Unusually cold weather continued over much of Texas on Tuesday, Jan. 7, pushing grid operator ERCOT to a new winter record peak demand of 57,277 MW during the hour ending at 8 a.m. Central time, but generator availability enabled the grid operator to meet its record demand without having to declare energy emergency alerts as it had done a day earlier.
“There was sufficient generation available Monday evening and Tuesday morning to serve expected needs and maintain the desired level of operating reserves, even with demand exceeding Monday’s 55,487 MW morning peak and 56,031 MW evening peak,” an ERCOT spokesperson told TransmissionHub Jan. 7.
The availability of generation, which included approximately 5,500 MW of wind generation at the time of the peak, also allowed ERCOT to lift the emergency and conservation alerts it had issued the day prior.
Shortly before 7 a.m. on Jan. 6, ERCOT declared an energy emergency alert 1 (EEA-1) and elevated it to an EEA-2 due to high demand because of cold temperatures. Demands on the system were made worse by the unplanned outages of two major generating units during the early morning hours, as the system approached its morning peak demand period.
Both units, totaling about 3,700 MW of generation, returned to service by noon Jan. 6, allowing ERCOT to lifted the EEAs before noon, although a conservation alert remained in effect for the remainder of the day and into Jan. 7.
An EEA-1, which is considered a “power watch,” is issued within ERCOT when reserves are below 2,300 MW. It requires the grid operator to commit all available generating units and take other preparatory steps. An EEA-2, or “power warning,” is issued when reserves are below 1,750 MW. In response to an EEA-2, the grid operator will deploy demand response resources and/or emergency response service resources. An EEA-3, or “power emergency,” requires the initiation of rotating outages.
ERCOT rescinded the conservation alert before noon Jan. 7.
The grid operator credited the return of the two major generation units, the public’s response to its conservation request, and other preparatory steps generation and transmission companies in the ERCOT region took for its successful handling of the new record demand.
The grid operator had advised generation and transmission operators to review their supplies to ensure adequate fuel was available, delay any planned generation or transmission outages, endeavor to return to service any facilities that were out of service, and implement any appropriate winterization procedures.
As the current spate of cold weather continues in the east, forcing grid operator PJM Interconnection to call for conservation and pushing up spot power and natural gas prices, its grip on Texas is forecast to ease later in the week. Overnight lows in the Dallas area are forecast to warm from their sub-freezing levels to the low 40s on Jan. 8 and into the low 50s toward the end of the week, according to The Weather Channel. Overnight lows are forecast to be even warmer ERCOT’s headquarters city of Austin.
ERCOT’s previous winter demand record of 57,265 MW was set on Feb. 10, 2011. ERCOT’s system peak demand in winter typically occurs between 6 a.m. and 9 a.m., and between 4 p.m. and 8 p.m. The all-time record overall was set on Aug. 3, 2011, when demand peaked at 68,305 MW.