PJM overcame the loss of nearly 40,000 MW of generation yesterday, keeping the lights on in the second day of an arctic blast that set a new winter demand record.
The new winter record – 141,500 MW — came during Tuesday evening’s peak as PJM operators scrambled to overcome 38,000 MW in generation outages. The new record exceeded the Feb. 5, 2007 mark of 136,675 MW by nearly 5,000 MW.
“We really exhausted every megawatt we had on the system” Tuesday, Adam Keech, director of wholesale market operations, told the Market Implementation Committee in a briefing yesterday.
Generator outages peaked at 39,520 MW at 8 a.m. Wednesday, as load fell to 134,500. As of 8 p.m. last night, about 27,000 MW of generation was idled as demand peaked at about 125,600.
PJM operators also overcame gas pipeline curtailments that idled up to 9,046 MW of generation yesterday.
“The pipelines came through pretty well,” Gary Helm, lead market strategist, told the MIC. “We only saw two compressor outages.”
Keech said operators’ ability to forecast load was hamstrung by a lack of comparable temperature data.
“We couldn’t find a temperature set [with extreme cold throughout the RTO] for the last decade. And if you go back that far the [RTO] footprint was so different it’s probably not even useful.” Keech said.
PJM resorted to a 5% voltage reduction when reserves grew short about 8 p.m. Monday, triggering scarcity pricing — sending prices briefly above $1,000/MWh. “It hasn’t been this cold in 20 years,” Keech said. “It’s an outlier. That’s why we have scarcity pricing.”
Prices were above $200/MWh for most of the period from Monday evening through Tuesday evening, peaking at more than $1,800/MWh during Tuesday’s morning and evening peaks.
Officials also rescinded outage requests and implored customers to reduce consumption. And they benefited from an unexpected influx of more than 8,000 MW of imports Tuesday morning — more than half from MISO — that allowed them to cancel an emergency deployment of demand response.
Had the steps not been sufficient, officials said they might have had to resort to rolling blackouts to prevent more widespread outages.
“How close were you to a bigger problem? One unit away?” one stakeholder asked Keech.
Weary from lack of sleep, Keech smiled uneasily. “It depends on the size of the unit,” he said.
