Texas power grid operator again feels strain of extreme heat

© Reuters. Utility poles lead to downtown Dallas during a heat advisory due to scorching weather in Dallas, Texas, U.S. July 12, 2022. REUTERS/Shelby Tauber/File Photo

By Arpan Varghese and Scott DiSavino

(Reuters) - Texas's power grid operator asked homes and businesses on Wednesday to again conserve electricity, by raising thermostats and turning off appliances, amid stifling heat that threatened to push power demand beyond the state's available supply.

For the second time this week, the Electric Reliability Council of Texas (ERCOT), which operates the state's power grid, said residents should cut power use between 2 p.m. and 9 p.m., the hottest hours of the day.

It asks residents to turn up thermostats, put off running high-power appliances like dishwashers and dryers, and to turn off swimming pool pumps. It is also seeking additional reserves and asking some big industrial customers to shut off machinery, ERCOT said.

The state has only about 906 megawatts above the day's forecast demand, ERCOT said. It takes emergency measures when the safety margin is less than 2,300 megawatts.

Temperatures across the state were once again above 100 degrees Fahrenheit (38 degrees Celsius), higher than the average for this time of the year. ERCOT blamed forced outages at coal and natural gas fed power plants, and low wind-power generation.

"Texans need to know why so many coal & natural gas plants are failing," energy consultant Doug Lewin tweeted on Wednesday. ERCOT data showed 2.7 gigawatts less power available from coal and gas plants than on Monday, when the state faced a similar shortfall, said Lewin.

It was the third time this year that ERCOT has called on residents to cut power usage despite steps taken to avoid a repeat of February 2021, when grid failure led to the deaths of more than 200 people in freezing weather.

ERCOT operates the grid for more than 26 million customers representing about 90% of the state's power load.

Texas homes and businesses heeded ERCOT's call to conserve energy on Monday. That allowed the grid to meet record demand without resorting to emergency measures, including rotating blackouts.

Power demand hit another all-time high on Tuesday as consumers continued to crank up their air conditioners to escape a brutal heat wave. ERCOT did not ask consumers to conserve energy on Tuesday.

AccuWeather forecast temperatures in Houston, the biggest city in Texas, will reach 104 F on Wednesday. That would be the hottest day in the city since August 2015 and compares with a normal high of 94 F for this time of year, according to federal data.

ERCOT forecast power use hit a preliminary 78,419 megawatts (MW) on Tuesday, topping the prior record of 78,264 MW on Monday, and will reach 78,963 MW on Wednesday.

One megawatt can power about 200 homes on a hot summer day in Texas.

Power prices at the ERCOT North Hub, which includes Dallas, jumped to a near 13-month high of $280 per megawatt hour for Wednesday, from $130 for Tuesday.

GRAPHIC: Texas power demand to soar to record high this year (https://graphics.reuters.com/TEXAS-POWER/ERCOT/gkplgzymyvb/chart.png)