The Texas power grid operator said electric usage this week could break the all-time peak seen earlier this month and urged consumers to reduce power use to avoid rolling outages.
A brutal heatwave now entering its fifth week has strained the state's power generating supply and pushed power prices to record levels.
Extreme heat covering the state led to record weekend power use Saturday and Sunday as Texans cranked up air conditioners to cope with triple-digit temperatures and drought.
Early Monday, the National Weather Service issued heat advisory notices for parts of Texas until 7 p.m. CDT Tuesday and Oklahoma until 10 p.m. CDT Wednesday.
It said the heat index was expected to peak at between 104 and 110 degrees between 10 a.m. and 7 p.m. CDT Monday in the affected areas of Texas, with those in Oklahoma expected to see a top heat index of 103 to 107 degrees Monday afternoon.
Houston, the state's biggest metropolitan area, hit 109 Fahrenheit Saturday and is forecast to see a high of 102 Monday. Dallas hit 106 on Saturday and is projected to hit 105 Monday.
That heat led the Electric Reliability Council of Texas (ERCOT) to set back-to-back weekend power use records as demand soared above 65,100 megawatts on Saturday afternoon, then hit 65,159 megawatts on Sunday, according to initial data posted on the ERCOT website.
Rolling outages?
That's very high demand for a typical weekday when schools and offices are open.
"We can't stress this enough; we need everyone to conserve electricity from 3-7 p.m. EDT," said ERCOT spokeswoman Theresa Gage. "If every person in ERCOT does a little, it makes a huge difference."
The loss of a single large generating unit could force the imposition of rolling outages, something that has occurred in ERCOT only three times in 21 years.
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Major Heatwave
Last week, Texas avoided having to interrupt electric service to residential customers by curtailing power to some industrial customers who agree to reduce use during emergencies.
Peak-hour demand has exceeded 66,000 megawatts on 15 weekdays this month and exceeded 67,000 megawatts on at least five days, according to initial data from ERCOT.
That far outpaces last summer when power demand peaked at 65,776 megawatts during the first week of school in late August.
ERCOT manages the flow of electricity to about 23 million people in Texas, representing 75 percent of the state's land area.