US heat wave leads to record-breaking grid loads

Extreme heat across the southern US has led to three days of record-breaking demand for electricity in Texas, according to the Electric Reliability Council of Texas (ERCOT), system operator for the state’s bulk transmission grid.

During the week, forced outages and de-ratings — generating units unable to run at peak capacity — prompted ERCOT to issue level 1 and 2 emergency alerts, which indicate that reserves are low and conservation is needed. However, the operator did not have to escalate to a level 3 emergency, as it did on Feb. 2 of this year.

A level 3 emergency indicates that reserves are critically low, and kicks into effect rotating outages across the system. Such rolling blackouts went into effect during an extreme cold wave in February.

The current level 1 emergency will stay in place until operating reserves return to higher than 2500 megawatts (MW).

“Electricity demand for Friday is expected to be lower than today, but we are still asking consumers and businesses to conserve through tomorrow due to the unusually high demand and the increased risk of generation outages during these type of conditions,” said Kent Saathoff, ERCOT’s vice president of system planning and operations. “As stated before, we are very appreciative of the businesses and consumers who have been reducing their electricity consumption 3-7 pm this week.”

Wind generation contributed approximately 1,400 MW during the peak hour. To meet demand, ERCOT also imported generation from other grids via direct current ties under emergency protocols from Southwest Power Pool in the Eastern interconnection and from Comisión Federal de Electricidad in Mexico.