 a.m. Monday morning, internal load stood at 11,246 megawatts compared to 11,385 megawatts of demand, for a shortfall of 120 megawatts. That in turn pushed the wholesale pool price to $999.99 per megawatt hour.Although the system have a theoretical maximum capacity of about 20,000 megawatts, about a third of that number relies on intermittent sources such as wind and solar. Wind alone accounts for 22% of Alberta’s installed capacity and it wasn’t blowing Monday morning..As of 9 a.m., wind was supplying just 5% while solar was negligible. Natural gas accounted for about 79% with coal chipping in another 7%.The present alert is somewhat unusual coming so early in the day. Peak demand hours are usually between 4 p.m. to 7 p.m. in the early evening. In the event of a rotating outage, the AESO directs Distribution Facility Owners (DFOs), such as municipalities, to reduce power on a pro-rata basis across the province. In that case, outages would occur simultaneously across Alberta. Critical facilities such as hospitals, fire, police and first responders are not included in rotating outages. Each rotating outage is expected to last approximately 30 minutes at a time and could be implemented on short notice.“Currently, the AESO projects the Alberta grid will face a 100 to 200 MW shortfall of electricity during peak evening hours,” it said.