The heat, both weather-related and political, continues to build on ERCOT following another stress test this weekend.

It began Friday when the Texas grid operator was forced to ask customers in its footprint to conserve power after it said six gas-fired facilities went offline for a variety of reasons — transmission outages, maintenance and fuel supplies — during the afternoon, taking 2.9 GW of power with them. Interim ERCOT CEO Brad Jones asked Texans to set their thermostats to 78 degrees or above and avoid using large appliances between 3 and 8 p.m. through the weekend.

“ERCOT continues to work closely with the power industry to make sure Texans have the power they need,” Jones said in a statement that was posted on Twitter and issued as a news release.

Jones’ statement and the advisory — ERCOT’s first tweet and news release since Feb. 2 — came shortly after business hours Friday. Staff sent a corrected release out 32 minutes later, revising “all reserve generation resources available are operating” to “all generation resources available are operating.”

By then, the grid operator had already survived a slim 2 GW or so margin between supply (almost 65 GW) and demand (63.7 GW) around 3 p.m. It continued to add capacity and was eventually able to meet Friday’s peak demand of 65.2 GW during the hour ending at 5 p.m.

“There’s no good reason why ERCOT waited until 5 p.m. Friday to alert the public, outside of politics. ERCOT and [the] PUC really owe it to Texans to communicate earlier and clearer,” tweeted energy consultant Doug Lewin, with Stoic Energy. “The statement … was worded so vaguely and was so confusing that it basically made no sense. They’ve got to do better. There’s no excuse for the 5 p.m. notice or the lack of clarity.”

ERCOT’s supply and demand curves looked scary Saturday morning, but the grid operator was eventually able to find more capacity.  | ERCOT

 

The first advisory came less than two and a half hours after Texas Gov. Greg Abbott posted a picture showing him meeting with ERCOT and PUC officials “to work closely to ensure Texas’ power grid remains reliable [and] meets the needs of Texans.”

It was a rare public statement on the grid from Abbott, who said in February that “the Texas power grid is more reliable and resilient than it has ever been.” (See ERCOT Breezes Through Latest Winter Storm.)

Coming on the heels of “categorically insane” heat and peak demand early last week that broke records for both May and June, the conservation call drew a more forceful response from Lt. Gov. Dan Patrick. (See ‘Insane’ Heat, Thermal Outages Stress ERCOT Grid.)

“This weekend’s energy conservation warning is another sign that we must have greater reliability,” Patrick said in a statement, noting he has “fought” for more gas-fired energy. “Work remains to be done. I will never waiver [sic] in my commitment to more reliable Texas power.”

Part of the problem is that about 20% of ERCOT’s thermal generation ha been on forced and planned outages near the May 15 deadline for completing maintenance work. That is partly because of the grid operator’s conservative-operations approach since last summer, when it has required more reserves to be online sooner and increased wear and tear on generating units.

ERCOT includes nuclear as thermal generation. One of the Comanche Peak nuclear plant’s two units, both of which have 1.25 GW of capacity, is returned from a refueling outage. It was operating at 45% Monday morning, according to the Nuclear Regulatory Commission.

On Saturday morning, ERCOT’s online dashboard showed the demand and supply curves meeting near 68 GW around 7 p.m. Mose Buchele, a reporter for Austin’s public radio station KUT, recalled a conversation he had had with Jones about his relationship with Abbott and other politicians.

“[Jones] said he ‘gets calls all the time’ saying ‘those lines look a little close today.’ [I] can only imagine the calls lately,” Buchele said, illustrating his tweet with ERCOT’s supply and demand chart.

Fortunately, five of the six gas units that were offline Friday returned to service as the percentage of thermal units offline dropped to about 13%. Demand reached nearly 66 GW before dropping off in the evening hours.

Demand peaked at 68.6 GW on Sunday as solar and wind power helped fill the gaps.

The grid operator on Monday extended its operating condition notice, its lowest-level communication in anticipation of a possible emergency condition, through Friday. It cited extreme hot weather, with forecasted temperatures above 94 degrees Fahrenheit in the North Central and South Central weather zones. Austin, in the center of the state, will flirt with 100-degree temperatures.

ERCOT was projecting demand to peak at 70.3 GW around 5 p.m. Monday. The grid operator said it would have 3.7 to 6.1 GW in operating reserves at that time.

Prices spiked Friday afternoon near ERCOT’s $5,000/MWh cap, settling between $4,408 and $4,681/MWh. Prices briefly broke triple digits twice during the rest of the weekend, with a peak of $305/MWh Sunday night.

Continued congestion in the Houston area helped hedged traders in the point-to-point market reap $137.9 million in profits May 9 through 11, one participant said.