Texas grid operator urges electricity conservation as heat wave drives up demand

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Even though a punishing heat wave across Texas drove record high power demand in recent days, Texans avoided rolling blackouts Monday after the Electric Reliability Council of Texas requested that they cut back on their energy use. And an ERCOT spokesperson told The Texas Tribune on Monday that the grid operator does not expect rolling blackouts this week.

ERCOT, the state’s power grid operator, asked Texans to turn up their thermostats and postpone running major appliances between 2 p.m. and 8 p.m. Monday. ERCOT also called on large electric customers to lower their electricity use. Nearly all industrial-scale Bitcoin miners in the state shut off their machines in response to the call, representing over 1% of total grid capacity, Bloomberg News reported.

On Monday, the Electric Reliability Council of Texas set a new unofficial peak record of demand, a spokesperson said. Total power demand reached 78.3 gigawatts, surpassing the previous record of 78.2 set on July 8. Almost half of 1 gigawatt — or 500 megawatts — of demand dropped off between 1:56 and 2 p.m., the spokesperson said. ERCOT sent out a request late Sunday asking Texans to cut back their energy use starting at 2 p.m. Monday.

Low winds also made it harder for the grid to keep up with demand during hotter-than-usual July temperatures. Projections showed wind generation coming in at less than 10% of its capacity on Monday, ERCOT said. In the spring, ERCOT forecast that an extremely low wind generation day for the summer would be around 1% of its capacity; a low wind generation day for the summer would be around 11% of its capacity; a normal wind generation day for the summer would be around 36% of its capacity.

Winds in Texas often drop during the daytime and pick up overnight, especially in the summer. ERCOT forecasts more wind power will be available to the grid on Tuesday.

Power grids must keep supply and demand in balance at all times. When Texas’ grid falls below its safety margin of excess supply, the grid operator starts taking additional precautions to avoid blackouts.

The first precaution is to ask the public to voluntarily cut back electricity usage. The next step is for the grid operator to tell the public the grid could be in serious condition, and Texans need to cut back electricity usage in order to help the grid. If the grid’s conditions still don’t improve, ERCOT would then implement controlled, rotating power outages, in which Texans in some areas could lose power for up to 45 minutes at a time.

When ERCOT on Sunday night asked Texans to voluntarily cut back electricity usage on Monday, the news release did not warn of possible rotating blackouts. ERCOT said there could be a possible shortage of reserve power in particular, not that there would be a shortage of power to cover demand on the grid.

Power grids around the world are facing tests this summer as climate change has led to hotter temperatures and Russia’s war with Ukraine has strained fuel supplies. In Japan, officials asked residents in late June to conserve electricity during unusually hot weather. In the U.S., officials have warned about possible power outages this summer due to record heat and demand for power.

In May, ERCOT asked Texans to conserve power during a heat wave that coincided with six power plant outages.

ERCOT has directed utilities to intentionally turn off the power for some Texans only three times over the last decade: February 2011, October 2014 and February 2021. In 2011 and 2014, the power outages rotated for short stretches as ERCOT had planned. During the 2021 winter storm, ERCOT directed utilities to turn off power for some consumers to reduce strain on the grid, but instead ERCOT lost control, causing millions of people to lose power for days. Hundreds of people died.

Climate change has made Texas heat both hotter and longer lasting. The average daily minimum and maximum temperatures in Texas have both increased by 2.2 degrees Fahrenheit in the last 125 years. The state just saw its hottest December on record since 1889.

Texas is facing extreme heat conditions this year, with much of the state under temperatures above 100 degrees. As of Monday morning, the National Weather Service has issued heat advisories or excessive heat warnings for 154 of the state’s 254 counties. Some regions are breaking heat records: On Sunday, Austin hit an all-time record high for July at 110 degrees, while San Antonio saw the hottest temperatures on record in the city at 106 degrees.

“We’re in the thick of some of the hottest temperatures we’ve seen in San Antonio ever. … By any measure, this is an extremely hot summer,” said Rudy Garza, CEO of CPS Energy, San Antonio’s power utility company.

San Antonio officials held a press conference Monday to update residents on the measures the city is taking to reduce its energy consumption. The temperature in city buildings are turned to 78 degrees or higher, and the San Antonio Water System turned off the water recycling pumps that put recycled water into the San Antonio River.

The H2Oaks Center, a plant that pulls water from three aquifers, was also turned off, and instead San Antonio drew water only from the Edwards Aquifer to supplement its needs.

“That particular plant that we’re going to shut down is really I think going to be helpful because it does use a lot of energy,” Robert Puente, president and CEO of SAWS, said Monday. “As a customer, you will not see faucets where you have lower pressure. You’ll still be able to use your sinks.”

The city of Dallas provided residents with a list of 15 cooling stations open Monday that will be air conditioned and provide limited supplies of water.

High temperatures were putting a strain on the power grid, with the demand for power in the state breaking records 26 times since May, said Renae Eze, a spokesperson for Gov. Greg Abbott.

“The ERCOT power grid has been able to meet those challenges and respond in record ways, providing more power than ever before and doing so more efficiently, in large part because of the reforms passed last session and the increase in power generation by more than 15% over last year,” Eze said.

After the 2021 winter storm, the Texas Legislature required power companies to upgrade plants to withstand more extreme weather and created a statewide emergency alert system. Energy experts say lawmakers also could have passed legislation to pay consumers to reduce electricity usage or help Texans better insulate their homes and reduce their electricity usage.

When ERCOT called for voluntary conservation, Democratic gubernatorial candidate Beto O’Rourke pinned the pressures on the grid on the governor.

“We can’t rely on the grid when it’s hot. We can’t rely on the grid when it’s cold. We can’t rely on Greg Abbott. It’s time to vote him out and fix the grid,” O’Rourke, who has made the power outages during last year’s winter storm a central theme of his campaign, said in a tweet on Monday.

But Eze characterized the call for voluntary conservation as “one of the many tools at their disposal to ensure enough power keeps flowing. And each time there’s a call for conservation, Texans step up and do their part to help by reducing some of the demand.”

Cecilia Lenzen and Ariana Perez-Castells contributed to this story.

Disclosure: CPS Energy and San Antonio Water System have been financial supporters of The Texas Tribune, a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune's journalism. Find a complete list of them here.

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