Texas grid operator CEO warns of energy emergency at nightfall amid heavy load, low wind forecasts

The Electric Reliability Council of Texas market is likely to enter Energy Emergency Alert status the evening of Aug. 24 as load nears its 85.4-GW record level and solar energy output diminishes along with low and flat wind power output, the grid operator's CEO said.

"We are expecting as you move through peak this evening and into the solar ramp-down to have extremely tight conditions this evening," ERCOT President and CEO Pablo Vegas said during a Public Utility Commission of Texas meeting. "At this time, it is a high likelihood that we expect to be in emergency operations this evening."

Excessive heat is likely to drive demand "to be at or near record levels," Vegas said, creating an expectation to enter Energy Emergency Alert status Aug. 24.

Call to conserve electricity

ERCOT issued a media release around noon CT Aug. 24 calling on power customers to conserve electricity use, if it is safe to do so, from 3 pm CT to 10 pm CT Aug. 24.

"ERCOT is not experiencing emergency conditions at this time, but forecasts are showing a high potential to enter emergency operations this evening because of expected low wind-power generation and high demand," the grid operator said. "ERCOT is using additional tools to manage the grid reliably, including using reserve power, calling upon reductions by large electric customers that have volunteered to lower their energy use, and bringing more generation online sooner."

On the Intercontinental Exchange Aug. 24, ERCOT North Hub intraday on-peak contracts soared almost $1,163 to price about $1,308.50/MWh.

"The challenge that complicates this is that we will see low wind performance throughout the solar ramp-down," Vegas said.

In a 10:30 am CT Aug. 24 forecast, ERCOT projected hourly load to peak in the hour ending at 5 pm CT at 85 GW. In an 11 am CT forecast, ERCOT projected its wind fleet to be producing at a level of about 6.6 GW for the hour ending at 5 pm CT Aug. 24, down from about 14.3 GW at that hour Aug. 23.

That forecast indicates wind output dipped below 2 GW for the hour ending at 10 am CT Aug. 24, and wind output will likely remain below 7 GW until the hour ending at 10 am CT.

So far this summer, wind output has tended to diminish around midday and rise in the evening, particularly for resources near the coast, Vegas said.

"What we are seeing today is a very different profile for wind," Vegas said. "It will remain flat through most of the afternoon, and it will not dip as low as it historically has, but it only goes up to about 6,000 MW throughout the afternoon and into and through the solar ramp, which is several thousand megawatts lower than we have historically experienced during this phase."

'Doing everything that we can'

ERCOT's thermal resources have been operating at or near normal forced-outage levels, Vegas said.

"We are doing everything that we can at this point to make sure the people will be clear that conservation will be important today during the afternoon and early evening hours," Vegas said.

ERCOT has communicated with the Midcontinent Independent System Operator and Southwest Power Pool about the Texas grid's need for output from any switchable resources that are at the seams with those adjacent grids, but Commissioner Jimmy Glotfelty said SPP is operating under conservative conditions due to extreme heat, and Commissioner Will McAdams said MISO has said it expects to enter an EEA in the afternoon.

"This is regional now, and it is important to understand that all grids are trying to manage through this," McAdams said. "It's an energy emergency alert, and it is likely that we would be there this evening. ... If we enter this, it means something, and we will have exercised all market-driven solutions, and therefore load-responsive behavior is important."