The regional grid operator for the central United States issued a conservative operations advisory on July 20, warning of “potential increase in resource outages” due to forecasts of potential high peak loads amid the heat wave stretching from North Dakota to Louisiana.
The operator, Southwest Power Pool (SPP), which services 17 U.S. states, reported at 9:47 p.m. CT on July 20 that the risks of power outages to the western sectors of its grid reported earlier in the day had stabilized.
It said it downgraded the earlier 5:07 p.m. CT Level 3 warning to a conservative operations advisory. No controlled service interruptions were ordered.
“Conservative Operations Advisories do not require the public to conserve energy, but are issued to raise awareness of potential threats to reliability among entities responsible for operating transmission and generation facilities,” the operator said, citing potential high peak loads in the heat wave and “potential low output from wind and other variable energy resources leading into peak hours.”
The Level 3 energy alert earlier Monday evening notified users that the operator had to rely on some or all of its operating reserves to serve consumer demand after several power plants unexpectedly tripped offline during the heat wave.
SPP said thin reserve margins meant an increased risk of outages but clarified it did not need to order rolling blackouts to protect grid operations.
According to the National Weather Service, extreme heat warnings were in effect for the afternoon and evening of July 21 for portions of Arkansas, Illinois, Indiana, Kansas, Kentucky, Mississippi, Missouri, Oklahoma, and Texas.
“Dangerously hot conditions with heat index values up to 115 expected,” the service said early Tuesday morning. “Heat related illnesses increase significantly during extreme heat and high humidity events.”
The strain on the central U.S. grid comes weeks after the nation’s largest grid operator, serving 67 million people on the East Coast, PJM Interconnection, said it had implemented emergency preparedness measures amid a heat wave in early July.
Electricity demand had also surged during the extreme weather to record levels across the 13-state territory the operator services.
The operator reported generator outages in the grid and overloaded transmission lines with surging air-conditioning demand.
