Continued record electric demand driven by triple-digit temperatures, 13 GW of thermal outages and reduced renewable production forced ERCOT to issue its second conservation appeal of the week Wednesday to Texans and businesses.
The Texas grid operator was expecting demand to peak at nearly 78.5 GW on Wednesday. By late morning, its supply and demand curves indicated more than a 2-GW gap during the afternoon peak between the fast-starting resources on top of the committed capacity and projected demand.
Demand eventually averaged almost 78.3 GW during the hour ending at 5 p.m. CT, falling just short of the record set Tuesday at 78.4 GW. It was the eighth record for peak demand ERCOT has set since May.
The grid operator expects demand to again exceed 78 GW on Thursday. It has peaked above 78 GW all week.
ERCOT issued its conservation appeal at 11:52 a.m. CT, asking Texans to voluntarily conserve electricity between 2 and 9 p.m. It said no outages were expected at the time.
“We want to be respectful of Texans, so we will only call for conservation if we need it,” staff said in an email to RTO Insider.
Staff said Monday’s conservation appeal successfully reduced demand by about 500 MW.
The grid operator’s operations center issued a watch because of a projected reserve capacity shortage without a market solution that could lead to an energy emergency alert. The watch, like the conservation appeal, was the second of the week. (See ERCOT Flirts with Capacity Shortage.)
“Today, there is a lot of variability,” staff said.
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ERCOT said the forced thermal outages exceeded its forecasts. It was expecting only 67 of its 80 GW of installed thermal capacity to be available during the afternoon’s tightest hour (3-4 p.m.). Wind generation was again below its historical usage, but cloud cover in West Texas initially reduced the amount of available solar generation by almost 2 GW.
Operating reserves stayed below 3 GW during much of the afternoon.
Interim ERCOT CEO Brad Jones reminded the Houston Chronicle on Tuesday that the grid operator is now calling for conservation earlier to help the grid avoid emergency conditions.
ERCOT deployed 927 MW of non-spinning reserves at 12:39 p.m. and then called on emergency response service at 2:55 p.m. shortly before physical responsive capability fell below 3 GW. That forced dispatchers to issue another advisory.
There is little respite in the future. Texas has already suffered through its hottest May and June on record and meteorologists expect more of the same through July. Heat advisories remain in effect for much of the state.
ERCOT on Monday night issued the season’s sixth operating condition notice (OCN), its lowest-level market communication, in anticipation of possible emergency conditions through Sunday. Staff expect temperatures above 103 degrees Fahrenheit in its North Central and South Central weather zones.
Prices hit four figures by 1 p.m., reaching the $5,000/MWh offer cap by 3 p.m. and $5,500/MWh heading into the hour ending at 7 p.m.
