By Tom Kleckner

After days of near misses, the ERCOT grid registered a new all-time demand peak of 74.5 GW on Monday as Texas continued to bake in heat extreme even for the Lone Star State.

Monday’s peak, coming during the interval ending at 5 p.m., smashed the old mark of 73.5 GW, set in July 2018. ERCOT initially broke the record during the hour ending at 4 p.m., when load hit 74.2 GW, almost 700 MW above the 2018 mark.

As the temperatures have soared, so have energy prices. Systemwide settlement prices hit $6,537.45/MWh for the 15-minute interval ending at 3 p.m. on Monday, after first hitting quadruple figures during the 2 p.m. interval.

ERCOT has recorded eight of its 12 highest peaks since Wednesday. Earlier this month, the grid operator set records for August demand (about 73.1 GW) and weekend demand (71.6 GW and 71.9 GW on Saturday and Sunday, respectively).

A ridge of high pressure settled over Texas last week, funneling hot air from the Western U.S. into the southern Great Plains. The National Weather Service has issued several heat advisories during that time, the latest for all Southeast Texas on Monday calling for heat indexes between 108 and 113 degrees Fahrenheit. Houston hit 100 F for the first time this year on Thursday, and Bayou City, Dallas and San Antonio are expected to stay above 100 into this Wednesday.

ERCOT has been able to meet demand without resorting to the emergency measures it warned it might have to take. The grid operator has an 8.6% reserve margin and 78.9 GW of available capacity. (See ERCOT: More Capacity, but Emergency Ops Still Expected.)

“ERCOT expects to have adequate generation to serve customers during this hot spell,” spokesperson Leslie Sopko said last week. The grid operator survived Monday’s high demand with about 3 GW of operating reserves.

ERCOT has issued heat warnings for the Dallas area that prevent utilities from cutting off power for delinquent bills. Houston utility Reliant Energy asked customers to reduce their electricity usage from 2 to 6 p.m. on both Monday and Tuesday.

Last week, real-time prices peaked systemwide at more than $2,400/MWh on Aug. 5.

Day-ahead power prices for Monday were above $220/MWh in the North hub Friday, the highest since reaching $300/MWh the day before the record peak last July. The hub’s next-day prices were at $38.50/MWh on Aug. 5.